Homing and orientation of Palinurus elephas (Fabricius) in three no-take areas of the central-western Mediterranean: implications for marine reserve design

Abstract

The homing and orientation skills of Palinurus elephas were investigated in three no-take areas of the central-western Mediterranean in order to inform future reserve design. In general, P. elephas did not show a particular ability to orient homeward. A considerable portion of tagged lobsters were recaptured in the same direction as the capture point but, the points of capture and recapture were at such a distance from each other as to exclude any possible return to the original den. Homing ability seemed to be constrained to where lobsters were only displaced a short distance. For distances longer than 0.5km, the lobster movements seem to become nomadic, without a particular direction. The movement pattern suggests that it will be important that any restocking of marine reserves must be performed with lobsters collected in adjacent zones at distance more than 0.5km. Lobsters captured in a fishing zone <0.5km outside the reserve will return to the point of capture whilethose collected from further away will not go back to their original place. Our results indicate that, for species like P. elephas, small reserves can protect most small subpopulations with a consequent benefit for the surrounding commercial areas

European spiny lobster recovery from overfishing enhanced through active restocking in Fully Protected Areas

“…elephas shows generally short-distance movements and poor homing skills when dislocated far ( i . e ., > 0.5 Km) from the capture point 34,35 but, at the same time, its migration is strongly density-dependent 28 . Thus, when below legal-size lobsters released within the FPA grow and the carrying capacity of the area is reached (promoting density dependent emigration), a ‘ fishery spillover’ (sensu Di Lorenzo et al .…”

“…Such a distance represents the mean annual distance covered by wild adult specimens of P . elephas 29,35,42 . Restocking was effectively carried out during five consecutive years, starting from 2011 up to 2015.…”

“…Data from outside FPAs were comprised within 5 nautical miles from the FPA center. Such distance has been set as it exceeds the theoretical maximum distance that a spiny lobster could reach from the release point at the center of the FPA after 5 years 29,35,42 . Number of replicate surveys conducted inside and outside each FPA during the five years is reported in Table 1.…”

The Use of Reproductive Indicators for Conservation Purposes: The Case Study of Palinurus elephas in Two Fully Protected Areas and Their Surrounding Zones (Central-Western Mediterranean)

“…However, the need for innovative management policies focusing, together with those already implemented, on reversing the decline of the stock, appeared essential. In this perspective, several no-take marine areas were established in central-western Sardinia, in 1998 firstly and in 2009 subsequently [ 15 , 35 , 36 , 37 ], as areas of restocking to protect lobster resource. Results of the implementation of more recent FPAs (in 2009) showed a burst in the variations in terms of catch per unit effort (CPUE) in density and biomass of European spiny lobster stocks (by ca.…”

“…30–50% increase in density and biomass CPUE outside the FPAs) by the end of the program [ 15 ]. Instead, data from a 15-year continuous monitoring of a pilot FPA established in 1998, where the restocking protocol was conducted for the first six years and protection kept in force once restocking ceased, demonstrated the persistence in terms of restocking benefits [ 15 , 35 , 36 , 37 ].…”