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Scientists Launch The World's First Marine Life Census

Date:
November 20, 2000
Source:
Stanford University
Summary:
Blue whales may be the largest animals ever to have inhabited the Earth. An adult can grow to 80 feet long and weigh up to 300,000 pounds. Despite their enormous size, very little is known about the feeding, breeding and migratory habits of these leviathans. But an international research team hopes to change all that by placing electronic tracking devices on a variety of whales, seals, seabirds, turtles, fish and squid whose lifestyles remain a mystery to science.
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Blue whales may be the largest animals ever to have inhabited the Earth. An adult can grow to 80 feet long and weigh up to 300,000 pounds.

Despite their enormous size, very little is known about the feeding, breeding and migratory habits of these leviathans.

But an international research team hopes to change all that by placing electronic tracking devices on a variety of whales, seals, seabirds, turtles, fish and squid whose lifestyles remain a mystery to science.

This week, more than 60 marine scientists and technicians came together at Stanford's Hopkins Marine Station in Pacific Grove, Calif., to design a pilot project demonstrating the feasibility of tracking thousands of sea creatures in the northern Pacific with the use of sophisticated electronic sensors.

This unprecedented effort is a major component of the Census of Marine Life -- a 10-year program to assess the distribution of species in the world's oceans.

"We haven't spent enough time exploring our own planet," says Barbara A. Block, the Charles and Elizabeth Prothro Professor of Marine Sciences at Hopkins.

"We don't like to tell anyone we're ignorant about the oceans, but we are," adds Block, who chaired the three-day workshop at Hopkins.

One goal of the meeting was to determine which animals would be the best candidates to launch the remote census project, which is scheduled to begin in 2002.

Scientists weighed the pros and cons of putting satellite-linked tags, timed data recorders and other electronic transmitting devices on different species of birds, marine mammals and fish. Among the criteria considered were the cost of each device (they can run thousands of dollars apiece) and the amount of effort required to physically tag each critter.

Two animals with proven track records among researchers were at the top of the list: the bluefin tuna, a large fish that Block has successfully tagged and studied; and the northern elephant seal, a marine mammal that has been the subject of intense research for nearly 30 years.

Other animals selected for the pilot project were blue sharks, albatrosses (the largest seabird), salmon sharks, leatherback turtles, yellowfin tuna, blue whales and loggerhead turtles. Runners-up included squid, California sea lions, loggerhead turtles, California gray whales, sperm whales, sooty shearwaters (a migratory bird) and three fish species: great white sharks, molas and striped marlins.

Some of these animals ­ including bluefin tuna and blue whales -­ are on the endangered species list. According to Block, the more we know about their behavior, the better their chance of recovery.

"It may be that electronic tags are the only thing that will prevent the virtual demise of these organisms," she argues.

Project scientists intend to place thousands of tracking devices on thousands of animals between 2002 and 2005 -­ with the goal of retrieving data from at least 30 percent of the instruments. Data will be made available in real time on the Internet so that elementary school students and other members of the public can observe the movements of their favorite animal any time day or night.

"The newest generation of archival tags have increased memory and are extremely small ­ approximately five grams ­ making external placement on small organisms possible," notes Block.

She points out that, for seals and other marine mammals large enough to carry satellite-linked data recorders, significant information can be obtained on migration, swimming speed, and diving behavior for intervals of a year or more.

Researchers singled out advances in pop-off satellite tags that float to the surface carrying stored data intact. One objective of the project is to use these tag-bearing animals as deep-sea explorers to record temperature, salinity and other difficult-to-obtain data.

"We can use these animals as oceanographic samplers ­ autonomous vehicles to sample the physical environment as well as gather biological information on their behavior, physiology and ecology," says Block.

She also points out that the tagging project will give researchers their first opportunity to observe the relationship among different species whose ranges often overlap across wide stretches of the Pacific.

"While single-species studies such as our Atlantic bluefin tuna project have been performed previously," she notes, "the emphasis now is on a multi-species effort to get a better handle on how a variety of animals interact across the food chain."

Another workshop is planned for next year, when project members will finalize their proposals and seek additional funding.


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The above post is reprinted from materials provided by Stanford University. Note: Materials may be edited for content and length.


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Stanford University. "Scientists Launch The World's First Marine Life Census." ScienceDaily. ScienceDaily, 20 November 2000. <www.sciencedaily.com/releases/2000/11/001120074351.htm>.
Stanford University. (2000, November 20). Scientists Launch The World's First Marine Life Census. ScienceDaily. Retrieved September 2, 2015 from www.sciencedaily.com/releases/2000/11/001120074351.htm
Stanford University. "Scientists Launch The World's First Marine Life Census." ScienceDaily. www.sciencedaily.com/releases/2000/11/001120074351.htm (accessed September 2, 2015).

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