Offshore aquaculture, also known as open water aquaculture or open ocean aquaculture, is an emerging approach to

mariculture Mariculture or marine farming is a specialized branch of aquaculture (which includes freshwater aquaculture) involving the cultivation of marine organisms for food and other animal products, in enclosed sections of the open ocean ( offshore mar ...

( seawater

aquafarming 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. lotus ...

) where

fish farm 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 ...

s are positioned in deeper and less sheltered waters some distance away from the

coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in ...

, where the cultivated

fish stocks Fish stocks are subpopulations of a particular species of fish, for which intrinsic parameters (growth, recruitment, mortality and fishing mortality) are traditionally regarded as the significant factors determining the stock's population dyna ...

are exposed to more naturalistic living conditions with stronger ocean currents and more diverse nutrient flow.Naylor, R., and Burke, M. (2005
"Aquaculture and ocean resources: raising tigers of the sea"
''Annual Review of Environmental Resources,'' 30:185–218.Sturrock H, Newton R, Paffrath S, Bostock J, Muir J, Young J, Immink A and Dickson M (2008) tp://139.191.159.34/pub/library/EUR%2023409/JRC45686preprint.pdf Part 2: Characterisation of emerging aquaculture systemsIn: ''Prospective Analysis of the Aquaculture Sector in the EU'', European Commission, EUR 23409 EN/2. . Existing "offshore" developments fall mainly into the category of exposed areas rather than fully offshore. As maritime classification society DNV GL has stated, development and knowledge-building are needed in several fields for the available deeper water opportunities to be realized. One of the concerns with inshore aquaculture, which operate on more sheltered (and thus calmer) shallow waters, is that the discarded nutrients from unconsumed feeds and feces can accumulate on the farm's seafloor and damage the

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 "t ...

ecosystem, and sometimes contribute to

algal bloom An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompass ...

s. According to proponents of offshore aquaculture, the wastes from aquafarms that have been moved offshore tend to be swept away and diluted into the open ocean. Moving aquaculture offshore also provides more ecological space where production yields can expand to meet the increasing market demands for fish. Offshore facilities also avoid many of the conflicts with other marine resource users in the more crowded inshore waters, though there can still be user conflicts offshore. Critics are concerned about issues such as the ongoing consequences of using

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...

and other

drug pollution Drug pollution or pharmaceutical pollution is pollution of the environment with pharmaceutical drugs and their metabolites, which reach the aquatic environment (groundwater, rivers, lakes, and oceans) through wastewater. Drug pollution is theref ...

s, and the possibilities of cultured fish escaping and spreading disease among

wild fish A wild fishery is a natural body of water with a sizeable free-ranging fish or other aquatic animal (crustaceans and molluscs) population that can be harvested for its commercial value. Wild fisheries can be marine ( saltwater) or lacustrine/ ...

Background

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 ...

is the most rapidly expanding food industry in the worldSkladany, M., Clausen, R., Belton, B. (2007
"Offshore aquaculture: the frontier of redefining oceanic property"
''Society and Natural Resources'', 20: 169–176. as a result of declining wild fisheries stocks and profitable business. In 2008, aquaculture provided 45.7% of the fish produced globally for human consumption; increasing at a mean rate of 6.6% a year since 1970.FAO. (2010
''The State of World Fisheries and Aquaculture''
Rome. FAO, 2010, 197p. In 1970, a National Oceanic and Atmospheric Administration (NOAA) grant brought together a group of oceanographers, engineers and marine biologists to explore whether offshore aquaculture, which was then considered a futuristic activity, was feasible.Hanson, J. A. (Ed.) (1974) ''Open sea mariculture: Perspectives, problems and prospects''. Stroudsburg, PA: Dowden, Hutchinson & Ross. In the United States, the future of offshore aquaculture technology within federal waters has become much talked-about.Rubino, Michael (Ed.) (2008
''Offshore Aquaculture in the United States: Economic Considerations, Implications & Opportunities''
U.S. Department of Commerce; Silver Spring, MD; USA. NOAA Technical Memorandum NMFS F/SPO-103. 263p. As many commercial operations show, it is now technically possible to culture finfish,

shellfish Shellfish is a colloquial and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater enviro ...

, and

seaweeds Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of ''Rhodophyta'' (red), '' Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

using offshore aquaculture technology. Major challenges for the offshore aquaculture industry involve designing and deploying

cage A cage is an enclosure often made of mesh, bars, or wires, used to confine, contain or protect something or someone. A cage can serve many purposes, including keeping an animal or person in captivity, capturing an animal or person, and displayin ...

s that can withstand storms, dealing with the logistics of working many kilometers from land, and finding species that are sufficiently profitable to cover the costs of rearing fish in exposed offshore areas.Stickney, R. R., Costa-Pierce, B., Baltz, D. M., Drawbridge, M., Grimes, C., Phillips, S., Swann, D. L. (2006
"Towards sustainable open ocean aquaculture in the United States"
''Fisheries,'' 31(12): 607–610.

Technology

To withstand the high energy offshore environment, farms must be built to be more robust than those inshore.Cressey, D. (2009) "Future fish". ''Nature,'' 458: 398–400. However, the design of the offshore technology is developing rapidly, aimed at reducing cost and maintenance.Mann, C. C. (2004

''Wired Mag.'' 12.05. While the

ranching A ranch (from es, rancho/Mexican Spanish) is an area of land, including various structures, given primarily to ranching, the practice of raising grazing livestock such as cattle and sheep. It is a subtype of a farm. These terms are most ofte ...

systems currently used for tuna use open net cages at the surface of the sea (as is done also in

salmon farming The aquaculture of salmonids is the farming and harvesting of salmonids under controlled conditions for both commercial and recreational purposes. Salmonids (particularly salmon and rainbow trout), along with carp, and tilapia are the three most ...

), the offshore technology usually uses submersible cages. These large rigid cages – each one able to hold many thousands of fish – are

anchor An anchor is a device, normally made of metal , used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ''ancora'', which itself comes from the Greek ἄγ ...

ed on the sea floor, but can move up and down the water column. They are attached to

buoys A buoy () is a floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents. Types Navigational buoys * Race course marker buoys are used for buoy racing, the most prevalent form of yac ...

on the surface which frequently contain a mechanism for feeding and storage for equipment. Similar technology is being used in waters near the Bahamas, China, the Philippines, Portugal, Puerto Rico, and Spain. By submerging cages or shellfish culture systems, wave effects are minimized and interference with boating and shipping is reduced. Offshore farms can be made more efficient and safer if remote control is used,Finfish aquaculture
Atlantic Marine Aquaculture Center, University of New Hampshire. Retrieved 7 October 2011. and technologies such as an 18-tonne buoy that feeds and monitors fish automatically over long periods are being developed.

Existing offshore structures

Multi-functional use of offshore waters can lead to more sustainable aquaculture "in areas that can be simultaneously used for other activities such as energy production". Operations for finfish and shellfish are being developed. For example, the Hubb-Sea World Research Institutes’ project to convert a retired oil platform 10 nm off the southern California coast to an experimental offshore aquaculture facility.
''North County Times'', 19 June 2005. The institute plans to grow

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which ...

s and

red abalone ''Haliotis rufescens'' (red abalone) is a species of very large edible sea snail in the family Haliotidae, the abalones, ormer shells or paua.Rosenberg, G. (2014)''Haliotis rufescens'' Swainson, 1822.Accessed through: World Register of Marine S ...

on the actual platform, as well as

white seabass White seabass or white weakfish, ''Atractoscion nobilis'', is a species of croaker occurring from Magdalena Bay, Baja California, to Juneau, Alaska. They usually travel in schools over deep rocky bottoms (0–122 m) and in and out of kelp beds. ...

, striped bass,

bluefin tuna Bluefin tuna is a common name used to refer to several species of 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, ...

, California halibut and California yellowtail in floating cages.

Integrated multi-trophic aquaculture

Integrated multi-trophic aquaculture (IMTA), or

polyculture In agriculture, polyculture is the practice of growing more than one crop species in the same space, at the same time. In doing this, polyculture attempts to mimic the diversity of natural ecosystems. Polyculture is the opposite of monoculture, i ...

, occurs when species which must be fed, such as finfish, are cultured alongside species which can feed on dissolved nutrients, such as seaweeds, or organic wastes, such as

suspension feeder Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...

s and deposit feeders.Troell, M., Joyce, A., Chopin, T., Neori, A., Buschmann, A. H., Fang, J. (2009
"Ecological engineering in aquaculture – Potential for integrated multi-trophic aquaculture (IMTA) in marine offshore systems"
''Aquaculture,'' 297: 1–9. This sustainable method could solve several problems with offshore aquaculture. The method is being pioneered in Spain, Canada, and elsewhere.

Roaming cages

Roaming cages have been envisioned as the "next generation technology" for offshore aquaculture. These are large mobile cages powered by thrusters and able to take advantage of ocean currents. One idea is that juvenile tuna, starting out in mobile cages in Mexico, could reach Japan after a few months, matured and ready for the market. However, implementing such ideas will have regulatory and legal implications.

Space conflicts

As oceans industrialise, conflicts are increasing among the users of marine space. This competition for marine space is developing in a context where natural resources can be seen as publicly owned. There can be conflict with the tourism industry, recreational fishers,Grimes J (1999
"Competition for Common Property Space: New Hampshire's Recreational and Open Ocean Aquaculture. Development"
Proceedings of the 1999 Northeastern Recreation Research Symposium, GTR-NE-269, pp. 378–383. wild harvest fisheries and the siting of marine renewable energy installations. The problems can be aggravated by the remoteness of many marine areas, and difficulties with monitoring and enforcement.Harte MJ, Campbell HV and Webster J (2010
"Looking for a safe harbor in a crowded sea: Coastal space use conflict and marine renewable energy development"
In: Shifting Shorelines: Adapting to the Future,The 22nd International Conference of The Coastal Society. On the other hand, remote sites can be chosen that avoid conflicts with other users, and allow large scale operations with resulting economies of scale. Offshore systems can provide alternatives for countries with few suitable inshore sites, like Spain.

Ecological impacts

The ecological impacts of offshore aquaculture are somewhat uncertain because it is still largely in the research stage. Many of the concerns over potential offshore aquaculture impacts are paralleled by similar, well established concerns over inshore aquaculture practices.

Pollution

One of the concerns with inshore farms is that discarded nutrients and feces can settle on the seafloor and disturb the

benthos Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.Working Group Report on Benthic Impacts and Farm Siting
In: Salmon Aquaculture Dialogue, WWF. The "dilution of nutrients" that occurs in deeper water is a strong reason to move coastal aquaculture offshore into the open ocean.Simpson, S. (2011
"The blue food revolution"
''Scientific American,'' 304(2): 54–61. How much nutrient pollution and damage to the seafloor occurs depends on the feed conversion efficiency of the species, the flushing rate and the size of the operation. However, dissolved and particulate nutrients are still released to the environment. Future offshore farms will probably be much larger than inshore farms today, and will therefore generate more waste. The point at which the capacity of offshore ecosystems to assimilate waste from offshore aquaculture operations will be exceeded is yet to be defined.

Wild caught feed

As with the inshore aquaculture of carnivorous fish, a large proportion of the feed comes from wild forage fish. Except for a few countries, offshore aquaculture has focused predominantly on high value carnivorous fish. If the industry attempts to expand with this focus then the supply of these

will become ecologically unsustainable.

Fish escapes

The expense of offshore systems means it is important to avoid fish escapes. However, it is likely there will be escapes as the offshore industry expands. This could have significant consequences for native species, even if the farmed fish are inside their native range. Submersible cages are fully closed and therefore escapes can only occur through damage to the structure. Offshore cages must withstand the high energy of the environment and attacks by predators such as sharks. The outer netting is made of Spectra – a super-strong polyethylene fibre – wrapped tightly around the frame, leaving no slack for predators to grip. However, the fertilised eggs of cod are able to pass through the cage mesh in ocean enclosures.Bekkevold, D., Hansen, M., Loeschcke, V. (2002
"Male reproductive competition in spawning aggregations of cod (''Gardus morhua L.'')"
''Molecular Ecology,'' 11: 91–102.

Disease

Compared to inshore aquaculture, disease problems currently appear to be much reduced when farming offshore. For example, parasitic infections that occur in mussels cultured offshore are much smaller than those cultured inshore. However, new species are now being farmed offshore although little is known about their ecology and epidemiology. The implications of transmitting pathogens between such farmed species and wild species "remains a large and unanswered question".Walker, P. (2004
"Disease emergence and food security: global impact of pathogens on sustainable aquaculture production"
Presented at Fish, Aquaculture and Food Security: Sustaining Fish as a Food Supply, Canberra, Australia. Spreading of pathogens between fish stocks is a major issue in disease control. Static offshore cages may help minimize direct spreading, as there may be greater distances between aquaculture production areas. However, development of roaming cage technology could bring about new issues with disease transfer and spread. The high level of carnivorous aquaculture production results in an increased demand for live aquatic animals for production and breeding purposes such as bait,

broodstock Broodstock, or broodfish, are a group of mature individuals used in aquaculture for breeding purposes. Broodstock can be a population of animals maintained in captivity as a source of replacement for, or enhancement of, seed and fry numbers.Waples ...

and milt. This can result in spread of disease across species barriers.

Employment

Aquaculture is encouraged by many governments as a way to generate jobs and income, particularly when wild fisheries have been run down. However, this may not apply to offshore aquaculture. Offshore aquaculture entails high equipment and supply costs, and therefore will be under severe pressure to lower labor costs through automated production technologies. Employment is likely to expand more at processing facilities than grow-out industries as offshore aquaculture develops.

Prospects

As of 2008, Norway and the United States were making the main investments in the design of offshore cages.Bostock J, Muir J, Young J, Newton R and Paffrath S (2008
Part 1: Synthesis report
In: ''Prospective Analysis of the Aquaculture Sector in the EU'', European Commission, EUR 23409 EN/1. .

FAO

In 2010, the Food and Agriculture Organization (FAO) sub-committee on aquaculture made the following assessments: ::"Most Members thought it inevitable that aquaculture will move further offshore if the world is to meet its growing demand for seafood and urged the development of appropriate technologies for its expansion and assistance to developing countries in accessing them ..Some Members noted that aquaculture may also develop offshore in large inland water bodies and discussion should extend to inland waters as well ..Some Members suggested caution regarding potential negative impacts when developing offshore aquaculture.FAO (2010
Report of the fifth session of the sub-committee on aquaculture
Report 950, Rome. . The sub-committee recommended the FAO "should work towards clarifying the technical and legal terminology related to offshore aquaculture in order to avoid confusion."

Europe

In 2002, the European Commission issued the following policy statement on aquaculture: ::"Fish cages should be moved further from the coast, and more research and development of offshore cage technology must be promoted to this end. Experience from outside the aquaculture sector, e.g. with oil platforms, may well feed into the aquaculture equipment sector, allowing for savings in the development costs of technologies." By 2008, European offshore systems were operating in Norway, Ireland, Italy, Spain, Greece, Cyprus, Malta, Croatia, Portugal and Libya. In Ireland, as part of their

National Development Plan National Development Plan (NDP, ga, Plean Forbartha Náisiúnta) was the title given by the Irish Government to a scheme of organised large-scale expenditure on (mainly) national infrastructure. The first five-year plan ran from 1988 to 1993, ...

, it is envisioned that over the period 2007–2013, technology associated with offshore aquaculture systems will be developed, including: "sensor systems for feeding, biomass and health monitoring, feed control, telemetry and communications ndcage design, materials, structural testing and modelling."

United States

Moving aquaculture offshore into the exclusive economic zone (EEZ) can cause complications with regulations. In the United States, regulatory control of the coastal states generally extends to 3 nm, while federal waters (or EEZ) extend to 200 nm offshore. Therefore, offshore aquaculture can be sited outside the reach of state law but within federal jurisdiction. As of 2010, "all commercial aquaculture facilities have been sited in nearshore waters under state or territorial jurisdiction."Upton, F. U., Buck, E. H. (2010
Open ocean aquaculture
''Congressional Research Service'', CRS Report for Congress. However, "unclear regulatory processes" and "technical uncertainties related to working in offshore areas" have hindered progress. The five offshore research projects and commercial operations in the US – in New Hampshire, Puerto Rico, Hawaii and California – are all in federal waters. In June 2011, the ''National Sustainable Offshore Aquaculture Act of 2011'' was introduced to the House of Representatives "to establish a regulatory system and research program for sustainable offshore aquaculture in the United States exclusive economic zone".New offshore aquaculture bill seeks to protect oceans
''Fis'', 7 July 2011.

Current species

By 2005, offshore aquaculture was present in 25 countries, both as experimental and commercial farms. Market demand means that the most offshore farming efforts are directed towards raising finfish. Two commercial operations in the US, and a third in the Bahamas are using submersible cages to raise high-value carnivorous finfish, such as

moi Moi or MOI may refer to: People * Moi (name), a list of people with the given name or surname * Moisés Delgado (born 1994), Spanish footballer commonly known as simply Moi * Moisés Rodríguez (born 1997), Spanish footballer commonly known a ...

cobia The cobia (''Rachycentron canadum'') is a species of carangiform marine fish, the only extant representative of the genus '' Rachycentron'' and the family Rachycentridae. Other common names include black kingfish, black salmon, ling, lemonf ...

, and mutton snapper. Submersible cages are also being used in experimental systems for halibut, haddock,

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 calle ...

, and

summer flounder The summer flounder or fluke (''Paralichthys dentatus'') is a marine flatfish that is found in the Atlantic Ocean off the East Coast of the United States and Canada. It is especially abundant in waters from North Carolina to Massachusetts. Des ...

in New Hampshire waters, and for

amberjack Amberjacks are Atlantic and Pacific fish in the genus '' Seriola'' of the family Carangidae. They are widely consumed across the world in various cultures, most notably for Pacific amberjacks in Japanese cuisine; they are most often found in th ...

red drum The red drum (''Sciaenops ocellatus''), also known as redfish, channel bass, puppy drum, spottail bass, or simply red, is a game fish found in the Atlantic Ocean from Massachusetts to Florida and in the Gulf of Mexico from Florida to northern Mexi ...

, snapper,

pompano Pompanos ( ) are marine fishes in the genus ''Trachinotus'' in the family Carangidae (better known as "jacks"). Pompano may also refer to various other, similarly shaped members of the Carangidae, or the order Perciformes. Their appearance is ...

, and

in the Gulf of Mexico. The offshore aquaculture of shellfish grown in suspended culture systems, like

scallops Scallop () is a common name that encompasses various species of marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related families ...

and mussels, is gaining ground. Suspended culture systems include methods where the shellfish are grown on a tethered rope or suspended from a floating raft in net containers.Lado-Insua, T., Ocampo, F. J., Moran, K. (2009
"Offshore mussel aquaculture: new or just renewed?" ''Oceans ’09 IEEE Bremen'': Balancing Technology with Future Needs, art. No. 5278263.
/ref> Mussels in particular can survive the high physical stress levels which occur in the volatile environments that occur in offshore waters. Finfish species must be feed regularly, but shellfish do not, which can reduce costs. The University of New Hampshire in the US has conducted research on the farming of

blue mussels The blue mussel (''Mytilus edulis''), also known as the common mussel, is a medium-sized edible marine bivalve mollusc in the family Mytilidae, the mussels. Blue mussels are subject to commercial use and intensive aquaculture. A species with a l ...

submerged in an open ocean environment.Shellfish aquaculture
''Atlantic Marine Aquaculture Center'', University of New Hampshire. Retrieved 3 October 2011. They have found that when farmed in less polluted waters offshore,
''NOAA Magazine'', Story 161. Retrieved 3 October 2011. the mussels develop more flesh with lighter shells.

Global status

Notes

Further references

* James. M.A. and Slaski, R. (2006) Appraisal of the opportunity for offshore aquaculture in UK waters. Report of Project FC0934, commissioned by Defra and Seafish from FRM Ltd., 119 p

* Lee C and O’Bryenn PJ (Eds.) (2007
Open Ocean Aquaculture—Moving Forward
Oceanic Institute workshop, Hawaii Pacific University. * Nolan, Jean T (2009
''Offshore Marine Aquaculture''
Nova Science. .

''NOAA''. Updated 18 July 2011. * Stickney RR, Costa-Pierce B, Baltz DM, Drawbridge M, Grimes C, Phillips S and Swann DL (2006
Toward Sustainable Open Ocean Aquaculture in the United States
''Fisheries'', 31 (12): 607–610.

''NOAA''. Updated 22 October 2007.

''NOAA''. Updated 5 September 2008.

''NOAA''. Updated 18 June 2008. * Mittal, Anu K. (2008
''Offshore Marine Aquaculture: Multiple Administrative and Environmental Issues Need to be Addressed in Establishing a U.S. Regulatory Framework''
Diane Publishing. .

''New York Times'', 23 April 2009. * Kapetsky JD and Aguilar-Manjarrez J (2007) tp://ftp.fao.org/docrep/fao/009/a0906e/a0906e01.pdf Estimating open ocean aquaculture potential in EEZ with remote sensing and GIS: a reconnaissanceIn: ''Geographic information systems, remote sensing and mapping for the development and management of marine aquaculture'', FAO fisheries technical paper 458. . * Watson, L and Drumm A (2007
Offshore Aquaculture Development in Ireland, next steps
FAO fisheries technical report. * James, Mark and Slaski, Richard (2007
Appraisal of the opportunity for offshore aquaculture in UK water
''CEFAS Finfish News, Issue 3.

''World Wildlife Fund''. Retrieved 16 October 2011.
Offshore aquaculture viewpoints
''PBS''. Retrieved 16 October 2011.

''Star Advertiser'', 28 November 2010.
Ocean of trouble: Report warns of offshore fish farming dangers
''Grist'', 12 October 2011. {{fisheries and fishing Aquaculture

Background

Technology

Existing offshore structures

Integrated multi-trophic aquaculture

Roaming cages

Space conflicts

Ecological impacts

Pollution

Wild caught feed

Fish escapes

Disease

Employment

Prospects

FAO

Europe

United States

Current species

Global status

See also

Notes

Further references