Interlocutor: Thank you.
Self-Assessment Module 5
Presenter: Swarms of jellyfish are causing Scottish fish farmers quite abit of concern. Margaret Smith has the report.
Woman" Silently, in their millions, they begin to appear. No one knowswhere the swarms come from or why - but they do come. In theShetlands, where fish farming is vital to the economy, the arrival ofthese jellyfish can spell disaster for the local people.
Jellyfish float towards small marine animals which they sting oncontact and then eat. Farmed salmon, trapped inside cages, cannotescape. The fish are driven mad by the irritation, and end upthrowing themselves against the sides of their cages, causingthemselves serious injuries.
Other jellyfish, which may not sting, drift into the cages and clog upthe gills of farmed fish, literally choking them to death. The death tollof farmed fish may measure in the millions.The effects on individual farmers can be catastrophic. It can mean atotal loss for a fish farm if a swarm appears.
The problem with these jellyfish is that we know very little aboutthem. Jellyfish are ancient creatures, which have a strange andcomplicated lifestyle, but they have been ignored by science. Sincewe can't eat them and they are of no economic value, nobody hasstudied them.
Now, all that is changing: jellyfish are causing us to lose money, andjellyfish studies are on the agenda.
Ten universities have been recruited by the European Union to takepart in a three-year study. Their first task is to understand the lifestyleof these transparent killers, and then try to control them or at leastpredict what they will do next.
Professor Lesley Duff of the Marine Biology department of theUniversity of Stifling briefed journalists this morning, and emphasisedthe amount of work that has to be done before an effective solutioncan be found. Some ideas include an early warning system for fishfarmers, which would allow them to stop feeding the fish for a fewdays and so make them stronger and able to live on less oxygen. Buthe didn't sound terribly optimistic about early solutions, pointing outthat the scientific community's knowledge about jellyfish isembarrassingly limited.
Research is focusing on three major areas around the North Sea.Sandsound Voe in Shetland, with its fish and mussel farms, is one ofthem. The second is Limf]orden in Denmark, an area of 1575 squarekilometres, which used to have an important fishery industry. After ajellyfish attack last year, the industry is in desperate trouble. Jellyfishare being blamed for eating the eggs of fish and - more worryingly -not allowing the ecosystem to recover. Finally, the third area is theMar Menor lagoon in Spain, an important tourist area. The lagoontraditionally supported an important population of fish, but stockshave almost disappeared. Jellyfish have always been present but twospecies, unrecorded until some years ago, have appeared. Theyunderwent a population explosion in 1993, a phenomenon that hasbeen repeated every summer since.Margaret Smith, north-west Scotland.