Lobster fisheries in the Oosterschelde : An overview of biology, management & available data

Lobsters have been fished in the Oosterschelde since 1881. The so-called Oosterschelde lobster (Homarus gammarus) is very popular with the consumer, but little is known about the lobster fishery. This report summarises the available data on the lobster fishery. The study was carried about by students of University of Applied Sciences Van Hall Larenstein Leeuwarden, as part of the Bachelors' programme Kust en Zee Management. The three main questions are: What do we know about lobster biology, how is the lobster fishery currently managed and what data is available? The research project was commissioned in cooperation between the fishing association OWV (Vereniging van Beroepsvissers op de Oosterschelde, Voordelta en Westerschelde) and Wageningen Marine Research, as part of preparations for a research grant proposal towards the development of a stock assessment. For implementing optimal management and to develop a stock assessment of the lobster population in the Oosterschelde in future, it is necessary to obtain a detailed overview of the current situation. A literature study was conducted and six lobster fishers who fish in the Oosterschelde were interviewed for this study. The fishers were asked to share information about their use of fishing gear, their license, how much lobster they catch and their views on the development of the lobster stock. In the Oosterschelde, there are 42 active lobster fishing licenses, of which 37 are affiliated with the fishing association OWV. Two years ago, a major change was made in the system. The "lobster race" has been changed into a lottery system, organized by OWV. This lottery system is an improvement in the lobster sector, as with the new system every lobster fisher has equal opportunities. The abundance of lobster varies due to natural factors, but a continuing downward trend has been observed in recent years by lobster fishers and recreational divers. An overview of available data on the stock is shown in Table 2, but these have not been structurally analysed. The observed downward trends can therefore not be explained. An overview of the different views on stock decline by interviewed fishers can be found in Table 4 and 5. Since the exact reasons for the declining lobster population are unknown, no focused action or policy can be undertaken and made. Plans to reduce the number of licences to reduce fishing effort and increase the economic viability failed in 2015 after a process of ten years. There was no stock assessment to base these decisions on, and lack of support to carry out the proposed changes. The study leads to four recommendations: 1. The early benthic phase (EBP) of the lobster is not feasible to use in a future stock assessment. Assessing larger individuals will give a more reliable view of the lobster population in the Oosterschelde; 2. Further research should be carried out into which natural and anthropogenic factors (Table 4 and 5) impact lobster stocks in the Oosterschelde; 3. A survey should be held among all lobster fishers to further improve insights into the perceptions on stock development and management as well as their willingness to contribute to future data collection projects. This will inform the development of a stock assessment and research priorities. 4. Communications between the fishers and the Ministry of Agriculture, Nature and Food Quality in relation to monitoring of (illegal) fishing activities should be improved