Thermal sensitivity of metabolic rate mirrors biogeographic differences between teleosts and elasmobranchs.

Environmental temperature affects physiological functions, representing a barrier for the range expansions of ectothermic species. To understand the link between thermal physiology and biogeography, a key question is whether among-species thermal sensitivity of metabolic rates is mechanistically constrained or buffered through physiological remodeling over evolutionary time. The former conception, the Universal Temperature Dependence hypothesis, predicts similar among- and within-species thermal sensitivity.

Biologging and Biotelemetry: Tools for Understanding the Lives and Environments of Marine Animals.

Addressing important questions in animal ecology, physiology, and environmental science often requires in situ information from wild animals. This difficulty is being overcome by biologging and biotelemetry, or the use of miniaturized animal-borne sensors. Although early studies recorded only simple parameters of animal movement, advanced devices and analytical methods can now provide rich information on individual and group behavior, internal states, and the surrounding environment of free-ranging animals, especially those in marine systems.

Factors affecting gestation periods in elasmobranch fishes.

Gestation periods vary greatly across elasmobranch species. Differences in body size and body temperature (i.e.

Life in the slow lane: field metabolic rate and prey consumption rate of the Greenland shark (Somniosus microcephalus) modelled using archival biologgers.

Field metabolic rate (FMR) is a holistic measure of metabolism representing the routine energy utilization of a species living within a specific ecological context, thus providing insight into its ecology, fitness and resilience to environmental stressors. For animals that cannot be easily observed in the wild, FMR can also be used in concert with dietary data to quantitatively assess their role as consumers, improving understanding of the trophic linkages that structure food webs and allowing for informed management decisions. Here, we modelled the FMR of Greenland sharks (Somniosus microcephalus) equipped with biologger packages or pop-up archival satellite tags (PSATs) in two coastal inlets of Baffin Island (Nunavut) using metabolic scaling relationships for mass, temperature and activity.

Accelerometer-based analyses of animal sleep patterns.

Body-motion sensors can be used to study non-invasively how animals sleep in the wild, opening up exciting opportunities for comparative analyses across species.

Water column structure influences long-distance latitudinal migration patterns and habitat use of bumphead sunfish Mola alexandrini in the Pacific Ocean.

Satellite-tracking of adult bumphead sunfish, Mola alexandrini, revealed long-distance latitudinal migration patterns covering thousands of kilometers. Horizontal and vertical movements of four bumphead sunfish off Taiwan were recorded with pop-up satellite archival tags in 2019-2020. Two individuals moved northward and traveled to Okinawa Island and Kyushu, Japan and two moved southwards; crossing the equator, to Papua New Guinea and New Caledonia.

Behavioural thermoregulation linked to foraging in blue sharks.

Unlabelled: Large pelagic fishes often dive and surface repeatedly as if they were airbreathers, raising a question about the functions of these movements. Some species (e.g.

Too big to study? The biologging approach to understanding the behavioural energetics of ocean giants.

Wild animals are under selective pressure to optimise energy budgets; therefore, quantifying energy expenditure, intake and allocation to specific activities is important if we are to understand how animals survive in their environment. One approach toward estimating energy budgets has involved measuring oxygen consumption rates under controlled conditions and constructing allometric relationships across species. However, studying 'giant' marine vertebrates (e.

Ultrahigh foraging rates of Baikal seals make tiny endemic amphipods profitable in Lake Baikal.

Understanding what, how, and how often apex predators hunt is important due to their disproportionately large effects on ecosystems. In Lake Baikal with rich endemic fauna, Baikal seals appear to eat, in addition to fishes, a tiny (<0.1 g) endemic amphipod (the world's only freshwater planktonic species).

A first look at the metabolic rate of Greenland sharks (Somniosus microcephalus) in the Canadian Arctic.

Metabolic rate is intricately linked to the ecology of organisms and can provide a framework to study the behaviour, life history, population dynamics, and trophic impact of a species. Acquiring measures of metabolic rate, however, has proven difficult for large water-breathing animals such as sharks, greatly limiting our understanding of the energetic lives of these highly threatened and ecologically important fish. Here, we provide the first estimates of resting and active routine metabolic rate for the longest lived vertebrate, the Greenland shark (Somniosus microcephalus).

Foraging behavior links sea ice to breeding success in Antarctic penguins.

Population trends and breeding success variability of Adélie penguins, a bioindicator of Antarctic environments, have been attributed to changing sea-ice extents; however, causative mechanisms remain unclear. By electronically tagging 175 penguins in four seasons with contrasting sea-ice conditions, we show that ice-free environments enhance, not deteriorate, foraging efficiencies and breeding success. In an ice-free season, penguins traveled by swimming rather than walking, leading to larger foraging areas, shorter trip durations, and lower energy expenditure than three ice-covered seasons.

A framework to estimate the likelihood of species interactions and behavioural responses using animal-borne acoustic telemetry transceivers and accelerometers.

Interactions between animals structure food webs and regulate ecosystem function and productivity. Quantifying subsurface behavioural interactions among marine organisms is challenging, but technological advances are promoting novel opportunities. Here, we present a framework to estimate when there is a high likelihood that aquatic animal subsurface interactions occur and test for a movement-related behavioural response to those interactions over short temporal scales (days) using a novel multi-sensor biologging package on a large marine predator, the Greenland shark (Somniosus microcephalus).

Global spatial risk assessment of sharks under the footprint of fisheries.

Effective ocean management and the conservation of highly migratory species depend on resolving the overlap between animal movements and distributions, and fishing effort. However, this information is lacking at a global scale. Here we show, using a big-data approach that combines satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries.

Distribution, body size and biology of the megamouth shark Megachasma pelagios.

We compiled historical reports of megamouth sharks Megachasma pelagios (mostly fishery by-catch and strandings) from 1976 to 2018 (n = 117) and found that they are distributed globally (highest latitude, 36°) with three hotspots: Japan, Taiwan and the Philippines. Despite possible biases due to variability in fishing effort, more individuals were reported at higher latitudes in the summer, suggesting seasonal, latitudinal migrations. Sex ratios were female-biased in Japan, but more even in Taiwan and the Philippines, suggesting some sexual segregation.

Swimming strategies and energetics of endothermic white sharks during foraging.

Some fishes and sea turtles are distinct from ectotherms by having elevated core body temperatures and metabolic rates. Quantifying the energetics and activity of the regionally endothermic species will help us understand how a fundamental biophysical process (i.e.

Global Monitoring of Persistent Organic Pollutants (POPs) Using Seabird Preen Gland Oil.

Situated at high positions on marine food webs, seabirds accumulate high concentrations of persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), and hexachlorocyclohexanes (HCHs). Our previous studies proposed the usefulness of seabirds preen gland oil as a nondestructive biomonitoring tool. The present study applied this approach to 154 adult birds of 24 species collected from 11 locations during 2005-2016 to demonstrate the utility of preen gland oil as a tool for global monitoring POPs, i.

Activity seascapes highlight central place foraging strategies in marine predators that never stop swimming.

Background: Central place foragers (CPF) rest within a central place, and theory predicts that distance of patches from this central place sets the outer limits of the foraging arena. Many marine ectothermic predators behave like CPF animals, but never stop swimming, suggesting that predators will incur 'travelling' costs while resting. Currently, it is unknown how these CPF predators behave or how modulation of behavior contributes to daily energy budgets.

Interacting with wildlife tourism increases activity of white sharks.

Anthropogenic activities are dramatically changing marine ecosystems. Wildlife tourism is one of the fastest growing sectors of the tourism industry and has the potential to modify the natural environment and behaviour of the species it targets. Here, we used a novel method to assess the effects of wildlife tourism on the activity of white sharks ().

A miniaturized threshold-triggered acceleration data-logger for recording burst movements of aquatic animals.

Although animal-borne accelerometers are effective tools for quantifying the kinematics of animal behaviors, quantifying the burst movements of small and agile aquatic animals remains challenging. To capture the details of burst movements, accelerometers need to sample at a very high frequency, which will inevitably shorten the recording duration or increase the device size. To overcome this problem, we developed a high-frequency acceleration data-logger that can be triggered by a manually defined acceleration threshold, thus allowing the selective measurement of burst movements.

Optimal swimming strategies and behavioral plasticity of oceanic whitetip sharks.

Animal behavior should optimize the difference between the energy they gain from prey and the energy they spend searching for prey. This is all the more critical for predators occupying the pelagic environment, as prey is sparse and patchily distributed. We theoretically derive two canonical swimming strategies for pelagic predators, that maximize their energy surplus while foraging.

Into the deep: the functionality of mesopelagic excursions by an oceanic apex predator.

Comprehension of ecological processes in marine animals requires information regarding dynamic vertical habitat use. While many pelagic predators primarily associate with epipelagic waters, some species routinely dive beyond the deep scattering layer. Actuation for exploiting these aphotic habitats remains largely unknown.

Great hammerhead sharks swim on their side to reduce transport costs.

Animals exhibit various physiological and behavioural strategies for minimizing travel costs. Fins of aquatic animals play key roles in efficient travel and, for sharks, the functions of dorsal and pectoral fins are considered well divided: the former assists propulsion and generates lateral hydrodynamic forces during turns and the latter generates vertical forces that offset sharks' negative buoyancy. Here we show that great hammerhead sharks drastically reconfigure the function of these structures, using an exaggerated dorsal fin to generate lift by swimming rolled on their side.