There’s increasing concern about unexplained structural decline of European lobster in the Netherlands’ Eastern Scheldt lobster fishery. Accurate stock assessment is essential for understanding these declines and implementing sustainable management, but scientific knowledge on lobster stocks in the Netherlands is lacking.
Seeing a need for action, the Association of Professional Fishers Oosterschelde, Westschelde and Voordelta (OWV) developed a fishing plan to improve regional fisheries management, seeking to engage with the government and stakeholders to develop science-based fishery management strategies.
The fishermen teamed up with Wageningen University & Research to implement LobStAR, a plan to improving stock assessments through scientific innovations and improvements in research and technology, backed with EMFF funding.
‘The lobster stock goes up and down due to natural factors. But how the lobster stock develops over time is not clear, while that information is important for sustainable management,’ explained OWV chair Sinke Sinke.
The initiative’s objectives were to improve understanding of the biology of the Eastern Scheldt lobster, to develop simple automatic catch registration, to develop simplified stock estimate systems and an app for data management and calculation for use by the sector, and to apply the vast empirical knowledge of local fishers to stock assessment and management.
Initial work focused on monitoring the growth, reproduction and mortality of the Eastern Scheldt lobster to better understand its lifecycle and development. Researchers studied the lobsters’ basic energy use and the relation between activity level and water temperature, and collaborated with fishers on field experiments where lobsters were tagged and released for long-term monitoring.
A automatic catch monitoring system which gathers important data on fishing effort and the catch has been used as part of the project.
Researcher Edwin van Helmond from Wageningen Marine Research explains that the aim is to make information collection easy for the fishermen.
‘Once the computer programme works well, it will no longer be necessary to collect this information manually. In fact, it will no longer be necessary to have scientific observers along,’ he said.
The CatchCam takes a digital photo of each catch which automatically enters in a database the lobsters’ size, sex and carapace length, which seconds later is sent to the fisher. The CatchCam automatically registers the precise location, registering only the catch and not personnel on board. The system operates autonomously, so fishers can go about their business while important data is collected.
Laboratory and field data from the project is being used to develop a simple stock assessment model, which in the future will be able to inform fishery management in the region. The project also conducted interviews and workshops with fishermen, and developed an annual questionnaire to appraise stock dynamics. This enables a valuable comparison with quantitative results.
