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Juvenile oceanic-stage sea turtles are particularly vulnerable to the increasing quantity of plastic coming into the oceans. In this study, we analysed the gastrointestinal tracts of 24 juvenile oceanic-stage loggerheads ( Caretta caretta ) collected off the North Atlantic subtropical gyre, in the Azores region, a key feeding ground for juvenile loggerheads. Twenty individuals were found to have ingested marine debris (83%), composed exclusively of plastic items (primarily polyethylene and polypropylene) identified by μ-Fourier Transform Infrared Spectroscopy. Large microplastics (1–5 mm) represented 25% of the total number of debris and were found in 58% of the individuals sampled. Average number of items was 15.83 ± 6.09 (± SE) per individual, corresponding to a mean dry mass of 1.07 ± 0.41 g. The results of this study demonstrate that plastic pollution acts as another stressor for this critical life stage of loggerhead turtles in the North Atlantic.

During 1997, exploratory cruises were conducted to study deep-water crabs south of Pico and Sao Jorge islands in the Azores archipelago. Baited traps were set at depths of 200-1000 m. The target species were the crabs Chaceon affinis and Cancer bellianus. The latter was the prevalent species shallower than 700 m, a total of 462 (247 males and 215 females) being caught at depths ranging from 200-700 m on rocky substrata. The catch rate of females was higher in shallow water (200-400 m) and that of males higher in deeper water (400-600 m). Sizes ranged from 45-218 mm carapace width (CW). Ovigerous females were not found, and possible reasons for this are advanced. An annual reproductive cycle is outlined. Size at first maturity was not estimated directly, but the observed minimum carapace width of females with spermatophores on their pleopods (132 mm) is suggested as the size of first maturity. Epizoitic barnacles were observed on the exoskeleton of some animals.

During 1997, quarterly exploratory cruises of the R/V “Archipelago” were carried out in order to study the deep water crab Chaceon affinis [Res. Camp. Sci. Monaco Fasc. VII (1894) 1], South of Pico island (Azores) and at the Menez Gwen hydrothermal vent area (SW of the Azores, within the Azorean Economic Exclusive Zone). The crabs were caught with bottom traps according to a specified survey design. Different areas between 300 and 1200 m depth were surveyed. Information from previous collections was also compiled and analysed. A total of 1153 crabs (726 males and 427 females) were caught at depths ranging from 600 to 1100 m on rocky and/or muddy bottoms. Size ranged from 39 to 177 mm carapace length (CL), the males being larger than females. Males were relatively more abundant at depths 800 m. The greatest abundance occurred at depths from 700 to 800 m. Ovigerous females, which were consistently >70 mm CL, were found only from October to March. An annual reproductive cycle is suggested. Size at first maturity for the females, was estimated to be within the size range of 83–97 mm CL. Other ecological and biological information such as distribution, morphometric aspects related to reproduction, occurrence of parasites and epibionts, are discussed, as well as by-catch species.

The pelagic juvenile stage of sea turtles is poorly studied. We present a growth model and estimates for duration of the pelagic juvenile stage for loggerhead sea turtles Caretta caretta in the North Atlantic based on length-frequency analyses and sizes of young-of-the-year stranded in the Azores. The size-specific growth model is a monotonic, nonlinear, declining function. The growth model is consistent with growth rates calculated from recaptures of tagged loggerheads. Logger- heads leave the pelagic habitat and recruit to neritic habitats over a range of sizes from 46 to 64 cm curved carapace length (CCL). From this size range and the growth model, we estimate the duration of the pelagic stage varies from 6.5 to 11.5 yr. Nonparametric smooths of the size frequency distribu- tions of loggerheads in pelagic (n = 1692) and neritic (n = 1803) habitats intersect at 53 cm CCL, which is equivalent to an 8.2 yr duration for the pelagic stage. More growth data from loggerheads

Squid are the fastest swimming invertebrates, but the metabolic cost of speed, as assessed in swim‐tunnels, is several‐fold higher than in fish, making squid appear uncompetitive. Because oxygen consumption can be correlated with jet pressure, it is possible to monitor pressure and thus estimate performance and energy costs in nature. Tracking in course and depth gave a 3‐D view of squid (Loligo forbesi) activities and costs for nearly three animal‐weeks; five days of this included telemetry of jet pressures. These 2–5 kg loliginids hovered off‐bottom most of the time, perhaps to avoid predation or damage to delicate skins. Hovering consumes about 50 ml O2 kg‐1 h‐1, twice as much as resting on bottom and half of overall average costs. Jet pressures were not well correlated with horizontal movements or tidal cycles, suggesting squid may “soar”; to reduce the cost of remaining in active current areas, acting as sit‐and‐wait predators. Maximal aerobic jetting was rare and usually associated with vertical cli...

Oceanic juvenile loggerhead sea turtles, Caretta caretta, foraging in Azorean waters, are incidentally caught in drifting longlines that target swordfish, Xiphias gladius, and blue shark, Prionace glauca. Data were recorded during a longline gear modification experiment conducted in 2000. The results show that the captures are not uniformly distributed in relation to fishing effort, with 81% of the loggerheads (N = 232) caught in one-third of the sets (N = 93). The highest turtle catch rates were around the eastern group of islands, an area characterized by the presence of mesoscale eddies induced by bathymetric features. High catch rates coincided with the presence of the thermohaline front, between August and October, and when targeting blue shark. To investigate the causes of these differences we fitted a general linear model to evaluate the influence of mean depth, minimum depth, sea surface temperature (SST), soak area, soak time, moon phase and wind force on turtle and target species catch rates. These results revealed that mean depth and SST were most important for loggerhead catch rates, while minimum depth was the only significant variable for swordfish and mean depth, SST, wind force, moon phase and soak time influenced blue shark catches. The distribution of loggerhead sea turtles can be predicted by monitoring fishing areas in relation to bathymetry and SST. The impact of longline fishing could be greatly and quickly reduced by regulating the blue shark fishery and by increasing fishermen awareness for sea turtle conservation.

The population of Loligo forbesi inhabiting the Azorean Archipelago achieves the largest size ever reported for this species but also for any Loliginidae. Despite their importance as a food source for local communities, very little is known about their biology and ecology. In this paper, we describe our efforts in capturing, transporting, handling, tagging and holding wild adult L. forbesi in the laboratory. Three culture trials were conducted in the Island of Faial, Azores. Over 84 squid were captured by jigging, transported in separate containers and placed in a recirculating seawater system composed of three 3.6 m circular tanks (8000 l capacity each). Drawings and technical details about the system (filtration system, tanks, liners, illumination, flow rates, etc.) as well as water quality parameters (ammonia, nitrite, nitrate, iron, pH, salinity and temperature) are presented. By keeping squid in separate bags and providing constant water flow, no mortality occurred during transport from fishing ground to the laboratory. Mean survival time for each trial was 8 days (1503 g mean weight), 17 days (595.1 g mean weight) and 11 days (826.1 g). A small female remained alive for 44 days. In this system, mortality was faster for larger squid. Low survival time could be attributed to bad water quality management, namely high ammonia levels and high temperature variations but also restricted swimming space for larger squid (>1000 g). Pin tags proved to be the most adequate method of distinguishing between individuals. Squid were fed a variety of fish species, either fresh or defrosted. Daily feeding rates varied between 0 and 7.8% body weight (BW day−1). Most squid lost weight or did not grow. However, some individuals showed a positive increase in BW, varying between 0.009 and 1.4% increase in BW day−1. Key factors to take into account for increasing laboratory survival are: (1) catching squid with jigs; (2) prevention of skin damage during transport; (3) maintenance of small individuals; (4) segregating sexes to reduce agonistic interactions; (5) providing good water quality; and (6) abundant food supply.

The increasing public perception that marine megafauna is under threat is an outstanding incentive to investigate their essential habitats (EMH), their responses to human and climate change pressures, and to better understand their largely unexplained behaviors and physiology. Yet, this poses serious challenges such as the elusiveness and remoteness of marine megafauna, the growing scrutiny and legal impositions on their study, and difficulties in disentangling environmental drivers from human disturbance. We argue that advancing our knowledge and conservation on marine megafauna can and should be capitalized in regions where exceptional access to multiple species (i.e., megafauna ‘hotspots’) combines with the adequate legal framework, sustainable practices, and research capacity. The wider Azores region, hosting EMHs of all key groups of vulnerable or endangered vertebrate marine megafauna, is a singular EMH hotspot on a migratory crossroads, linking eastern and western Atlantic margins and productive boreal waters to tropical seas. It benefits from a sustainable development model based on artisanal fisheries with zero or minor megafauna bycatch, and one of the largest marine protected area networks in the Atlantic covering coastal, oceanic and deepsea habitats. Developing this model can largely ensure the future integrity of this EMH hotspot while fostering cutting-edge science and technological development on megafauna behavior, biologging and increased ocean observation, with potential major impacts on the Blue Growth agenda. An action plan is proposed.