04-01-2009, 04:50 PM
Interview with Dr. Zach Palmer on the National Oceanographic Institute Shark Experiment
The Blue shark's long-term survival is at risk and marine biologists from around the world are trying to help. The following is a transcript of NPR's interview with Dr. Zach Palmer, conducted by Derrick Rees on Monday, Mar 8, 2009.
Q. Dr. Palmer, we can't say thank you enough for giving NPR this time, so thank you.
A. You bet.
Q. We understand that scientists are introducing Blue sharks into the Great Salt Lake.
A. That's correct, Derrick. It's a global collaboration under the direction of the National Oceanographic Institute to save at-risk species.
Q. Are sharks species really endangered?
A. More than 100 out of 400 shark species are being commercially exploited. Blue sharks are the most heavily fished sharks in the world. The Blue shark is listed as a "Near Threatened" shark species by the IUCN. It's been misunderstood to the point of endangerment. They have been so overexploited that even their long-term survival can no longer be guaranteed.
Q. What can you tell us about the Blue shark?
A. Well, the Blue shark, or Prionace glauca, are light-bodied with long pectoral fins. The top of the body is deep blue, lighter on the sides, and the underside is white. The animal grows to about 12.5 ft long and weighs about 400 lb. They mate in early summer and birth in late summer, hence our timing. They are fast-moving sharks and they feed at or close to the surface. They rarely attack humans. Their diet includes octopi, shrimp, and sea birds.
Q. So, what is your plan?
A. Fortunately, the Blue shark is a prolific species with good rebound potential. The US Institute of Marine Sciences has selected four healthy pairs of Blues to introduce into a controlled breeding environment. Scripps Institute of Oceanography is handling our logistics - they often work with Sea World in San Diego. They'll transport the sharks to Willard Bay, about 50 miles north of Salt Lake City. They're scheduled to arrive by 3am on 2 April and should be released at dawn. It will take about three hours to safely unload and release them into the waters. We will tag each shark's pectoral fin with a transmitter just prior to release. Satellite tagging will allow us to track each shark independently, so we'll know the location of each one. The sharks will also have a second tag that transmits location whenever the dorsal fin breaks the water's surface.
Q. Why relocate sharks at all?
A. Blue sharks fare poorly in captivity - most specimens dying within 60 days. Our hope is that in this contained but wild environment they will thrive. Success with the Blues in Salt Lake could lead to saving much rarer breeds of sharks. This is a truly groundbreaking event.
Q. Why did you select the Great Salt Lake?
A. The Great Salt Lake was our best choice. It's a large, self-contained body of colder salt water. Blues prefer waters with a temperature range of 44 to 60°F but will tolerate temperatures of 70°f or above. They breed in river mouths, similar to the brackish water of Willard Bay. The Great Salt Lake also has an abundance of seagulls, and other waterfowl.
Q. What concerns are there?
A. To be honest, there were a few. First, the salinity of the water averages about 12%, making it much saltier than the ocean. The sharks have been in an acclimatizing tank since February to adjust to the higher salt levels. We were also concerned about the selenium and mercury levels in the lake, but we determined they were within limits. Also, public opinion was a factor. We had to approach this very carefully because we didn't want to alarm anyone. Blue sharks are found off the coasts of every continent - this won't be much different. It also helped that it's a remote area of the country. There was surprisingly little resistance from the public.
Q. Dr. Palmer, I want say thank you from National Public Radio.
A. My pleasure.
_________________________
References:
1. The International Union for the Conservation of Nature and Natural Resources (IUCN) is the world's main authority on the conservation status of species. The IUCN Red List contains the names of endangered animal and plant species, and unfortunately includes many shark species.
2. The U.S. Congress passed the Endangered Species Act in 1973, giving protection to the Blue shark. In Section 1531 of the Act, Congressional findings state that since certain species of wildlife have been threatened with extinction, "the United States has pledged itself as a sovereign state in the international community to conserve to the extent practicable the various species of fish or wildlife and plants facing extinction" (United 1, 2).
3. ECU - In Feb 2008 UK Biodiversity Minister Todd Martin announced the Blue shark would receive legal protection under the Wildlife and Countryside Act.
I read this last night and wondered if this could be an April fools joke[
][signature]