CMS: Whales, dolphins and porpoises suffer dramatic declines from by-catch in fishing nets

Toothed whales are currently suffering from a major threat which is unsustainable loss from by-catch in fishery operations. For 86% of all toothed whale species, entanglement and death in gillnets, traps, weirs, purse seines, longlines and trawls poses a major risk.
Lack of food and forced dietary shifts due to overfishing pose additional threats to 13 species.
These are among the findings of a report launched today on the website of the Convention on the
Conservation of Migratory Species of Wild Animals (UNEP/CMS). A corresponding poster available
online shows for the first time all toothed whale species sorted according to their conservation status
as defined by the IUCN Red List of Threatened Species ™. This encyclopaedia on all 72 species of
toothed whales includes the most recent scientific findings on the distribution, migration, behaviour
and threats to this group of whales. Maps showing the currently known distribution of each species
were provided by IUCN and the Global Mammal Assessment.
UNEP/CMS Executive Secretary Elizabeth Mrema said: “During the International Year of Biodiversity,
the Convention on Migratory Species continues to address major threats such as by-catch, ship
strikes, ocean noise impacts and climate change to safeguard these charismatic marine mammals.
Governments need to enhance their efforts towards implementing targeted action plans under the
Convention. ”
Toothed whales occur in a wide range of marine and freshwater habitats, from the Arctic to the tropics.
Some species live in large river systems such as the Amazon, Ganges, Indus and Yangtze. For 41 of
all toothed whales species, our knowledge is too limited to even know if they are threatened or not. At
the same time 6 species of toothed whales that are listed on Appendix I of the Convention are on the
brink of extinction.
Many populations of toothed whales were hunted almost to extinction and 50 species continue to be
hunted, often at unsustainable levels. Ingestion of plastic debris or the effects of pollution by an ever
increasing cocktail of chemicals have been reported for 48 species. Habitat degradation from dams
and withdrawal of water from rivers and lakes threatens 18 species while ship strikes have a serious
impact on 14 species. Noise caused by seismic explorations, marine construction projects as well as
military sonar pose ever increasing threats to these marine mammals.
Based on the Review of Small Cetaceans published by CMS in 2003, this report includes the Sperm
Whale as the only large toothed whale as well as the Australian Snubfin Dolphin and the Guiana
Dolphin as new species. Since 2003, the conservation status of the toothed whales has worsened
dramatically. The Baiji River Dolphin, which used to live in the Yangtze River, is now probably extinct
as no living specimens have been documented in the wild since 2002. With only 150 individuals
remaining in the wild, the Vaquita, a porpoise living in the northern Gulf of California, is facing the
same destiny. Entanglement in fishing gear claimed an unsustainably high death toll on both species.
Data collection on the distribution, behaviour and migration of toothed whales, as reflected in research
for the CMS can facilitate the development and implementation of action plans that can help reduce
the threats to many whale species. Being an official partner of the International Year of Biodiversity,
the Convention on Migratory Species has joined the Convention on Biological Diversity (CBD) to raise
awareness of the importance of biodiversity on a global scale. CMS, which has been recognized as
CBD’s lead partner on issues regarding migratory species, continues to take steps to stress the
importance of biodiversity for our well-being and enhance efforts to reduce the rate of biodiversity loss.

Full reports:
The full species reports for the toothed whales can be downloaded from The publication
is a joint effort of CMS, ACCOBAMS, ASCOBANS, IUCN, WWF and Loro Parque Foundation. The
Convention on the Conservation of Migratory Species of Wild Animals, also known as the Bonn
Convention, works for the conservation of a wide array of endangered migratory animals such as
whales and dolphins worldwide through the negotiation and implementation of agreements and
species action plans. With currently 113 member countries, many of them in Africa, CMS is a fastgrowing
convention with special importance due to its expertise in the field of migratory species.
Under the Convention, the following regional treaties were concluded to protect whales and dolphins:
Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous
Atlantic Area (ACCOBAMS), Agreement on the Conservation of Small Cetaceans of the Baltic, North
East Atlantic, Irish and North Seas (ASCOBANS), Memorandum of Understanding for the
Conservation of Cetaceans and their Habitats in the Pacific Islands Region and the Memorandum of
Understanding concerning the Conservation of the Manatee and Small Cetaceans of Western Africa
and Macaronesia.

For more information please contact:
Veronika Lenarz, Public Information, UNEP/CMS Secretariat, on Tel.: +49 228 815 2409 or e-mail:,