The sociology and habits of recreational anglers on the Island of Majorca (western Mediterranean) were evaluated using telephone and on-site surveys, as well as fishing logbooks and recreational fishing competitions. The recreational fishery is one of the island's main leisure activities, 5.14% of the population (37 265 people) participating. Enthusiasts tend to be mainly middle class (most anglers own boats moored at marinas), middle-aged males (90% male, mean age 46 ± 2 years). The most popular fishing method is from a boat (62.9%), followed by fishing from shore (32.4%), and spearfishing (3.6%). The mean time spent fishing is 3.86 ± 0.03 h d−1, and more than one type of gear (mean 1.27 ± 0.21) is used simultaneously by a single angler. The frequency of fishing is 4–6 times per month, mainly on holidays and weekends, increasing in summer. The activity has a sizeable impact on the coastal fauna, with diverse catches of at least 1209.25 t year−1 (about 615 000 fishing outings year−1). Thus, the amount of carbon extracted annually is at least 137.34 kg C km−2 year−1, and the recreational fishery removes about 31% of production at trophic level 4. Although these are gross estimates and more detailed study of the effect on trophic level and local production is needed, the values do highlight the pressure the recreational fishery exerts on coastal fish communities. Assuming that this level of exploitation is common to north-shore Mediterranean countries, there may be cause for concern about sustainable exploitation in the recreational fishery, and the effectiveness of current protection measures is discussed. Despite the limitations of the study, recreational fisheries clearly should be taken into account when considering measures for fisheries management. Moreover, fishing has considerable social import, and the benefits must be taken into account when investments to protect exploited resources are being contemplated.

δ15N and δ13C were determined for plants, invertebrates and fishes collected from 3 sites on the southern coast of the Mediterranean island of Mallorca, Spain. The sites were separated by distances of 1250 to 3750 m. The mean δ15N of plants was 1.1 to 4.1‰, benthic invertebrates 5.9 to 6.9‰, planktonic invertebrates 5.5 to 5.8‰ and fishes 84 to 13.8‰. δ15N became enriched with increasing trophic level. The mean δ13C of plants was -11.4 to -16.3‰, benthic invertebrates -14.8 to -16.8‰, planktonic invertebrates -19.3 to -19.8‰ and fishes -16.1 to -19.2‰. There were significant differences in the isotopic composition of individual species within the plant, invertebrate or fish groupings at each site and there were significant differences in the isotopic composition of the same species at different sites. Depleted 13C was associated with benthic food chains and enriched 13C with planktonic chains. The data suggest that benthic food chains are important to the rocky reel associated fishes studied, as might be expected in a nutrient poor system where planktonic production is relatively low. However, the variance in δ13C composition between sites was such that the relative significance of the 2 pathways could not be determined. 15N measurements indicated that some of the fish species studied had adopted different feeding strategies at different sites and, as a result, individuals of the same species could sometimes be assigned to different trophic groups at different sites. The data suggest that these fishes exhibit plasticity in their feeding strategies and this may provide them with greater adaptive flexibility to respond to site-specific changes in food availability. Moreover, the data provide empirical support for current theories of food web dynamics which suggest that trophic 'levels' are dynamic rather than fixed and that 'multichannel omnivory' is an important feature of food webs.Peer Reviewe

Comparativa de abundancias y biomasa de la ictiofauna profunda(200-1800 metros)de las proximidades de las islas Baleares. Mapas, gráficos y listado de especies.A total of 13 026 fishes belonging to 82 species and 43 famllies were collected in a continuous transect between depths of 200 and 1800 m south of the Baleanc Islands (Algerian basin, western Mediterranean). The analysis of 32 bottom trawls showed the existence of 4 groups associated with the upper slope (groups 1 and 2, from 200 to 400 and 400 to 800 m, respectivelv), middle slope (group 3, from 800 to 1400 m) and lower slope (group 4, below a depth of 1400 m) Thc differcnces in the mean values of the ecological parameters species richness, abundance, biomass and mean fish weight were also indicative of distinctive characteristics between these fish assemblages. Species richness decreased significantly with depth. The highest values of diversity corresponded to the samples from group 2. Biomass did not show any specific trend throughout the whole bathymetric range. Mean fish weight show 2 different trends along the continental slope: a bigger-deeper phenomenon at the upper 1000 to 1200 m depth. and a smaller-deeper phenomenon below this depth. Our results are compared with those obtained in the north Atlantic basin and in the western Mediterranean (Balearic basin), and the main factol-s affecting these deep-sea fish assemblages are discussed.EU FAIR PROJECT CT 95-0655. European Commission DC;-XIV, Fisheries.Peer reviewe

The feeding ecology of eight demersal elasmobranchs, three sharks (Etmopterus spinax, Scyliorhinus canicula and Galeus melastomus) and five batoids (Myliobatis aquila, Leucoraja naevus, Raja polystigma, R. miraletus and R. clavata), from the Balearic Sea (western Mediterranean) was analyzed. For each species, the diet and feeding habits were characterized by depth strata using quantitative indices such as diet overlap, diet breadth and prey diversity. Diet variation with size and depth were also tested for the most abundant species. For shelf-living species, natantian and reptantian crustaceans together with teleosts were the most important preys. On slope bottoms, euphausiids were the preferential prey for S. canicula and G. melastomus, while E. spinax fed mainly on cephalopods. The most specialist and generalist diet corresponded to G. melastomus living on the upper slope and S. canicula from the continental shelf, respectively. High overlap was found between all the skates on the continental shelf and the sympatric sharks S. canicula and G. melastomus on the slope. Significant overlap was also found between S. canicula and R. clavata on the continental shelf. Size was found to significantly affect the diet of S. canicula, G. melastomus and R. clavata, whereas depth affected exclusively S. canicula.