Anadromous alewives (Alosa pseudoharengus) are abundant in the Canadian Maritimes, where they support lucrative commercial fisheries. Little is known about their coastal movement, and their potential ...to interact with anthropogenic structures. Acoustic telemetry can provide detailed information on the spatiotemporal distribution and survival of fishes in coastal areas, using information transmitted from tagged fishes and recorded by moored receivers. However, few acoustic telemetry studies have been performed on clupeids as they are extremely sensitive to handling, and are often compromised by surgical tag implantation. This research assesses the feasibility of a surgical tagging protocol using novel High Residency acoustic tags in alewives, and establishes a baseline of short-term tagging effects. Alewives from the Gaspereau River population were tagged between 2018 (n = 29) and 2019 (n = 96) with non-transmitting models of Vemco/Innovasea V5 HR tags. Tagging effects were evaluated based on recovery rate, reflex impairment, and necropsy-based health assessments. Alewives responded well to tagging, with low mortality (3%) and no observed instances of tag shedding 72 hours post-surgery. The use of sutures to close the incision site had no effect on recovery times. Water temperature and spawning condition had the greatest effect on the behavioural response of fish to tagging. Our findings suggest that, with proper handling and smaller acoustic tags, telemetry studies on alewives are feasible.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In the Bay of Fundy, Atlantic sturgeon from endangered and threatened populations in the USA and Canada migrate through Minas Passage to enter and leave Minas Basin. A total of 132 sub-adult and ...adult Atlantic sturgeon were tagged in Minas Basin during the summers of 2010-2014 using pressure measuring, uniquely coded, acoustic transmitters with a four or eight year life span. The aim of this study was to examine spatial and seasonal distribution of sturgeon in Minas Passage during 2010-2014 and test the hypothesis that, when present, Atlantic sturgeon were evenly distributed from north to south across Minas Passage. This information is important as tidal energy extraction using in-stream, hydrokinetic turbines is planned for only the northern portion of Minas Passage. Electronic tracking data from a total of 740 sturgeon days over four years demonstrated that Atlantic sturgeon used the southern portion of Minas Passage significantly more than the northern portion. Sturgeon moved through Minas Passage at depths mostly between 15 and 45 m (n = 10,116; mean = 31.47 m; SD = 14.88). Sturgeon mean swimming depth was not significantly related to bottom depth and in deeper regions they swam pelagically. Sturgeon predominately migrated inward through Minas Passage during spring, and outward during late summer-autumn. Sturgeon were not observed in Minas Passage during winter 2012-2013 when monitoring receivers were present. This information will enable the estimation of encounters of Atlantic sturgeon with in-stream hydrokinetic turbines.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Anthropogenic noise associated with shipping has emerged as a major disruptor of aquatic animal behavior worldwide. The Arctic marine realm has historically experienced little noise-generating human ...activity; however, the continual loss of sea ice has facilitated a dramatic increase in shipping activity. Here, we use a combination of acoustic telemetry and modeling of ship noise to examine the temporospatial habitat use of key Arctic forage fish, Arctic cod (Boreogadus saida) in the presence and absence of vessels in Resolute Bay, Nunavut, Canada. The presence and movement of vessels induced a horizontal shift in the home ranges of Arctic cod with low core overlap when compared to periods without vessel activity. Home range displacement occurred near the vessel. Individuals also altered their swimming behaviors in response to vessel presence with searching decreasing and travelling increasing in proportion. Results indicate that Arctic cod perceive vessel noise and presence as a threat and react by moving away and decreasing exploratory activities. These changes in fish behavior also coincide with the critical open water feeding period suggesting an interruption in exploitation of important and seasonally abundant food resources, and carry broader implications for dependent seabirds and marine mammals, and indirectly for all Arctic indigenous peoples’ subsistence and long-term cultural traditions. Our study implies that strategic management is required for aquatic acoustic disturbance as an environmental stressor in the Arctic marine ecosystem, and highlights ecologically and socially important impacts that require timely conservation action.
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BFBNIB, FZAB, GIS, IJS, INZLJ, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZRSKP
Sea ice reduction in the Arctic is allowing for increased vessel traffic and activity. Vessel noise is a known anthropogenic disturbance, but its effects on Arctic fish are largely unknown. Using ...acoustic telemetry — Vemco positioning system — we quantified the home ranges and fine-scale movement types (MT) of shorthorn sculpin (Myoxocephalus scorpius), a common benthic Arctic fish, in response to vessels and environmental drivers during open water over 3 years (2012–2014). Low overlap of core home ranges (50%) for all years and a change of overall MT proportions (significant in 2012 only) were observed when vessels were present compared with absent. However, changes in MTs associated with vessel presence were not consistent between years. Photoperiod was the only environmental driver that influenced (R
2
= 0.32) MTs of sculpin. This is the first study of vessel impacts on Arctic fish using acoustic telemetry and demonstrates that individuals alter their behavior and home ranges when vessels are present. Given increasing vessel traffic in the Arctic, additional study on the impact of vessels on these ecosystems is warranted.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
The anadromous alewife is a commercially fished clupeid in Atlantic Canada, whose oceanic migration is poorly understood. Migration of alewives is presently investigated from the lower ...reaches of Gaspereau River into Minas Basin, Bay of Fundy. Seventy-five post-spawning adults were tagged on their downstream migration; within two days of being tagged, most alewives had left Gaspereau River and 57 entered into the Southern Bight of Minas Basin. Thirty-one alewives were detected in Minas Passage and their average time from tagging to final detection was 28 days with standard deviation of 11 days. None of the alewives were detected in Minas Passage until day 20 after the start of tagging. After day 20, the residence timescale in Minas Basin was only 8.8 days with 95% CI of 8.4–9.3 days. Fast tidal currents prevail in much of the study area, and alewives travelled many large tidal excursions in Minas Basin and Minas Passage. Separation distances between pairs of alewives increased greatly after day 20, indicating tidal mixing over large distances within the study area. Offshore movement was associated with seasonal warming, with alewives moving down the spatial temperature gradient and into deeper waters. Offshore, larger tidal displacements widely dispersed tagged alewives through Minas Basin and to Minas Passage. During transit of Gaspereau River, 18 ± 2 alewives were lost with corroborating evidence of mortality for 4 of these. By day 20, the apparent mortality within Minas Basin was ≤ 10 alewives. Individual alewives were observed to make many transits through Minas Passage during their migration, where they may become exposed to in-stream tidal turbines.
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Tidal hydroelectric power has been proposed as one potential solution for sustainable energy sources. The first tidal turbine in North America began continuous operation in the Annapolis River ...estuary (44 °45′N; 65° 29′W) in June, 1985. The machine is an axial‐flow, hydraulic‐lift propeller turbine, a type known to cause fish mortality. Anadromous populations of American shad Alosa sapidissima, striped bass Morone saxatilis and Atlantic sturgeon Acipenser oxyrinchus utilize the Annapolis River for spawning and other life history phases. After power generation commenced obvious turbine mortalities of these fishes began appearing downstream of the turbine. Assessments of the A. sapidissima adult spawning runs during 1981–1982 (pre‐operation) and 1989–1996 (operational) indicated significant changes in population characteristics after power generation began. Adult length, mass, age and per cent repeat spawners declined and total instantaneous mortality (Z) increased from 0.30 to 0.55. The pre‐turbine spawning runs had older fish with numerous adult cohorts whereas by 12 years after operation began runs consisted of younger fish with fewer adult cohorts. During 1972–1987 numerous studies indicated the Annapolis River had an important angling fishery for M. saxatilis, but detailed annual records kept by a fishing contest during 1983–1987 and an elite angler family during the period 1976–2008 demonstrated a rapid decline in the number of fish >4.0 kg after turbine operation began. Pre‐turbine catch by the angling family of fish >4.0 kg accounted for 84.1% of total catch, but declined significantly to 39.6% of total catch from 1986–1999, and to none from 2000–2008. The existence of an A. oxyrinchus stock in the Annapolis River was unknown before turbine operation, but during 1985–2017, 21 mortalities were recovered by chance seaward of the turbine. Mechanical strike and cavitation mortalities consisted of juveniles, mature males and gravid and spent females of ages 10 to 53 years found during June to October, the period when this anadromous species returns to its natal river to spawn. The results of the long‐term studies at Annapolis indicate managers should realize substantial risks exist for the fish resources of the world's oceans from deployment of instream propeller turbines.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
White sturgeon are the largest freshwater fish in North America and are the focus of an intense catch-and-release (C&R) fishery; the effects are largely unknown. We assessed the effect of fight and ...handling time, water temperature, river discharge rate, and fish size on physiological and reflex impairment responses of wild white sturgeon to angling. Sixty of these fish were tagged with acoustic transmitters to assess survival and post-release behaviour. Survival was high (100%). Water temperature and discharge influenced post-capture blood physiology. Specifically, lactate, chloride, and cortisol concentrations were elevated in individuals fought longer, and captured at higher water temperatures and river discharge. Cortisol was affected by fish size, with lower concentrations found in larger individuals. Only lactate and chloride were positively related to reflex impairment scores. Post-release movements were correlated with physiological state, fight characteristics and the environment. Specifically, higher blood lactate and chloride and those with longer fight times moved shorter distances after release. Contrastingly, higher levels of circulating glucose and potassium, as well as larger fish captured during periods of high discharge moved longer distances. Sturgeon tended to move shorter distances and at slower rates when reflex impairment was high, although reflex impairment in general did not explain a significant proportion of the variance in any movement metric. Our results show intriguing variance in the physiological and behavioural response of individual white sturgeon to C&R angling, with some degree of environmental dependence, and highlights the importance of understanding drivers of such variation when managing fisheries.
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•Multi-faceted approach to studying the effects of angling in sturgeon•Stress physiology, reflex impairment, survival and behaviour were examined.•Survival was 100% but high variability in physiological and behavioural responses•Physiological disturbance greater in fish caught in high water temperatures and river discharges•Post-release movements related to stress physiology and environment
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IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, SAZU, SBCE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In 2009, the Fundy Ocean Research Centre for Energy (FORCE) developed a 1.6 x 1.0 km Crown Lease Area (CLA) to test Marine Hydrokinetic devices (MHKs) in Minas Passage (MP), a strait that connects ...the Bay of Fundy to Minas Basin (MB), Nova Scotia. Minas Basin is an important summer feeding aggregation site for numerous fishes including Atlantic sturgeon (Acipenser oxyrinchus Mitchill, 1815) stocks from Canada and the US. In this study, acoustic tagging technology was used to describe sturgeon presence in the CLA, as well as an adjacent site proposed for MHKs deployment. During 2018 and 2019, 33.9% (n = 19/56 Atlantic sturgeon tagged) and 29.9% (n = 23/77 Atlantic sturgeon tagged) respectively, of sturgeon acoustically tagged in MB during 2014–2019 were detected in these two FORCE sites. Binomial General Linear Models (GLMs) were fit to determine if environmental parameters influenced the presence, or depth of Atlantic sturgeon in the FORCE sites. The only significant predictor of Atlantic sturgeon depth and presence at the FORCE sites was tide type. Atlantic sturgeon was found to have a higher likelihood of being detected during ebb tide (12%) as opposed to flood tide (3%). Apparent decline in the presence of sturgeon during flood tide was probably due to poor signal reception caused by turbulence from higher current speeds. Tagged sturgeon travelled through the FORCE sites pelagically at similar depths (27.5 ± 14.57 m) to those proposed for seabed mounted MHKs (~30 m), travelling deeper during flood tide than ebb, suggesting they may be at risk of spatial overlap with MHKs. While this study indicated that the duration Atlantic sturgeon utilized the FORCE sites throughout the summer appeared to be low, sturgeon from both endangered and threatened stocks migrated through this region during their yearly entry and exit to MB and were present for approximately 12% of the days assessed in this study.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Shorthorn sculpin (Myoxocephalus scorpius) are among the most numerous consumers in the Arctic nearshore marine habitats. Despite this, little is known about their movement ecology or predator-prey ...interactions, particularly with Arctic cod (Boreogadus saida), an important forage fish in the Arctic. Using acoustic telemetry, the movements of tagged sculpin and cod were quantified based on specific locations using a Vemco positioning system during open water when both species were present in the near shore. Movement trajectories of sculpin distinguish three unique types: foraging and feeding behaviour and large transiting movements. The relative time of each of these movement types were correlated to biotic (presence of large numbers of acoustically tagged Arctic cod) and abiotic factors (percent ice coverage and temperature). This study provides unique data on the movement, feeding ecology, and behaviour of an abundant Arctic benthic fish that demonstrates similar movement types to temperate fish. However, further study is needed to quantify specifically the trophic interactions of these important fish and impact on food webs in the rapidly changing Arctic.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Quantifying animal movements can reveal spatial and temporal patterns of habitat use and may improve our understanding of the foraging strategies of marine predators where direct observations of ...feeding behaviour are rare or impossible because of turbidity. Fine-scale movement data from 25 acoustically tagged Atlantic sturgeon Acipenser oxyrinchus (Mitchill, 1815) were gathered using a Vemco Positioning System array of hydroacoustic receivers in the intertidal zone of Minas Basin, Bay of Fundy, Canada, during summer 2011. From these data, sturgeon relocations and movement trajectories were determined. Sturgeon movement trajectories were categorized into 3 movement types by analyzing 4 calculated metric variables including (1) mean distance between successive relocations; (2) mean relative angle or ‘turning angle’; (3) mean rate of movement (ROM; m s−1); and (4) a linearity ratio. Movement Type 1 trajectories were characteristically slow and winding, with short steps between relocation, whereas Type 2 movements were fast and tortuous. Movement Type 3 trajectories were fast and linear, with large steps between relocations. Considerable variability in movement type was recognized with 11 individuals performing all 3 types of movement during the monitoring period. Movement Types 1 and 2 occurred primarily over the intertidal zone, where sediment type was comprised of larger sand and sandy/silt particles. This association with larger grain size may coincide with a diet preference for sand-tube dwelling polychaetes and indicates the importance of the intertidal zone to foraging Atlantic sturgeon. All movement types were equally likely to occur throughout a 24 h day and throughout all tidal stages; however, there was higher overall crepuscular activity which revealed a temporal pattern not previously recognized for Atlantic sturgeon.
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