Science Update - Fish
Chris - Time now to go across the ocean to the guys at Science Update, Chelsea Wald and Bob Hirshon.
Chelsea - This week on Science Update we'll be talking about fish. Many species of the world's fish have been over - fished to a tiny fraction of their original numbers. In order to help rebuild one population, scientists in Florida are undertaking an ambitious underwater surveillance programme.
Bob - High tech listening devices, surgically implanted transmitters, tracking thousands of subjects without their knowledge. Is it a controversial homeland security programme? Well maybe. But what we're talking about is a fish research project. University of Miami marine biologist Jerry Alt and his colleagues are implanting acoustic transmitters into thousands of Florida grouper in and around a marine reserve. Then they're re-releasing them and listening to them with underwater microphones.
Gerry - The transmitter itself is pinging about every twenty seconds or three times a minute. Each pinger has a unique acoustic code so we can identify individual fish.
Bob - By understanding how the grouper use the protected waters, the researchers hope to figure out how to replace their over-fished population while still keeping area fisheries well stocked.
Chelsea - Fortunately there are still some places that fishing nets can't reach. One of them is the abyssal plain; the ocean floor located about 4000 metres under the surface. The total darkness and intense pressure there have made it a very challenging place for researchers to get to know.
Bob - Yes, scientists at Scripps Institution of Oceanography in La Hoya California have now taken the first long term look at the abyssal plain and what they found was surprising. The population of a fish called the grenadier tripled in fifteen years. Marine biologist David Bailey says that this boom is likely the result of natural ocean cycles like El Nino that affect the production of nutrients on the surface.
David - How productive the surface waters are affect how much food arrive on the sea floor, which affects the fish we're working on.
Bob - He says that so far there's little sign of human influence on these fish populations; a rarity anywhere on the planet.
Chelsea - So let's hope it stays that way. For next week's science update: a riddle. What's brown, sounds like a bell and can cure the energy crisis?
Bob - I don't know? What is brown, sounds like a bell and can help cure the energy crisis?
Chelsea - Well you'll just have to tune in next week to find out. Until then, I'm Chelsea Wald.
Bob - And I'm Bob Hirshon for AAAS the science society. Back to you Naked Scientists.