Blue Sharks, Whale Sharks Receive Increased International Protection

“The fishery for blue sharks has been estimated to remove 20 million animals every year, this may well be the single largest removal of a large wild vertebrate from the ecosystem in the world.” – Ms. Gillian Shirley Tuagalu, Samoa Delegation, CMS COP12

A joint proposal by Samoa and Sri Lanka successfully listed blue sharks on Appendix II of CMS. The 21 Island Countries and Territories in the Pacific Region are all Large Ocean States, with management responsibilities of over 10% of the planet’s ocean area, with many migratory marine species from Blue Whales to Blue sharks.

In 2014 COP11 in Quito was dubbed the “Sharks Conference” as Parties agreed to list a number of sawfish and mobular rays to the Appendices.  This year COP12 has agreed to additional protection to further species of fish – listing the Whale Shark already included on Appendix II on Appendix I and adding the Dusky Shark, the Blue Shark, the Angelshark, the Common Guitarfish and the White-spotted Wedgefish to Appendix II.

At the COP held in the Philippines in October 2017 placed the globally endangered Whale Shark under Appendix I, the most protected status under the Convention. Of special concern are highly migratory species that are being overfished globally such as blue sharks (Prionace glauca). Once a common species killed as bycatch, these sharks are now the most common large shark in the Hong Kong fin trade. The fishery for blue sharks has been estimated to remove 20 million animals every year – this may well be the single largest removal of a large wild vertebrate from the ecosystem in the world.

Atlantic stock assessments undertaken by the Regional Fisheries Management Organization, the International Commission for the Conservation of Atlantic Tuna ICCAT reported that blue shark stocks cannot sustain the current levels of take, which have increased by 50% in recent years.

Stock assessments for large migratory species are inherently inaccurate. Many sharks are killed as bycatch by shark finning or other IUU fishing and the catch goes unreported. Even if the data provided is comprehensive and reliable, many assumptions are made in stock assessment models. In most fisheries, and most of the industrialized shark fisheries in particular, especially the Pacific Ocean where observer coverage on board longline vessels is extremely low at less than 5%. Compounding the lack of data, and unaccounted take is the trans-shipment on the high seas, with no observer on board either the fishing vessel or the receiving vessel. Stock assessments of sharks tend to under-estimate catch rather than to accurately estimate the extent of stock depletion.

Stock assessments also do not take into account the ecological impacts of overfishing or impacts of removing top predators like sharks on underlying trophic levels. Overfishing large sharks causes direct impacts on the trophic relationships between fish species on ocean ecosystems, contributing to a decline in reef health and the balance of other species.

Listing blue sharks on Appendix II of CMS will not shut down shark fisheries or even stop shark finning, yet it will help raise international awareness among CMS parties increased fisheries protection, increase funding for better population status and science and increase enforcement of illegal harvest and fin trade to ensure the maintenance and presence of healthy population of blue sharks for the future.

The Memorandum of Understanding (MOU) on the Conservation of Migratory Sharks is the first global instrument for the conservation of migratory species of sharks.

The International Union for the Conservation of Science (IUCN) estimated that one-quarter of chondrichthyan species are threatened worldwide (Dulvy et al. 2014). Sharks are under serious threat around the globe. In accordance with recent scientific studies (Worm et al. 2013) the number of sharks being killed every year ranges between 63 and 273 million individuals.

The MOU is a legally non-binding international instrument. It aims to achieve and maintain a favorable conservation status for migratory sharks based on the best available scientific information and taking into account the socio-economic value of these species for the people in various countries.

Currently 29 species of sharks are listed in Annex I of the MOU:

Basking Shark (Cetorhinus maximus)

Great White Shark (Carcharodon carcharias)

Longfin Mako Shark (Isurus paucus)

Porbeagle (Lamna nasus)

Shortfin Mako Shark (Isurus oxyrinchus)

Spiny Dogfish (Squalus acanthias)

Whale Shark (Rhincodon typus)

Silky Shark (Carcharhinus falciformis)

Great Hammerhead Shark (Sphyrna mokarran)

Scalloped Hammerhead Shark (Sphyrna lewini)

Thresher Sharks

  • Alopias superciliosus
  • Alopias vulpinus
  • Alopias pelagicus

Giant Manta Ray (Manta birostris)

Reef Manta Ray (Manta alfredi)


  • Anoxypristis cuspidata
  • Pristis clavata
  • Pristis pectinata
  • Pristis zijsron
  • Pristis pristis

Mobula Rays

  • Mobula mobular
  • Mobula japonica
  • Mobula thurstoni
  • Mobula tarapacana
  • Mobula eregoodootenkee
  • Mobula kuhlii
  • Mobula hypostoma
  • Mobula rochebrunei
  • Mobula munkiana

Annex I is open for further listings of species which may include any of the migratory species, subspecies or populations in the Class Chondrichthyes (sharks, rays, skates and chimaeras).

The objectives of the Conservation Plan are listed in Annex III:

  • Improving the understanding of migratory shark populations through research, monitoring and information exchange
  • Ensuring that directed and non-directed fisheries for sharks are sustainable
  • Ensuring to the extent practicable the protection of critical habitats and migratory corridors and critical life stages of sharks
  • Increasing public awareness of threats to sharks and their habitats, and enhance public participation in conservation activities
  • Enhancing national, regional and international cooperation