Important Shark and Ray Areas (ISRA) are discrete three-dimensional portions of habitat that are important for one or more species of chondrichthyans (sharks, rays and chimaeras) and have the potential to be managed for conservation. [1] This project is led by the Shark Specialist Group of the International Union for Conservation of Nature (IUCN) Species Survival Commission. [2] [3]
The identification of ISRA is a purely biocentric, fact-based process founded on the application of scientific criteria supported by the best available scientific evidence. This makes the ISRA identification process completely independent of political pressures. The main objective of ISRA is to attract the attention of politicians and decision-makers to the need to maintain a favourable conservation status of sharks in those specific areas, through the implementation of appropriate management measures, which could include the designation of a marine protected area or other area-based management measures. [4] The project is funded by the Shark Conservation Fund, among others. [5]
There are four criteria for a marine habitat to be considered an ISRA, which are related to its vulnerability, its three-dimensional geographic distribution, its life history, and special attributes of the species. [6] Once the ISRA zones are approved and declared, they are incorporated into an electronic map on the project page. [7]
As of May 2024, 499 ISRAs, 19 Candidate ISRAs and 132 Areas of Interest have been identified. [8] Candidate ISRAs and Areas of Interest are areas where more information is needed but have the potential to become ISRAs.
ISRAs are identified through an expert-led process planned over a series of 13 regional workshops covering global waters. The thirteen regions are:
At the first regional workshop, October 2022, the ISRA project team and local specialists identified 65 ISRAs in the Pacific region of Central and South America (from the Gulf of California in Mexico to southern Chile, including the oceanic islands of Revillagigedo, Easter Island, among others). [9] [10]
At the second regional workshop, May 2023, 65 ISRAs were identified for the Mediterranean and Black Sea region. [11] [12] [13]
At the third regional workshop, September 2023, 125 ISRAs have been identified for the Western Indian Ocean region. [14]
At the fourth regional workshop, January 2024, 122 ISRAs were identified for the Asia region. [15] [16]
The identification of ISRAs is achieved through the application of scientifically-based criteria. The definition of these ISRA criteria is of vital importance for the effectiveness of the tool in terms of its application, standardization and consistency across all identified areas, as well as to ensure comparability between ISRAs at national, regional, and international scales. The criteria are designed to cover important aspects of shark biology (e.g., age, growth and reproduction), ecology and population structure, and include multiple aspects of species vulnerability, distribution and movement patterns, abundances, specific habitat requirements and key life-cycle activities, as well as areas of high diversity and endemism. [6]
Criterion A - Vulnerability are important areas for the persistence and recovery of sharks, rays, and/or chimaeras that are endangered according to the IUCN Red List of Threatened Species or national listings.
Criterion B - Restricted Distribution are areas that contain the regular and/or predictable presence of sharks, rays and/or chimaeras with a restricted distribution and that are occupied permanently or seasonally.
Criterion C - Life History are important areas for sharks, rays and/or chimaeras where they carry out key functions throughout their life cycle (including reproduction, feeding, resting, movement or indefinite aggregations). Sub-criterion C1 - Reproductive Areas are important areas for mating, giving birth, laying eggs or that provide shelter and other benefits to newborn or under-yearling sharks. Subcriterion C2 - Feeding Areas are areas important for shark nutrition during one or more life cycle stages. Subcriterion C3 - Resting Areas are areas important for energy conservation in sharks and are often related to environmental conditions or temporal factors. Subcriterion C4 - Movement are areas regularly or predictably used by sharks during movements, such as migrations, which contribute to the connectivity of important areas. Subcriterion C5 - Indefinite Aggregations are areas where regular and/or predictable aggregations or groupings of sharks occur, year-round or seasonally, but their function is currently unknown.
Criterion D - Special Attributes are areas important for sharks that are considered distinctive for biological, behavioral, or ecological attributes (unique or associated with a unique habitat type), or that support significant species diversity. Subcriterion D1 - Distinctive are areas where sharks display distinctive biological, behavioral, or ecological characteristics. Subcriterion D2 - Diversity are areas that contain significant shark diversity.
Chondrichthyans (sharks, rays, and chimaeras) face a global extinction crisis. According to the IUCN Red List of Threatened Species, over one third of chondrichthyans are currently estimated to be threatened with extinction. [17] Over the past century, fishing has had a significant and cumulative impact on chondrichthyans and this threat has been exacerbated by habitat loss and climate change. Threat levels are highest in coastal areas where 75% of threatened species are found. This makes sharks one of the most threatened taxa in the marine environment, second only to amphibians globally. [18]
The Ganges shark is a critically endangered species of requiem shark found in the Ganges River and the Brahmaputra River of India and Bangladesh. It is often confused with the more common bull shark, which also inhabits the Ganges River and is sometimes incorrectly referred to as the Ganges shark. The genus is currently considered to contain three recent species; genetic evidence has shown that both the Borneo river shark and Irrawaddy river shark should be regarded as synonyms of the Ganges shark, expanding the range of the species to Pakistan, Myanmar, Borneo, and Java. While the other members of the genus Glyphis occur in coastal marine waters as well as rivers, the Ganges shark is found only in fresh water, making it the world's only exclusively freshwater shark. The species remains poorly known and very rare.
The bareskin dogfish is a little-known, deepwater dogfish shark of the family Etmopteridae. This species is found in the western Pacific from southern Japan to western and southeastern Australia as well as in New Zealand waters.
The smooth deep-sea skate is a skate in the family Arhynchobatidae. It is found off New Zealand, at depths of from 200 to 1,300 m on the continental shelf. Their length is from 30 to 50 cm.
The prickly deep-sea skate, or spinydeep-sea skate, is a deep sea skate in the family Arhynchobatidae. It lives off New Zealand, at depths of from 170 to 1,400 m on the continental shelf. Their length is from 60 to 80 cm.
The dark ghostshark is a shortnose chimaera of the family Chimaeridae, found on the continental shelf around the South Island of New Zealand. In June 2018 the New Zealand Department of Conservation classified the dark ghostshark as "Not Threatened" under the New Zealand Threat Classification System.
The pale ghost shark is a shortnose chimaera of the family Chimaeridae. It is endemic to New Zealand waters.
The New Zealand catshark is a catshark of the family Scyliorhinidae in the order Carcharhiniformes. This species is endemic to in the deep waters around New Zealand. Its length is up to 45 centimetres (18 in). The New Zealand catshark is a small, little-known deep water bottom shark. It is dark brown around the top with a few widely spaced pale spots, and white below. It feeds on bottom-living crustaceans. It is also completely harmless to humans.
The sherwood dogfish or Sherwood's dogfish is a very rare sleeper shark of the family Somniosidae, found only around New Zealand. The only specimen studied was about 80 cm long.
The spotted estuary smooth-hound or rig is a houndshark of the family Triakidae, found on the continental shelves and in estuaries around New Zealand. It is closely related to the gummy shark of Australia. Males can grow up to a length of 125 cm, while females can reach a length of 151 cm.
McMillan's catshark is a catshark of the family Scyliorhinidae, in the order Carcharhiniformes. McMillan's catshark is a small, rare, and little-known deepwater shark that is endemic to New Zealand. It is found at depths of 985–1350m on the lower continental slope around New Zealand, on the West Norfolk Ridge, and off North Cape. It can grow to a length of 45 cm.
The whitetail dogfish is a very rare sleeper shark of the family Somniosidae, found from the eastern Indian Ocean round southern Australia to New Zealand, at depths of between 150 and 500 m. Its length is up to 1.1 m.
The white-bodied catshark is a catshark of the family Scyliorhinidae.
The flaccid catshark is a catshark of the family Scyliorhinidae. It is endemic to the waters around New Zealand.
The black roughscale catshark is a catshark of the family Scyliorhinidae. It is recorded from the north Atlantic, eastern South Atlantic, in the Indian Ocean and around Australia and New Zealand. The species can be found on continental shelf at depths between 510 and 1,520 m. It can grow up to 90 cm (35 in).
The smoothnose wedgefish is a species of fish in the Rhinidae family. It is found in northern Indian Ocean and northwestern Pacific Ocean, ranging from the Arabian Sea and Persian Gulf east to Bangladesh, and South China Sea to southern Japan. Populations elsewhere are now recognized as separate species. Its natural habitat is shallow coastal seas and off the mouths of rivers. It is threatened by habitat loss and overfishing.
The northern spiny dogfish, also known as the brown dogfish, grey spiny dogfish or Griffin's dogfish, is a marine species of the family Squalidae, found off New Zealand's North Island. The length of the longest specimen measured is 89.9 cm (35.4 in).
The Kermadec spiny dogfish is a dogfish described in 2007. It is a member of the family Squalidae, found off the Kermadec Islands. The length of the longest specimen measured is 68.1 cm (26.8 in).
Rhinochimaera pacifica, commonly known as the Pacific spookfish, knifenose chimaera, narrownose chimaera, Pacific long-nosed chimaera, or Pinocchiofish, is a species of chimaera in the family Rhinochimaeridae. It lives in various parts of the Pacific Ocean and can be characterized by its long snout.
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