Bottlenose Dolphin (Tursiops truncatus)
The cetaceans, being quite large marine organisms, are often the subject of avid protection from the general public, environmental organizations, and governments. With television shows such as “Whale Wars” and movies such as “The Cove,” human impacts on cetacean populations have been increasingly under the spotlight. Human activity, through direct fishing, entanglement in fishing gear, and harvesting for entertainment, has brought various cetacean populations to levels that are of concern to biologists.
Gray Whale (Eschrichtius robustus)
Although whale “hunts” continue among Native North Americans and by Scandinavian countries, the most controversial example is the “Scientific Research” based takes by the government subsidized Japanese whaling program. The Japanese whaling program is often defended with excuses being “Scientific Research” or “Culture and Tradition,” regardless of any bit of truth. Despite claims by the Japanese government, studies have shown that their annual allotted take of over 20,000 cetaceans is neither scientifically based nor sustainable. Additionally, Greenpeace, the world’s largest non-profit environmental organization, recently showed that the harvested whale meat was being illegally given to friends of the government for private sale, despite the bill of the “Scientific Research” trips being footed by the Japanese people.
Outside of intentional fishing, almost every fishery worldwide results in accidental cetacean deaths. One of the largest causes of unintentional cetacean death is known as entanglement. Entanglement occurs when a cetacean (frequently a whale) is caught in a net meant to catch other, often actinopterygiian, fishes. One of the highest rates of whale entanglement occurs in Alaskan waters, especially in the gillnet fisheries. Even in the areas of high rates of entanglement, these accidental deaths are insignificant in comparison to that of Japanese whaling take.
Entangled Dall’s Porpoise
In addition to cetacean deaths, these marine mammals are often removed from their environment in order to provide entertainment for humans in ocean theme parks and aquariums. Sparked by movies and television shows in the 60’s featuring dolphins, the demand for both dolphins and orcas has skyrocketed. Their removal from the marine environment has recently been highlighted in the general public, largely due the movie, “The Cove.”
The protection of cetaceans from these human activities is quite important. However, it is important to realize that their large size does not necessarily make them more ecologically important than other marine species. A movement towards marine protection on a broad scale would likely be a more advantageous use of educational and protection resources. There are many reasons to be concerned about the state of our world oceans, with the overfishing of cetaceans being only one small aspect. Combining scientific research with public education and international policy will hopefully help to protect our oceans from ecological destruction.
Sources:
- Ackerman, Reuben. “Japanese Whaling in the Pacific Ocean: Defiance of the International Whaling Norms in the Name of “Scientific Research,” Culture, and Tradition” 2002.
- Kasuya, T. “Japanese Whaling and Other Cetacean Fisheries”. 2007
- Hofman, R.J.. “Cetacean Entanglement in Fishing Gear.” 1990
- Johnson, A. et al. “Fishing Gear Involved in Entanglements of Right and Humpback Whales.” 2006
- All pictures credited under GNU Free Documentation License per Wikimedia Commons License Agreement.