Browsing by Author "Pierce, Graham J."
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- Corrigendum: The significance of cephalopod beaks as a research tool: An updatePublication . Xavier, José C.; Golikov, Alexey V.; Queirós, José P.; Perales-Raya, Catalina; Rosas-Luis, Rigoberto; Abreu, José; Bello, Giambattista; Bustamante, Paco; Capaz, Juan Carlos; Dimkovikj, Valerie H.; González, Ángel F.; Guímaro, Hugo; Guerra-Marrero, Airam; Gomes-Pereira, José N.; Hernández-Urcera, Jorge; Kubodera, Tsunemi; Laptikhovsky, Vladimir; Lefkaditou, Evgenia; Lishchenko, Fedor; Luna, Amanda; Liu, Bilin; Pierce, Graham J.; Pissarra, Vasco; Reveillac, Elodie; Romanov, Evgeny V.; Rosa, Rui; Roscian, Marjorie; Rose-Mann, Lisa; Rouget, Isabelle; Sánchez, Pilar; Sánchez-Márquez, Antoni; Seixas, Sónia; Souquet, Louise; Varela, Jaquelino; Vidal, Erica A. G.; Cherel, YvesIn the published article, there was an error in the author list, and author Jorge Hernández-Urcera was erroneously excluded. The corrected author list appears below.
- A dataset of cetacean occurrences in the Eastern North AtlanticPublication . Correia, Ana M.; Gandra, Miguel; Liberal, Marcos; Valente, Raul; Gil, Ágatha; Rosso, Massimiliano; Pierce, Graham J.; Sousa-Pinto, IsabelThe CETUS project is a cetacean monitoring program that takes advantage of cargo ships to undertake survey routes between Continental Portugal, Macaronesian archipelagos and West Africa. From 2012 to 2017, over 50 volunteers participated in the program, actively surveying more than 124.000 km, mostly beyond national jurisdictions in the high seas, for which little or no previous data existed. In total, the collection comprises 3058 georeferenced transect lines and 8913 positions, which are associated with 2833 cetacean sightings, 362 occurrences of other pelagic megafauna, 5260 estimates of marine traffic and 8887 weather observations. This dataset may provide new insights into the distribution of marine mammals in the Eastern North Atlantic and was published following the OBIS-ENV-DATA format (with the most recent biodiversity data standards at the time of writing). Consequently, it may serve as a model for similar visual line transect data collections yet to be published.
- Do fisher associations really represent their members’ needs and opinions? The case study of the octopus fishery in the Algarve (south Portugal)Publication . Rangel, Mafalda; Pita, Cristina; de Oliveira, Manuela Maria; Guimarães, Maria Helena; Rainha, Rita; Sonderblohm, Carlos; Monteiro, Pedro; Oliveira, Frederico; Ballesteros, Marta; Gonçalves, Jorge Manuel Santos; Pierce, Graham J.; Erzini, KarimFishers’ participation in the fishery management decision-making process is generally low, particularly in small-scale fisheries (SSF). Within the overarching goal of improving fisheries governance, fishers’ participation is crucial. Yet, how can fishers participate in the decision-making processes which affect their actions, and to what extent do fisher associations represent their interests? These questions were tackled by means of an empirical case study in the “Tertúlia do Polvo” project, focusing on the octopus SSF in the Algarve region (south Portugal), where the octopus fishery is managed top-down with sporadic participation of fishers. During the study (2014 and 2015), seven participatory workshops (tertúlias) were held, involving fisher associations, management authorities and researchers, to propose and discuss management measures for the fishery. Also, a face-to-face questionnaire survey (121 valid replies) was undertaken with local fishers to gauge their opinions about the management measures proposed during the workshops. Results show a strong agreement between the outcomes achieved during the workshops and the main concerns and possible solutions identified by fishers. Taking into consideration the difficulty in structuring and assuring a transparent and effective participation of fishers in the management of their activity, the results obtained are promising. In this study, the use of a participatory process (restricted to a small group of stakeholders) combined with consultation (targeting a sample of the fisher population) allowed the validation of the overall results obtained. Such a methodological approach can be tried in other fishing communities to implement efficient and effective collaborative management, contributing to improved fisheries governance.
- Fishers' perceptions about the EU discards policy and its economic impact on small-scale fisheries in Galicia (North West Spain)Publication . Villasante, Sebastian; Pierce, Graham J.; Pita, Cristina; Pazos Guimerans, César; Garcia Rodrigues, João; Antelo, Manel; Da Rocha, José Maria; Garcia Cutrini, Javier; Hastie, Lee C.; Veiga, Pedro; Sumaila, U. Rashid; Coll, MartaThis paper investigates the impact of the European Union landing obligation in the Galician (North West of Spain) multispecies small-scale gillnet fishery. By combining results from semi-structured interviews with small-scale fishers and a bioeconomic model, we found that the percentage of discards for small-scale fisheries is usually low, which is consistent with general empirical observations globally but can be high when quotas are exhausted. Our results also confirm that the landing obligation would generate negative impacts on fishers' activities by investing more time on-board to handle previously discarded fishes, and putting at risk the security of fishers at sea due to full use of allowable storage on-board coupled with often adverse sea conditions in Galician bays. The application of the landing obligation policy to small-scale fisheries would result in short-and long-term losses of fishing days and yields, with high negative impacts on sustainable fisheries such as the Galician multi species small-scale gillnet fishery. The expected number of fishing days under the landing obligation is estimated to be reduced by 50% during the five years following the implementation of the policy. The future yield (catches) under the landing obligation would be only 50% of catches expected in the absence of the landing obligation, regardless of the total volume of quotas allocated to the fleet. (C) 2016 Elsevier B.V. All rights reserved.
- Seasonal movements of veined squid Loligo forbesi in Scottish (UK) watersPublication . Viana, Mafalda; Pierce, Graham J.; Illian, Janine; MacLeod, Colin D.; Bailey, Nick; Wang, Jianjun; Hastie, Lee C.In order to protect and sustainably manage fishery resource species, it is essential to understand their movements and habitat use. To detect the hypothesised migration of maturing veined squid Loligo forbesi from the west coast of Scotland (UK) to the North Sea and identify possible inshore-offshore movements, we analysed seasonal, spatial and environmental patterns in abundance and size distribution, based on commercial fishery landings data and trawl survey data from Scottish coastal waters (International Council for the Exploration of the Sea, ICES areas IVa, IVb and VIa). A geographic information system (GIS) was used to build monthly contour maps of abundance. Generalised additive mixed models (GAMM) were used to quantify patterns in size distribution and abundance. In most years, there was no evidence of movement from the West to the East coast of Scotland. Evidence of inshore-offshore movements during the life-cycle of the cohort that recruits in autumn (winter breeders) was found instead. The winter breeding cohort appears to spawn in inshore waters and some evidence suggests that the spawning grounds of the summer breeders are also inshore. Across seasons, higher abundance of L. forbesi can generally be found in the north of Scotland at intermediate water depths and in warmer waters.
- Stranding patterns and feeding ecology of striped dolphins, Stenella coeruleoalba, in Western Iberia (1981–2014)Publication . Marçalo, Ana; Giménez, Joan; Nicolau, Lídia; Frois, Jessica; Ferreira, Marisa; Sequeira, Marina; Eira, Catarina; Pierce, Graham J.; Vingada, JoséThe striped dolphin, Stenella coeruleoalba, is one of the most abundant cetacean species off the Western Iberian coast, however, studies on the species regarding biology, ecology, threats or conservation efforts are lacking. This study investigates stranding patterns (years 1981–2014) and diet (2002–2014) of striped dolphins (Stenella coeruleoalba) off the Portuguese mainland coast. Stranded animals were sampled along the whole coast (n = 252). Most stranded striped dolphins were recorded in the first half of the year and strandings increased over time. Analysis of stomach contents (n = 36) showed that striped dolphins in the area are mostly piscivorous (80% by number and weight of the diet), taking pelagic, meso-pelagic and demersal species. In terms of reconstructed biomass prey, sardine (Sardina pilchardus) and blue whiting (Micromesistius poutassou) were the most important. Prey items revealed that both sexes forage at a range of depths (pelagic and demersal systems) in both neritic and oceanic habitats, although females feed more often in coastal waters. Moreover, diet results also indicate that striped dolphins may co-occur with other neritic cetacean species, such as the common dolphin, Delphinus delphis, thus sharing some preferred prey species. The study revealed that striped dolphins on the Iberian coast interact with coastal fisheries sharing the same target species. Management measures for fisheries will need to be consistent with an ecosystem-based approach.
- The significance of cephalopod beaks as a research tool: An updatePublication . Xavier, José C.; Golikov, Alexey V.; Queirós, José P.; Perales-Raya, Catalina; Rosas-Luis, Rigoberto; Abreu, José; Bello, Giambattista; Bustamante, Paco; Capaz, Juan Carlos; Dimkovikj, Valerie H.; González, Angel F.; Guímaro, Hugo; Guerra-Marrero, Airam; Gomes-Pereira, José N.; Hernández-Urcera, Jorge; Kubodera, Tsunemi; Laptikhovsky, Vladimir; Lefkaditou, Evgenia; Lishchenko, Fedor; Luna, Amanda; Liu, Bilin; Pierce, Graham J.; Pissarra, Vasco; Reveillac, Elodie; Romanov, Evgeny V.; Rosa, Rui; Roscian, Marjorie; Rose-Mann, Lisa; Rouget, Isabelle; Sánchez, Pilar; Sánchez-Márquez, Antoni; Seixas, Sónia; Souquet, Louise; Varela, Jaquelino; Vidal, Erica A. G.; Cherel, YvesThe use of cephalopod beaks in ecological and population dynamics studies has allowed major advances of our knowledge on the role of cephalopods in marine ecosystems in the last 60 years. Since the 1960's, with the pioneering research by Malcolm Clarke and colleagues, cephalopod beaks (also named jaws or mandibles) have been described to species level and their measurements have been shown to be related to cephalopod body size and mass, which permitted important information to be obtained on numerous biological and ecological aspects of cephalopods in marine ecosystems. In the last decade, a range of new techniques has been applied to cephalopod beaks, permitting new kinds of insight into cephalopod biology and ecology. The workshop on cephalopod beaks of the Cephalopod International Advisory Council Conference (Sesimbra, Portugal) in 2022 aimed to review the most recent scientific developments in this field and to identify future challenges, particularly in relation to taxonomy, age, growth, chemical composition (i.e., DNA, proteomics, stable isotopes, trace elements) and physical (i.e., structural) analyses. In terms of taxonomy, new techniques (e.g., 3D geometric morphometrics) for identifying cephalopods from their beaks are being developed with promising results, although the need for experts and reference collections of cephalopod beaks will continue. The use of beak microstructure for age and growth studies has been validated. Stable isotope analyses on beaks have proven to be an excellent technique to get valuable information on the ecology of cephalopods (namely habitat and trophic position). Trace element analyses is also possible using beaks, where concentrations are significantly lower than in other tissues (e.g., muscle, digestive gland, gills). Extracting DNA from beaks was only possible in one study so far. Protein analyses can also be made using cephalopod beaks. Future challenges in research using cephalopod beaks are also discussed.
- Towards global traceability for sustainable cephalopod seafoodPublication . Gleadall, Ian G.; Moustahfid, Hassan; Sauer, Warwick H. H.; Ababouch, Lahsen; Arkhipkin, Alexander I.; Bensbai, Jilali; Elegbede, Isa; Faraj, Abdelmalek; Ferreiro-Velasco, Pedro; González-Gómez, Roberto; González-Vallés, Carmen; Markaida, Unai; Morillo-Velarde, Piedad S.; Pierce, Graham J.; Pirro, Stacy; Pita, Cristina; Roumbedakis, Katina; Sakurai, Yasunori; Scheel, David; Shaw, Paul W.; Veiga, Pedro; Willette, Demian A.; Winter, Andreas; Yamaguchi, TadanoriCephalopods are harvested in increasingly large quantities but understanding how to control and manage their stocks, and tracking the routes of the consumption that exploits them, lag behind what has been developed for exploiting finfish. This review attempts to redress the imbalance by considering the status of the major cephalopod stock species and the traceability of cephalopod seafood along the trade value chain. It begins with a general overview of the most important exploited cephalopods, their stock status and their market. Four major cephalopod resources are identified: the three squid species Todarodes pacificus, Dosidicus gigas and Illex argentinus; and one species of octopus, Octopus vulgaris. The techniques and problems of stock assessment (to assess sustainability) are reviewed briefly and the problems and possible solutions for assessing benthic stock such as those of octopuses are considered. An example of a stock well managed in the long term is presented to illustrate the value of careful monitoring and management: the squid Doryteuthis gahi available in Falkland Islands waters. Issues surrounding identification, mislabelling and illegal, unreported and unregulated (IUU) fishing are then reviewed, followed by a discussion of approaches and techniques of traceability as applied to cephalopods. Finally, some of the mobile apps currently available and in development for tracking seafood are compared. This review concludes with observations on the necessity for the strengthening and international coordination of legislation, and more rigorous standards for seafood labelling and for taxonomic curation of DNA sequences available in public databases for use in seafood identification.
- Trends and drivers of marine fish landings in Portugal since its entrance in the European UnionPublication . Bueno-Pardo, Juan; Pierce, Graham J.; Cabecinha, Edna; Grilo, Catarina; Assis, Jorge; Valavanis, Vasilis; Pita, Cristina; Dubert, Jesus; Leitão, Francisco; Queiroga, HenriqueMarine landings in Portugal have decreased at a higher rate than fishing effort in the last 20 years. Identifying the variables driving the quantity and composition of landings is pivotal to understand the dynamics of the fisheries sector, which entails complex social and environmental aspects. In this study, we investigate the main drivers of marine fish landings in continental Portugal between 1989 and 2014. To identify common trends in time series, and quantify the importance of environmental factors, we applied a dynamic factor analysis considering four regions and three types of gear (trawling, purse-seine, and a multi-gear fishery). Our results show the importance of fishing effort as the most relevant factor driving marine landings in Portugal, both at the long and short terms. In addition, the effect of environmental factors such as the winter river discharge and the spring East Atlantic Teleconnection index should not be neglected, probably through mechanisms affecting coastal productivity. We provide a comprehensive amount of information that permits to improve our understanding of the trends of the most important commercial species in Portugal during the period of study.