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- Portuguese commercial fisheries of swordfish, Xiphias gladiusPublication . Roxo, André; Mendes, Susana; Correia, JoãoSwordfish (Xiphias gladius) plays an important role in Portuguese fisheries. Portuguese commercial swordfish landings were analyzed from 1986 to 2012. Commercial landings of five incidental catches of pelagic sharks—bigeye thresher shark (Alopias superciliosus), thresher shark (Alopias vulpinus), shortfin mako shark (Isurus oxyrinchus), blue shark (Prionace glauca), and smooth hammerhead shark (Sphyrna zygaena)—were also evaluated for the same period. A total of 653 landings of swordfish (12,625 t) were observed in 62 ports. Annual landings for the fishery generally decreased over time, with a corresponding increase in price per kilogram. The most fished shark was blue shark, with 12,715 t in 48 ports. It was followed by shortfin mako, thresher, smooth hammerhead, and bigeye thresher (with 5113 t, 672 t, 19 t, and 0.45 t, respectively). Lowest landings of swordfish were observed in the first semester of each year, while catch levels of blue sharks were high during the same period. Shortfin mako catches did not raise until 2005. The remaining species studied always displayed lower landings, suggesting that most of them are bycaught.
- Optimising sealed transports of small ornamental fishPublication . Silva, Rui E.; Morais, Hugo A.; Rodrigues, Nuno V.; Reis, Tiago; Correia, João P.This paper reports on simulated long-term transports of small ornamental fish inside sealed containers. The species involved were Diplodus sargus, Gobius paganellus, Gobiusculus flavescens, Lepadogaster lepadogaster, and Lipophrys pholis. The objective of such simulations was to determine the maximum bioload that it is possible to move inside a sealed container, while ensuring 100% survivorship, ultimately resulting in financial savings for the end-receiver. Transports were simulated over 24, 48 and 72 hours, with increasing animal bioloads per bag. Fifty percent of the trials were performed with “regular” saltwater while the other half involved seawater buffered with Amquel®, sodium carbonate and sodium bicarbonate, with the objective of keeping ammonia low and pH similar to initial baseline values. At the end of each trial, temperature, dissolved oxygen, pH and ammonia were analysed and survival rates determined. L. lepadogaster endured the highest bioloads and displayed 100% survivorship (i.e. up to 30 g/L), which is not surprising given the intertidal nature of this species. D. sargus exhibited mortalities with bioloads as low as 3.23 g/L, which echoes its predominantly pelagic nature and relatively lesser ability to endure confinement. The three remaining species showed varying degrees of tolerance to increasing bioloads in transport: L. pholis, also an intertidal species, tolerated up to 20 g/L over 72 hours, while G. paganellus tolerated up to 7 g/L over 72 hours, and G. flavescens (a predominantly pelagic species) could tolerate no more than 6 g/L up to 72 hours.
- First record of a whale shark Rhincodon typus in continental EuropePublication . Rodrigues, N.V.; Correia, J. P. S.; Graças, J.T.C.; Rodrigues, F.; Pinho, R.; Hirofumi, M.A whale shark Rhincodon typus was found in a set-net in southern Portugal in October 2011. This was the first record for continental Europe and represents an increase of the species' known range. Upwelling events and increase in sea-surface temperatures are possible reasons for this occurrence.
- Stress responses of the sea cucumber Holothuria forskali during aquaculture handling and transportationPublication . Tonn, Nina; Novais, Sara C.; Silva, Cátia S. E.; Morais, Hugo A.; Correia, João P. S.; Lemos, Marco F. L.Animal welfare during handling and transportation to aquaculture facilities or public aquaria is commonly estimated by addressing injury and mortality levels. Although these procedures have been optimized for different species, data on individual species’ cellular capabilities to tolerate stress are still scarce. In the present study, several biomarkers related with oxidative stress and energy metabolism were assessed in Holothuria forskali during animal acclimation, pre-transport, transport and quarantine. Combined analyses confirmed that sea cucumbers experienced high oxidative stress during transport, but had the capability to deal with it using a complex of cellular defence mechanisms, which enabled recovery from oxidative stress without permanent damage. Through a better understanding of individual species and the development of optimal parameters, this approach has the potential to improve animal wellbeing during and after acclimation, transportation and recovery processes.
- The potential of cholinesterases as tools for biomonitoring studies with sharks: Biochemical characterization in brain and muscle tissues of Prionace glaucaPublication . Alves, Luís M.; Lemos, Marco F.L.; Correia, João P. S.; Costa, Nuno A.R. da; Novais, Sara C.Cholinesterases (ChE) are a family of enzymes that play an essential role in neuronal and motor functions. Because of the susceptibility of these enzymes to anticholinergic agents and to other contaminants, their activity is frequently used as biomarker in pollution monitoring studies. The three known types of ChE in fish are acetilcholinesterase (AChE), butyrylcholinesterase (BChE) and propionylcholinesterase (PChE). The presence of these enzymes in each tissue differs between species, and thus their usage as biomarkers requires previous enzyme characterization. Sharks, mostly acting as apex predators, help maintain the balance of fish populations performing a key role in the ecosystem. Blue sharks (Prionace glauca) are one of the most abundant and heavily fished sharks in the world, thus being good candidate organisms for ecotoxicology and biomonitoring studies. The present study aimed to characterize the ChE present in the brain and muscle of the blue shark using different substrates and selective inhibitors, and to assess the in vitro sensitivity of these sharks' ChE to chlorpyrifos-oxon, a metabolite of a commonly used organophosphorous pesticide, recognized as amodel anticholinesterase contaminant. The results suggest that the brain of P. glauca seems to contain atypical ChEs, displayingmixed properties of AChE and BChE, and that the muscle tissue seems to contain mainly AChE. In vitro exposures to chloropyrifosoxon inhibited blue shark's ChE in both tissues, the brain being the most sensitive tissue and therefore the most suitable for detection of exposure to low concentrations of anticholinergic compounds in the environment. This study indicates that ChE activity in blue sharks has the potential to be used as a sensitive and reliable biomarker in marine biomonitoring programs.
- Blue sharks (Prionace glauca) as bioindicators of pollution and health in the Atlantic Ocean: Contamination levels and biochemical stress responsesPublication . Alves, Luís M.; Nunes, Margarida; Marchand, Phillippe; Le Bizec, Bruno; Mendes, Susana; Correia, João P. S.; Lemos, Marco F.L.; Novais, Sara C.Marine ecosystems are constantly being threatened by contaminants produced by human activities. There is an urge to better understand their impacts on marine organisms and develop reliable tools for biomonitoring studies, while also assessing their potential impacts on human health.Given their position on top of food webs, sharks are particularly susceptible to bioaccumulation, making thempotential sentinel species ofmarine contamination. Themain objective of this studywas to find suitable biomarkers for futuremarine pollution biomonitoring studies by correlating biochemical responses with tissue contaminant body burden in blue sharks (Prionace glauca), a species heavily caught and consumed by humans, while also addressing their general health. The chemical contaminants analysed comprised different persistent organic pollutants (POPs) families from polychlorinated compounds to brominated flame retardants (BFRs) and perfluorinated compounds (PFCs) and different trace and heavymetals. Concentrations of some contaminants in sharks' tissueswere found to be above the legally allowed limits for human consumption. A canonical correspondence analysis (CCA) was performed and some strong associations were found between biochemical responses and contaminants' accumulation levels. DNA damage and lipid peroxidation levels, as well as the inhibition of the antioxidant enzyme glutathione peroxidase, were the main effects and consequences of contamination. The impact of contamination on these vital macromolecules underlines the suboptimal conditions of the sampled P. glauca, which can ultimately lead to the degradation of core ecological aspects, such as swimming, feeding, and reproduction. It can be concluded that P. glauca demonstrates great potential to be used as environmental sentinel and suitable biomarker candidates were identified in this work.Moreover, this study also highlights the risks that the consumption of blue shark derived products can pose to human health, which is of upmost interest as the sampled organismswere still juveniles and already presented values above regulatory limits.
- The effect of rapid decompression on barotrauma and survival rate in swallowtail seaperch (Anthias anthias): defining protocols for mitigating surfacing mortalityPublication . Silva, Luís; Rosa, Rui Guedes; Campino, Nelson; Martins, Inês; Pinho, Mário Rui; Correia, João; Morato, TelmoSwallowtail seaperch, Anthias anthias, is a popular fish in the public aquaria industry worldwide, but is subject to barotrauma and high mortality rates if an appropriate decompression profile is not used. Here, we analyze behavioral response to pressure reductions in swallowtail to define protocols for mitigating surfacing mortality. Four different pressure reduction rates were tested (15%, 25%, 35%, and 45%) in several lifting steps from an initial depth of 30 m. Decompression using this procedure was done with 12 and 24 h acclimation duration at each step allowing fish to recover from the pressure reduction. Fish condition was assessed based on swimming behavior, immediately after each new pressure reduction also after each acclimation time. Additionally, fish condition was monitored in a post-decompression trial for 14 days. During decompression, both conditions - initial and final - showed statistically significant differences in the reduction rates tested but showed no differences in acclimation times, and no interaction of the two factors. Neither pressure nor acclimation time affected the condition of the animal in post-decompression trials. Ascension steps near the surface are associated with larger decreases in neutrally buoyant fish compared to deeper decompression steps. Close monitoring of the effect of decompression on A. anthias in the control group, showed that a 29% reduction in pressure could indicate an approximate value of the free vertical range of this species, while swimbladder rupture can occur between 63 and 70% of pressure reduction. The optimal protocol for mitigating surfacing mortality combines two decompression profiles used in this experiment with a total duration of 84 h and comprising 4 lifting steps. The protocol developed to mitigate surfacing mortality was designed for conditions where oceanic cages or containers can be lifted gradually.
- Capture, husbandry and long-term transport of pilotfish, Naucrates ductor (Linnaeus, 1758), by sea, land and airPublication . Correia, João Pedro Santos; Maurício, Francisco de Vaissier Ferro; Rosa, Rui Miguel Guedes da; Marçal, Tiago; Campino, Nelson Silva; Silva, Luís; Morato, TelmoThis is a report on the capture, transport, and husbandry of pilotfish, Naucrates ductor. The objective of this work was to evaluate the most adequate process for capturing, transporting and maintaining pilotfish, while gaining understanding on their behavior. Collection was done in the Azores, by hook and line. Seventy six individuals were then transported to shore, where they were maintained for two months. After this, they were transported by sea over four days. This transport was then followed by an eight day transport by road along Portugal, Spain and multiple public aquaria in France. The animals endured this trip with no losses and multiple notes on husbandry and behavior are provided. Subsequently (2014 to 16), other animals were shipped by air to Atlanta (Georgia, USA), Plymouth (UK), Budapest (Hungary), Springfield (Missouri, USA), and Dubai (UAE), which involved multiple trials prior to the first shipment, to ensure survivorship and wellbeing during the long transit times. The trials revealed that shipping must occur in the presence of an ammonia quencher and pH buffering agents, including the addition of povidone-iodine to decrease bacterial growth, and ice, to keep temperature low.
- (Very) long‐term transport of Silurus glanis, Charcharhinus melanopterus, Scomber colias, Trachurus picturatus, Polyprion americanus, Rhinoptera marmoratus, Salmo salar, Scomber scombrus, Sardina pilchardus, and others, by land, water and airPublication . Correia, João; Daghfous, Gheylen; Silva, David; Graça, Gonçalo; Beltran, Ivan; Reis, João; Marques, José P.; Silva, Luís; Guedes, Rui; Morato, TelmoIn this paper, we cover 4 years of live fish transports that ranged from 14 to 200 h (8 days), and bioloads from 3.8 to 76.9 kg/m3. The key ingredients for success in all trips, where virtually no mortality occurred, was atributed to (1) pre‐buffering the water with sodium bicarbonate and sodium carbonate at 50 g/m3 (each)—and/or ATM Alka‐HaulTM at 25 g/m3—and applying additional (partial or full) doses throughout each transport, whenever the tanks were accessible; (2) pre‐quenching ammonia with ATM TriageTM at 32 g/m3, and applying additional (partial or full) doses throughout each transport, whenever the tanks were accessible; (3) keeping the dissolved oxygen saturation rate above 100%, ideally above 150%; (4) Keeping temperature on the lower limit of each species' tolerance range; (5) Using foam fractionators to effectively eliminate organic matter from the water and (6) Using pure sine wave inverters, which allows for a steady supply of electrical current throughout the transport. The use of a ‘preventive’ versus ‘corrective’ pH buffering philosophy is also discussed.
- Assessment of trends in the Portuguese elasmobranch commercial landings over three decades (1986–2017)Publication . Alves, Luís M.; Correia, João P. S.; Lemos, Marco F.L.; Novais, Sara C.; Cabral, HenriquePortugal plays a major role in shark, skate and ray fisheries in the European Union. With the decline of these animals raising concerns amongst scientists all over the world, we set out to provide an updated assessment on elasmobranch landings in Portugal between 1986 and 2017. The dataset analysed in this study consisted of 15,521 records, each with information concerning the species (or higher taxonomic level), port, month, year, and weight of fish landed. A non-parametric change points assessment statistical technique was used to evaluate important changes in landings throughout the time series. Principal components analysis was also performed to mean values of landings per year for the most captured species, and similar analysis was conducted using fishing ports instead of year, for the same sub-set of species / taxa. According to the data, more than 143 thousand metric tons of elasmobranchs were landed in Portuguese ports between 1986 and 2017, divided by 58 taxa of sharks, skates and rays. The most landed taxa were demersal rays and skates (Raja spp.), followed by spotted dogfishes (Scyliorhinus spp.), blue shark (Prionace glauca), Portuguese dogfish (Centroscymnus coelolepis), leafscale gulper shark (Centrophorus squamosus), gulper shark (Centrophorus granulosus) and shortfin mako (Isurus oxyrinchus). Together, these seven taxa accounted for more than 75% of all landings. Several cases of misreporting were identified and discussed. Overall, landings of elasmobranchs in Portugal show marked decreases and changes in composition, with deep-sea sharks being the most influential group during the studied period.