Brown Crab Cancer pagurus Size at Maturity Study
The role of establishing the size of maturity of a species within a commercially exploited fishery is crucial for ensuring the longevity and sustainability of a stock. As fishing pressures can influence size at maturity it is important to undertake size at maturity studies every four years to monitor any changes, with the last study in Scotland conducted in Shetland in 2007 (1,2).
Geographic location is also known to affect size at maturity within other crustacea through the effect of environmental variables such as Sea temperature, salinity and food availability, with increases of latitudeue northwards causing species to grow and mature slower. Therefore to evaluate the impact of fishing and environmental variables on C.pagurus within the Orkney Fishery this study will compare and contrast size at maturity with historical literature to see if such spatial variation exists.
This study also forms the most northerly sample area within a current national study being co-ordinated by Bangor Universities Fisheries and Conservation Sciences group. This study will compare size at maturity around the UK and Ireland, with 6 other institutions involved.
This study is currently underway with preliminary results scheduled to be published in March 2015.
For the latest updates on this project follow us on twitter at https://twitter.com/OSFisheries
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(1) Tallack S.,M.,L.,(2007) J. Mar. Biol. Ass. U. K., 87, 507-515. http://dx.doi.org/10.1017/S0025315407054100
(2)Tallack S.,M.,L.,(2007) J. Mar. Biol. Ass. U. K., 87, 1181-1189. http://dx.doi.org/10.1017/S0025315407054094
Update – 12/01/2015
Lab dissections of samples collected in November and December 2014 have begun.
As part of the dissection process samples will have claw morphometrics, external carapace condition and internal maturation stage data collected, along with tissue samples for genetic profiling.
5 down 315 to go!
The Orkney Shellfish Research Project
The Orkney Research Project is a four year project which is designed to highlight interactions between the inshore fishing industry in Orkney’s waters and the up and coming marine renewable industry working with The Crown Estate and Orkney Islands Council with the aim of allowing both industries to develop and co-exist. In addition to the renewables part of the project, we have teamed up with WWF-UK and Marks and Spencer to implement the UK’s first Fishery Improvement Project (FIP) on the Brown Crab fishery.
The project can be divided into the marine renewables part and the FIP part.
The Marine Renewable – Fishing Interaction part
To understand what and where there will be interactions between the inshore fishing industry and the developing marine renewables industry we have installed 20 Vessel Monitoring Systems (VMS) on board fishing vessels to track the fishing activity in terms of where the fishing grounds are and the routes that the boats take to get to their fishing grounds. This data will enable informed decisions to be made regarding the position of any marine renewable devices in Orkney’s inshore waters. The fishing industry has a long history in Orkney and many of the fishing grounds have been passed down through generations, collecting this data is a vital part of protecting fishing grounds and ensuring that fishing remains a major part of Orkney’s economy.
The Fishery Improvement Project Part
The Fishery Improvement Project was initiated by Marks and Spencer who work closely with The World Wildlife Fund for Nature (WWF) who together work with fisheries around the world giving advice and tools to ensure the fishery is as sustainable as possible. The Brown crab factory owned by Orkney Fishermens Society in Stromness, provide crab for Marks and Spencer among other retailers. With the involvement of M&S and WWF we are developing a Fishery Improvement Project. The project work involves collecting biological data on the brown crab stocks around Orkney, this is done by onshore market sampling of fishermen’s landings, offshore sampling of everything caught on a typical fishing trip e.g. by-catch species, undersized brown crabs and other marketable catch. With the scientific advice from Dr Mike Bell we are doing stock assessments on the local brown crab stocks. The FIP work will aid the fishery to be as sustainable as possible.
Together the Marine Renewables- Fishing interactions part and the FIP will collect important data on the inshore fishing activity and the crustacean stocks in Orkney’s waters. This information is vital and will enable the fishermen in the Inshore Fisheries Group to make informed decisions about their industry.
The Annual FIP Report is available Orkney FIP 2014
For more information please contact: