First V-notching experience of a spiny lobster: V-notch recovery and impact on health and growth of Palinurus elephas

Abstract

V-notching is a conservation technique to delay fishing mortality widely used in fisheries of clawed lobsters. Here we present results of the first V-notching experience of a spiny lobster. The study was conducted on the European spiny lobster Palinurus elephas (Fabricius, 1787) with the aim of assessing: 1) V-notch effects on survival, incidence of shell disease and growth, and 2) the pattern of V-notch regrowth. Results of the 20-month-long tank experiment with 36 lobsters showed that V-notching had no impact on shell disease or growth. However, abnormally high summer temperatures in the experiment lowered survival of V-notched individuals relative to control specimens. Three dimensions of the V-notch mark (depth, width and area) were examined to assess V-notch regrowth, and depth is recommended for regulatory purposes. In this study, four moults, and almost two years, were necessary for V-notch depth to shrink by 50%, an amount that would turn legal a V-notched clawed lobster after one moult. We discuss the applicability of these results under conditions in the wild.