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Metabolic ecology predicts that ectotherm metabolic rates, and thus consumption rates, will increase with body size and temperature. Predicted climatic increases in temperature are likely to increase the consumption rates of ectothermic predators; however, the ecological impact of these increases will partly depend on whether prey productivity changes with temperature at a similar rate. Furthermore, total predator consumption and prey productivity will depend on species abundances that vary across habitat types. Here we combine energetics and biotelemetry to measure consumption rates in a critically endangered coral reef predator, the Nassau grouper (Epinephelus striatus), in The Bahamas. We estimate that, at present, the Nassau grouper needs to consume 2.2% ± 1.0% body weight day−1, but this could increase up to 24% with a predicted 3.1°C increase in ocean temperature by the end of the century. We then used surveys of prey communities in two major reef habitat types (Orbicella reef and Gorgonian plain), to predict the proportion of prey productivity consumed by grouper and how this varied by habitat with changing climates. We found that at present, the predicted proportion of prey productivity consumed by Nassau grouper decreased with increasing prey productivity and averaged 1.2% across all habitats, with a greater proportion of prey productivity consumed (maximum of 5%) in Gorgonian plain habitats. However, because temperature increases consumption rates faster than prey productivity, the proportion of prey productivity consumed in a Gorgonian plain habitat could increase up to 24% under future climate change scenarios. Our results suggest that increasing ocean temperatures will lead to significant energetic challenges for the Nassau grouper because of differential impacts within reef food webs, but the magnitude of these impacts will probably vary across prey productivity gradients. [ABSTRACT FROM AUTHOR]

Acoustic telemetry is a popular approach used to track many different aquatic animal taxa in marine and freshwater systems. However, information derived from focal studies is typically resource‐ and geography‐limited by the extent and placement of acoustic receivers. Even so, animals tagged and tracked in one region or study may be detected unexpectedly at distant locations by other researchers using compatible equipment, who ideally share that information. Synergies through national and global acoustic tracking networks are facilitating significant discoveries and unexpected observations that yield novel insight into the movement ecology and habitat use of wild animals. Here, we present a selection of case studies that highlight unexpected tracking observations or absence of observations where we expected to find animals in aquatic systems around the globe. These examples span freshwater and marine systems across spatiotemporal scales ranging from adjacent watersheds to distant ocean regions. These unexpected movements showcase the power of collaborative telemetry networks and serendipitous observations. Unique and unexpected observations such as those presented here can capture the imagination of both researchers and members of the public, and improve understanding of movement and connectivity within aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Bluegill (Lepomis macrochirus) and pumpkinseed (Lepomis gibbosus) sunfish function as a trophic link between invertebrates and piscivores in temperate freshwater food webs, but little is known about their movement in large-scale riverine ecosystems. To address this, pumpkinseed and bluegill were implanted with acoustic transmitters and monitored for 5 months (June to November 2015) within a 0.39 [km.sup.2] acoustic array in the Detroit River. Residence index analysis revealed site fidelity of sunfish to the side of the river they were tagged and a lack of movement across a shipping channel. Bluegill were more active at night and pumpkinseed more active during daylight hours, possibly partitioning resources on a temporal basis, unlike in smaller lakes where the species partition the littoral and pelagic habitats. Pumpkinseed presence was positively correlated with water temperature and level, whereas bluegill presence was not related to any environmental parameters examined. This study demonstrates that anthropogenic alterations (e.g., channelization) influence the movement and distribution of fishes and that fish behaviour in a large river ecosystem can differ from smaller temperate lakes. Si le crapet arlequin (Lepomis macrochirus) et le crapet-soleil (Lepomis gibbosus) tiennent lieu de lien trophique entre invertebres et piscivores dans les reseaux trophiques de milieux d'eau douce temperes, les connaissances sur leurs deplacements dans les ecosystemes de grande envergure sont limitees. Pour examiner cette question, des crapets arlequins et des crapets-soleil ont ete dotes d'emetteurs acoustiques, puis suivis pendant 5 mois (de juin a novembre 2015) dans un reseau acoustique de 0,39 [km.sup.2] dans la riviere Detroit. L'analyse de l'indice de residence revele une fidelite au site des crapets du cote de la riviere ou ils ont ete marques et l'absence de deplacements traversant un chenal de navigation. Les crapets arlequins etaient plus actifs la nuit et les crapets-soleil, le jour, ce qui pourrait refleter un partage des ressources sur une base temporelle, contrairement a ce qui est observe dans de plus petits lacs ou les especes se divisent les habitats littoraux et pelagiques. La presence de crapets-soleil etait positivement correlee a la temperature et au niveau de l'eau, alors que celle de crapets arlequins n'etait reliee a aucun des parametres du milieu examines. L'etude montre que les modifications d'origine humaine, telle que la canalisation, influencent les deplacements et la repartition de poissons et que le comportement des poissons dans l'ecosysteme d'une grande riviere peut etre different de celui qui est observe dans les petits lacs temperes. [Traduit par la Redaction], Introduction Fish movements and distributions form the basis of the structure and functioning of aquatic ecosystems (Hussey et al. 2015). As a source of substantial energy subsidies to food webs, [...]

Abstract: We used an array of fixed acoustic receivers (N =42) to track the summer marine movements of 121 anadromous Arctic char (Salvelinus alpinus) equipped with acoustic transmitters at three [...]

Tonic immobility is a widely used technique for the surgical implantation of acoustic tags in elasmobranchs (sharks, skates, and rays), yet it is still not broadly recognised as an acceptable procedure by many regulatory bodies, animal care committees, and even journal ethics standards. To highlight its regular use and applicability as a field procedure, a literature search was conducted on the anaesthetic technique adopted for all existing elasmobranch-focused acoustic telemetry papers, up to 31 December 2013. A total of 57 studies were identified that contained relevant details on surgical methodological procedures. Of these, the majority of studies (43, or 75.4%) employed tonic immobility, while 10 (17.6%) used general chemical anaesthetic and 4 (7%) used local chemical anaesthetic. These studies identify that tonic immobility provides an effective anaesthetic for surgical implantation in elasmobranchs, as it offers several benefits over chemical anaesthetics, both from a practical and from an animal welfare perspective. Practically, rapid induction and recovery optimizes the surgical procedure, desirable under often complex field conditions, where general chemical anaesthetics prolong duration and administration is often unfeasible because of the size of study animals. Benefits over chemical anaesthetic for animal welfare include no risk of overdose, no uptake of chemicals to body tissues, minimal disruption to respiration, thereby reducing potential for negative sublethal impacts that influence postrelease behaviour, and immediate and full recovery. Given these benefits and its long-standing use in field studies, it is recommended that tonic immobility be recognised as an acceptable anaesthetic technique for surgical procedures on elasmobranchs. Si l'immobilite tonique est une technique tres repandue pour l'implantation chirurgicale d'etiquettes acoustiques chez les elasmobranches (requins et raies), elle n'est pas encore largement reconnue comme procedure acceptable par de nombreux organismes de reglementation, comites de protection des animaux, ou meme par les normes deontologiques de revues. Dans le but de mettre en relief son utilisation courante et son applicabilite comme procedure de terrain, une recherche documentaire a ete effectuee sur les techniques d'anesthesie adoptees dans tous les articles existants, en date du 31 decembre 2013, ou la telemetrie acoustique est utilisee pour etudier les elasmobranches. Au total, 57 etudes ont ete recensees qui contiennent des details pertinents sur la methodologie des interventions chirurgicales. L'immobilite tonique a ete employee dans la majorite de ces etudes (43, ou 75,4%), alors que des anesthesiques chimiques generaux ont ete utilises dans 10 etudes (17,6%) et des anesthesiques chimiques locaux, dans 4 etudes (7%). Ces etudes relevent le fait que l'immobilite tonique constitue une methode anesthesique efficace pour l'implantation chirurgicale chez les elasmobranches, puisqu'elle presente plusieurs avantages par rapport aux anesthesiques chimiques, des points de vue tant pratique que du bien-etre des animaux. Du point de vue pratique, l'induction et le retablissement rapides optimisent l'intervention chirurgicale, ce qui est souhaitable dans des conditions de terrain souvent complexes dans lesquelles les effets des anesthesiques chimiques sont prolonges ou leur administration n'est souvent pas possible en raison de la taille des animaux etudies. Les avantages par rapport a l'anesthesie chimique en ce qui concerne le bien-etre des animaux comprennent l'absence de risque de surdose et d'absorption de produits chimiques par les tissus, une perturbation minimale de la respiration, ce qui limite la possibilite d'impacts negatifs non mortels ayant une incidence sur le comportement apres la liberation, et un retablissement immediat et complet. Etant donne ces avantages et l'utilisation de longue date de l'immobilite tonique dans les etudes de terrain, il est recommande que cette methode soit reconnue en tant que technique anesthesique acceptable pour des interventions chirurgicales sur les elasmobranches. [Traduit par la Redaction], Introduction Studies employing acoustic telemetry to investigate the spatial ecology of fish emerged in the late 1980s and have been rapidly increasing over the past few decades (Hussey et al. [...]

Niche partitioning might be predicted to be particularly dynamic in 'novel ecosystems' characterized by human‐altered environmental conditions and biological invasions. Restoration efforts for native species in such systems can be informed by detailed characterization of niche partitioning.In Lake Ontario, fishery management agencies have been engaged in a long‐term struggle to restore native top predators including lake trout (Salvelinus namaycush). Meanwhile, management agencies continue to stock non‐native species like Chinook salmon (Oncorhynchus tshawytscha) into the lake to support a recreational fishery and to help control the abundance of a non‐native forage fish, the alewife (Alosa pseudoharengus).We used pop‐off data storage tags to study fine scale (9.1M lines of data from 22 animals) behaviour and habitat use by lake trout (native) and Chinook salmon (non‐native) in Lake Ontario in terms of depth and temperature, recorded at ≤70 s intervals for periods of up to 12 months.Chinook salmon occupied warmer and shallower waters during summer than did lake trout, and their niche breadth was wider. They achieved greater niche breadth in part because they were much more active vertically, cumulatively traveling 103 ± 1 m/hour during summer (model‐estimated median), whereas most lake trout were relatively inactive vertically (7 ± 1 m/hour). In each of our analyses, there was more inter‐individual variation among lake trout than among Chinook salmon, driven by some lake trout that spent considerable time making forays into warmer, shallower waters.Synthesis and applications. Our results illustrate the different foraging tactics used by two species in the Great Lakes and reflect their distinct life histories. Physical niche partitioning between Chinook salmon and lake trout helps to explain how these species can co‐exist in a multi‐species fishery even while having overlap in diet. The diversity of behaviours exhibited here by native lake trout have likely helped them persist during dramatic changes to the forage base in recent decades; that flexibility could help underlie their long‐term prospects for restoration during future changes to the ecosystem. [ABSTRACT FROM AUTHOR]

An intact and uncompromised internal acoustic transmitter was non‐lethally recovered from a lemon shark Negaprion brevirostris, after 13 years at liberty. The shark, first tagged at an estimated age of 2 years old near South Bimini, Bahamas in 2004, was recaptured in 2017 with a total length of 264 cm. The tagged shark displayed typical growth rate, pregnancy, natal homing and pupping behaviour of other individuals in this population. This observation provides important evidence regarding the effects from long‐term retention of implanted acoustic transmitters in a carcharhinid shark. [ABSTRACT FROM AUTHOR]