Scientists are hoping to revitalize the lobster population off the German island of Helgoland, and are enlisting the help of a nearby offshore wind farm whose rocky foundations make a good habitat. But there's potential for trouble: These aggressive crustaceans have a tendency to eat each other.
Lobsters are not the most pleasant of creatures. "They are cannibals and behave aggressively towards one another," says Heinz-Dieter Franke of the Biological Institute Helgoland (BAH). Unfortunately, that adds complexity to efforts to boost their dwindling populations.
For centuries, lobster fishing was a thriving industry in Helgoland. In the 1930s, some 80,000 of these large marine crustaceans were caught here per season, but the local lobster population was decimated by World War II. Researchers believe that vast quantities of toxins flushed into the sea when the island was heavily bombed and mined during the fighting damaged the lobsters' sensitive sense of smell, which affected reproductive patterns.
"Since then, the population has remained stable but extremely low," explains Franke. Further obstacles to their survival rates include a rise of more than one degree in the temperature of the sea around Helgoland over the last forty years, as well as increasingly mild winters. With lobsters having difficulties mating, the local fishermen are netting merely 300 and 500 of them a year.
Laboratory scientists are therefore exploring ways to artificially breed lobsters. Female lobsters caught by the fishermen can produce up to 50,000 fertilized eggs. Once they have matured out of the larva stage, the crustaceans are stored in the BAH's freshwater breeding tanks.
Thin plastic walls ensure that each creature has its own compartment -- otherwise their cannibalistic tendencies would get the better of the project.
Expensive and Time-Consuming
In the last 10 years, the scientists have bred over 10,000 lobsters. Once a year, the young lobsters are released into the ocean. But it still isn't enough. Despite the BAH's best efforts, Helgoland's lobster population is struggling to survive. Franke and his team have calculated that some 250,000 lobsters would need to be bred over a period of five years to replenish the island's lobster population.
But breeding and feeding the crustaceans in their individual compartments is a time-consuming undertaking, and the BAH estimates that it would cost €1 million to achieve this target. "An institute of our size is not equal to this task," says Franke. But so far, it has failed to identify funding sources, even though he is optimistic that it makes commercial sense.
"Were the project to succeed, fishermen would be able to catch 30,000 to 40,000 lobsters per year and that would mean the investment had paid off," he says. But given the long-term nature of the project, he understands why sponsors are hard to find. It takes lobsters eight years to reach sexual maturity, so it will be some time before Helgoland's lobster pots are full again.
But Franke and his colleagues are hoping to attract funding with a new approach. They are planning to boost the island's populations not only on its bedrock but also in the offshore wind parks currently under construction off the North Sea coast.