ecological effects of marine protected areas empafish project ...

EMPAFISH Booklet no. 1 Ecological effects of Atlanto-Mediterranean MPAs in the EU
1993). The principal objective was to evidence regeneration of communities
and habitats, the second one was to demonstrate the possibilities of
managing fishing resources, by benefiting to artisanal fishing métiers. The
first studies started in 1983-1985-1986 with Ody and Bregliano using visual
census, to look at reserve effect on species composition, densities and
biomasses of fishes (Bregliano 1985; Ody 1987). The fish fauna of artificial
reefs has been compared to the one of rocky bottoms. From 1989 to 1994
other surveys have been performed in the Côte Bleue by Harmelin and
Bachet, and a special survey has been dedicated to target species of reserve
effect (1995, 1999, 2001) (Harmelin 1995, 1999; Daniel et al. 1999). Fish
indices have been developped by Harmelin with the PMCB team in 1999 and
2001/2002. The impact of protection has been evaluated inside the reserve of
Carry and Couronne by a presence/absence test with target species (Daniel et
al. 2002).
UVC monitoring program conducted in Couronne since 1995 (before
implementation of the reserve) showed how specific composition of fish fauna
was restored. Noble species came back since 2001 (Jouvenel et al. 2002). The
fish fauna is surveyed every 3 years (1998/2001/2004) by visual censuses
and experimental fishing (Jouvenel et al. 1995, 1998, 2002). Abundances of
different species increase since 1995 inside the protected area. Since 2001,
densities are more equilibrated between protected and unprotected zones, as
a likely indication of spillover across the boundaries. The biomass increases
inside the MPA and is amplified when artificial reefs effect is added to reserve
effect, despite decreasing biomass of prey species that is probably linked to
predators increasing as Dicentrarchus labrax. The demographic structure is
more balanced inside the reserve, and since 2004 natural mortality is the
main structuring factor in fishes assemblages.
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o Fish assemblage (commercial species)
The use of standardised experimental fishing is complementary to UVC, and
provides data concerning the nocturnal fish fauna and precise measures of
length and weights of caught fishes inside and outside the reserve of
Couronne. Moreover, simulations of professional and/or recreational fishing
inside and outside the reserves allow evaluations of yields around the
protected area.
Standardised experimental fishing program has shown an increase of mean
species richness per unit effort between 1995 and 2004 (4.4 to 7.4
species/E.U.). Captures and individual mean weights were constantly
increasing since 1995 inside the marine reserve (92 to 246 individuals; 110.7
to 216.4 g/individual). Yields were increasing in the protected area as
compared to boundaries (1,077 to 4,570 g/E.U.) with more Mullus surmuletus
and Phycis phycis. Simulations of recreational line fishing showed also an
amplification of biomass increase on natural grounds inside the reserve.
When reserve effect was combined with artificial reefs effect, biomass was
rapidly increased, reaching 671 g/m 3 of artificial reef. Since 2004, installation
of D. labrax and Conger conger seemed to regulate the abundance of other
species around the reef. Fish families more sensible to protection measures –