Fine-scale Acoustic Telemetry Research Articles

Timing is everything; operational changes at a pumping station with a gravity sluice to provide safe downstream passage for silver European eels and deliver considerable financial savings

Catadromous European eel (Anguilla anguilla) are a critically endangered fish species due in part to in-river anthropogenic barriers (e.g., pumping stations, weirs, hydropower facilities). European legislation stipulates that safe downstream passage must be provided at hazardous intakes. Where present, gravity sluices have the potential to act as safe and low-cost downstream passage for seaward migrating silver eels at pumping station, but operational changes are required. This study used catchment-wide and fine-scale acoustic telemetry to investigate if operational changes (OC) at a pumping station (PS) with a co-located gravity sluice (GS) facilitated safe downstream passage for silver European eels. Specifically, night-time pump operations were ceased, river levels prior to sluicing were elevated and the GS was opened during key eel migration windows, i.e., at night during the new moon phase in autumn. No tagged eels passed through any pumps and the majority (2018 = 87.5%, 2020 = 88.9%) that approached the PS during OC passed downstream through the GS. Most eels approached during the first period of night sluicing after release (2018 = 73.9% and 2020 = 76.5%) and passed downstream during the first sluice event they experienced at the PS (2018 = 66.7% and 2020 = 75.0%). During the final approach prior to passage, very few retreats back upstream occurred at a median (IQR) distance of 34 (7.25) m from the GS and were predominantly a short distance (1–8 m). Overall, OC at a PS with a GS are considered a win-win-win, despite opening the sluice for <3% of the study period, given safe downstream passage was maximised, the financial benefits of sluicing water (∼£14,670 in direct operational costs over two years) and the relative ease of implementation.

Seasonal habitat utilization provides evidence for site fidelity during both spawn and non-spawning seasons in Lake Ontario cisco Coregonus artedi

The Lake Ontario cisco Coregonus artedi population declined in the 20th century, and restoration of this species is a management objective. Management tools to restore cisco are limited because little is known about cisco spawning behavior and habitat use. We tagged 76 cisco from a remnant population in Chaumont Bay, Lake Ontario with acoustic transmitters and characterized seasonal habitat use from 2016 to 2021. We also used fine-scale acoustic telemetry, coregonine egg collections, and trap net catches to better understand cisco spawning behaviors related to spawn timing and site selection. Network analysis and Bayesian standard ellipse area indicated that cisco utilization of lake regions and bathythermal niche space varied by season. During spawning season, male cisco concentrated in Chaumont Bay over shallow (∼3 m) rocky shoals where cisco egg deposition was the greatest. Spawning site fidelity to Chaumont Bay was observed for all male cisco surviving to successive years (n = 23). Acoustic-tagged females did not survive consecutive spawning seasons, but trap net catches indicated females were less abundant and occupied spawning areas for less time than males. Post spawn, some individual male cisco (n = 5/23) had differential, yet consistent, annual migrations to separate regions of Lake Ontario, suggesting fidelity to feeding sites. Our results reveal seasonal habitats used by male cisco and, importantly, caution that environmental changes to a single spawning site could negatively affect the remnant Chaumont Bay cisco population. Specialized conservation efforts may be necessary when cisco spawning aggregations have diverse post-spawn migratory behaviors but a central spawning ground.

Residency and Fine-scale Habitat Use of Juvenile Goliath Grouper (Epinephelus Itajara) in a Mangrove Nursery

The Atlantic goliath grouper (Epinephelus itajara) is the largest grouper species in the Atlantic and exhibits high site fidelity and limited range of movement. By 1990, the goliath grouper population in US waters had declined approximately 95% relative to unfished levels, leading to a harvest ban in 1990. Since then, the south Florida population has grown but the magnitude of recovery remains unknown due to uncertainties about life history characteristics. However, despite these unknowns, the state of Florida approved a limited recreational harvest of goliath grouper. In 2021, fine-scale habitat use of three juvenile goliath grouper was investigated using acoustic telemetry and a positioning solver. All three individuals exhibited high site fidelity as well as a diel habitat use pattern, utilizing seagrass habitat during the night and mangrove habitat during the day. Fine-scale acoustic telemetry provides insight into not only habitat use, but broader habitat preferences as well. This study illustrates the need to consider deep seagrass-dominated channels lined with red mangroves when protecting juvenile goliath grouper populations within Florida Bay, especially as the population is opened to harvest.

Does hatchery rearing of lake trout affect their reproductive behavior in the wild?

Stocking of hatchery-reared fishes has been used with variable success as a management action to promote the recovery of populations and species. The practice has been controversial for several reasons, including uncertainty about whether the hatchery rearing experience may affect reproduction after release. Fine-scale acoustic telemetry was used during three spawning seasons to test whether hatchery rearing affects the reproductive behavior of lake trout using a spawning shoal complex in northern Lake Huron. Within sex, wild- and hatchery-reared fish behaved similarly, but significant behavioral differences occurred between sexes. Lake trout of both sexes moved synchronously onto the spawning shoals at the completion of autumn thermal turnover and occupied the same spawning sites (confirmed visually by presence of fertilized eggs) on the shoals. Male lake trout tended to congregate directly on spawning sites, with duration of occupancy varying greatly among years. Female lake trout spent less time on spawning shoals than males and congregated less at spawning sites on shoals. Most fish visited multiple spawning sites among shoals per season, with many making multiple transits among individual spawning sites. We found no evidence to support the hypothesis that hatchery rearing impairs spawning behavior of lake trout and, therefore, conclude that behavior deficiencies on the spawning ground are likely not an impediment to rehabilitation of lake trout in northern Lake Huron. Our study narrows the field of possible impediments to lake trout rehabilitation in the Great Lakes and provides insights that expand the conceptual model of lake trout spawning behavior.

Seasonality can affect ecological interactions between fishes of different thermal guilds

Seasonality could play a crucial role in structuring species interactions. For example, many ectotherms alter their activity, habitat, and diet in response to seasonal temperature variation. Species also vary widely in physiological traits, like thermal preference, which may mediate their response to seasonal variation. How behavioral responses to seasonality differ between competing species and alter their overlap along multiple niche axes in space and time, remains understudied. Here, we used bulk carbon and nitrogen stable isotopes combined with stomach content analysis to determine the seasonal diet overlap between a native cold-water species [lake trout (Salvelinus namaycush)] and a range-expanding warm-water species [smallmouth bass (Micropterus dolomieu)] in two north-temperate lakes over 2 years. We coupled these analyses with fine-scale acoustic telemetry from one of the lakes to determine seasonal overlap in habitat use and activity levels. We found that dietary niche overlap was higher in the spring, when both species were active and using more littoral resources, compared to the summer, when the cold-water lake trout increased their reliance on pelagic resources. Telemetry data revealed that activity rates diverged in the winter, when lake trout remained active, but the warm-water smallmouth bass reduced their activity. Combining stable isotopes and stomach contents with acoustic telemetry was a powerful approach for demonstrating that species interactions are temporally and spatially dynamic. In our case, the study species diverged in their diet, habitat, and activity more strongly during certain times of the year than others, in ways that were consistent with their thermal preferences. Despite large differences in thermal preference, however, there were times of year when both species were active and sharing a common habitat and prey source (i.e., resource overlap was greater in spring than summer). Based on our findings, important ecological processes are occurring during all seasons, which would be missed by summer sampling alone. Our study stresses that quantifying multiple niche axes in both space and time is important for understanding the possible outcomes of altered seasonal conditions, including shorter winters, already arising under a changing climate.

Using acoustic telemetry to quantify potential contaminant exposure of Vermilion Rockfish (Sebastes miniatus), Hornyhead Turbot (Pleuronichthys verticalis), and White Croaker (Genyonemus lineatus) at wastewater outfalls in southern California

Contaminant Exposure Models (CEMs) were developed to predict population-level tissue contaminant concentrations in fishes by pairing sediment-bound contaminant concentrations (DDTs, PCBs) and fine-scale acoustic telemetry data from a habitat-associated species (Vermilion Rockfish, Sebastes miniatus), nomadic flatfish species (Hornyhead Turbot, Pleuronichthys verticalis), and nomadic benthic/midwater schooling species (White Croaker, Genyonemus lineatus) tagged near wastewater outfalls in southern California. Model results were compared to contaminant concentrations in tissue samples. The CEMs developed require further refinement before implementation into management efforts but may act as steppingstones to help shift primary monitoring methods away from the regular field collection of fish for tissue contaminant analyses and towards behavioral modeling and habitat mapping. We also developed Kernel Density Estimates that can be used by managers immediately to identify regions that contribute most to contaminant exposure in species of concern. Prioritizing remediation efforts in these areas are likely to be most effective at improving fish health.

Evaluating the impact of hydropower on downstream migrating anguillid eels: Catchment-wide and fine-scale approaches to identify cost-effective solutions

Hydropower is an increasingly popular source of renewable and ‘green’ (in terms of emissions) energy, but reduced longitudinal connectivity and diverting flow through turbines can have negative impacts on catadromous anguillid eel species that have declined globally. There is an urgent need for environmental managers to perform remediation actions, such as protecting flows for migratory fish and providing passage solutions at infrastructure, under increasing legislative pressure. To deliver this, a more comprehensive understanding of eel migration in catchments with hydropower is required. Here, we illustrate the importance of catchment-wide and fine-scale acoustic telemetry, coupled with the influence of eel maturation (i.e. sex steroid levels), to determine the impact of Wairua run-of-river Power Station (WPS) on downstream migrating shortfin eels (Anguilla australis; n = 25) in Wairua River, New Zealand. Migration speed through the unregulated reach upstream of WPS was positively correlated with flow, but not eel length or sex steroids. Three eels passed a diversion weir (DW) to follow the natural watercourse and eight entered the WPS canal. Eels predominantly entered (95.2%) and were last detected (85.7%) in WPS forebay during hours of darkness. Eleven (52%) of the 21 eels that entered WPS forebay were impinged or entrained, all when three or four turbines were in operation (power generation >3.04 MW). Ten (48%) passed WPS spillway during significantly higher spill than impinged or entrained eels, with four passing during no turbine operation, after experiencing high flows near the intake (multiple receivers in WPS forebay used to quantify fine-scale behaviour). On average, eels were impinged or entrained at WPS significantly quicker (6.40 ± 11.13 days) than eels that entered the spillway (25.17 ± 15.12 days), but eel length and sex steroids did not significantly influence fate. Of the eels that migrated through the entire 55 km study reach, passage time at DW and WPS equated to 0.01–0.02% and 47.62–92.17% of their migration, respectively. Mitigation for WPS (and similar power schemes) should focus on operational or physical changes at DW to minimise eels entering power station forebay(s). Turbine shutdowns, ensuring WPS spillway is available and the provision of a bypass channel in WPS forebay are also discussed as ways to conserve the species with the potential to save costs for water resource managers.

Fine-scale acoustic telemetry in a riverine environment: movement and habitat use of the endangered Mary River cod Maccullochella mariensis

Understanding movement and habitat requirements of endangered species is critical to conservation management. We evaluate fine-scale acoustic telemetry to study breeding-related movement and habitat use of the endangered Mary River cod Maccullochella mariensis in a riverine environment and, in relation to key environmental variables, to inform management. Movement activity varied significantly in relation to water temperature and diel period, and spatial occupancy and habitat selection varied substantially in relation to the nesting behaviour of Mary River cod. Important nesting habitat included a large hollow log mid-channel and well-shaded logs and log jams adjacent to the river bank. Extrapolating this information to the general population was inhibited by relatively small sample sizes, due in part to the restricted spatial scale of the hydrophone arrays and longitudinal movements of tagged fish beyond the acoustic range of our array. Notwithstanding this, our results demonstrate that (1) fine-scale acoustic telemetry can quantify complex biological behaviours in riverine environments; (2) Mary River cod require specific environmental stimuli and habitat to support the reproductive cycle; and (3) changing environmental conditions may influence Mary River cod behaviour, and understanding this response is necessary for sustainable management. Findings from this study can inform future applications of this methodology in riverine environments and contribute to the development of management strategies and habitat restoration activities supporting the recovery of Mary River cod populations.

Movement, home range, and depredation of invasive lionfish revealed by fine-scale acoustic telemetry in the northern Gulf of Mexico

Fine-scale movement dynamics of adult invasive lionfish may inform the spatial scale of negative impacts to local food webs, the design and efficacy of ongoing removal efforts, and the speed at which lionfish may spread into new habitats, but have not previously been characterized. An acoustic Vemco positioning system (VPS) was used to track fine-scale (<10 m) movements of adult lionfish (288–395 mm total length; n = 20) tagged in situ at artificial reefs off Destin, Florida (USA). We estimated the spatial scale of movement, activity patterns, and individual home ranges, as well as whether these variables were affected by lionfish size or density. Lionfish were tracked up to 89 days and had 95% kernel utilization distribution (KUD) home ranges between 158 and 4051 m2. Daily distances moved (range 93–807 m) exceeded previous estimates, and 40% of tagged lionfish were tracked moving to reefs up to 2 km from initial tagging locations. Movement pattern and velocity data revealed two (10%) tagged lionfish were consumed by fast-moving predators, while another two emigrated outside the array. Acoustic detection of the remaining tagged fish ended prematurely following two hurricanes that passed over the array, which may implicate the storms in displacing tagged fish, causing tag loss, or contributing to lionfish mortality. Overall, results suggest invasive lionfish have larger home ranges and display greater movement than reported previously which has important implications for artificial reef management in Florida, and elsewhere, in response to the lionfish invasion.

Coarse- and fine-scale acoustic telemetry elucidates movement patterns and temporal variability in individual territories for a key coastal mesopredator

Great barracuda (Sphyraena barracuda) are a high trophic level predator that uses a wide variety of habitats globally throughout tropical and subtropical waters. Despite the important top-down pressure this species likely exerts on fish communities within its foraging territories, the specifics of spatial ecology remain relatively unknown. This study tracked 17 great barracuda throughout Buck Island Reef National Monument, a marine-protected area located in St. Croix, U.S. Virgin Islands (17.786944° N, − 64.620556° W) from July 2014 to May 2016. Broad- and fine-scale acoustic telemetry was used to examine individual variability and study population patterns in residency, site fidelity, territoriality, and complexity of spatial use within home ranges. Network analysis of broad-scale data revealed spatial and temporal differentiation among the population in location of core use areas and showed that these areas contained multiple unique receiver groups or communities, a product of spatial or temporal variation within core activity spaces. Results from the fine-scale positioning system reinforced spatial and temporal partitioning in core use areas between individuals, indicating territorial behaviors, and showed evidence for both resident and transient movements. Preliminary fine-scale analysis also suggested diel variation in location of activity spaces. Although ubiquitous throughout all shallow water habitats, detection patterns for the study population appear to be influenced by high residency, territoriality, spatial partitioning, and diel variation. Understanding the complexities of individual space use is fundamental to ecologically founded and effective area-based spatial management frameworks at community scales.

Distinct diel and seasonal behaviours in rainbow trout detected by fine-scale acoustic telemetry in a lake environment

The fine-scale behavioural activities of rainbow trout (Oncorhynchus mykiss) in nature are not well understood, but are of importance for identifying interactions with the ecosystem and of interest to conservationists and recreational anglers. We have undertaken a high-resolution acoustic telemetry study to identify the distinct movement patterns of 30 rainbow trout in a freshwater lake, specifically examining swim speed, area of movement, and site preference in both summer and winter. Activity levels were reduced in winter compared with summer across all fish, but ranking of individuals was consistent. In summer, 16/30 fish displayed diel movement, in which they travelled to a different area of the lake at dawn and returned at dusk, while other fish maintained their site preference regardless of the time of day or swam more randomly throughout the lake. These patterns were minimized in winter, where there was a reduction in cross-lake movement under ice and only 4/30 fish displayed diel movement. Winter conditions may limit the capability (physiological limitations) and (or) motivation (prey availability) for diel behaviours observed in summer.

Tropical storms influence the movement behavior of a demersal oceanic fish species

Extreme weather events strongly influence marine, freshwater, and estuarine ecosystems in myriad ways. We quantified movements of a demersal oceanic fish species (gray triggerfish Balistes capriscus; N = 30) before, during, and after two hurricanes in 2017 using fine-scale acoustic telemetry at a 37-m deep study site in North Carolina, USA. During storms, gray triggerfish movement and emigration rates were 100% and 2550% higher, respectively, than on days with no storms. We found that increased movement rates were much more strongly correlated with wave orbital velocity (i.e., wave-generated oscillatory flow at the seabed) than either barometric pressure or bottom water temperature, two covariates that have been demonstrated to be important for organisms in shallower water. Higher movement rates during storms were due to increased mobility at night, and emigrations typically occurred at night in the direction of deeper water. Overall, we found significant storm effects on the movement behavior of a demersal fish species in the open ocean, despite our study occurring in deeper water than previous studies that have examined storm effects on animal movement. We conclude that tropical storms are a driving force behind the structure of marine ecosystems, in part by influencing movements of mobile animals.

Environmental drivers of habitat use by a marine fish on a heterogeneous and dynamic reef flat

Intertidal and subtidal zones consist of heterogeneous habitats and dynamic environmental conditions, providing diverse options for fish to take advantage of marine resources. We explored how various environmental factors affected habitat use of an ecologically and economically important tropical marine fish, bonefish (Albula vulpes), on a fringing reef flat in Culebra, Puerto Rico, using a fine-scale acoustic telemetry positioning system. Machine learning algorithms and Bayesian inference via integrated nested Laplace approximation indicated diel period was the most important predictor of bonefish habitat use; bonefish occupied seagrass and mixed bottom (seagrass, macroalgae, sand) habitats most often at night, a deep-water soft sediment lagoon during the day, and infrequently used a shallow coral rubble reef crest. Zero-truncated (presence only) positioning frequency revealed more constrained utilization distributions during daytime and periods of higher water temperatures. Bonefish occupancy was highest in seagrass and mixed bottom habitats at lower water temperatures, and declined rapidly throughout the flat above 30 °C, which is consistent with temperature-mediated physiological constraints on performance (i.e. collapse of aerobic scope). Other factors including lunar phase, tidal state, and tide height had limited influence on bonefish habitat use. Building on a body of research, we propose several drivers of bonefish habitat use patterns amongst the diverse regions and habitats occupied, including predation risk, angling pressure, tidal variations, and temperature-related physiological performance. Our results emphasise the importance of conserving important seagrass foraging habitat through management and restoration.

Movement patterns of a commercially important, free-ranging marine invertebrate in the vicinity of a bait source

BackgroundCatch per unit effort is a cost-effective index of abundance and fishing effort, and an integral part of many fisheries stock assessments. Trap fisheries data are often generated using non-standardised methodology and the information to improve the accuracy of estimates is not always available due to current ecological knowledge gaps. Despite its economic importance, the European lobster Homarus gammarus has been relatively understudied compared to the closely related H. americanus. Previous studies investigating behaviour of Homarus spp. in relation to bait sources have been undertaken in aquariums or mesocosms rather than on free-ranging lobsters in the field. This study uses fine-scale acoustic telemetry data, and a null model approach to investigate free-ranging H. gammarus behaviour and movement in relation to baited commercial traps.ResultsThe distribution of lobsters {textit{n}} = 11 was largely similar in the presence and absence of traps. The time spent within 20 m of a trap ranged from 3 min to 16 h 55 min ({textit{n}} = 27), and the distance at which lobsters began approaching a trap varied considerably (5.40 m to 125 m, {textit{n}} = 22); the mean distances were larger than calculated by previous studies. A fifth of trap approaches resulted in movement against the current indicating a potential olfactory response to a bait plume. A pre-existing non-random association with a trap location may increase the time spent near the trap and reduce the minimum distance between the lobster and the trap.ConclusionsThis is the first study to assess the movement patterns of free-ranging H. gammarus in relation to a bait source. The larger approach distances in this study were likely due to the unrestricted ranging behaviour of the tagged lobsters. Aquarium and mesocosm studies provide greater experimental control, but may restrict movement and underestimate the area of bait influence. The use of null models to infer movement patterns of free-ranging lobsters has many advantages over aquarium-based studies. These include better highlighting of individual variability in behaviour, and the potential to elucidate the effects of bait plumes on catchability. Wider application of this approach can be used to improve estimates of catch and stock assessments.

Eurasian perch, Perca fluviatilis, spatial behaviour determines vulnerability independent of angler skill in a whole-lake reality mining experiment

To understand the determinants of angling vulnerability arising from the interplay of fish and angler behaviour, we tracked 33 large Eurasian perch, Perca fluviatilis, with fine-scale acoustic telemetry at a whole-lake scale while simultaneously tracking boats of small groups of experimental anglers (n = 104) who varied by self-reported skill. We report two key findings. First, perch vulnerability was strongly related to a repeatable habitat choice behaviour, but unrelated to swimming activity as a personality trait; importantly, highly vulnerable perch were captured throughout the lake and not only in their preferred habitat, suggesting covariance between spatial habitat choice and a behavioural determinant of vulnerability. Second, catch per unit effort of large perch increased with self-reported angling skill, an effect unrelated to skill-dependent lure use or an angler’s ability to encounter perch. Importantly, high-skill anglers captured more fish but not different spatial behavioural phenotypes. Our study has implications for designing protected areas by showcasing that angling could systematically alter the habitat use of exploited populations at whole-ecosystem scales, without necessarily changing average swimming activity and home range extension.

Patterns of home ranging, site fidelity, and seasonal spawning migration of barred sand bass caught within the Palos Verdes Shelf Superfund Site

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 539:255-269 (2015) - DOI: https://doi.org/10.3354/meps11482 Patterns of home ranging, site fidelity, and seasonal spawning migration of barred sand bass caught within the Palos Verdes Shelf Superfund Site Garry N. Teesdale*, Barrett W. Wolfe, Christopher G. Lowe Department of Biological Sciences, California State University, Long Beach, 1250 Bellflower Blvd, Long Beach, California 90840, USA *Corresponding author: gnteesdale@gmail.com ABSTRACT: Barred sand bass Paralabrax nebulifer (Family: Serranidae; BSB) are among the most popular recreational game fishes in southern California and an important food fish. Patterns of residency and habitat use are critical for determining the potential for BSB to be impacted by point source anthropogenic contaminants prevalent in the densely populated coastal environment near Los Angeles, California. Home ranging behavior, degree of site fidelity, residency, habitat selection, and seasonal spawning migration of BSB were observed over 27 mo using a large, continuous coverage, fine-scale acoustic telemetry array (~20 km2). The 55 tagged individuals used small core areas (mean ± SD = 2682 ± 2005 m2 over 329 ± 227 d) and showed high affinity for the rock/sand ecotone at a depth of 20 to 30 m. Overall weekly residency to the array was 70 ± 25% of tagged fish present from the first tag date through the end of the study, with lower residency during the summer spawning season (June to August). Individuals leaving the array emigrated in a southeasterly direction 98% of the time, and 100% of the BSB detections outside the array occurred to the southeast of the Palos Verdes Shelf Superfund Site (PVSSS; 26.4 ± 0.8 km). BSB of legal size (>360 mm TL) exhibit high long-term site fidelity to small areas within the PVSSS and make seasonal migrations to spawning aggregations beyond the boundaries of the ‘do not consume’ zone defined by the Office of Environmental Health Hazard Assessment in 2009. KEY WORDS: Barred sand bass · Paralabrax · Serranidae · Home range · Site fidelity · Spawning migration · Palos Verdes · Superfund · DDT · Acoustic telemetry · VPS Full text in pdf format PreviousNextCite this article as: Teesdale GN, Wolfe BW, Lowe CG (2015) Patterns of home ranging, site fidelity, and seasonal spawning migration of barred sand bass caught within the Palos Verdes Shelf Superfund Site. Mar Ecol Prog Ser 539:255-269. https://doi.org/10.3354/meps11482 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 539. Online publication date: November 12, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Fine-scale movement, activity patterns and home-ranges of European lobster Homarus gammarus

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 536:203-219 (2015) - DOI: https://doi.org/10.3354/meps11374 Fine-scale movement, activity patterns and home-ranges of European lobster Homarus gammarus Daniel J. Skerritt1,*, Peter A. Robertson2,3, Aileen C. Mill3, Nicholas V. C. Polunin1, Clare Fitzsimmons1 1School of Marine Science and Technology, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK 2Animal and Plant Health Agency, Sand Hutton, York, YO41 ILZ, UK 3School of Biology, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK *Corresponding author: daniel.skerritt@ncl.ac.uk ABSTRACT: Understanding an animal’s movement, distribution and activity pattern is vital for effective delivery of evidence-based management; however, such data are sparse for many economically important fishery targets, particularly the European lobster Homarus gammarus. This study aimed to elucidate high-resolution movement and activity patterns of a large cohort (n = 44; carapace length = 65-98 mm) of adult European lobsters, using a passive fine-scale acoustic telemetry VEMCO Positioning System (VPS) off Northumberland (UK). This is the first application of VPS on this species and the first offshore VPS study within the UK, providing novel positional data generated via triangulation based on time difference of arrival of acoustic signals. Individual home-ranges using kernel density and minimum convex polygons showed seasonal variation: 95% utilisation distribution ranged from 244 to 7722 m2 during spring (mean ± SE: 11104 ± 397 m2), and declined to 237-784 m2 during autumn (mean ± SE: 455 ± 66 m2s.e.). The study also provides evidence of behavioural differences between sexes, with males using more space than females. Daily cumulative step-length and daily minimum convex polygons highlighted that while space-use decreased during the autumn, daily distance moved increased for the majority of lobsters observed, coupled with longer durations of diel activity during autumn. These results suggest that using home-range analyses alone to describe lobster movement may inadequately represent its full behaviour. This study demonstrates the potential for passive acoustic telemetry tracking of otherwise cryptic and difficult to study marine benthic animals. KEY WORDS: Homarus gammarus · Behaviour · Diel-cycle · Acoustic telemetry · Tracking Full text in pdf format PreviousNextCite this article as: Skerritt DJ, Robertson PA, Mill AC, Polunin NVC, Fitzsimmons C (2015) Fine-scale movement, activity patterns and home-ranges of European lobster Homarus gammarus. Mar Ecol Prog Ser 536:203-219. https://doi.org/10.3354/meps11374 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 536. Online publication date: September 29, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Behavioral attributes of turbine entrainment risk for adult resident fish revealed by acoustic telemetry and state-space modeling

Background: Fish entrainment through turbine intakes is one of the major issues for operators of hydropower facilities because it causes injury and/or mortality and adversely affects population abundance. Entrainment reduction strategies have been developed based on the behavior of downstream migrating fishes, particularly diadromous species. However, knowledge of the behavior of migratory fishes has very limited application for reducing the entrainment of resident fishes, including several species that represent important recreational and aboriginal fishery resources in reservoirs. In this study, we used fine-scale acoustic telemetry and state-space modeling to investigate behavioral attributes associated with entrainment risk of resident adult bull trout (Salvelinus confluentus) in a large hydropower reservoir in British Columbia, Canada. Results: We found that adult bull trout resided longer in the vicinity of the powerhouse and moved closer to the turbine intakes in the fall and particularly in the winter. Bull trout were more likely to engage in exploratory behavior (characteristic of foraging or reduced activity) during periods when their body temperature was lower or higher than 6°C. We also detected diel changes in behavioral attributes, with bull trout distance to intakes and probability of exploratory behavior slightly increasing at night. Conclusions: We hypothesize that the exploratory behavior in the forebay is associated with foraging for kokanee (nonanadromous form of Oncorhynchus nerka), which have been shown to congregate near the dams of hydropower reservoirs in the winter. Our study findings should be applicable to bull trout populations residing in other reservoirs and indicate that entrainment mitigation (for example, use of deterrent devices) should be focused on the fall and winter. This work also provides a framework for combining acoustic telemetry and state-space models to understand and categorize movement behavior of fish in reservoirs and, more generally, in any environment with fluctuating water levels.

Using acoustic telemetry to observe the effects of a groundfish predator (Atlantic cod, Gadus morhua) on movement of the American lobster (Homarus americanus)

American lobster (Homarus americanus) landings have more than quadrupled in the last two decades (1990–2010), coinciding with the collapse of Gulf of Maine groundfish fisheries such as Atlantic cod (Gadus morhua). Recently there has been speculation that the release of lobster from predatory control may have resulted in both lower predation rates and increased foraging areas. We used fine-scale acoustic telemetry within a 200 m × 250 m field enclosure to test the hypothesis that cod induce lobsters to decrease movement and seek refuge. We found a large amount of variation in the behavioral response of individual lobsters to predators; however, the addition of cod into the enclosure reduced maximum daily home range area and significantly reduced the distance traveled from shelter habitat area for all individuals. When predators were removed from the enclosure, lobsters responded by increasing home range area and significantly increasing the distance traveled from shelter habitat area. These results represent the first experimental evidence for American lobster range contraction and subsequent expansion in the presence and absence of cod, respectively.

Home range and habitat utilization of adult California sheephead, Semicossyphus pulcher (Labridae), in a temperate no-take marine reserve

The California sheephead, Semicossyphus pulcher Ayres (Labridae), is a carnivorous, temperate, rocky-reef/kelp-bed species that is highly sought in recreational and commercial fisheries. Fine-scale acoustic telemetry tracking was used to ascertain the home range and habitat utilization of S. pulcher. Sixteen adult S. pulcher (26–38 cm SL) were surgically fitted with small acoustic transmitters and manually tracked for up to 144 h during multiple, 24-h periods between March 2001 and August 2002 within the Catalina Marine Science Center Marine Life Reserve (33°26′N; 118°29′W). A geographic information system was used to calculate home range sizes (95% kernel utilization distributions) and habitat use. Tracking of the first five fish over 24 h confirmed that S. pulcher were strictly diurnal, so the remaining 11 fish were tracked from 1 h before sunrise to 1 h after sunset. Home ranges varied greatly, from 938 to 82,070 m2, with a mean (±SD) of 15,134±26,007 m2. Variability in home range sizes among fish was attributed to differences in habitat shape (embayment vs. contiguous coastline) and to natural habitat boundaries (deep, sandy expanses) in adjacent areas within the reserve. There was a significant relationship between fish length and proportion of time spent in different habitats (sand vs. reef). S. pulcher were found within rocky-reef areas 54% of the time, and, within these areas, a greater percentage of daytime was spent in high-relief areas. Based on the relatively small size and persistence of home ranges of adult S. pulcher, no-take reserves, if they contain appropriate habitat, would provide adequate protection for their stocks.