RT journal article
T1 Changes in the juvenile fish assemblage of a Mediterranean shallow Posidonia oceanica seagrass nursery area after half a century
A1 Diaz-Gil, Carlos
A1 Grau, Amalia
A1 Grau, Antonio María
A1 Palmer, Miquel
A1 Cabrera Castro, Remedios
A1 Jordà, Gabriel
A1 Catalán, Ignacio
A2 Biología
K1 Seagrass meadow
K1 nursery habitat management
K1 juvenile fish assemblages
AB The within-year dynamics of the juvenile fish community in a shallow seagrass-dominated nursery habitat (Posidonia oceanica) in a Mediterranean bay were compared between two surveys separated by 50 years (1960 and 2012-2013). A nocturnal survey over depths ranging from 2 to 10 m over patchy seagrass meadows was conducted for one year (2012-2013) through 72 epibenthic tows spread fortnightly in 4 nearby stations, mimicking a survey conducted in 1960 in terms of sampling intensity, sampling zone, temporal coverage and sampling gear. Although a large proportion of the fish species were similar among surveys, remarkable and statistically significant differences were detected. A striking feature was that one of the most common and abundant Sparidae species currently, Diplodus annularis, did not appear in 1960. Other strong differences included the nonappearance of the European eel Anguilla anguilla in the recent survey. Furthermore, one of the most valuable species for artisanal fisheries in the area, the black scorpionfish Scorpaena porcus, was almost 10 times less abundant in 1960. A finer-scale study of the 2012-2013 survey allowed a quantitative analysis between species composition and potential environmental drivers through redundancy analysis that well described the current pattern of time-dependent recruitment pulses in nearshore meadows of the area throughout the year, with marked effects of surface temperature and photoperiod. The comparison between surveys suggests that some major differences between surveys are not likely to be attributable to interannual stochasticity in recruitment or environmental variability but may be related to i) unaccounted-for habitat transformation and/or ii) the strong decrease in juvenile fishing mortality in this shallow nursery area since the enforcement of bans on littoral epibenthic trawling activities characteristic of this area.
PB NATL CENTRE MARINE RESEARCH
SN 1108-393X
YR 2019
FD 2019
LK http://hdl.handle.net/10498/22312
UL http://hdl.handle.net/10498/22312
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 12-nov-2026