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November 19, 2005

Grizzlies Go & Orcas Are On

Out With The Old, In With The New...

Last week we talked about how the Yellowstone Grizzlies are being de-listed from the Endangered Species Act (ESA). However, as I mentioned, this might allow for other animals to be listed and given the funds they need to make a turn-around.

The orcas, or killer whales, especialy those of the Pacific Northwest in the Puget Sound, have to tolerate a lot of shipping and ferry traffic. This traffic doesn't just result in collisions and sound pollution, it also results in oil and chemical spills and such.

Also know as the sea wolf, due to its wolf-pack hunting methods, the whales are known for several different kinds of community behavior - including resident and transient populations. These communities are thought to have genetic differences, including very different communications and sounds, and even slightly different dorsal fins. However the most significant difference between resident and transient communities is what they eat and where they live.

It is the transient orcas that are known for opportunistic preying habits, including eating other marine mammals like seals, sea lions, dolphins, and even young whales. These whales move around, following food sources. Resident orcas tend to stay in one area and eat only fish - especially salmon. This diet makes the resident killer whale very vulnerable when their food supply suffers from overfishing and high contaminant levels like the salmon populations of the Pacific Northwest have. It is the Southern Resident killer whale population of the Puget Sound that is being listed.

Acknowledging that a population of orcas — one of the icons of the Pacific Northwest — was in greater danger than it initially feared, the Bush administration on Tuesday gave the group the most protections possible under the Endangered Species Act.

...

The service noted that the population saw a 20 percent decline in the 1990s. Threats include vessel traffic, oil spills, toxic chemicals and food limits, especially salmon.

In addition, the group has only a few sexually mature males that can help repopulate.

The population stood at 97 in the 1990s, and then declined to 79 in 2001. It now stands at 89 whales.

Endangered listing requires that federal agencies make sure their actions are not likely to harm the whales. As a result, agencies that deal with chemicals and vessel traffic will have to more closely monitor how their rules impact the population.

More At: MSNBC: Orca population to be listed as endangered

Did you know that there is a community of killer whales living in the Monterey Bay? Transients have been spotted for quite some time in the Monterey Bay, often peaking during the the late spring when Gray Whale mothers and their calves swim by on their migration to the north.

In January 2000, some marine biologists identified some resident pods from Washington State and the Puget sound had swum down to the Monterey Bay in search of better eating, most likely the salmon. National Geographic caught it all on tape and whale identification confirmed the pod's origins.

Photo courtesy of The Marine Mammal Commission, an independent agency of the U.S. Government, established under Title II of the Marine Mammal Protection Act.

Posted by sorsha at November 19, 2005 2:51 PM