Small whales

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As a small cetaceans representatives of are whales called that not one of the 13 great whale species including the 1946 International Convention for the Regulation of Whaling were listed. This classification of whales is politically and under international law motivated and has no scientific or taxonomic background. There is also no clear limit to body length when distinguishing between large and small cetaceans. Some small whale species can easily reach the size of the minke whale , the smallest large whale species. Almost all small whales belong to the toothed whales . The only toothed whale species that has been assigned to the large whales is the sperm whale .

Small whale families

The following families are counted among the small whales:

threat

The small whales mostly live near the coast or in rivers and migrate between breeding and feeding habitats. While the population of large whales has declined mainly due to intensive, international whaling , the small whales are subject to other anthropogenic influences and threats in their habitats and due to their often considerably smaller size . One of the most common, unnatural causes of death of small whales is unwanted bycatch in fishing nets , in which the small whales suffocate. The more intense shipping traffic near the coast and the shallower water depths on the coasts and in the rivers increase the risk of collisions with ship propellers . The underwater noise from underwater construction sites near the coast, such as from offshore wind farms or work on and on drilling platforms, and the water pollution are more intense in the habitat of many small whale species than in habitats distant from the coast .

Some nations interpret the list of the 13 large whale species from 1946 in such a way that the responsibility for determining catch quotas of the International Whaling Commission (IWC) is limited exclusively to these species and the small whale species are therefore less strictly protected. That is why whaling nations like Japan are resorting to hunting small whales. For some species of small whales, hunting is one of the main human threats alongside bycatch. In addition, there are also habitat losses and food shortages due to overfishing in many places .

Protection and Research

In order to be able to counter the special threats to small whales with suitable protective measures, the IWC has decided that its Scientific Committee should also deal with small whales. For this purpose, the SCSC (sub-committee on small cetaceans) was founded in 1979, which has since dealt with small cetaceans. In 2009, the animal welfare organization WDC recommended to this subcommittee that it deal with the question of the effects of climate change on small whales. In 2010 it was decided at the annual meeting of the scientific committee of the IWC that the influence of climate change on the small whales should be examined with a focus on the following topics:

  • limited habitats
  • Changes in the distribution area
  • the arctic

The SCSC publishes research results on specially studied species and regions every year. The research priorities are redefined every year and the results and recommendations are published. As a result of the international research work on small whale protection and its recommendations, the SCSC cites, among other things, a recovery of the Californian harbor porpoise - an endemic species in the Gulf of California that is threatened with extinction . Here fishermen are to use nets in which the bycatch of small whales is reduced by acoustic signals from pingers . The acceptance of the fishermen to use the more expensive nets is limited and the measurability of the success based on the few sightings as a result of the very small number of individuals is controversial. To facilitate international cooperation in research on small whale protection, representatives of the IWC's Scientific Committee are invited to the meetings of ASCOBANS , ACCOBAMS and CMS as observers.

The ASCOBANS regional protection agreement for the conservation of small whales in the North Sea and Baltic Sea, the Northeast Atlantic and the Irish Sea is limited to the small whales occurring in the region and excludes, for example, the sperm whale. While ACCOBAMS includes all whales occurring in the Black Sea, the Mediterranean Sea and the adjoining Atlantic zone and is not a protection agreement specifically aimed at small whales.

The effectiveness of bubble curtain systems was examined to reduce the influence of underwater noise . These studies were funded by the BMU. Since the effectiveness is limited by their dependence on the flow strength and direction of flow and the targeted limit values ​​could not be fully adhered to with the examined bubble curtain systems, a funded study at the Alpha Ventus wind farm was discontinued. There are currently no standardized procedures for reducing underwater noise. Further research and development work is required, including with regard to the significance of the interference.

Web links

Individual evidence

  1. ↑ a b IWC (English): Small cetaceans
  2. ↑ Ascobans : Small whales in need! ( Memento of the original from December 3, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.ascobans.org
  3. ^ Spiegel Online: Conservationists: The Japanese slaughtered over 16,000 small whales
  4. ↑ WDC: Small whales and climate change: WDCS at workshop in Vienna ( Memento of the original from February 2, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.wdcs-de.org
  5. ↑ Bundesdrucksache 17/2642: Effects of the construction of offshore wind farms on harbor porpoise populations