ecological effects of marine protected areas empafish project ...

EMPAFISH Booklet no. 1 Ecological effects of Atlanto-Mediterranean MPAs in the EU
Formigas islets – Dollabarat bank : ecological studies
� General
The fish, invertebrate and algal assemblages associated with the
environments of the Formigas Bank have been studied since the late 1890s’
after some expeditions to the site (e.g. Milne-Edwards & Bouvier 1899;
Piccone 1899). Modern exploration, including observation by SCUBA divers
and scientific collection of organisms in shallow-water habitats, started in the
1970’s (Ardré et al. 1973; Gofas 1989; Arruda et al. 1992; Brum et al. 1995;
Ávila & Azevedo 1997). The sampling has become more regular since 1998
when the underwater visual census (UVC) survey program was set up
(Tempera et al. 2001a; Afonso 2002). More recently a study was started to
characterise the patterns of pre-settlement dispersal and recruitment of
several reef species (Fontes et al. 2005). Deepwater fish fauna, the major
component of the bank, that spreads down to more than 1800 m deep, has
been studied by means of independent fishing cruises since the early 1990s
(Menezes et al. 1998, 2000). Some effort has been in place to survey the
bottoms and associated biotopes in sublittoral and circalittoral depths, using
SCUBA diving, UVC, ROV and drop-down video (e.g. Tempera et al. 2001a,
2001b). These studies of the bank summit have been exposing remarkable
biotopes including dense Cystoseira beds, overhangs dominated by black
corals, kelp forests down to unreported depths and sediments pockets with
intense bioturbation. Data on multispecies interactions (including cetaceans,
seabirds, seaturtles and fish) and on tuna catches, the only extractive activity
authorized since the 2003 revision of the reserve protection measures is
available from the POPA observers program.
� Reserve effect
The UVC monitoring program has shown that the shallow water assemblage of
the bank is highly specific and found nowhere else in the region (Afonso
2002; Afonso et al. 2006). This stems from a unique mixture of demersal
species typical of coastal habitats, and oceanic species, either seasonal
visitors or residents, which seems to be highly dependent on increased local
upwelling. Changes in this balance might be related to the recent decrease of
the shallow Cystoseira coverage observed in Dollabarat. This dramatic
alteration is reflected on algal-associated species, such as labrids, and may
confound the effects of protection. Increases in biomass and abundance were
not detected in commercially important species since 1998. However, this is
considered to reflect the short time past since the introduction of the stricter
regulations, which prohibited all exploitation except of tuna. It is expected
that the continuing of the monitoring program will allow such distinction in the
future, although stricter enforcement of the regulation is required to
guarantee the meeting of the reserve objectives.
� Population connectivity
The issue of connectivity between populations of the reserve and those
residing in other banks and islands is being addressed through studies of
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