Small-scale fisheries in Madeira: recreational vs artisanal fisheries

Small-scale recreational and artisanal fisheries are popular activities in the Autonomous Region of Madeira, and to date no information is available on their impact on regional coastal ecosystems. Through fishers’ surveys and official registers of fish landings, we described and characterized these fisheries in Madeira, comparing artisanal and recreational fisheries. In 2017, artisanal boats landed 91 species in fishing ports, while recreational catches landed 58 species. The most frequent catches were Dentex gibbosus, Phycis phycis and Pagrus pagrus for artisanal fishery and P. pagrus, Serranus atricauda and Diplodus spp. for recreational fishery. Comparing the same techniques, artisanal fishery always showed higher catch per unit effort values than recreational boat fishery. Nevertheless, the low number of artisanal fishery boats in comparison with the recreational ones reflected the lower total landings of the artisanal fishery, which in 2017 were 62.3 t, compared with the 509.8 t estimated catches for the recreational fishery. Though the estimated recreational fishing data were based on surveys and thus subject to various biases, this activity seems to negatively affect coastal ecosystems and, together with artisanal fishing, exerts a combined pressure on targeted species. Improved legislation for both fisheries is essential for an appropriate management of resources.

Diet and feeding strategy of the forkbeard Phycis phycis (Pisces: Phycidae) from the Portuguese continental coast

The diet and feeding behaviour of the forkbeard Phycis phycis was studied based on 246 stomachs collected between May 2011 and April 2012 from a commercial fleet operating off the central west coast of Portugal. A total of 44 prey items were identified in the stomachs which were merged into major groups to avoid problems with low expected frequencies. The following taxonomic categories were considered: non-decapod Crustacea, Caridea, Anomura, Munida spp., Processa spp., Brachyura, Pisces, Trisopterus luscus. In order to investigate possible diet differences between fish size classes, a cluster analysis was performed using the mean abundance of each prey group by forkbeard 5 cm length class, and three length groups (LG) were obtained: <22.5, 27.5–37.5 and >42.5 cm. Seasonally, Caridea was the main prey group during winter and autumn while Pisces was predominant during the rest of the year. Caridea was the most important prey group for LG1 and LG2 while in LG3 Pisces was the principal one. The forkbeard feeding behaviour may be characterized as presenting a shift pattern from a more generalist diet (small Crustacea, mainly Caridea) in the young adults to a more specialist strategy (teleosts) in the adults.

Age and growth of forkbeard, Phycis phycis, in Portuguese continental waters

The forkbeard, Phycis phycis, is an important commercial species in Portugal; however, little information is available on its biology. Age and growth of the forkbeard from Portuguese continental waters were studied using 687 otoliths from specimens caught between May 2011 and December 2012. Otoliths were transversally sectioned, and assigned ages were validated by marginal increment analysis and edge analysis, and indices of precision were also calculated to corroborate ageing within and between readers. Validation techniques showed that an annual growth increment is formed every year, corresponding to the succession of an opaque and a translucent growth zone. Specimens ranged from 15.5 to 67.1 cm total length (TL), and their estimated ages ranged between 0 and 18 years. The forkbeard is a relatively slow growing, long lived species, that does not show sexual dimorphism in growth. The von Bertalanffy growth parameters estimated for forkbeard from the Portuguese continental waters were L∞ = 75.14 cm TL, k = 0.10 yr−1 and t0 = −2.09 yr.

Age and growth of the forkbeard Phycis phycis (Gadidae) from the Azorean archipelago, North Atlantic

The forkbeard Phycis phycis is one of the main target species of the demersal fishery in the Azores, north-eastern Atlantic. Age and growth of the forkbeard were studied using 477 otoliths from individuals caught between April 2000 and August 2004. Otoliths were burned and sectioned, a preparation method that improved the easiness of readings. Individuals ranged from 21 to 71 cm in total length, and their estimated ages between 2 and 18 years old. Forkbeard is a relatively slow growing, long lived species, that does not show sexual dimorphism in growth. The von Bertalanffy growth parameters estimated for the Azorean forkbeard were L∞ = 79.64 cm, k = 0.09 yr−1 and t0 = −1.88 years.