Ecological and fishery responses to the populations management of the brown meagre (Sciaena umbra; Linnaeus, 1758) in the Bonifacio Strait Natural Reserve (NW Mediterranean, France)

Abstract

Both spearfishing and traditional fishery target the brown meagre (Sciaena umbra, Linnaeus, 1758). With the current state of overexploitation, MPAs were created as tools for both conserve biodiversity and manage fisheries as sustainable activities. In the Bonifacio Strait Natural Reserve, mean biomasses recorded in situ and catches records of artisanal fishery since 1995, have been used to study the temporal evolution of the brown meagre populations in a north western Mediterranean Marine Protected Area. The increase of biomasses found in the whole of the area is higher in regulated zones than in fished areas. Spearfishing seems to have an important impact on these populations and its prohibition positively affect their development. In the other hand, artisanal fishery does not seem to have a great impact on this species because of the close biomasses evaluated in zones where it could be practiced and in areas where it is forbidden, and the continuous increase of catches observed in traditional nets. With this increase of the average biomasses and the mean catches shown over time, firstly, limited spearfishing pressure permits to enhance brown meagre stocks in MPAs; secondly, the artisanal fishery seems to take advantage of spillover and larvae exportation and it has to be incorporated into the management of MPAs as a sustainable activity, in order to maintain this traditional Mediterranean heritage. Moreover, the abundance of Sciaena umbra could be used as an indicator of fishing pressure exerted on fishes stocks.