Economic sustainability analysis of shrimp fisheries in the sea of Marmara

Shrimp fisheries constitute an important marine food resource at the global scale, with more than 30% of Turkey's total shrimp landings originating from the Sea of Marmara. However, fisheries in the Sea of Marmara have experienced severe stock declines over the past five decades due to overfishing and increasing environmental pressures, a situation further exacerbated by the mucilage event in 2021. Stocks of the deep-water rose shrimp, which are currently subject to overexploitation, pose ecological risks while simultaneously threatening economic sustainability. Despite its significance, studies focusing on the economic structure of shrimp fisheries conducted using beam trawl in the Sea of Marmara remain limited. This study aims to assess the economic sustainability of shrimp fisheries using beam trawls in the Sea of Marmara by analyzing accounting records from 19 fishing vessels. The dataset covers the 2024 fishing season, and a detailed evaluation of operational cost components and fishing revenues was conducted. The results indicate that more than 75% of total fishing income is derived from the sale of the target species, shrimp. Revenues from bycatch sales, accounting for an average of 24.4%, emerged as a short-term buffer against cost fluctuations for fishers. Fuel expenses (46.2%) and labor costs (35.2%) represent the two largest components of seasonal operational costs. Nevertheless, with an average daily net profit of approximately TRY 10,000 and a profitability ratio ranging between 48% and 50%, shrimp fishing using beam trawls demonstrates a strong capacity to cover high operational costs and generate substantial income. Although bycatch contributes to short-term economic sustainability by providing additional revenue, high bycatch levels may lead to ecologically unacceptable outcomes. Therefore, the sustainability of shrimp fisheries should be addressed not solely based on economic profitability, but through an integrated approach that also emphasizes ecosystem health, improved operational efficiency, and the safeguarding of fishers' social welfare.