Unusual dolphin species visit Puget Sound

Two dolphins of a species usually seen in warmer waters off southern California or Mexico, have once again been spotted around Puget Sound, baffling conservationists to why such species would head north.

Sightings of unidentified cetaceans were first reported early May and a month later the animals were identified as long beaked common dolphins, a species that has never previously been seen in Puget Sound. The only previously recorded sighting in local waters was in April 1953 when a long beaked common dolphin stranded itself off Victoria. One of the questions now being asked is whether there are more long beaked common dolphins in the area as, unlike the harbour and Dall's porpoises more commonly seen locally, they are a gregarious species that usually travels in large groups and perhaps they are part of a larger group that haven't been seen yet.

The common dolphins are the third tropical species to turn up in Puget Sound or Juan de Fuca Strait within the last seven months.In January a bottlenose dolphin, a species that rarely goes north of central California, stranded and died near the Nisqually Delta in Puget Sound, after being seen in the area for at least a month prior to its death, and in December a Bryde's whale died after being severely injured by a ship. Another Bryde's whale stranded and died in southern Puget Sound in January 2010. Bryde's whales usually prefer tropical or warm temperate waters. The appearance of warm-water species is totally inexplicable, especially as it is a La Nina year, meaning the water is colder than usual.

One possibility is that the long beaked common dolphins, which usually eat sardines, squid and other small fish, are looking for other food as the local fishermen have reported a lot of herring right now and therefore it's easy for the animals to switch from sardine to herring. Concerns are being raised however for the dolphins' as there is algae on their skin and tropical species usually do not survive in the area. There was however an exception with a group of false killer whales, seen in the 1980s which survived. Puget Sound is an arm of the Pacific Ocean in the Pacific Northwest of the United States, defined as a bay with numerous channels and branches.