Passive fishing gears in ecosystem-approach fisheries: preliminary trials on shrimp fishing with simple trap systems in the Black Sea

Abstract

Passive fishing gears are increasingly considered important monitoring tools in ecosystem-approach fisheries because they may cause lower physical disturbance to the seabed compared with active fishing gears. This study presents preliminary trials on shrimp fishing using simple baited trap systems along the southern Black Sea coast. In the study, three simple traps were deployed in a seagrass-associated area and three traps in a nearby control area; the traps were set between November 2025 and April 2026 with soak times of 24, 48 and 72 hours. Captured organisms were recorded at species level, while rostrum length, carapace length, total length and body weight were measured for shrimp individuals. According to the available catch records, a total of 184 shrimp individuals were obtained, of which 46 were captured in the seagrass area and 138 in the control area. Standardized shrimp CPUE was calculated as 0.035 individuals/trap/hour in the seagrass area and 0.106 individuals/trap/hour in the control area. In morphometrically measured individuals, mean carapace length (CL) was determined as 12.48±0.51 mm in the seagrass area and 12.24±0.35 mm in the control area. When all measured individuals were evaluated together, mean CL was 12.29±0.29 mm. Although shrimp catch efficiency was higher in the control area, a higher diversity of benthic and epibenthic organisms was observed in traps associated with the seagrass habitat. Preliminary findings indicate that simple trap systems can be used for small-scale shrimp sampling and habitat-sensitive biodiversity monitoring. However, differences between areas also suggest that trap performance is affected by habitat structure, soak time and seasonal conditions.