Winter in temperate regions is characteristically the coldest period of the year. Species in these regions adapt to freezing temperatures with physiological or behavioural mechanisms to mitigate the threats of cold exposure. For aquatic species, taking refuge under the ice minimizes the risk of experiencing freeze injury. The northern map turtle ( Graptemys geographica (LeSueur, 1817)) is one species that overwinters under the ice of lakes and rivers. Here, we observed the behaviour of free-ranging map turtles at a known overwintering site throughout an entire winter using biologgers equipped with tri-axial acceleration, temperature, and depth sensors. We observed that map turtles maintain localized locomotor activity at the overwintering site continuously during the winter. The extent and patterns of locomotor activity and habitat use varied between adult females, adult males, and juvenile females. Adult females were observed at the shallowest depths, coldest temperatures and moved the least, whereas juvenile females were observed at the deepest depths, warmest temperatures and moved the most. All groups remained at temperatures near freezing (0.98–1.39 °C) and at average depths ranging from 1.34 to 1.7 m. These behavioural patterns are consistent with a strategy to survive the winter while remaining aerobic and likely reflect differences in physiological demands.

Flats ecosystems are dynamic, shallow, nearshore marine environments that are interconnected and provide immense ecological and socio-economic benefits. These habitats support a diversity of fish populations and various fisheries, yet they are increasingly threatened by anthropogenic stressors, including overfishing, habitat degradation, coastal development, and the cascading effects of climate change. Effective habitat management and restoration are essential but are often missing for flats ecosystems. Despite navigating a landscape of imperfect knowledge for these systems, decisive action and implementation of habitat protection and restoration is currently needed through policy and practice. We present a comprehensive set of 10 strategic guiding principles necessary for integrating habitat management and restoration for the conservation of interconnected flat ecosystems. These principles include calls for comprehensive ecosystem-based ­management, integrating adaptive strategies that leverage diverse partnerships, scientific research, legislative initiatives, and local and traditional ecological knowledge. Drawing on successes in other environmental management realms, we emphasize the importance of evidence-informed approaches to address the complexities and uncertainties of flats ecosystems. These guiding principles aim to advance flats habitat management and restoration, promoting ecological integrity and strengthening the socio-economic resilience of these important marine environments.

Objective There is an ongoing effort to enhance the welfare and survival of black bass Micropterus spp. released after angling tournaments. Live-well additives are substances added to live-well water that are intended to help fish recover during retention. Aside from claims made by manufacturers, little information is available on the additives' effectiveness for recovery or their potential welfare consequences. Thus, our objective was to test whether live-well additives influence fish physiology and postrelease behavior. Methods Two techniques were used to test the influence of live-well additives on the welfare of angled Largemouth Bass M. nigricans (LMB) held in a live well with lake water (control) or one of three additive products. Prior to fish release, pop-off biologging packages were fastened to a subset of LMB to monitor behavior (locomotor activity, depth, and water temperature use) for 5 min (n = 61) and blood samples were taken from another subset of LMB to assess their physiology (n = 47). We obtained baseline (n = 9) blood samples from LMB immediately upon capture. Result Regardless of treatment, postrelease locomotor activity increased with increasing time spent in the live wells. Live-well additive type alone did not have an influence on the postrelease locomotor activity. Further, LMB retained in the live wells had greater blood glucose and lactate concentrations relative to baseline LMB, suggesting that fish did not recover from angling during retention in live wells. Other than elevated plasma chloride levels of LMB held in one of the live-well additives, plasma chloride and sodium concentrations for LMB in live wells with additives and for those in the control live well did not differ, suggesting that the LMB had not recovered while retained. Conclusion Our results suggest that the live-well additives tested did not enhance recovery or reduce confinement stress of LMB retained in live wells under the tested circumstances. Additional research on live-well additives is needed given that our findings did not align with the claims made by the manufacturers of these products. We suggest that anglers intending to retain fish in live wells should use fresh, well-oxygenated lake water.

Mass mortality events appear to be increasing in intensity and frequency, so understanding their causes and consequences is imperative for wildlife conservation. We report on a mass mortality event in a population of Northern Map Turtles ( Graptemys geographica (LeSueur, 1817)). At a communal overwintering site, 142 carcasses (ca. 10% of population) were recovered, seemingly depredated by river otters ( Lontra canadensis (Schreber, 1777)). We compared the size and sex of the carcasses to those of turtles that survived. Smaller turtles and males were more likely to be depredated than larger turtles and females. Using captures made at the same overwintering site between 2003 and 2022, we assessed the vulnerability of this population to mass mortality events during winter. Nearly 60% of the 1875 turtles marked between 2003 and 2022 used the overwintering site where the mass mortality event occurred at least once. On average, turtles overwintered at the site at least 38% of the winters between their first and last capture. Our study shows how behaviour and physiology interact to predispose a species to mass mortality events and ecological traps. Protecting overwintering sites and minimizing human pressures affecting winter depredation may be essential for the preservation of certain turtle populations.

Satellite telemetry has revolutionized the study of aquatic animal movement by enabling high-resolution tracking across vast spatial and temporal scales. Here we undertake a global systematic review of studies since 1982 to summarise state of knowledge by taxonomic group, sample size, life history stage studied, and tracking mode (i.e., archival vs. near real-time). We then classify studies according to defined research and management themes, highlight geographic trends aligned with FAO major fishing areas, and examine how these themes are distributed globally. Of a total of 1137 studies, encompassing over 30 000 tagged individuals across diverse aquatic taxa, mammals, fish, and reptiles were the most studied. Research has largely focused on marine systems, particularly in the northern Atlantic and Pacific, but freshwater ecosystems remain underrepresented. Most studies explored general movement patterns, with fewer addressing applied conservation topics such as movement barriers or protected area effectiveness. Overall, integration with complementary methods (e.g., genetic or physiological sampling) was limited. Addressing identified gaps in underrepresented taxa (e.g., invertebrates), regions (e.g., the Indian Ocean), and emerging topics (e.g., climate change responses) will be critical to fully realize the potential of satellite telemetry for conservation and management of aquatic biodiversity.

Understanding the functional role of habitats to wild animals can aid in implementing management actions to protect critical habitat from anthropogenic threats. However, habitat function is challenging to measure across extensive space and time, particularly in marine systems. We used acoustic telemetry tags equipped with tri-axial accelerometer sensors to track the movement and locomotor activity of permit Trachinotus falcatus in coastal marine habitats of the Florida Keys (USA) so that we could remotely characterize their behavioural ecology and infer habitat function. Recent research in this system explored space use by permits and identified shallow seagrass flats and offshore reefs and wrecks as important foraging and spawning habitats, respectively. Predictive models applied here identified variation in permit activity patterns across a diversity of spatial (i.e. habitat type and site) and temporal (e.g. time of day, lunar phase) factors as well as complex interactions. Based on known permit behavioural ecology, peaks in activity in the late afternoon to evening at putative spawning sites were used to infer the spatial-temporal dynamics of likely spawning activity. This spawning signature was observed at 8 offshore reef locations, with considerable seasonal variation amongst sites. Timing of spawning may therefore vary among sites, while the functional role of some sites likely extends beyond spawning (e.g. staging, foraging). These data provide insights into permit spawning sites and behaviour and highlight the potential for acoustic telemetry equipped with acceleration sensors to generate knowledge relevant to habitat and fisheries management.