Scientists from Swansea University are appealing to UK fishermen for information on crab and lobster shell disease and the locations of American lobster.
Researchers at the university want to create a map that illustrates hot spots of brown crab and lobster “black spot” shell disease. The work is part of collaborative project, SUSFISH, between Welsh and Irish universities investigating the impacts of climate change on commercial shellfish productivity within the Irish Sea.
Shell disease is caused by bacteria which degrade the shell. This forms the characteristic black spot lesions. Black spot affects a variety of commercial crustacean species and in severe cases will cause mortality.
According to the Shellfish Association of Great Britain (SAGB), the disease is thought to occur in some areas and not others, suggesting that it may be affected by environmental factors.
The economic cost of black spot has not been calculated but discards and mortality during storage in keep pots and vivier tanks could be a significant burden to fishermen, the SAGB said.
Recent reports of American/Canadian lobsters being caught in European waters have highlighted potential problems caused by alien species and their associated diseases. In the United States, the southern New England lobster fishery was recently decimated by a new epizootic shell disease.
This new disease causes lobsters’ shells to rot away.
Infected lobsters are often unable to molt properly and may die in the process. Also, diseased animals may have weakened immune systems allowing other infections to kill the lobster.
From a population perspective, it is the large females which produce the most offspring that are considered most at risk. US researchers have reported infection rates as high as 30 percent in Massachusetts and 43 percent in Rhode Island.
An American lobster with the epizootic disease was caught in Norway waters last year.
The team at Swansea University aim to map records of American lobsters caught or seen by commercial fishermen around the UK and Irish coasts. This will enable them to identify any hot spots of the aliens and to assess the level of risk to European lobster populations.
A Fisheries Challenge Fund grant was recently awarded by the Marine Management Organisation (MMO) to the Swansea University team and Dr Michael Tlusty from the New England Aquarium, Boston, US, to carry out further research on the threat of epizootic shell disease to the UK’s native lobster.
The researchers are working with the SAGB, which will provide integral support to the grant.
According to the MMO, annual UK lobster landings of around 2,800 metric tons account for half of all European landings with a first sale value in 2009 of GBP 26.5 million (EUR 30.2 million, USD 43.2 million), while annual UK crab landings of 2,500 metric tons accounted for half of all European landings with a first sale value of GBP 30.5 million. (EUR 34.8 million, USD 49.7 million)
