The Chatham Rise is an area of ocean floor to the east of

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 ...

, forming part of the

Zealandia Zealandia (pronounced ), also known as (Māori) or Tasmantis, is an almost entirely submerged mass of continental crust that subsided after breaking away from Gondwanaland 83–79 million years ago.Gurnis, M., Hall, C.E., and Lavier, L.L., ...

continent. It stretches for some from near the

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

in the west, to the

Chatham Islands The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about te ...

in the east. It is New Zealand's most productive and important

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 stocked bodies of water such as ponds, canals, park wetlands and reservoirs. Fishing techniques inclu ...

ground, as well as important habitat for

whale Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and ...

s. Relative to the rest of the

Pacific Ocean 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 ...

waters around New Zealand, the Chatham Rise is relatively shallow, no more than deep at any point. This shallowness is made more remarkable by the depth of the ocean immediately to the north and south. To the northeast, the

Hikurangi Trench The Hikurangi Trench, also called the Hikurangi Trough, is an oceanic trench in the bed of the Pacific Ocean off the east coast of the North Island of New Zealand, lying between the southern end of the Cook Strait and the Chatham Rise. It is the ...

, an extension of the much deeper

Kermadec Trench The Kermadec Trench is a linear ocean trench in the south Pacific Ocean. It stretches about from the Louisville Seamount Chain in the north (26°S) to the Hikurangi Plateau in the south (37°S), north-east of New Zealand's North Island. Toget ...

, drops to below close to the New Zealand coast, and further from the coast the Rise borders on the

Hikurangi Plateau The Hikurangi Plateau is an oceanic plateau in the South Pacific Ocean east of the North Island of New Zealand. It is part of a large igneous province (LIP) together with Manihiki and Ontong Java, now located and north of Hikurangi respective ...

. To the south, similar depths are achieved in the Bounty Trough. Past the eastern end of the rise, the sea floor drops away to the

abyssal plain An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between and . Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth's surface. T ...

Geology

Geologically and tectonically, the Chatham Rise can be thought of as an extension of the eastern South Island. It was largely dry land at the end of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

(66 million years ago) and formed a large

peninsula A peninsula (; ) is a landform that extends from a mainland and is surrounded by water on most, but not all of its borders. A peninsula is also sometimes defined as a piece of land bordered by water on three of its sides. Peninsulas exist on all ...

extending from New Zealand to the Chatham Islands at that time. The Cretaceous landscape of the Chatham Rise was characterized by a

volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...

landscape.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s found on the Chatham Islands characterize the

flora Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' gut flora'' or '' skin flora''. E ...

and

fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is ''flora'', and for fungi, it is '' funga''. Flora, fauna, funga and other forms of life are collectively referred to as '' biota''. Zoo ...

of the Chatham Rise in the late

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceo ...

. The region had forests dominated by

gymnosperm The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, ''Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμνό� ...

s (such as ''

Araucaria ''Araucaria'' (; original pronunciation: .ɾawˈka. ɾja is a genus of evergreen Conifer, coniferous trees in the family Araucariaceae. There are 20 extant taxon, extant species in New Caledonia (where 14 species are endemism, ende ...

'', '' Mataia'' and ''

Podocarpus ''Podocarpus'' () is a genus of conifers, the most numerous and widely distributed of the podocarp family, the Podocarpaceae. The name comes from Greek πούς (poús, “foot”) + καρπός (karpós, “fruit”). ''Podocarpus'' species ...

'') and

Lycopodiopsida Lycopodiopsida is a class of vascular plants known as lycopods, lycophytes or other terms including the component lyco-. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching s ...

(clubmosses). Some

angiosperm Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s were also present.

Dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s such as

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

s dwelt on the peninsula and probably evolved into numerous

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

forms (Stilwell ''et al.'' 2006).

Commercial fishing

The Chatham Rise is New Zealand's most productive and important commercial

fishing ground 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, bo ...

. The region is analogous to the North Sea's "Broad Fourteens", but is significantly deeper. Warm subtropical surface waters from the north and cold

subantarctic The sub-Antarctic zone is a region in the Southern Hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° and 60° south of the Equator. The subantarctic region includes many islands ...

surface waters from the south meet in the vicinity of the Chatham Rise to create a

subtropical front A subtropical front is a surface water mass boundary or front, which is a narrow zone of transition between air masses of contrasting density, air masses of different temperatures or different water vapour concentrates. It is also characterized by ...

. Nutrient rich waters from the south mix with warm northern waters and create ideal conditions for

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

and the animals that feed on them. The fishing grounds near the subtropical front and particularly the Chatham Rise provide 60% of New Zealand's fish catch. Because the Chatham Rise is relatively shallow, it is accessible to both

midwater trawling Midwater trawling is trawling, or net fishing, at a depth that is higher in the water column than the bottom of the ocean. It is contrasted with bottom trawling. Midwater trawling is also known as pelagic trawling and bottom trawling as benthic ...

and

bottom trawling 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 towin ...

. Species include the main hoki,

hake The term hake refers to fish in the: * Family Merlucciidae of northern and southern oceans * Family Phycidae (sometimes considered the subfamily Phycinae in the family Gadidae) of the northern oceans Hake Hake is in the same taxonomic order (Gad ...

ling Ling may refer to: Fictional characters * Ling, an ally of James Bond's from the film ''You Only Live Twice'' * Ling, a character in the ''Mulan'' franchise * Ling, a playable character from the mobile game '' Mobile Legends: Bang Bang'' * Ling ...

silver warehou The silver warehou, ''Seriolella punctata'', is a medusafish of the family '' Centrolophidae'' found in the southern Indian and southern Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends ...

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

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 deep sea (oreo)

dory A dory is a small, shallow-draft boat, about long. It is usually a lightweight boat with high sides, a flat bottom and sharp bows. It is easy to build because of its simple lines. For centuries, the dory has been used as a traditional fishin ...

fisheries.NZ Ministry of Fisheries
''Fisheries and their ecosystems.''
Retrieved 13 June 2008. The traditional approach to

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 ...

has been to focus on a single species – determining how many can be caught before the breeding population is affected to the point of harming the species fishery. There is a current trend towards

ecosystem based fisheries 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, ...

.University of Liverpool (2006)
"Marine Ecologists To Help Rebuild Decreasing Fish Stocks"
ScienceDaily. Removing any fish affects other

marine life Marine life, sea life, or ocean life is the plants, animals and other organisms that live in the salt water of seas or oceans, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. M ...

up and down the

food chain A food chain is a linear network of links in a food web starting from producer organisms (such as grass or algae which produce their own food via photosynthesis) and ending at an apex predator species (like grizzly bears or killer whales), det ...

, such as marine life that eat the fish, and the marine life eating the marine life that eat the fish. Scientists from

NIWA The National Institute of Water and Atmospheric Research or NIWA ( mi, Taihoro Nukurangi), is a Crown Research Institute of New Zealand. Established in 1992, NIWA conducts research across a broad range of disciplines in the environmental scien ...

are examining over 40,000 fish stomachs to see what different species are eating across the Chatham Rise. These studies, combined with other studies on marine mammals and sea birds and with relevant ocean and climate studies, will show how the different parts fit together in the Chatham Rise ecosystem.

Notes

References

* Stilwell, Jeffrey D.; Consoli, Christopher P.; Sutherland, Rupert; Salisbury, Steven; Rich, Thomas H.; Vickers-Rich, Patricia A.; Currie, Philip J.; Wilson, Graeme J. (2006): Dinosaur sanctuary on the Chatham Islands, Southwest Pacific: First record of theropods from the K–T boundary Takatika Grit. ''Palaeogeography, Palaeoclimatology, Palaeoecology'' 230(): 243–250. {{Coord, -43.7, 179.7, dim:1000000, display=title Historical geology Geography of the New Zealand seabed Zealandia Pacific Ocean Fishing areas of the Pacific Ocean Geography of the Chatham Islands Fishing in New Zealand