Seabird bycatch in Portuguese mainland coastal fisheries: An assessment through on-board observations and fishermen interviews

Competition with fisheries and incidental capture in fishing gear are the major current threats for seabirds at sea. Fishing is a traditional activity in Portugal and is mainly composed of a great number of small vessels. Given the lack of knowledge on effects of the Portuguese fishing fleet on seabird populations, bycatch was assessed in mainland coastal waters for 2010–2012. Interviews and on-board data were divided into 5 strata, according to fishing gear: Bottom trawling, Bottom longline, Purse seine, Beach seine, Polyvalent (≥12 m) and Polyvalent (<12 m). Polyvalent included Setnets, Traps and Demersal longlines. Overall, 68 birds were recorded to be bycaught. The average catch per unit effort (CPUE) was 0.05 birds per fishing event. Polyvalent (<12 m), Polyvalent (≥12 m) and Purse seiners had the biggest seabird bycatch rates, with 0.5 (CPUE=0.1), 0.11 (CPUE=0.05) and 0.2 (CPUE=0.11) birds per trip, respectively. Within Polyvalent gear, Setnets captured the largest diversity of seabird species (CPUE=0.06), while Demersal longline had the highest CPUE (0.86). Northern gannet was the most common bycaught species. Although more observation effort is required, our results suggest that substantial numbers of Balearic shearwater might be bycaught annually, mainly in Purse seine and Setnets

Quantification of interactions between the Portuguese sardine purse-seine fishery and cetaceans

Interactions between cetaceans and the purse-seine fishery operating along the whole Portuguese continental coast were studied based on on-board observations from 2010 to 2011. Cetacean presence and mortality were estimated and characteristics under which interactions were most likely to occur were identified. Observations were made on 163 fishing trips (0.7% of the average annual number of fishing trips) and 302 fishing operations/hauls. Cetaceans were present during 16.9% of fishing events; common dolphins (Delphinus delphis) accounted for 96% of occurrences, mostly overnight in summer and early autumn. Regression models showed that cetacean presence during a fishing set was significantly (p < 0.05) associated with sardine catches, effort, and latitude/longitude. Encirclement and mortality occurred in 2.3 and 1.0% of fishing events, respectively. Encircled species were the common dolphin, bottlenose dolphin (Tursiops truncatus), and harbour porpoise (Phocoena phocoena), but only common dolphin showed mortality (three individuals); raised to fleet level, estimated total mortality rates of common dolphins were 69 (95% CI 37–110) in the north and 91 (95% CI 55–165) in the south for 2010 and 78 (95% CI 47–140) in the south only for 2011. The estimated annual mortality rate due to purse seining is 113 (95% CI 3–264) common dolphins, which is ∼0.63% of the current most optimistic estimate of population size for the Portuguese fishing area (SCANS II). The wide confidence limits, as well as variation between years, reflect low observer coverage, emphasizing the need for increased monitoring to cover gaps in the spatial and seasonal distribution of observer effort and provide reliable estimates of bycatch

Do pingers cause stress in fish? An experimental tank study with European sardine, Sardina pilchardus (Walbaum, 1792) (Actinopterygii, Clupeidae), exposed to a 70 kHz dolphin pinger

Acoustic deterrent devices (pingers) that are designed to alert marine mammals to the presence of fishing gear have been successfully employed to reduce cetacean–fishery interactions. However, pinger sounds may affect fisheries target species: noise can induce short-term stress responses in fish that are reflected in increased blood cortisol concentrations and behavioural alterations, which may ultimately result in reduced catch rates. In order to test this hypothesis, the present study analyses the hormonal and behavioural stress response of European sardine (Sardina pilchardus) to a commercially available pinger—the 70 kHz dolphin pinger. The responses of wild captive fish to the pinger sounds were tested in tank experiments, measuring the stress level of fish by analysing blood plasma cortisol concentration and swimming behaviour. Mixed effect models were used for statistical analysis. During the experiments, pinger sounds caused subtle, but significant elevations in sardine plasma cortisol concentration and fish school compaction. However, when compared to the rates of increase reported for acute stress responses in similar studies, the observed increment was very small. This suggests that the sounds of the trialled pinger are not likely to significantly alter sardine behaviour and should consequently not have any negative impact on sardine catch rates

Postglacial climate changes and rise of three ecotypes of harbour porpoises,Phocoena phocoena, in western Palearctic waters

Despite no obvious barriers to gene flow in the marine realm, environmental variation and ecological specializations can lead to genetic differentiation in highly mobile predators. Here, we investigated the genetic structure of the harbour porpoise over the entire species distribution range in western Palearctic waters. Combined analyses of 10 microsatellite loci and a 5085 base-pair portion of the mitochondrial genome revealed the existence of three ecotypes, equally divergent at the mitochondrial genome, distributed in the Black Sea (BS), the European continental shelf waters, and a previously overlooked ecotype in the upwelling zones of Iberia and Mauritania. Historical demographic inferences using approximate Bayesian computation (ABC) suggest that these ecotypes diverged during the last glacial maximum (c. 23–19 kilo-years ago, kyrbp). ABC supports the hypothesis that the BS and upwelling ecotypes share a more recent common ancestor (c. 14 kyrbp) than either does with the European continental shelf ecotype (c. 28 kyrbp), suggesting they probably descended from the extinct populations that once inhabited the Mediterranean during the glacial and post-glacial period. We showed that the two Atlantic ecotypes established a narrow admixture zone in the Bay of Biscay during the last millennium, with highly asymmetric gene flow. This study highlights the impacts that climate change may have on the distribution and speciation process in pelagic predators and shows that allopatric divergence can occur in these highly mobile species and be a source of genetic diversity

Biology & Ecology of anchovies and sardine.

Apart from being commercially and socially significant, anchovies and sardines populations occupy crucial positions in the oceans’ ecosystems. Low in the food chain, clupeoids tend towards abundance, as if their purpose in life was to be eaten and fuel the upper levels of marine trophic chains. The present book covers a broad spectrum of topics on the biology (sytematics, phylogeography, reproduction, feeding) and ecology (habitat characterization, recruitment variability) of anchovies and sardines. It also puts together important information on the state of their fisheries, exploitation and management

Environmental assessment of sardine (Sardina pilchardus) purse seine fishery in Portugal with LCA methodology including biological impact categories.

Purpose: The purse seine fishery for sardine is the most important fishery in Portugal. The aim of the present study is to assess the environmental impacts of sardine fished by the Portuguese fleet and to analyse a number of variables such as vessel size and time scale. An additional goal was to incorporate fishery-specific impact categories in the case study.\ud Methods: Life CycleAssessmentmethodologywas applied, and\ud data were collected from nine vessels, which represented around 10 % of the landings. Vessels were divided into two length categories, above and below 12 m, and data were obtained for the years 2005 to 2010. The study was limited to the fishing phase only. The standard impact categories included were energy use, global warming potential, eutrophication potential, acidification potential and ozone depletion potential. The fishery specific impact categories were overfishing, overfishedness, lost potential yield, mean trophic level and the primary production required, and were quantified as much as possible.\ud Results and discussion: The landings from the data set were\ud constituted mainly by sardine (91 %), and the remainders wereother small pelagic species (e.g. horse mackerel). The most important input was the fuel, and both vessel categories had the same fuel consumption per catch 0.11 l/kg. Average greenhouse gas emissions (carbon footprint) were 0.36 kg CO2 eq. per kilo sardine landed. The fuel use varied between years, and variability between months can be even higher. Fishing mortality has increased, and the spawning stock biomass has decreased resulting in consequential overfishing for 2010. A correlation between fuel use and stock biomass was not found, and the stock condition does not seem to directly influence the global warming potential in this fishery. Discards were primarily nontarget small pelagic species, and there was also mortality of target species resulting from slipping. The seafloor impact was considered to be insignificant due to the fishing method.\ud Conclusions: The assessment of the Portuguese purse seine fishery resulted in no difference regarding fuel use between large and small vessels, but differences were found between years. The stock has declined, and it has produced below maximum sustainable yield. By-catch and discard data were missing but may be substantial. Even being difficult to quantify, fishery impact categories complement the environmental results with biological information and precaution is need in relation to the stock management. The sardine carbon footprint from Portuguese purse seine was lower than that of other commercial species reported in

Monitorização da população reprodutora de Roque-de-castro Oceanodroma castro do Farilhão Grande, Berlengas 2011-2012

Breeding Madeiran Storm-petrels Oceanodroma castro on Farilhão Grande islet was first described in the early 80s. Despite being an important breeding colony at nationally and global level for the species distribution, few studies regarding monitoring and/or research have been developed. In order to update the knowledge about this population, SPEA, under the FAME project, made 7 visits to the islet between 2011 and 2012. We used mist-nets, nocturnal vocalizations and ground search to assess the population size. The population was estimated to be 473 individuals, resulting in 102-201 breeding pairs, which may indicate a high population decreasing. Comparison with previous studies emphasizes the need to conduct a directed census in order to obtain more robust estimate of this population. For the first time it was used a tracking device (GLS) in Madeiran Storm-petrels to assess movements and distribution of the species during the breeding season. The only GLS recovered showed that the individual made a 5 days trip over open sea to the west coast of Morocco. The walls built in 2002, during an action performed previously by SPEA, which host some Madeiran Storm-petrel nests, were rebuilt. We also implemented 36 new artificial nests that will enable future work with this population. A census of Yellow-legged Gull Larus michahellis that breeds on the islet took place, and 170-180 pairs were estimated. During the several visits to the island, it was detected gulls like signs of predation on Madeiran Storm-petrel. This effect however will be better reported later