Overfishing is the removal of a species of
fish
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...
(i.e.
fishing
Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment, but may also be caught from fish stocking, stocked bodies of water such as fish pond, ponds, canals, park wetlands and reservoirs. ...
) from a
body of water
A body of water or waterbody (often spelled water body) is any significant accumulation of water on the surface of Earth or another planet. The term most often refers to oceans, seas, and lakes, but it includes smaller pools of water such a ...
at a rate greater than that the species can replenish its
population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction usi ...
naturally (i.e. the
overexploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term ap ...
of the
fishery
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, ...
's existing
fish stock), resulting in the species becoming increasingly
underpopulated in that area. Overfishing can occur in water bodies of any sizes, such as
pond
A pond is an area filled with water, either natural or artificial, that is smaller than a lake. Defining them to be less than in area, less than deep, and with less than 30% emergent vegetation helps in distinguishing their ecology from tha ...
s,
wetland
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in t ...
s,
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of ...
s,
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
s or
ocean
The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wor ...
s, and can result in
resource depletion
Resource depletion is the consumption of a resource faster than it can be replenished. Natural resources are commonly divided between renewable resources and non-renewable resources (see also mineral resource classification). Use of eith ...
, reduced biological growth rates and low
biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bio ...
levels. Sustained overfishing can lead to
critical depensation
In population dynamics, depensation is the effect on a population (such as a fish stock) whereby, due to certain causes, a decrease in the breeding population (mature individuals) leads to reduced production and survival of eggs or offspring. The ...
, where the fish population is no longer able to sustain itself. Some forms of overfishing, such as the
overfishing of sharks, has led to the upset of entire
marine ecosystem
Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the sur ...
s. Types of overfishing include: growth overfishing, recruitment overfishing, ecosystem overfishing.
The ability of a fishery to recover from overfishing depends on whether its overall
carrying capacity
The carrying capacity of an environment is the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available. The carrying capacity is defined as ...
and the variety of ecological conditions are suitable for the recovery. Dramatic changes in species composition can result in an
ecosystem shift
Regime shifts are large, abrupt, persistent changes in the structure and function of ecosystems, the climate, financial systems or other complex systems.Lewontin, R. (1969) Meaning of Stability. ''Brookhaven Sym Biol'', 13Holling, C.S. (1973) Resil ...
, where other equilibrium energy flows involve species compositions different from those that had been present before the depletion of the original fish stock. For example, once
trout
Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', '' Salmo'' and '' Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salm ...
have been overfished,
carp
Carp are various species of oily freshwater fish from the family Cyprinidae, a very large group of fish native to Europe and Asia. While carp is consumed in many parts of the world, they are generally considered an invasive species in parts of ...
might exploit the change in
competitive
Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indivi ...
equilibria and take over in a way that makes it impossible for the trout to re-establish a breeding population.
Since the growth of global
fishing enterprises after the 1950s, intensive fishing has spread from a few concentrated areas to encompass nearly all fisheries. The scraping of the
ocean floor
The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'.
The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...
in
bottom dragging is devastating to
coral
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and se ...
,
sponges
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...
and other slower-growing
benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning " ...
species that do not recover quickly, and that provide a habitat for commercial fisheries species. This destruction alters the functioning of the ecosystem and can permanently alter species' composition and
biodiversity
Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...
.
Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...
, the collateral capture of unintended species in the course of fishing, is typically returned to the ocean only to die from injuries or exposure. Bycatch represents about a quarter of all marine catch. In the case of
shrimp
Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are ref ...
capture, the bycatch is five times larger than the shrimp caught.
A report by
FAO in 2020 stated that "in 2017, 34 percent of the fish stocks of the world’s marine fisheries were classified as overfished".
Mitigation options include: Government regulation, removal of
subsidies, minimizing fishing impact,
aquaculture
Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...
and
consumer awareness
Consumer behavior is the study of individuals, groups, or organizations and all the activities associated with the purchase, use and disposal of goods and services. Consumer behaviour consists of how the consumer's emotions, attitudes, and pr ...
.
Scale
Overfishing has stripped many fisheries around the world of their
stocks
Stocks are feet restraining devices that were used as a form of corporal punishment and public humiliation. The use of stocks is seen as early as Ancient Greece, where they are described as being in use in Solon's law code. The law describing ...
. The
United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be ...
Food and Agriculture Organization
The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
estimated in a 2018 report that 33.1% of world fish stocks are subject to overfishing. Significant overfishing has been observed in pre-industrial times. In particular, the overfishing of the western
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
from the earliest days of
European colonisation of the Americas
During the Age of Discovery, a large scale European colonization of the Americas took place between about 1492 and 1800. Although the Norse had explored and colonized areas of the North Atlantic, colonizing Greenland and creating a short ter ...
has been well documented.
The fraction of fish stocks that are within biologically sustainable levels has exhibited a decreasing trend, from 90% in 1974 to 66.9% in 2015. In contrast, the percentage of stocks fished at biologically unsustainable levels increased from 10% in 1974 to 33.1% in 2015, with the largest increases in the late-1970s and 1980s.
In 2015, maximally sustainably fished stocks (formerly termed fully fished stocks) accounted for 59.9% and underfished stocks for 7% of the total assessed stocks.
While the proportion of underfished stocks decreased continuously from 1974 to 2015, the maximally sustainably fished stocks decreased from 1974 to 1989, and then increased to 59.9% in 2015.
In 2015, among the 16 major statistical areas, the
Mediterranean
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...
and
Black Sea
The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...
had the highest percentage (62.2%) of unsustainable stocks, closely followed by the Southeast
Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
61.5% and Southwest
Atlantic
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
58.8%. In contrast, the Eastern Central Pacific, Northeast Pacific (Area 67), Northwest Pacific (Area 61), Western Central Pacific and Southwest Pacific had the lowest proportion (13 to 17%) of fish stocks at biologically unsustainable levels.
Daniel Pauly
Daniel Pauly is a French-born marine biologist, well known for his work in studying human impacts on global fisheries and in 2020 was the most cited fisheries scientist in the world. He is a professor and the project leader of the Sea Around Us ...
, a
fisheries scientist
Fisheries science is the academic discipline of managing and understanding fisheries. It is a multidisciplinary science, which draws on the disciplines of limnology, oceanography, freshwater biology, marine biology, meteorology, conservation, ...
known for pioneering work on the human impacts on global fisheries, has commented:
According to the Secretary General of the 2002
World Summit on Sustainable Development
The World Summit on Sustainable Development 2002, took place in South Africa, from 26 August to 4 September 2002. It was convened to discuss ustainable developmentorganizations, 10 years after the first Earth Summit in Rio de Janeiro. (It was the ...
, "Overfishing cannot continue, the depletion of fisheries poses a major threat to the food supply of millions of people."
The fishing down the food web is something that occurs when overfishing arises. Once all larger fish are caught, the fisherman will start to fish the smaller individuals, which would lead to more fish needing to be caught to keep up with demand. This decreases fish populations, as well as genetic diversity of the species, making them more susceptible to disease, and less likely to adapt to their stressors and the environment. Additionally, catching smaller fish leads to breeding of smaller offspring, which can be problematic for fish. In many species, the smaller the female, the less
fecund
Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the natural capability to pr ...
it is, impacting the fish population.
Types
There are three recognized types of biological overfishing: growth overfishing, recruit overfishing, and ecosystem overfishing.
Growth overfishing
Growth overfishing occurs when fish are harvested at an average size that is smaller than the size that would produce the
maximum yield per recruit. A
recruit __NOTOC__
Recruit can refer to:
Military
* Military recruitment
* Recruit training, in the military
* '' Rekrut'' (English: Recruit), a military recruit or low rank in German-speaking countries
* Seaman recruit Books
*''Le Réquisitionnaire'' (E ...
is an individual that makes it to maturity, or into the limits specified by a fishery, which are usually size or age. This makes the total yield less than it would be if the fish were allowed to grow to an appropriate size. It can be countered by reducing fishing mortality to lower levels and increasing the average size of harvested fish to a size that will allow maximum yield per recruit.
Recruitment overfishing
Recruitment overfishing happens when the mature adult population (spawning
biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
) is depleted to a level where it no longer has the reproductive capacity to replenish itselfthere are not enough adults to produce offspring.
Increasing the spawning stock biomass to a target level is the approach taken by managers to restore an overfished population to sustainable levels. This is generally accomplished by placing moratoriums,
quotas
Quota may refer to:
Economics
* Import quota, a trade restriction on the quantity of goods imported into a country
* Market Sharing Quota, an economic system used in Canadian agriculture
* Milk quota, a quota on milk production in Europe
* Indi ...
, and
minimum size limits on a fish population.
Ecosystem overfishing
Ecosystem overfishing occurs when the balance of the
ecosystem
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...
is altered by overfishing. With declines in the abundance of large predatory species, the abundance of small
forage type increases causing a shift in the balance of the ecosystem towards smaller fish species.
Examples and evidence for overfishing
Examples of overfishing exist in areas such as the
North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...
, the
Grand Banks of Newfoundland
The Grand Banks of Newfoundland are a series of underwater plateaus south-east of the island of Newfoundland on the North American continental shelf. The Grand Banks are one of the world's richest fishing grounds, supporting Atlantic cod, swordf ...
and the
East China Sea
The East China Sea is an arm of the Western Pacific Ocean, located directly offshore from East China. It covers an area of roughly . The sea’s northern extension between mainland China and the Korean Peninsula is the Yellow Sea, separated b ...
. In these locations, overfishing has not only proved disastrous to fish stocks, but also to the fishing communities relying on the harvest. Like other
extractive industries
Extractivism is the process of extracting natural resources from the Earth to sell on the world market. It exists in an economy that depends primarily on the extraction or removal of natural resources that are considered valuable for exportation w ...
such as forestry and hunting, fisheries are susceptible to economic interaction between ownership or stewardship and
sustainability
Specific definitions of sustainability are difficult to agree on and have varied in the literature and over time. The concept of sustainability can be used to guide decisions at the global, national, and individual levels (e.g. sustainable livi ...
, otherwise known as the
tragedy of the commons
Tragedy (from the grc-gre, τραγῳδία, ''tragōidia'', ''tragōidia'') is a genre of drama based on human suffering and, mainly, the terrible or sorrowful events that befall a main character. Traditionally, the intention of tragedy ...
.
* Tuna has been caught by the locals in the upper Adriatic for centuries. Increasing fishing prevented the large schools of
little tunny
The little tunny (''Euthynnus alletteratus''), also known as the false albacore, little tuna, bonita, bonito, or blue bonito, is a species of tuna in the family Scombridae. It can be found in the Atlantic Ocean and the Mediterranean and Blac ...
from migrating into the
Gulf of Trieste
The Gulf of Trieste ( it, Golfo di Trieste, sl, Tržaški zaliv, hr, Tršćanski zaljev, german: Golf von Triest) is a very shallow bay of the Adriatic Sea, in the extreme northern part of the Adriatic Sea. It is part of the Gulf of Venice and ...
. The last major tuna catch was made in 1954 by the fishermen of Santa Croce, Contovello and
Barcola
Barcola is a maritime neighbourhood of Trieste, Italy. It is a popular tourist place with beaches and long promenades, near the Habsburg-established Miramare Castle.
Barcola is highly valued for the high quality of life and the free access to the ...
.
* The Peruvian coastal
anchovy
An anchovy is a small, common forage fish of the family Engraulidae. Most species are found in marine waters, but several will enter brackish water, and some in South America are restricted to fresh water.
More than 140 species are placed in 1 ...
fisheries crashed in the 1970s after overfishing and an
El Niño
El Niño (; ; ) is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (approximately between the International Date L ...
season
largely depleted anchovies from its waters. Anchovies were a major natural resource in
Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = Seal (emblem), National seal
, national_motto = "Fi ...
; indeed, 1971 alone yielded 10.2 million metric tons of anchovies. However, the following five years saw the Peruvian fleet's catch amount to only about four million tons.
This was a major loss to Peru's economy.
* The
collapse of the Atlantic northwest cod fishery
In 1992, Northern Cod populations fell to 1% of historical levels, due in large part to decades of overfishing. The Canadian Federal Minister of Fisheries and Oceans, John Crosbie, declared a moratorium on the Northern Cod fishery, which f ...
off
Newfoundland
Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...
, and the 1992 decision by
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
to impose an indefinite
moratorium on the
Grand Banks
The Grand Banks of Newfoundland are a series of underwater plateaus south-east of the island of Newfoundland on the North American continental shelf. The Grand Banks are one of the world's richest fishing grounds, supporting Atlantic cod, swordf ...
, is a dramatic example of the consequences of overfishing.
* The
sole fisheries in the
Irish Sea
The Irish Sea or , gv, Y Keayn Yernagh, sco, Erse Sie, gd, Muir Èireann , Ulster-Scots: ''Airish Sea'', cy, Môr Iwerddon . is an extensive body of water that separates the islands of Ireland and Great Britain. It is linked to the Ce ...
, the west
English Channel
The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" (Cotentinais) or ( Jèrriais), (Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kana ...
, and other locations have become overfished to the point of virtual collapse, according to the UK government's official
Biodiversity Action Plan. The United Kingdom has created elements in this plan to attempt to restore the fishery, but
the expanding global human population and the expanding demand for fish has reached a point where demand for food threatens the stability of these fisheries, if not the species' survival.
* Many
deep sea fish
Deep-sea fish are fish that live in the darkness below the sunlit surface waters, that is below the epipelagic or photic zone of the sea. The lanternfish is, by far, the most common deep-sea fish. Other deep sea fishes include the flashlight ...
are at risk, such as
orange roughy
The orange roughy (''Hoplostethus atlanticus''), also known as the red roughy, slimehead and deep sea perch, is a relatively large deep-sea fish belonging to the slimehead family (Trachichthyidae). The UK Marine Conservation Society has categoriz ...
and
sablefish
The sablefish (''Anoplopoma fimbria'') is one of two members of the fish family Anoplopomatidae and the only species in the genus ''Anoplopoma''. In English, common names for it include sable (US), butterfish (US), black cod (US, UK, Canada), ...
. The deep sea is almost completely dark, near freezing, and has little food. Deep sea fish grow slowly because of limited food, have slow metabolisms, low reproductive rates, and many do not reach breeding maturity for 30 to 40 years. A fillet of orange roughy at the store is probably at least 50 years old. Most deep sea fish are in international waters, where there are no legal protections. Most of these fish are caught by
deep trawlers near
seamount
A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abru ...
s, where they congregate for food.
Flash freezing
In physics and chemistry, flash freezing is the process whereby objects are frozen in just a few hours by subjecting them to cryogenic temperatures, or through direct contact with liquid nitrogen at . It is commonly used in the food industry.
Fl ...
allows the trawlers to work for days at a time, and modern
fishfinder
A fishfinder or sounder (Australia) is an instrument used to locate fish underwater by detecting reflected pulses of sound energy, as in sonar. A modern fishfinder displays measurements of reflected sound on a graphical display, allowing an oper ...
s target the fish with ease.
*
Blue walleye
The blue walleye (''Sander vitreus'' var. ''glaucus''), also called the blue pike, was a unique Polymorphism (biology), color morph (formerly considered a subspecies) of walleye which was Endemism, endemic to the Great Lakes of North America. mor ...
became extinct in the
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...
in the 1980s. Until the middle of the 20th century, the walleye was a commercially valuable fish, with about a half million tonnes being landed in the period from about 1880 to the late-1950s, when the populations collapsed, apparently through a combination of overfishing,
anthropogenic
Anthropogenic ("human" + "generating") is an adjective that may refer to:
* Anthropogeny, the study of the origins of humanity
Counterintuitively, anthropogenic may also refer to things that have been generated by humans, as follows:
* Human im ...
eutrophication
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...
, and
competition
Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indivi ...
with introduced
rainbow smelt
The rainbow smelt (''Osmerus mordax'') is a North American species of fish of the family Osmeridae. Walleye, trout, and other larger fish prey on these smelt. The rainbow smelt prefer juvenile ciscoes, zooplankton such as calanoid copepods ('' L ...
.
File:Psephurus gladius.jpg, The Chinese paddlefish
The Chinese paddlefish (''Psephurus gladius''; : literal translation: "white sturgeon"), also known as the Chinese swordfish, is an Extinction, extinct species of fish that was formerly native to the Yangtze and Yellow River basins in China. Wit ...
, once common to the Yangtze River
The Yangtze or Yangzi ( or ; ) is the longest list of rivers of Asia, river in Asia, the list of rivers by length, third-longest in the world, and the longest in the world to flow entirely within one country. It rises at Jari Hill in th ...
, has gone extinct due to overfishing and dam construction
* The
World Wide Fund for Nature
The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the Wor ...
and the
Zoological Society of London
The Zoological Society of London (ZSL) is a charity devoted to the worldwide conservation of animals and their habitats. It was founded in 1826. Since 1828, it has maintained the London Zoo, and since 1931 Whipsnade Park.
History
On 29 ...
jointly issued their "Living Blue Planet Report" on 16 September 2015 which states that there was a dramatic fall of 74% in worldwide stocks of the important scombridae fish such as
mackerel
Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment.
...
,
tuna
A tuna is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae (mackerel) family. The Thunnini comprise 15 species across five genera, the sizes of which vary greatly, ranging from the bullet tuna (max length: ...
and
bonito
Bonitos are a tribe of medium-sized, ray-finned predatory fish in the family Scombridae – a family it shares with the mackerel, tuna, and Spanish mackerel tribes, and also the butterfly kingfish. Also called the tribe Sardini, it consists of ...
s between 1970 and 2010, and the global overall "population sizes of mammals, birds, reptiles, amphibians and fish fell by half on average in just 40 years."
* Overfishing of the critically endangered
Pacific bluefin tuna
The Pacific bluefin tuna (''Thunnus orientalis'') is a predatory species of tuna found widely in the northern Pacific Ocean, but it is migratory and also recorded as a visitor to the south Pacific.
In the past it was often included in '' T. thyn ...
has resulted in the few still caught selling for astronomical prices. In January 2019, a 278 kilogram (612 pound) tuna sold for 333.6 million yen, or over US$3 million, US$4,900 per pound. Fishers, driven by the fish's high value, use extraordinary techniques to catch them, leaving the population on the verge of collapse.
*
Shark
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimo ...
s and
rays
Ray may refer to:
Fish
* Ray (fish), any cartilaginous fish of the superorder Batoidea
* Ray (fish fin anatomy), a bony or horny spine on a fin
Science and mathematics
* Ray (geometry), half of a line proceeding from an initial point
* Ray (gra ...
: The global abundance of oceanic sharks and rays has declined by 71% since 1970, owing to an 18-fold increase in relative fishing pressure. As a consequence, three-quarters of the species comprising this group are now threatened with extinction.
*A study in 2003 found that, as compared with 1950 levels, only a remnant (in some instances, as little as 10%) of all large ocean-fish stocks are left in the seas. These large ocean fish are the species at the top of the food chains (e.g.,
tuna
A tuna is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae (mackerel) family. The Thunnini comprise 15 species across five genera, the sizes of which vary greatly, ranging from the bullet tuna (max length: ...
,
cod
Cod is the common name for the demersal fish genus '' Gadus'', belonging to the family Gadidae. Cod is also used as part of the common name for a number of other fish species, and one species that belongs to genus ''Gadus'' is commonly not call ...
, among others). This article was subsequently criticized as being fundamentally flawed, although much debate still exists and the majority of fisheries scientists now consider the results irrelevant with respect to large
pelagic
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...
s (the open seas).
In management
Several countries are now effectively managing their fisheries. Examples include
Iceland
Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...
and
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
.
The
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
has turned many of its fisheries around from being in a highly depleted state.
Consequences
According to a 2008 UN report, the world's fishing fleets are losing US$50 billion each year due to depleted stocks and poor
fisheries management
The goal of fisheries management is to produce sustainable biological, environmental and socioeconomic benefits from renewable aquatic resources. Wild fisheries are classified as renewable when the organisms of interest (e.g., fish, shellfish, am ...
. The report, produced jointly by the
World Bank
The World Bank is an international financial institution that provides loans and grants to the governments of low- and middle-income countries for the purpose of pursuing capital projects. The World Bank is the collective name for the Interna ...
and the UN
Food and Agriculture Organization
The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
(FAO), asserts that half the world's
fishing fleet
A fishing fleet is an aggregate of commercial fishing vessels. The term may be used of all vessels operating out of a particular port, all vessels engaged in a particular type of fishing (as in the "tuna fishing fleet"), or all fishing vessels of ...
could be scrapped with no change in catch. In addition, the
biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
of global
fish stocks have been allowed to run down to the point where it is no longer possible to catch the amount of fish that could be caught. Increased incidence of
schistosomiasis
Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected. Symptoms include abdominal pain, diarrhea, bloody s ...
in Africa has been linked to declines of fish species that eat the snails carrying the disease-causing parasites. Massive growth of
jellyfish
Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...
populations threaten fish stocks, as they compete with fish for food, eat fish eggs, and poison or swarm fish, and can survive in oxygen depleted environments where fish cannot; they wreak massive havoc on commercial fisheries. Overfishing eliminates a major jellyfish competitor and predator, exacerbating the jellyfish population explosion. Both climate change and a restructuring of the ecosystem have been found to be major roles in an increase in jellyfish population in the Irish Sea in the 1990s.
According to the 2019 ''
'' published by the
, overfishing is a primary driver of mass
extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
in the world's oceans. A 2021 study published in the journal ''
Nature
Nature, in the broadest sense, is the physics, physical world or universe. "Nature" can refer to the phenomenon, phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. ...
'' asserted that the "primary cause" of ocean
defaunation
Defaunation is the global, local or functional extinction of animal populations or species from ecological communities. The Human overpopulation, growth of the human population, combined with advances in harvesting technologies, has led to more int ...
is overfishing.
Other studies have shown that overfishing has reduced fish and marine mammal
biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
by 60% since the 1800s, and is currently driving over one-third of
shark
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimo ...
s and
rays
Ray may refer to:
Fish
* Ray (fish), any cartilaginous fish of the superorder Batoidea
* Ray (fish fin anatomy), a bony or horny spine on a fin
Science and mathematics
* Ray (geometry), half of a line proceeding from an initial point
* Ray (gra ...
to extinction.
Acceptable levels
The notion of overfishing hinges on what is meant by an "acceptable level" of fishing. More precise
biological
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary in ...
and
bioeconomic terms define acceptable level as follows:
* Biological overfishing occurs when fishing
mortality
Mortality is the state of being mortal, or susceptible to death; the opposite of immortality.
Mortality may also refer to:
* Fish mortality, a parameter used in fisheries population dynamics to account for the loss of fish in a fish stock throug ...
has reached a level where the stock
biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
has negative
marginal growth (reduced rate of biomass growth), as indicated by the red area in the figure. (Fish are being taken out of the water so quickly that the replenishment of stock by breeding slows down. If the replenishment continues to diminish for long enough, replenishment will go into reverse and the population will decrease.)
* Economic or bioeconomic overfishing additionally considers the cost of fishing when determining acceptable catches. Under this framework, a fishery is considered to be overfished when catches exceed
maximum economic yield
In mathematical analysis, the maxima and minima (the respective plurals of maximum and minimum) of a function (mathematics), function, known collectively as extrema (the plural of extremum), are the largest and smallest value of the function, e ...
where
resource rent In economics, rent is a surplus value after all costs and normal returns have been accounted for, i.e. the difference between the price at which an output from a resource can be sold and its respective extraction and production costs, including norm ...
is at its maximum. Fish are being removed from the fishery so quickly that the profitability of the fishery is sub-optimal. A more dynamic definition of economic overfishing also considers the
present value
In economics and finance, present value (PV), also known as present discounted value, is the value of an expected income stream determined as of the date of valuation. The present value is usually less than the future value because money has inte ...
of the fishery using a relevant
discount rate to maximise the flow of resource rent over all future catches.
Harvest control rule
A model proposed in 2010 for predicting acceptable levels of fishing is the Harvest Control Rule (HCR),
which is a set of tools and protocols with which management has some direct control of harvest rates and strategies in relation to predicting stock status, and long-term maximum sustainable yields. Constant catch and constant fishing mortality are two types of simple harvest control rules.
Input and output orientations
Fishing capacity
A conventional idea of a sustainable fishery is that it is one that is harvested at a sustainable rate, where the fish population does not decline over time because of fishing practices. Sustainability in fisheries combines theoretical disciplin ...
can also be defined using an input or output orientation.
* An input-oriented fishing capacity is defined as the maximum available
capital stock
A corporation's share capital, commonly referred to as capital stock in the United States, is the portion of a corporation's equity that has been derived by the issue of shares in the corporation to a shareholder, usually for cash. "Share capi ...
in a fishery that is fully utilized at the maximum technical efficiency in a given time period, given resource and market conditions.
* An output-oriented fishing capacity is defined as the maximum catch a vessel (fleet) can produce if inputs are fully utilized given the biomass, the fixed inputs, the age structure of the fish stock, and the present stage of technology.
Technical efficiency of each vessel of the fleet is assumed necessary to attain this maximum catch. The degree of
capacity utilization
Capacity utilization or capacity utilisation is the extent to which a firm or nation employs its installed productive capacity. It is the relationship between output that ''is'' produced with the installed equipment, and the potential output whic ...
results from the comparison of the actual level of output (input) and the capacity output (input) of a vessel or a fleet.
Reducing overfishing
In order to meet the problems of overfishing, a precautionary approach and Harvest Control Rule (HCR) management principles have been introduced in the main fisheries around the world. The Traffic Light color convention introduces sets of rules based on predefined critical values, which can be adjusted as more information is gained.
The
United Nations Convention on the Law of the Sea
The United Nations Convention on the Law of the Sea (UNCLOS), also called the Law of the Sea Convention or the Law of the Sea Treaty, is an international agreement that establishes a legal framework for all marine and maritime activities. , 167 c ...
treaty deals with aspects of overfishing in articles 61, 62, and 65.
*Article 61 requires all coastal states to ensure that the maintenance of living resources in their
exclusive economic zones is not endangered by
over-exploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term app ...
. The same article addresses the maintenance or restoration of populations of species above levels at which their reproduction may become seriously threatened.
*Article 62 provides that coastal states: "shall promote the objective of optimum utilization of the living resources in the exclusive economic zone without prejudice to Article 61"
*Article 65 provides generally for the rights of, inter alia, coastal states to prohibit, limit, or regulate the exploitation of marine mammals.
According to some observers, overfishing can be viewed as an example of the
tragedy of the commons
Tragedy (from the grc-gre, τραγῳδία, ''tragōidia'', ''tragōidia'') is a genre of drama based on human suffering and, mainly, the terrible or sorrowful events that befall a main character. Traditionally, the intention of tragedy ...
; appropriate solutions would therefore promote
property right
The right to property, or the right to own property (cf. ownership) is often classified as a human right for natural persons regarding their possessions. A general recognition of a right to private property is found more rarely and is typically h ...
s through, for instance,
privatization
Privatization (also privatisation in British English) can mean several different things, most commonly referring to moving something from the public sector into the private sector. It is also sometimes used as a synonym for deregulation when ...
and
fish farming
upright=1.3, Salmon farming in the sea (mariculture) at Loch Ainort, Isle of Skye">mariculture.html" ;"title="Salmon farming in the sea (mariculture">Salmon farming in the sea (mariculture) at Loch Ainort, Isle of Skye, Scotland
Fish farming or ...
. Daniel K. Benjamin, in ''Fisheries are Classic Example of the 'Tragedy of the Commons, cites research by Grafton, Squires and Fox to support the idea that privatization can solve the overfishing problem: According to recent research on the
British Columbia
British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
halibut
Halibut is the common name for three flatfish in the genera '' Hippoglossus'' and ''Reinhardtius'' from the family of right-eye flounders and, in some regions, and less commonly, other species of large flatfish.
The word is derived from ''h ...
fishery, where the commons has been at least partly privatized, substantial ecological and economic benefits have resulted. There is less damage to fish stocks, the fishing is safer, and fewer resources are needed to achieve a given harvest."
Another possible solution, at least for some areas, is
quotas
Quota may refer to:
Economics
* Import quota, a trade restriction on the quantity of goods imported into a country
* Market Sharing Quota, an economic system used in Canadian agriculture
* Milk quota, a quota on milk production in Europe
* Indi ...
, restricting fishers to a specific quantity of fish. A more radical possibility is declaring certain areas of the sea "
no-go zones" and make fishing there strictly illegal, so the fish have time to recover and repopulate.
In order to maximise resources some countries, e.g.,
Bangladesh
Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mos ...
and Thailand, have improved the availability of family planning services. The resulting smaller populations have a decreased environmental footprint and reduced food needs.
Controlling consumer behavior and demand is critical in mitigating action. Worldwide, a number of initiatives emerged to provide consumers with information regarding the conservation status of the seafood available to them. The "Guide to Good Fish Guides" lists a number of these.
Government regulation
Many regulatory measures are available for controlling overfishing. These measures include
fishing quota
Catch share is a fishery management system that allocates a secure privilege to harvest a specific area or percentage of a fishery's total catch to individuals, communities, or associations. Examples of catch shares are individual transferable quot ...
s,
bag limits, licensing,
closed season
A hunting season is the designated time in which certain game animals can be killed in certain designated areas. In the United States, each state determines and sets its own specific dates to hunt the certain game animal, such as California, in ...
s, size limits and the creation of
marine reserve
A marine reserve is a type of marine protected area (MPA). An MPA is a section of the ocean where a government has placed limits on human activity. A marine reserve is a marine protected area in which removing or destroying natural or cultural ...
s and other
marine protected areas
Marine protected areas (MPA) are protected areas of seas, oceans, estuaries or in the US, the Great Lakes. These marine areas can come in many forms ranging from wildlife refuges to research facilities. MPAs restrict human activity for a conserv ...
.
A model of the interaction between fish and fishers showed that when an area is closed to fishers, but there are no catch regulations such as
individual transferable quotas, fish catches are temporarily increased but overall fish
biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
is reduced, resulting in the opposite outcome from the one desired for fisheries. Thus, a displacement of the fleet from one locality to another will generally have little effect if the same quota is taken. As a result,
management measures such as temporary closures or establishing a
marine protected area
Marine protected areas (MPA) are protected areas of seas, oceans, estuaries or in the US, the Great Lakes. These marine areas can come in many forms ranging from wildlife refuges to research facilities. MPAs restrict human activity for a conserv ...
of fishing areas are ineffective when not combined with individual fishing quotas. An inherent problem with quotas is that fish populations vary from year to year. A study has found that fish populations rise dramatically after stormy years due to more nutrients reaching the surface and therefore greater primary production. To fish sustainably, quotas need to be changed each year to account for fish population.
Individual transferable quotas (ITQs) are fishery rationalization instruments defined under the
Magnuson-Stevens Fishery Conservation and Management Act as limited access permits to harvest quantities of fish.
Fisheries scientists
Fisheries science is the academic discipline of managing and understanding fisheries. It is a multidisciplinary science, which draws on the disciplines of limnology, oceanography, freshwater biology, marine biology, meteorology, conservation, e ...
decide the optimal amount of fish (
total allowable catch
The Common Fisheries Policy (CFP) is the fisheries policy of the European Union (EU). It sets quotas for which member states are allowed to catch each type of fish, as well as encouraging the fishing industry by various market interventions. I ...
) to be harvested in a certain fishery. The decision considers carrying capacity, regeneration rates and future values. Under ITQs, members of a
fishery
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, ...
are granted rights to a percentage of the total allowable catch that can be harvested each year. These quotas can be fished, bought, sold, or leased allowing for the least-cost vessels to be used. ITQs are used in
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
,
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
,
Iceland
Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...
,
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, and the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
.
In 2008, a large-scale study of fisheries that used ITQs compared to ones that didn't provided strong evidence that ITQs can help to prevent collapses and restore fisheries that appear to be in decline.
China bans fishing in the
South China Sea
The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by the shores of South China (hence the name), in the west by the Indochinese Peninsula, in the east by the islands of Taiwan and northwestern Phil ...
for a period each year.
Removal of subsidies
Because government provided financial subsidies can make it economically viable to fish beyond biologically sustainable levels, several scientists have called for an end to
fishery subsidies paid to deep-sea fisheries. In international waters beyond the 200 nautical mile
exclusive economic zones of coastal countries, many fisheries are unregulated, and
fishing fleet
A fishing fleet is an aggregate of commercial fishing vessels. The term may be used of all vessels operating out of a particular port, all vessels engaged in a particular type of fishing (as in the "tuna fishing fleet"), or all fishing vessels of ...
s plunder the depths with state-of-the-art technology. In a few hours, massive nets weighing up to 15 tons, dragged along the bottom by
deep-water trawlers, can destroy deep-sea corals and sponge beds that have taken centuries or millennia to grow. The trawlers can target
orange roughy
The orange roughy (''Hoplostethus atlanticus''), also known as the red roughy, slimehead and deep sea perch, is a relatively large deep-sea fish belonging to the slimehead family (Trachichthyidae). The UK Marine Conservation Society has categoriz ...
,
grenadier
A grenadier ( , ; derived from the word '' grenade'') was originally a specialist soldier who threw hand grenades in battle. The distinct combat function of the grenadier was established in the mid-17th century, when grenadiers were recruited fr ...
s, or sharks. These fish are usually long-lived and late maturing, and their populations take decades, even centuries to recover.
Fisheries scientist
Daniel Pauly
Daniel Pauly is a French-born marine biologist, well known for his work in studying human impacts on global fisheries and in 2020 was the most cited fisheries scientist in the world. He is a professor and the project leader of the Sea Around Us ...
and economist
Ussif Rashid Sumaila
Ussif Rashid Sumaila is a professor of ocean and fisheries economics at the University of British Columbia, Canada, and the Director of the Fisheries Economics Research Unit at the UBC Institute for the Oceans and Fisheries (formerly known as th ...
have examined subsidies paid to
bottom trawl
Bottom trawling is trawling (towing a trawl, which is a fishing net) along the seafloor. It is also referred to as "dragging". The scientific community divides bottom trawling into benthic trawling and demersal trawling. Benthic trawling is tow ...
fleets around the world. They found that US$152 million per year are paid to deep-sea fisheries. Without these subsidies, global deep-sea fisheries would operate at a loss of US$50 million a year. A great deal of the subsidies paid to deep-sea trawlers is to subsidize the large amount of fuel required to travel beyond the 200 mile limit and drag weighted nets.
"There is surely a better way for governments to spend money than by paying subsidies to a fleet that burns 1.1 billion litres of fuel annually to maintain paltry catches of old growth fish from highly vulnerable stocks, while destroying their habitat in the process" – ''Pauly''.
"Eliminating global subsidies would render these fleets economically unviable and would relieve tremendous pressure on over-fishing and vulnerable deep-sea ecosystems" – ''Sumaila''.
Over 30 billion euros in public
subsidies
A subsidy or government incentive is a form of financial aid or support extended to an economic sector (business, or individual) generally with the aim of promoting economic and social policy. Although commonly extended from the government, the ter ...
are directed to
fisheries
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...
annually.
Minimizing fishing impact
Fishing techniques may be altered to minimize bycatch and reduce impacts on marine habitats. These techniques include using varied gear types depending on target species and habitat type. For example, a net with larger holes will allow undersized fish to avoid capture. A
turtle excluder device
A turtle excluder device (TED) is a specialized device that allows a captured sea turtle to escape when caught in a fisherman's net.
In particular, sea turtles can be caught when bottom trawling is used by the commercial shrimp fishing indus ...
(TED) allows sea turtles and other megafauna to escape from shrimp trawls. Avoiding fishing in spawning grounds may allow fish stocks to rebuild by giving adults a chance to reproduce.
Aquaculture
Aquaculture involves the farming of fish in captivity. This approach effectively privatizes fish stocks and creates incentives for farmers to conserve their stocks. It also reduces environmental impact. However, farming
carnivorous fish
Predatory fish are hypercarnivorous fish that actively prey upon other fish or aquatic animals, with examples including shark, billfish, barracuda, pike/muskellunge, walleye, perch and salmon. Some omnivorous fish, such as the red-bellied piranha ...
, such as
salmon
Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...
, does not always reduce pressure on wild fisheries, since carnivorous farmed fish are usually fed
fishmeal
Fish meal is a commercial product made from whole wild-caught fish, bycatch and fish by-products to feed farm animals, e.g., pigs, poultry, and farmed fish.R. D. Miles and F. A. Chapman.FA122: The Benefits of Fish Meal in Aquaculture DietsFisherie ...
and
fish oil
Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), precursors of certain eicosanoids that are known to reduce inflammation in the body a ...
extracted from wild
forage fish
Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food ...
. The various species of Pacific salmon and Atlantic salmon are relatively easy to raise in captivity and such aquacultural operations have existed for more than 150 years. Largescale releases of salmon raised in captivity to supplement wild salmon runs will usually increase fishing pressure on the much less abundant wild salmon runs.
Aquaculture played a minor role in the harvesting of marine organisms until the 1970s. Growth in aquaculture increased rapidly in the 1990s when the rate of wild capture plateaued. Aquaculture now provides approximately half of all harvested aquatic organisms. Aquaculture production rates continue to grow while wild harvest remains steady.
Fish farming can enclose the entire
breeding cycle Breeding in the wild is the natural process of animal reproduction occurring in the natural habitat of a given species. This terminology is distinct from animal husbandry or breeding of species in captivity. Breeding locations are often chosen for ...
of the fish, with fish being bred in captivity. Some fish prove difficult to breed in captivity and can be caught in the wild as juveniles and brought into captivity to increase their weight. With scientific progress, more species are being made to breed in captivity. This was the case with
southern bluefin tuna
The southern bluefin tuna (''Thunnus maccoyii'') is a tuna of the family (biology), family Scombridae found in open southern Hemisphere waters of all the world's oceans mainly between 30th parallel south, 30°S and 50th parallel south, 50°S, to ...
, which were first bred in captivity in 2009.
Consumer awareness
As global citizens become more aware of overfishing and the ecological destruction of the oceans, movements have sprung up to encourage abstinence—not eating any seafood—or eating only "sustainable seafood".
Sustainable seafood Sustainable seafood is seafood that is caught or farmed in ways that consider the long-term vitality of harvested species and the well-being of the oceans, as well as the livelihoods of fisheries-dependent communities. It was first promoted throug ...
is a movement that has gained momentum as more people become aware of overfishing and
environmentally destructive fishing methods. Sustainable seafood is seafood from either fished or farmed sources that can maintain or increase production in the future without jeopardizing the
ecosystem
An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...
s from which it was acquired. In general, slow-growing fish that reproduce late in life, such as orange roughy, are vulnerable to overfishing. Seafood species that grow quickly and breed young, such as anchovies and
sardines
"Sardine" and "pilchard" are common names for various species of small, oily forage fish in the herring family Clupeidae. The term "sardine" was first used in English during the early 15th century, a folk etymology says it comes from the I ...
, are much more resistant to overfishing. Several organizations, including the
Marine Stewardship Council
The Marine Stewardship Council (MSC) is a non-profit organization which aims to set standards for sustainable fishing. Fisheries that wish to demonstrate they are well-managed and sustainable compared to the MSC's standards are assessed by a te ...
(MSC), and
Friend of the Sea
Friend of the Sea is a project of the World Sustainability Organization for the certification and promotion of seafood from sustainable fisheries and sustainable aquaculture. It is the only certification scheme which, with the same logo, certifies ...
, certify seafood fisheries as sustainable.
The Marine Stewardship Council has developed an environmental standard for sustainable and well-managed fisheries. Environmentally responsible fisheries management and practices are rewarded with the use of its blue product
ecolabel
Ecolabels (also "Eco-Labels") and Green Stickers are labeling systems for food and consumer products. The use of ecolabels is voluntary, whereas green stickers are mandated by law; for example, in North America major appliances and automobiles us ...
. Consumers concerned about overfishing and its consequences are increasingly able to choose seafood products that have been independently assessed against the MSC's environmental standard. This enables consumers to play a part in reversing the decline of fish stocks. As of February 2012, over 100 fisheries around the world have been independently assessed and certified as meeting the MSC standard. Thei
where-to-buypage lists the currently available certified seafood. As of February 2012, over 13,000 MSC-labelled products are available in 74 countries around the world
Fish & Kidsis an MSC project to teach schoolchildren about marine environmental issues, including overfishing.
The
Monterey Bay Aquarium
Monterey Bay Aquarium is a nonprofit public aquarium in Monterey, California. Known for its regional focus on the marine habitats of Monterey Bay, it was the first to exhibit a living kelp forest when it opened in October 1984. Its biologists ...
's
Seafood Watch __NOTOC__
Seafood Watch is a sustainable seafood advisory list, and has influenced similar programs around the world. It is best known for developing science-based seafood recommendations that consumers, chefs, and business professionals use to i ...
Program, although not an official certifying body like the MSC, also provides guidance on the sustainability of certain fish species. Some seafood restaurants have begun to offer more sustainable seafood options. The
Seafood Choices Alliance
The Seafood Choices Alliance was a program of the nonprofit ocean conservation organization, SeaWeb. It was established in 2001 to bring together the disparate elements and diverse approaches in a growing "seafood choices" movement in the United ...
is an organization whose members include chefs that serve sustainable seafood at their establishments. In the US, the
Sustainable Fisheries
A conventional idea of a sustainable fishery is that it is one that is harvested at a sustainable rate, where the fish population does not decline over time because of fishing practices. Sustainability in fisheries combines theoretical disciplin ...
Act defines sustainable practices through national standards. Although there is no official certifying body like the MSC, the
National Oceanic and Atmospheric Administration
The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...
has create
FishWatchto help guide concerned consumers to sustainable seafood choices.
In September 2016, a partnership of Google and
Oceana and
Skytruth SkyTruth is a nonprofit environmental watchdog that uses satellite imagery and remote sensing data to identify and monitor threats to the planet's natural resources. Its stated mission is to "share the view from space to promote conservation for peo ...
introduced
Global Fishing Watch
''Global Fishing Watch'' is a website launched in September 2016 by Google in partnership with Oceana and SkyTruth "to provide the world’s first global view of commercial fishing activities." At any moment, 200,000 vessels are publicizing thei ...
, a website designed to assist citizens of the globe in monitoring fishing activities.
Global goals
The United Nations has included sustainable fishing and ending subsidies that contribute to overfishing as key targets for 2030 as part of their
Sustainable Development Goal 14
Sustainable Development Goal 14 (Goal 14 or SDG 14) is about "Life below water" and is one of the 17 Sustainable Development Goals established by the United Nations in 2015. The official wording is to "Conserve and sustainably use the oceans, seas ...
called "Life Below Water".
Barriers to effective management
The
fishing industry
The fishing industry includes any industry or activity concerned with taking, culturing, processing, preserving, storing, transporting, marketing or selling fish or fish products. It is defined by the Food and Agriculture Organization as including ...
has a strong financial incentive to oppose some measures aimed at improving the sustainability of fish stocks.
Recreational fisherman also has an interest in maintaining access to fish stocks. This leads to extensive
lobbying
In politics, lobbying, persuasion or interest representation is the act of lawfully attempting to influence the actions, policies, or decisions of government officials, most often legislators or members of regulatory agency, regulatory agencie ...
that can block or weaken government policies intended to prevent overfishing.
Outside of countries' exclusive economic zones, fishing is difficult to control. Large oceangoing fishing boats are free to exploit fish stocks at will.
In waters that are the subject of territorial disputes, countries may actively encourage overfishing. A notable example is the
cod wars
The Cod Wars ( is, Þorskastríðin; also known as , ; german: Kabeljaukriege) were a series of 20th-century confrontations between the United Kingdom (with aid from West Germany) and Iceland about fishing rights in the North Atlantic. Each o ...
where Britain used its navy to protect its trawlers fishing in
Iceland
Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...
's exclusive economic zone. Fish are highly transitory. Many species will freely move through different jurisdictions. The conservation efforts of one country can then be exploited by another.
While governments can create regulations to control people's behaviors this can be undermined by
illegal fishing activity. Estimates of the size of the illegal catch range from 11 to 26 million tonnes, which represents 14-33% of the world's reported catch. Illegal fishing can take many forms. In some developing countries, large numbers of poor people are dependent on fishing. It can prove difficult to regulate this kind of overfishing, especially for weak governments. Even in regulated environments, illegal fishing may occur. While industrial fishing is often effectively controlled, smaller scale and recreational fishermen can often break regulations such as
bag limit
A bag limit is a law imposed on hunters and fishermen restricting the number of animals within a specific species or group of species they may kill and keep. Size limits and hunting seasons sometimes accompany bag limits which place restrictions ...
s and seasonal closures. Fisherman can also easily fish illegally by doing things such as underreporting the amount of fish they caught or reporting that they caught one type of fish while actually catching another. There is also a large problem with the surveillance of illegal fishing activity. In 2001, the UN
Food and Agriculture Organization
The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...
(FAO), passed the International Plan of Action to Prevent, Deter and Eliminate
Illegal, Unreported and Unregulated Fishing
Illegal, unreported and unregulated fishing (IUU) is an issue around the world. Fishing industry observers believe IUU occurs in most fisheries, and accounts for up to 30% of total catches in some important fisheries.
Illegal fishing takes pl ...
(IPOA-IUU). This is an agreement with the intention to stop port states from allowing boats to dock that participated in illegal, unreported or unregulated fishing. It also gives details for port states on effective measures of inspecting and reporting illegal fishing. Some illegal fishing takes place on an industrial scale with financed commercial operations.
The fishing capacity problem is not only related to the conservation of
fish stocks but also to the sustainability of fishing activity. Causes of the fishing problem can be found in the property rights regime of fishing resources. Overexploitation and rent dissipation of fishermen arise in open-access
fisheries
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...
as was shown in Gordon.
In open-access resources like fish stocks, in the absence of a system like
individual transferable quotas, the impossibility of excluding others provokes the fishermen who want to increase catch to do so effectively by taking someone else' share, intensifying competition. This
tragedy of the commons
Tragedy (from the grc-gre, τραγῳδία, ''tragōidia'', ''tragōidia'') is a genre of drama based on human suffering and, mainly, the terrible or sorrowful events that befall a main character. Traditionally, the intention of tragedy ...
provokes a capitalization process that leads them to increase their costs until they are equal to their revenue, dissipating their rent completely.
Resistance from fishermen
There is always disagreement between fishermen and government scientists... Imagine an overfished area of the sea in the shape of a hockey field with nets at either end. The few fish left therein would gather around the goals because fish like structured habitats. Scientists would survey the entire field, make lots of unsuccessful hauls, and conclude that it contains few fish. The fishermen would make a beeline to the goals, catch the fish around them, and say the scientists do not know what they are talking about. The subjective impression the fishermen get is always that there's lots of fish - because they only go to places that still have them... fisheries scientists survey and compare entire areas, not only the productive fishing spots. – ''Fisheries scientist Daniel Pauly
Daniel Pauly is a French-born marine biologist, well known for his work in studying human impacts on global fisheries and in 2020 was the most cited fisheries scientist in the world. He is a professor and the project leader of the Sea Around Us ...
''
See also
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Biodiversity
Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...
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Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...
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Catch and release
Catch and release is a practice within recreational fishing where after capture, often a fast measurement and weighing of the fish is performed, followed by posed photography as proof of the catch, and then the fish are unhooked and returned ...
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Environmental impact of fishing
The environmental impact of fishing includes issues such as the availability of fish, overfishing, fisheries, and fisheries management; as well as the impact of industrial fishing on other elements of the environment, such as bycatch. These is ...
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Factory ship
A factory ship, also known as a fish processing vessel, is a large ocean-going vessel with extensive on-board facilities for processing and freezing caught fish or whales. Modern factory ships are automated and enlarged versions of the earlier wh ...
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Pacific bluefin tuna
The Pacific bluefin tuna (''Thunnus orientalis'') is a predatory species of tuna found widely in the northern Pacific Ocean, but it is migratory and also recorded as a visitor to the south Pacific.
In the past it was often included in '' T. thyn ...
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Shark finning
Shark finning is the act of removing fins from sharks and discarding the rest of the shark back into the ocean. This act is prohibited in many countries. The sharks are often still alive when discarded, but without their fins.Spiegel, J. (2000 ...
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Holocene extinction
The Holocene extinction, or Anthropocene extinction, is the ongoing extinction event during the Holocene epoch. The extinctions span numerous families of bacteria, fungi, plants, and animals, including mammals, birds, reptiles, amphibians, f ...
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Human overpopulation
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
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Jellyfish blooms
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Life history theory
Life history theory is an analytical frameworkVitzthum, V. (2008). Evolutionary models of women's reproductive functioning. ''Annual Review of Anthropology'', ''37'', 53-73 designed to study the diversity of life history strategies used by differen ...
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List of harvested aquatic animals by weight
This is a list of aquatic animals that are Commercial fishing, harvested commercially in the greatest amounts, listed in order of tonnage per year (2012) by the Food and Agriculture Organization. Species listed here have an annual tonnage in exces ...
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Natural environment
The natural environment or natural world encompasses all life, living and non-living things occurring nature, naturally, meaning in this case not Artificiality, artificial. The term is most often applied to the Earth or some parts of Earth. Th ...
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Maximum sustainable yield In population ecology and economics, maximum sustainable yield (MSY) is theoretically, the largest yield (or catch) that can be taken from a species' stock over an indefinite period. Fundamental to the notion of sustainable harvest, the concept of ...
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Oceanic carbon cycle
The oceanic carbon cycle (or marine carbon cycle) is composed of processes that exchange carbon between various pools within the ocean as well as between the atmosphere, Earth interior, and the seafloor. The carbon cycle is a result of many inter ...
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Perverse subsidies
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Population dynamics of fisheries
A fishery is an area with an associated fish or aquatic population which is harvested for its commercial or recreational value. Fisheries can be wild or farmed. Population dynamics describes the ways in which a given population grows and shrinks o ...
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Sustainable fishing
A conventional idea of a sustainable fishery is that it is one that is harvested at a sustainable rate, where the fish population does not decline over time because of fishing practices. Sustainability in fisheries combines theoretical discipl ...
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The United Nations Ocean Conference
The 2017 United Nations Ocean Conference was a United Nations conference that took place on 5-9 June 2017 which sought to mobilize action for the conservation and sustainable use of the oceans, seas and marine resources.
The Earth's waters are s ...
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Tragedy of the commons
Tragedy (from the grc-gre, τραγῳδία, ''tragōidia'', ''tragōidia'') is a genre of drama based on human suffering and, mainly, the terrible or sorrowful events that befall a main character. Traditionally, the intention of tragedy ...
*
World Oceans Day
World Oceans Day is an international day that takes place annually on 8 June. The concept was originally proposed in 1992 by Canada's International Centre for Ocean Development (ICOD) and the Ocean Institute of Canada (OIC) at the Earth Summit ...
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Overconsumption
Overconsumption describes a situation where a consumer overuses their available goods and services to where they can't, or don't want to, replenish or reuse them. In microeconomics, this may be described as the point where the marginal cost of a ...
References
Sources
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* Roberts, Callum (2007
''The Unnatural History of the Sea''Island Press.
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External links
We’ve removed 90% of all large fish from the oceans. Just 10% to go.Australian Broadcasting Corporation
The Australian Broadcasting Corporation (ABC) is the national broadcaster of Australia. It is principally funded by direct grants from the Australian Government and is administered by a government-appointed board. The ABC is a publicly-own ...
. 13 February 2021.
{{Doomsday
Environmental impact of fishing
Environmental controversies
Fisheries law
Environmental crime
Illegal occupations
Illegal, unreported and unregulated fishing