Browsing by Author "Campos, Aida"
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- Development of a responsive fisheries management system for the Portuguese crustacean bottom trawl fishery: Lessons learntPublication . Silva, C.; Mendes, H.; Rangel, Mafalda; Wise, L.; Erzini, Karim; Borges, M. D.; Ballesteros, M.; Santiago, Jose Luis; Campos, Aida; Vioarsson, J.; Nielsen, K. NA prototype for a Responsive Fisheries Management System (RFMS) was developed in the context of the European FP7 project EcoFishMan and tested on the Portuguese crustacean trawl fishery. Building on Results Based Management principles, RFMS involves the definition of specific and measurable objectives for a fishery by the relevant authorities but allows resource users the freedom to find ways to achieve the objectives and to provide adequate documentation. Taking into account the main goals of the new Common Fisheries Policy, such as sustainable utilization of the resources, end of discards and unwanted catches, a management plan for the Portuguese crustacean trawl fishery was developed in cooperation with the fishing industry, following the process and design laid out in the RFMS concept. The plan considers biological, social and economic goals and assigns a responsibility for increased data collection to the resource users. The performance of the plan with regard to selected indicators was evaluated through simulations. In this paper the process towards a RFMS is described and the lessons learnt from the interaction with stakeholders in the development of an alternative management plan are discussed. (C) 2014 Elsevier Ltd. All rights reserved.
- Effects of reallocating fishing effort from trawling to creels in a Norway lobster fisheryPublication . Eichert, Moritz; Campos, Aida; Fonseca, Paulo; Lopes, Pedro; Marques, Lino; Castro, MargaridaThe consequences of reallocating fishing effort from trawling to creels in an area off the West coast of Portugal for the operation of the trawl fleet, as well as on the population dynamics and the global catch value for a high valued species, the Norway lobster (Nephrops norvegicus) are evaluated. The results suggest that only small portions of the area of interest are used by the trawl fleet, opening the possibility for a trawl ban without major disruption of the trawling activity. Economic benefits are expected, since predictions two scenarios tested, heavy and moderate exploitation, indicate no loss of catch value with much lower operational costs. Social benefits to local communities can also be expected since a much lower investment is needed for creel fishing, making this fishery attractive to small local companies already operating in the region. The proposed ban is consistent with the ecosystem approach to fisheries management and the Common Fisheries Policy (CFP) where the transition towards more responsible fishing practices is encouraged.
- Fishers, let us talk: validating métiers in a multi-gear coastal fishing fleetPublication . Szynaka, Monika; Fernandes, Mariana; Anjos, Mariana; Erzini, Karim; Gonçalves, Jorge Manuel Santos; Campos, AidaIn the multi-gear coastal fleet in the Algarve (South Portugal), fishers own licenses for various fishing gears. However, they generally do not use all these licenses, and therefore, it is difficult to estimate the impacts this fleet has on the local environment. In this study, two types of questionnaires were used directed to the local fishers from the multi-gear fleet during interviews carried out between November 2019 and July 2021 with the objective to validate the métiers proposed for this fleet in a previous study using multivariate analysis on past landing profiles. A total of 10 out of the 11 proposed métiers were validated, including four métiers with gillnets, three with dredges, two with trammel nets, and one with traps. Additional métiers were identified not found in the previous study. The results obtained with the two types of questionnaires are presented, and their usefulness in validating the gear used and the seasonality of fishing activities are discussed, as well as their contribution to a clearer distinction between target species and commercial by-catch.
- Further improvements in sorting grids for the crustacean trawl fishery off the Southern coast of PortugalPublication . Millar, Russell B.; Barros, Luisa; Fonseca, Paulo; Santos, Paulo T.; Campos, AidaBottom-trawl fishing for crustaceans off the Portuguese south and southwest coasts is a very important segment of the Portuguese fishing fleet, where annual rates of discarding have ranged from approximately 38% to as much as 70% of the total catch. Past experiments to address this problem encompassed the testing of different codend mesh sizes and configurations, square mesh windows and rigid grids to enhance species and size-selectivity. While the use of a Nordmore grid has proved quite efficient in separating out blue whiting (Micromesistius poutassou), it also led to some losses of the two main crustacean target species, Norway lobster (Nephrops norvegicus) and rose shrimp (Parapenaeus longirostris). The present study addresses that limitation by using a modified grid with 20 mm bar spacing and two open sections, designed with the purpose of separating fish and crustacean species into upper and lower codends. Good separation was achieved, with about 80% of the blue whiting (in number) directed towards the upper trawl section and caught in the upper codend, while a similar percentage of Norway lobster was caught in the lower codend. The grid bars had 50% retention for Norway lobster at 34.1 mm carapace length. The results herein will enable this gear configuration to be finetuned with regard to codend mesh sizes and bar spacing, so as to optimize both retention of Norway lobster and exclusion of blue whiting. For example, compared to using the minimum 70 mm diamond mesh size, using an 80 nun diamond mesh upper codend would reduce Norway lobster catch weight by just 1.6% but reduce the number of blue whiting caught by 42%.
- Identifying métiers using landings profiles: an octopus-driven multi-gear coastal fleetPublication . Szynaka, Monika; Erzini, Karim; Gonçalves, Jorge Manuel Santos; Campos, AidaThe multi-gear coastal vessels in the Algarve (South Portugal) own licenses for various fishing gears. However, it is generally uncertain what gears they use, which is problematic as each individual gear is responsible for unique impacts on the resources and the environment. In this study, landing profiles identified for the multi-gear coastal fleet (2012–2016) were used as support in defining potential métiers using k-mean clustering analysis (CLARA) along with information from past studies on métiers. The results showed that more than 50% of the vessels were engaged in the octopus fishery year-round, using traps, while a small percentage (~13%) were entirely dedicated to clam dredging. In general, gillnets (21%) were used to target monkfish, hake and bastard soles, while trammel nets (6%) were used to target cuttlefish, with some vessels alternating the fishing gears (either seasonally or annually) according to target species. The method for the initial characterization of this fleet’s métiers and its efficiency with limited data is discussed, as well as the utility of this segmentation in support of management advice.
- Is Europe ready for a results-based approach to fisheries management? The voice of stakeholdersPublication . Santiago, Jose Luis; Ballesteros, Marta A.; Chapela, Rosa; Silva, Cristina; Nielsen, Kare N.; Rangel, Mafalda; Erzini, Karim; Wise, Laura; Campos, Aida; Borges, Maria F.; Sala, Antonello; Virgili, Massimo; Vidarsson, Jonas R.; Baudron, Alan; Fernandes, Paul G.The reformed Common Fisheries Policy (CFP), adopted by the European Union in 2013, aims to achieve sustainable exploitation of marine resources. Beyond the mainstream of stakeholders' engagement, the literature increasingly calls for shared accountability in fisheries management. In such scenarios, identifying stakeholders' insights becomes critical for a successful design of innovative management approaches. This paper analyses how the stakeholders perceive a results-based management system for four fisheries in different European sea-basins as well as at a pan-European level. The results indicate a need for adaptive and participatory management approaches, building on regional adaptations within transparent and plural frameworks for fisheries. To succeed, the system should explicitly address its associated public and private costs; neither participation nor accountability comes for free. (C) 2015 Elsevier Ltd. All rights reserved.
- Modelling the impact of deep-water crustacean trawl fishery in the marine ecosystem off Portuguese Southwestern and South Coasts: I) the trophic web and trophic flowsPublication . Angeles Torres, Maria; Fonseca, Paulo; Erzini, Karim; Borges, Teresa C.; Campos, Aida; Castro, Margarida; Santos, Jorge Manuel Bastos; Costa, Maria Esmeralda; Marçalo, Ana; Oliveira, Nuno; Vingada, JoseThe concentration of the population in coastal regions, in addition to the direct human use, is leading to an accelerated process of change and deterioration of the marine ecosystems. Human activities such as fishing together with environmental drivers (e.g. climate change) are triggering major threats to marine biodiversity, and impact directly the services they provide. In the South and Southwest coasts of Portugal, the deep-water crustacean trawl fishery is not exemption. This fishery is recognized to have large effects on a number of species while generating high rates of unwanted catches. However, taking into account an ecosystem-based perspective, the fishing impacts along the food web accounting for biological interactions between and among species caught remains poorly understood. These impacts are particularly troubling and are a cause of concern given the cascading effects that might arise. Facing the main policies and legislative instruments for the restoration and conservation of the marine environment, times are calling for implementing ecosystem-based approaches to fisheries management. To this end, we use a food web modelling (Ecopath with Ecosim) approach to assess the fishing impacts of this particular fishery on the marine ecosystem of southern and southwestern Portugal. In particular, we describe the food web structure and functioning, identify the main keystone species and/or groups, quantify the major trophic and energy flows, and ultimately assess the impact of fishing on the target species but also on the ecosystem by means of ecological and ecosystem-based indicators. Finally, we examine limitations and weaknesses of the model for potential improvements and future research directions.
- One device does not fit all: limited results of using a Sort-X grid in the multi-species trawl fishery in the Gulf of CádizPublication . Gamaza, MariÁngeles; Fonseca, Paulo; Campos, Aida; Erzini, Karim; Sobrino, IgnacioA Sort-X grid device with four different bar-spacing grids (25, 30, 40 and 50 mm) was tested in the Gulf of Cádiz (GoC) on-board commercial trawlers. A total of 83 fish, five crustacean and nine cephalopods species were sampled in 282 hauls. Most of the target and commercial bycatch species were sorted out by the grid with the exception of hake. Merluccius merluccius (L.). Additionally, common pandora, Pagellus erythrinus (L.), sardine, Sardina pilchardus (Walbaum), octopus, Octopus vulgaris Lamark, and cuttlefish, Sepia officinalis L., also showed a sizeable retention for some of the grid bar spacing. Statistical modelling of selectivity at length for hake found influence of depth on the selection parameters. Lengths at 50% retention for hake were estimated to be 27.4, 30.3, 36.3 and 42.3 cm TL for 25–50 mm bar spacing, respectively, all above the minimum conservation reference size (MCRS) in the GoC. The probability of hake contacting the grid was estimated as 0.95. Overall, although the selective device showed a good performance for hake, it is not appropriate for improving the fishing pattern of a multi-species trawl fishery such as that of the GoC.
- Portuguese fisheries in seamounts of Madeira-Tore (NE Atlantic)Publication . Campos, Aida; Lopes, Paulo; Fonseca, Paulo; Figueiredo, I.; Henriques, Victor; Gouveia, N.; Delgado, J.; Gouveia, L.; Amorim, A.; Araujo, G.; Drago, T.; dos Santos, A.The activity of the Portuguese fishing fleet operating near seamounts of the Madeira Tore geologic complex was analyzed. The main objective is to identify the different fisheries taking place in the area, characterize the spatial patterns of vessels activity and estimate the fishing intensity, thus contributing to better inform management decisions. Vessel Monitoring System (VMS) and e-logbook data for the period 2012–2014 were used. The combined analysis of these data allowed the identification of fishing events and the estimation of the fishing intensity by gear type, as well as the characterization of general patterns relating to fishing operations. A total of 47 vessels displayed fishing activity in the studied area, mainly longliners based either on the mainland or the Madeira archipelago, visiting different seamounts in fishing trips lasting two to three weeks, and a few pole and line bait boats. Bottom and pelagic longlining alternate throughout the year, the former mostly in spring and summer, targeting the wreckfish Polyprion americanus and the European conger, Conger conger, while the latter is carried out in autumn and winter using a surface longline targeting the swordfish Xiphias gladius and a drifting longline set deeper in the water column, targeting the black scabbard fish Aphanopus carbo. A global evaluation of the fishing intensity and estimation of fishing impact in this area calls for the availability of VMS data, elogbooks and landing declarations from non-Portuguese fleets, making monitoring in these areas a top priority to assess the sustainability of human activities.
- Predicting gear used in a multi-gear coastal fleetPublication . Leitão, Pedro; Campos, Aida; Castro, MargaridaKnowledge of the gear used in multi-gear fisheries is crucial for supporting fisheries management. Still, the high complexity and lack of data in the Portuguese multi-gear coastal fleet compromise this task. The present study developed a method to predict main fishing gear used in each fishing trip for the Portuguese multi-gear coastal fleet based on landing records (species caught, port, and month of landing). Landing records were used to predict gear (available for part of the fleet with electronic logbooks) using a machine learning model (random forest). This model was then applied to the remaining trips of the fleet, without electronic logbooks, to predict the gear used. A total of six gear types were considered: bivalve dredges, traps, gillnets, trammel nets, drifting longlines, and bottom longlines. The overall model prediction error was 14 %; bivalve dredges and longlines had the lowest errors, and trammel nets and gillnets were the highest. The study sheds new light on important aspects of the dynamics of this fleet, namely a decreasing trend in the use of longlines, poor electronic logbook coverage for some gear types, and greater diversity in the catches obtained with nets compared to other gear types.
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