Catches of Sepia officinalis in the small-scale cuttlefish trap fishery off the Algarve coast (southern Portugal)

Abstract

Abstract The present study reports a detailed description of the catches of cuttlefish (Sepia officinalis) in the trap fishery performed seasonally off the Algarve coast (southern Portugal). A total of 86 fishing surveys were performed during the fishing season (May–September) from 2009 to 2014, on sandy bottoms at bathymetrics ranging from 8 to 10\u2009m depth. During the whole study period, fishing operations involved 6311 cuttlefish traps with a gear catch rate of 37% (frequency of traps with cuttlefish) and a mean of 0.9 S. officinalis caught per trap. A total of 5883 S. officinalis (1424.0\u2009kg) were caught, being only recorded 282 dead individuals (mortality rate of 4.6%). The mean fishing yield (standardised CPUE’s in number and weight) was 46.6 individuals and 11.3\u2009kg 50 traps−1. Overall, males (n\u2009=\u20093188) outnumbered females (n\u2009=\u20092695), producing a significant male-biased (1 M: 0.85\u2009F) sex ratio. On average, females were significantly larger and heavier (124.4\u2009±\u200922.9\u2009mm ML; 253.1\u2009±\u2009148.8\u2009g TW) than males (121.9\u2009±\u200924.0\u2009mm ML; 230.7\u2009±\u2009143.1\u2009g TW). Accordingly, the length-frequency distributions displayed significant gender differences, with 89.6% of females and 85.8% of males accomplishing the MCRS (100\u2009mm ML). This markedly seasonal, highly sustainable and low impacting small-scale fishery constitutes a locally important socio-economic activity during spring and summer. Undamaged catches and highly fresh individuals further contribute to the considerable price reached by S. officinalis caught using this artisanal fishing gear.