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Dissertação de Mestrado apresentada no Ispa – Instituto Universitário para obtenção de grau de Mestre na especialidade de Biologia Marinha e Conservação. A pesca comercial do Cavaco (Scyllarides latus) e da Lagosta (Palinurus elephas) tem vindo sempre a crescer devido ao seu alto valor comercial, no entanto, não há muito conhecimento sobre o estado destas duas espécies. Conhecer o estado das diferentes espécies através de estudos de avaliação dos “stocks” pesqueiros é essencial para a implementação de medidas de proteção mais eficazes, de forma a garantir uma exploração sustentável. Desde 1985 que se sabe que a maioria das capturas destas espécies são vendidas clandestinamente. O Cavaco está atualmente classificado como “Data Deficient” na Lista Vermelha da IUCN, comprovando que os estudos sobre esta espécie são escassos, e a Lagosta está classificada como “Vulnerável”. A determinação de um tamanho mínimo legal de captura para estas espécies provou não ser efetiva em 1998, contudo, nada foi alterado em termos de regulamentação desde essa data. Os últimos estudos realizados nos Açores para S. latus foram há quase 40 anos, e já passou uma década desde o último estudo sobre P. elephas. Com este estudo pretende-se contribuir com nova informação para esclarecer o estado das populações de S. latus e P. elephas nos Açores, comparando-o com os dados históricos. Para tanto, foram analisados: os padrões de migração vertical para S. latus; os tamanhos dos espécimes comparando profundidades e sexos; e os tamanhos médios das populações ao longo dos anos, comprovando que o tamanho médio de P. elephas diminuiu quase 1cm em 20 anos. Este conhecimento é essencial para alertar a população e o governo para criar melhores medidas de regulação, a fim de cessar a depleção destas espécies. ABSTRACT: The commercial fishing of the Slipper lobster (Scyllarides latus) and the Spiny lobster (Palinurus elephas) has always been increasing, due to these species’ high commercial value, however, there is not much knowledge about their status. Getting to know the status of different species through studies on the assessment of fish stocks is essential for the implementation of better protection measures, to ensure a sustainable exploitation. Since 1985 that it is known that most catches of these species are sold clandestinely. The S. latus is currently classified as “Data deficient” on the IUCN Red List, proving that the studies on this species are scarce, and the P. elephas is classified as “Vulnereble”. The determination of a minimum legal capture size for these species has proven not to be effective in 1998, however, nothing has been changed in terms of regulations since then. The last studies conducted in the Azores for S. latus were almost 40 years ago, and a decade has passed since the last study on P. elephas. This study pretends to contribute with new information to enlighten the recent S. latus and P. elephas populations’ status in the Azores, comparing them to the historical data. For that, it was analyzed: the vertical migration patterns for S. latus; the specimens sizes comparing depths and sexes; and that the populations’ mean sizes through the years, proving that the P. elephas mean size has almost decreased 1cm in 20 years. This knowledge is essential to alert the population and the government to create better regulation measures, in order to cease these species depletion.

This paper describes the Ancient Greek and Latin terminology for marine lobsters, especially for ‘European lobster, Homarus gammarus L.’, ‘common spiny Lobster, Palinurus elephas Fabricius’ and ‘No...

International audience; The detection ranges of broadband sounds produced by marine invertebrates are not known. to address this deficiency, a linear array of hydrophones was built in a shallow water area to experimentally investigate the propagation features of the sounds from various sizes of european spiny lobsters (Palinurus elephas), recorded between 0.5 and 100 m from the animals. The peak-to-peak source levels (SL, measured at one meter from the animals) varied significantly with body size, the largest spiny lobsters producing SL up to 167 dB re 1 µpa 2. the sound propagation and its attenuation with the distance were quantified using the array. This permitted estimation of the detection ranges of spiny lobster sounds. Under the high ambient noise conditions recorded in this study, the sounds propagated between 5 and 410 m for the smallest and largest spiny lobsters, respectively. Considering lower ambient noise levels and different realistic propagation conditions, spiny lobster sounds can be detectable up to several kilometres away from the animals, with sounds from the largest individuals propagating over 3 km. Our results demonstrate that sounds produced by P. elephas can be utilized in passive acoustic programs to monitor and survey this vulnerable species at kilometre scale in coastal waters. Passive acoustic monitoring (PAM) of marine species has recently gained attention by biologists and is now used worldwide. This is due to the increased knowledge of animal sound repertoires, and the behavioral contexts in which they are produced 1-3. In addition, the density of seawater enables sounds to propagate over greater distances compared to air 4. Estimating the detection ranges between a particular sound-producing species and a receiver can give crucial information about its spatial distribution in an ecosystem. These calculations rely on the measurements of the source level (SL, i.e. the sound pressure level recorded at 1 m from the source) and the transmission loss (TL, i.e. the attenuation of the sound as it propagates away from the source) of animal sounds underwater. For example, marine mammal sounds can be detected kilometres away in shallow and deep oceans with hydrophones 5-7. Fish also produce sounds in shallow waters that can be detectable from few meters 8,9 to hundreds of meters away 10,11. However, data available on sound propagation and detection ranges for crustaceans are scarce, though crustaceans are known to emit a large diversity of sounds 12-14. Marine arthropods produce sounds that are mostly characterized by broadband pulses, i.e. short transient sounds with a large bandwidth 15-17. Estimating their sound propagation may be challenging as they inhabit shallow coastal waters (at depths below tens of meters). This implies complex sound fields due to physical constraints such as the presence of boundaries created by the water surface and the seabed 18,19 , and it is thus difficult to accurately model sound propagation 20. Until now, detection ranges of crustacean sounds have relied on crude estimations of SLs performed using distant measurements that are then artificially back-propagated to 1 m by using theoretical propagation models 21,22. In addition, some studies have been performed in tanks. Tank experiments are very convenient since distances between receivers and animals can be precisely measured 23. However, tank acoustics are complicated. The relatively small volumes and close boundaries of tanks highly affect sound propagation as well as SL estimates 13,14 ; these tank effects have been largely ignored by most previous studies (as a counter example, see 15 for an experimental illustration on the differences of crustacean sounds recorded in tanks and in situ). Thus, there is a need to combine theory with empirical measurements of site-specific sound propagation

Research known as Citizen Science (CS) has been recognized as an important tool for both biodiversity restoration and fisheries management projects through active involvement of citizens and therefore for public environmental awareness too. CS projects should be well designed and state clear questions, that will benefit both the research goals and the citizen scientists themselves. In January 2019, the “Red Fish Project” group was created on Facebook consisting of SCUBA divers and fishers and offering the main data source and the relevant digital material. The project’s establishment was based on previous personal experience and following specific protocols. Further information was provided by personal communications. Till October 21st, 2020 the FB group consisted of 464 members who recorded 348 European spiny lobster individuals from all sub-regions of the Aegean Sea. Based on the findings of the present study it seems that most of the citizens were unaware that the species is listed as “Vulnerable” in the IUCN Red List. Lastly, we discuss the important role of the spiny lobster in the country’s culture and that it can be listed as a charismatic, flagship species for citizens to be ocean-literate since it has been shown, that it can raise the interest of recreational divers and increase their awareness.

Fully Protected Areas (FPAs) represent a powerful tool for marine resources management. Among the parameters to consider for their optimal design, the movements of the species to protect are of particular importance. We examined the movement patterns of744 spiny lobsters, Palinurus elephas, tagged during a restocking program carried out in 12 Sardinian FPAs. Once the lobsters were captured, tagged, transported and released in the center of the FPA, the linear distances performed by 80% of the lobsters from the recapture (RC) to the release point (RE), (recapture distance, RC-RE) increased as a function of the point in which they were captured for the first time (release distance, C-RE), until a maximum value of about 13500 m. By a management perspective, these results highlight a behaviour, perhaps attributable to homing, representing an important starting point to take into consideration when planning FPAs. In fact, since release and recapture distances appeared related, in order to preserve a portion of the lobsters within the FPA and to guarantee a spillover of specimens in the surrounding commercial areas, the longer is the release, the bigger would be the FPA.

Crustaceans suffer from diseases that can alter their survival and ecology with additional economic consequences for fisheries and aquaculture. Many parasites have been described from crustaceans and with the advent of novel technologies such as next generation sequencing, the discovery of novel parasites has become increasingly efficient. Molecular techniques are beginning to surpass more conventional tools for parasite discovery, but they typically do not provide information on pathology. Histopathology remains one of the least expensive methods for parasite discovery and allows for both detection of parasites and descriptions of the pathology they cause. When used in concert with modern molecular and electron microscopy techniques, the approach is powerful; however, there are few informational tools for the interpretation of histological slides from crustaceans. Those available do not provide comprehensive images of all organs and early works were limited to lower resolution than currently available. More recent texts provide in-depth details of infection in histological section, but few provide images of healthy material or describe a baseline from which to compare. Here, we provide a series of image plates derived from histologically processed tissues from three palinurid lobsters: Panulirus argus, Palinurus elephas and Panulirus guttatus. Histology from these lobsters shows high visual similarity in all tissue types. We provide a histological atlas of healthy tissue that can be used as a baseline resource for pathobiologists working on these common species (and related crustaceans) and we discuss how disease may result in visual aberrations to these tissues.

A specific study has been carried out for the first time to investigate the homing capability and daily home range of the spiny lobster Palinurus elephas by means of ultrasonic telemetry. Nine lobsters collected in the Capo Gallo — Isola delle Femmine marine protected area (northwestern Sicily, central Mediterranean) were tagged with miniaturized transmitters and released at a single site inside the protected area. The lobsters were monitored with the purpose of calculating their horizontal and vertical positions, analysing their movement patterns to assess their homing capability, and calculating their daily home range. Five lobsters moved back close to the capture sites within the first 20 hours after release (‘homed’). The remaining four lobsters ‘relocated’ to a different refuge. Homed lobsters had a larger home range than relocated lobsters. This study provides the first description of a homing pattern with high spatial resolution in the wild European spiny lobster as inferred by ultrasonic telemetry.

Censos visuales con escafandra autónoma, en arrecifes artificiales y en roca natural, en los que se cuentan y miden los ejemplares de langosta asentados. Se han fondeado 36 colectores artificiales a 25 m de profundidad, en tres zonas: Favàritx, La Mola e Illa de l’Aire. Los colectores constan de una base de hormigón, de un peso de 50 kg, sobre la que se fijan 3 pisos de 4 ladrillos cada uno. Los censos en roca natural se llevan a cabo en dos zonas: Cap de Cavalleria e Illa de l’Aire.

Vitellogenin is an essential protein involved in ovary maturation in many animals. Detection of this protein correlated with reproductive capacity may be important if carried out on marine organisms such as the red spiny lobster Palinurus elephas, a crustacean economically important crop from wild fish catches. Moreover, in recent years, vitellogenin has assumed an important role as a possible biomarker of marine environmental pollution, as its expression levels can be influenced by the presence of similar oestrogen pollutants and affect the reproductive sphere of marine organisms such as crustaceans. The P. elephas vitellogenin protein and its coding gene have never been isolated, so there is little information about its presence in this lobster. The aim of the present study was to develop a molecular strategy to create, for the first time, an antibody for the detection and quantization of vitellogenin in P. elephas.

Determining the drivers of key ecological processes of commercial marine species is important to acquire basic and essential knowledge for fisheries management and conservation. Here we report on a long-term monitoring of the settlement of the European spiny lobster, Palinurus elephas, the most commercially important spiny lobster species in the Mediterranean and north-eastern Atlantic. Densities of recently settled individuals (early benthic juveniles –EBJs) were recorded annually, as an approximation to annual settlement, from 2000 to 2016 (17 years) in three zones of the north-western Mediterranean: Catalonia (CAT), the Columbretes Islands (COL), and the Balearic Islands (BAL). Settlement, the end point that integrate most of the variability occurred during dispersion, is a complex ecological process governed by the interaction of biotic and abiotic factors that can be in turn influenced by the atmospheric and oceanographic conditions. Using linear regression of the size structure of EBJs, we demonstrate that settlement occurs synchronously in the three study zones. Densities of EBJs were handled as time series, and regression analysis revealed that CAT and COL covaried significantly, but none of them with BAL. Therefore, CAT and COL were analysed together using generalized linear model and much of their joint variability was explained by the mesoscale oceanographic index IDEA. Settlement in BAL showed a different pattern, explained by the joint effect of the atmospheric oscillations NAO and WEMO. Complexity of P. elephas settlement cannot be fully accounted neither for CAT-COL nor for BAL because settlement seems be driven by more complex unknown multi-factorial processes. Therefore, further studies are necessary to gain insight into other factors that allow short-or medium-term predictions of settlement. Expanding the study area across the Mediterranean would also allow establishing a complete knowledge of the ecology of the species applicable to the management of the fishery., RECMARE, Recuperación de una poblacion explotada en una nueva area protegida adyacente a una reserva marina efectiva, SI

Stock overexploitation, bycatch, discards and gear impacts on the environment are outstanding issues for Mediterranean fisheries. The adoption of alternative fishing gears is an appealing solution to ensure a more sustainable exploitation of resources. We discuss the pros and cons of pots as alternative gears by reviewing their main designs, spatial distribution and target species in the Mediterranean basin. We assessed the technical factors affecting the catch efficiency of the different pot designs for four target species: spiny lobster, Palinurus elephas; Norway lobster, Nephrops norvegicus; common octopus, Octopus vulgaris and pandalid shrimps, Plesionika spp. We found that pot volume is important to catch Octopus; mesh size to catch Nephrops and Plesionika; entrance surface to catch Octopus, Nephrops and Plesionika; pot shape/colour and entrance shape/position to catch Octopus and Plesionika; and bait type to catch Octopus and Nephrops. The literature review shows that pot fisheries have several considerable advantages over conventional gears, especially in terms of discards, bycatch, seabed impacts (particularly compared with bottom trawls and passive set nets), size and species selectivity, gear depredation, catch quality and gear cost, besides saving time and labour. Disadvantages hampering their wider diffusion include ghost fishing, a low catch of finfish species, the narrow range of species targeted by each pot design and the current early stage of research. These data make a clear case for using pots as alternative gears to traditional ones in the Mediterranean Sea in some areas and seasons to catch certain target species.

The European spiny lobster Palinurus elephas is a vulnerable species that inhabits and is harvested in the Mediterranean Sea and the adjacent Atlantic waters. The fisheries associated with the spiny lobster are mainly conducted with tangle nets, trammel nets, pots, and creels. The fishing pressure has greatly reduced their numbers, changing them from a common shallow coastal species to a largely remnant population. The relative research on the species&rsquo, biology and fisheries from the eastern Mediterranean Sea is almost absent. The fishery along the Chalkidiki Peninsula, Greece, is multispecies, and fishing is conducted by a small number of artisanal fishermen mainly using trammel nets. The lobster stock&mdash, both spiny and clawed lobsters&mdash, declined significantly during the late 1980s and early 1990s, later than most cases in the Mediterranean Sea. However, data regarding the nature and status of the fishery associated with the spiny lobster in Greece are lacking. Data regarding the characteristics of the spiny regional fishery were obtained by interviews and questionnaires. Additionally, fishery surveys were conducted during the main lobster fishing season from 1 May 2017 to 31 August 2017. Sixteen species were identified (15 finfish species and one invertebrate species) as targeted. In total, 79 spiny lobsters were sampled in this study, the population&rsquo, s sex ratio significantly diverts from the theoretical 1:1 (&chi, 2 = 4.57, p &lt, 0.05), and males were dominant. Both male and female individuals demonstrate negative allometric growth profiles. In addition, no significant differences were observed between sexes. In Greece, thus far, the knowledge and information are sporadic, limited, and/or species-specific, most of which regard finfish fisheries. Furthermore, the national legislation is rather complicated&mdash, or too generalized&mdash, thus creating great uncertainties. The in-depth knowledge and experience of fishermen should be further acknowledged and utilized, and wider collaborations among scientists, practitioners, and policy-makers should be established. The present study poses some thoughts on the effectiveness of the recent EU Landing Obligation and its contribution to the potential restoration of the species.

International audience; The common spiny lobster (Palinurus elephas, Fabricius, 1787) is an iconic species of the Mediterranean Sea. Despite the existence of dataon the artisanal fishery of P. elephas in the Mediterranean Sea and particularly in Corsica, knowledge on the biology and life history traits of thisiconic species is still lacking. This paper identifies the main gaps in current knowledge and suggests future directions of research to answer thesefundamental questions, which are currently unanswered.

The European spiny lobster is a species of great commercial value, yet a limited scientific knowledge exists on its biology, ecology, and physiology, especially for the stocks from east Mediterranean waters. The northern brown shrimp, a non-indigenous established species, is commercially exploited in regions of the Mediterranean Sea. Both species’ proximate composition and fatty acid profile were assessed for the first time in the Mediterranean region, exhibiting an overall significant statistical difference. Protein, fat, and energy contents were significantly higher in the northern brown shrimp, whereas moisture and ash contents were significantly higher in the European spiny lobster. The proximate composition for both species was well within the reported range for other lobster and prawn species in the Mediterranean Sea.

Elasmobranchs are among the species most threatened by overfishing and a large body of evidence reports their decline around the world. As they are large predators occupying the highest levels of marine food webs, their removal can alter the trophic web dynamic through predatory release effects and trophic cascade. Suitable management of threatened shark species requires a good understanding of their behaviour and feeding ecology. In this study we provide one of the first assessments of the trophic ecology of the “vulnerable” smooth-hounds Mustelus mustelus and M. punctulatus in the Central Mediterranean Sea, based on stomach contents and stable isotope analyses. Ontogenetic diet changes were addressed by comparing the feeding habits of three groups of individuals: juveniles, maturing and adults. Our results highlighted that the two species share a similar diet based mostly on the consumption of benthic crustaceans (e.g. hermit crabs). Their trophic level increases during ontogeny, with adults increasing their consumption of large-sized crustaceans (e.g. Calappa granulata, Palinurus elephas), cephalopods (e.g. Octopus vulgaris) and fish (e.g. Trachurus trachurus). Our results provide also evidence of ontogenetic shifts in diet for both species showing a progressive reduction of interspecific trophic overlap during growth. The results of this study contribute to improve the current knowledge on the trophic ecology of these two threatened sharks in the Strait of Sicily, thus providing a better understanding of their role in the food web.

The high variability of trammel fisheries, due to a marked seasonality in target species and fishing activities needs to be investigated with high spatial and temporal resolution. The present study focuses on trammel net fishery in southwestern Sicily (central Mediterranean Sea) identifying and characterizing the main metiers in relation to some key aspects of the fishery such as the target species, composition of landings, main fishing grounds and time of the year. For this purpose, a multivariate statistical approach based on landings and effort data of the Mazara del Vallo southwestern Sicily, Italy) trammel fleet in the period 2009–2013 was applied. A total of 153 different landed species and four different trammel net metiers were identified. These metiers showed differences in target species (i.e. Sepia officinalis, Palinurus elephas, Mullus surmuletus and a mix of species), fishing season, fishing grounds and dimension of fishing vessels. The metiers identified were significantly different in terms of total average landing per unit of effort (LPUE) with metier 1 targeting M. surmuletus, showing the highest average LPUE (2047 (192 s.e.) g*(h)−1*103 m net) and metier 2 targeting S. officinalis, exhibiting the lowest value (1175 (119 s.e.) g*(h)−1*103 m net). The study provides new knowledge on the dynamics of trammel fisheries in southwestern Sicily also showing that the complex nature of this peculiar fishery should be taken into account in any future sampling program aimed at the monitoring and management of artisanal fisheries in this area and more in general in the Mediterranean Sea.

International audience; Spiny lobsters (Palinurus elephas) have been overfished in European waters, and adult breeders are now scarce. Our recent study highlighted the high acoustic potential of this species, which can emit loud broadband pulse trains, called “antennal rasps,” with peak-to-peak source levels (estimated at 1 m from the source) above 160 dB re 1 μPa² [Jézéquel et al., Marine Ecology Progress Series 615 (2019)]. These acoustic properties imply that these sounds could be detected during in situ passive acoustic monitoring. However, before using a such tool, we need to understand how antennal rasps propagate in situ and at what distance they could be detected above the ambient noise. To answer these questions, we recorded spiny lobster antennal rasps in the Iroise Sea (Brittany, France). We used a linear array of 8 hydrophones, with distances between animals and receivers ranging from 0.5 m to 100 m. We recorded antennal rasps from 38 individuals of various sizes. Our results demonstrate that large spiny lobsters can be detected at 100 m, and that sound properties might be directly influenced by the size of the individuals.

The European spiny lobster Palinurus elephas emits sound (“rasp”), moving the base of their antennas, as response to the presence of predator and for interspecific communication. During the last decade, three-axial accelerometers have been used to mainly describe diel activity patterns, circadian rhythms and rate of energy consumption of different lobster species, but these devices can also record sound emission in terms of mechanical vibration of carapace. In order to evaluate the efficiency of accelerometers in recording sound production (rasp events and number of pulses inside each rasp) and in discriminating of that from other behavioural events, accelerometers were used in combination with hydrophone and during mesocosm free ranging conditions. Three-axial accelerometers were able to detect sound production events in P. elephas. All the rasp events (n = 405) recorded with hydrophones were also detected by the accelerometers considering its data sampled at different frequency (from 800 Hz to 12 Hz). However, the detection of the number of pulses within each rasp sound decreased with sampling frequency of accelerometer data (median of predictive error for 800 Hz = 0.33; median of predictive error for 12 Hz = 0.65). During mesocosm free condition, three behavioural categories were identified: walk, tail flip, and rasp, the last with averaged (15.16 ± 3.52 m/s2 ) and maximum (29.49 ± 9.37 m/s2 ) values of acceleration significantly higher than the other two. Findings from this study prove that accelerometers register only lobster body vibrations providing a clear signal that is not distorted by other noises in the environment. They also allowed to identify rasps for each tagged lobster, something not possible using hydrophones in both, aquaria or natural habitat. Accelerometer resulted an useful tool to detect behaviours even with low mobility species. Moreover, the possibility to couple accelerometer and other biologging techniques would help to improve our understanding of the behaviour of a large range of free-living species. Fil: Zenone, Arturo. Istituto per l'ambiente Marino Costiero; Italia. Consiglio Nazionale delle Ricerche; Italia Fil: Ceraulo, Maria. Istituto per l'ambiente Marino Costiero; Italia. Consiglio Nazionale delle Ricerche; Italia Fil: Ciancio Blanc, Javier Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Buscaino, Giuseppa. Istituto per l'ambiente Marino Costiero; Italia. Consiglio Nazionale delle Ricerche; Italia Fil: D'Anna, Giovanni. Consiglio Nazionale delle Ricerche; Italia. Istituto per l'ambiente Marino Costiero; Italia Fil: Grammauta, Rosario. Consiglio Nazionale delle Ricerche; Italia. Istituto per l'ambiente Marino Costiero; Italia Fil: Mazzola, Salvatore. Consiglio Nazionale delle Ricerche; Italia. Istituto per l'ambiente Marino Costiero; Italia Fil: Giacalone, Vincenzo Maximiliano. Consiglio Nazionale delle Ricerche; Italia. Istituto per l'ambiente Marino Costiero; Italia

International audience; Spiny lobsters (Palinuridae) are capable of emitting sounds called antennal rasps. In the bioacoustics literature, such broadband sounds have mostly been characterized from tank recordings where reverberation and resonant frequencies might strongly distort their features. Hence, in this study, we compared antennal rasps produced by European spiny lobsters Palinurus elephas in both tank and in situ conditions. We found significant differences in all sound features (temporal, intensity and spectral features) between tank and in situ recordings, confirming that antennal rasps-and broadband sounds generally -cannot be accurately characterized in tanks if sound reverberation is ignored. In recordings of antennal rasps made in situ, we show that the main acoustic power is located in the low frequency band (below 1 kHz), which was missed by all earlier studies done in tanks where such low frequencies cannot be properly measured. The hearing capacities of crustaceans suggest roles for intra-specific communication of these sounds, and their high levels indicate they could be heard above noise. Indeed, we outline that antennal rasps are among the loudest sounds known in the marine animal kingdom, with peak-to-peak sound pressure levels (calculated at 20 cm from the source) above 175.7 dB re 1 mu Pa-2, and peak-to-peak source levels (estimated at 1 m from the source) ranging from 154.2 to 160.6 dB re 1 mu Pa-2. These acoustic properties imply they could be detected in situ during passive acoustic monitoring. This study also highlights the importance of using appropriate measurement methods when characterizing sounds produced by marine invertebrates.

A dedicated observer programme was carried out in gillnet and entangling net fisheries off the west and southwest coasts of Ireland to monitor interactions with seals. No seals were observed as bycatch in gillnet fisheries suggesting the risk of bycatch in observed gillnet fisheries is low. Grey seals (Halichoerus grypus) and to a lesser extent harbour seals (Phoca vitulina) were observed as bycatch principally in large mesh tangle nets targeting crawfish (Palinurus elephas). Observed bycatch levels, proximity of grey seal colonies to crawfish fisheries and similar habitat preferences suggest that the risk of seal bycatch in tangle net fisheries for crawfish on the west and southwest coasts of Ireland is high. Factors affecting bycatch in tangle nets were modeled to investigate potential bycatch mitigation measures. Crawfish and monkfish (Lophius spp.) catches, depth of gear deployment and larger mesh size were significantly positively correlated with seal bycatch. Development of mitigation measures such as improved net visibility, use of smaller mesh size and reintroduction of pots has major potential to reduce seal bycatch in the observed tangle net fishery. Growing seal populations in regions where tangle netting for crawfish is most prevalent could be related to factors such as benefits accrued from depredation and possible immigration from adjacent populations in the UK. More explicit conservation objectives will likely be needed to provide an impetus for development of proposed mitigation measures and bycatch reductions in Ireland. Results of this study also have broader ramifications for management of pinniped bycatch in large mesh gillnet and entangling net fisheries, which are widespread but poorly studied in European Community waters.

The knowledge of the activity pattern of marine organisms represents a crucial aspect in the studies on their ecology. In this paper, we used for the first time data from tri-axial accelerometers to provide an accurate description of the activity pattern of the European spiny lobster, Palinurus elephas. Sixteen lobsters (8 males, 8 females) were tagged with tri-axial accelerometers in order to monitor their activity in a mesocosm during four replicate trials. In each trial the lobsters were submitted to three treatments of the duration of one day each: exploration, presence of food and presence of a predator. The variance of roll body angle (VariRoll) was chosen among a number of available variables as a proxy of lobster activity during each treatment. The lobsters were more active during the night and in low-light hours than during the day. Moreover, they were i) more active without food or predator, ii) less active in the presence of a predator, iii) with an intermediate activity level (i.e. values of VariRoll) in the presence of food. Besides contributing to the knowledge of P. elephas ecology, the results of this study provide a new analytical method to describe activity patterns in slow-moving animals.

Knowledge of larval dispersal, population dynamics and connectivity in relation to the management and conservation of commercially important species is vital if existing fisheries are to remain sustainable into the future. Larval dispersal of the commercially exploited spiny lobster, Palinurus elephas, was modeled from Marine Protected Areas located in the southwest of England for a 16-month period using a General Individuals Transport Model (GITM). The model included physical particle advection based on current fields from a 3D hydrodynamics model and a larval behavior module. Our results demonstrate the overall dispersal patterns of P. elephas larvae and highlight populations capable of self-seeding and those which are seemingly reliant on larvae from more distant populations. The results indicate where further research may be required to fully understand how populations of P. elephas are maintained at regional, national and international scales while providing us with the opportunity to discuss the effectiveness of current approaches to conservation and fisheries management.

Fully protected areas (FPAs) help preserving biodiversity and reversing the global decline of fishery resources. Stocks of the European spiny lobster Palinurus elephas (Fabr. 1787), among the most precious gourmet seafood worldwide, are currently facing a dramatic decline. Previous attempts of recovery based on fishery restrictions or active post-larval restocking in marine reserves provided unsuccessful outcomes. Here we present results of a 5-year restocking program carried through a Collaborative Fishery Research (CFR) project, in three ad-hoc established FPAs replenished using below-legal size wild juveniles. Results showed that Catch per Unit Effort (CPUE) in terms of both density and biomass burst (by ca. 300–700%) just 2 years since FPAs establishment, regardless of location. We also report tangible spillover effects (ca. 30–50% increase in density and biomass CPUE outside the FPAs) by the end of the program. Data from a 15-years lasting monitoring of a pilot FPA established in 1998, where the restocking protocol was conducted and protection kept in force once restocking ceased, demonstrated the persistence in time of restocking’ benefits. We foster that creation of FPAs assisted with local restocking under oriented CFR programs can represent an option for the recovery of European spiny lobster stocks from overfishing.