Evaluation and quantification of shell damage and survival of the striped venus clam (Chamelea gallina) harvested by hydraulic dredges

The impact of hydraulic dredging on Chamelea gallina populations in the mid-western Adriatic Sea was assessed by evaluating and quantifying the damage exerted on harvested (non-sieved) and sorted (sieved by the mechanical vibrating sieve: commercial or discarded) individuals and by estimating the survival probability of discarded clams. The results showed that: i) dredging had a higher impact on determining shell damage than the mechanical vibrating sieve, ii) damage probability was strongly associated with shell length and in discard samples the effect of the shell length was greater due to the longer time spent by the individuals inside in the vibrating sieve before being rejected to the sea, iii) the survivability of the entire discarded fraction of clams was high. The findings support the Regulation (CE) 1380/2013 which foresees that discards from the Venus clam fishery must be returned to the sea and shall not be landed.