A project to establish a crab hatchery has started in Whitby in a bid to boost marine conservation and stocks in the North Sea.
With support from RWE Wind Farm, Whitby Lobster Hatchery is going to attempt, for the second time, to rear a crab to the juvenile stage from eggs harvested from crabs landed by local fishing boats.
It comes as numbers of brown crabs have decreased over the last few years due to over-fishing and poor management.
Despite each crab laying two to three million eggs in the wild during the March to November breeding season, the vast majority don’t survive due to unfavourable weather conditions and predators.
Last year, the Hatchery managed to get one crab to eight weeks old, the crucial settlement stage when egg larvae turn into miniature crablets but it didn’t survive.
This year the Hatchery has changed the production of food for crabs, created habitats using plastic mesh structures, increased the size of the tanks and is researching what triggers the switch from larvae to post larvae.
Joe Redfern, marine biologist and founder of the Whitby Lobster Hatchery, says the goal is to get just one to the settlement stage.
He said: “The goal this year would be to get just one at settlement stage. It has never been done before. It is thought a hatchery can increase brown crab numbers by ten to 20 per cent and there are not that many in a position to take it up.”
Whitby Lobster Hatchery was established in 2021 to ensure lobster populations in the North Sea were maintained, given they have replaced white fish as the main target species for fishing.
Last year the Hatchery released more than 20,000 juvenile lobsters back into the North Sea. It was the Hatchery’s most successful year to date, releasing 5,000 more than the previous year.
For various reasons, added Mr Redfern, there hasn’t been the same emphasis on the need to boost crab stocks – until now.
He said: “Crabs have been more abundant than lobster and are lower in value. You get ten times less the price for crabs than lobster because there are more of them. There has been more value in a lobster hatchery because they are a high value species.
“There is also difficulty with the husbandry of crabs, feeding, cleaning and moving them around. The larvae can be barely seen with the naked eye, but with lobsters, you can see the larvae and juvenile lobsters much easier.”
Crab numbers in the sea have declined by around 50 per cent due to over-fishing.
Mr Redfern explained corporate boats can work 40,000 pots at a time, potentially resulting in less care and consideration at sea.
It has resulted in investors in the shell-fish industry calling for solutions, such as crab hatcheries.
Mr Redfern added: “There is big concern from investors into crab fishing they are going to go out of business. This has come about in the last three to five years and we have had it in our minds, can we try it with brown crabs?
“For us, this is rooted in conservation, the benefits to the fishing community are second to that. We are focused on making sure there are crabs and lobsters in the sea for years to come.
“I would like to thank RWE for their ongoing support for our project and the sustainability and conservation of the North Sea.”
