Atlantic Bluefin Tuna Tagging Programme in Ireland 2017

It is important that stock origin, habitat utilisation and large-scale movement patterns of Atlantic bluefin are characterised in detail to ensure that the population models and concepts used in Atlantic bluefin tuna stock assessment and Management Strategy Evaluation (MSE) are parameterised as accurately as possible. Investigation of the distribution and movements of Atlantic bluefin tuna in Irish waters is now a priority for Ireland. The ocean waters off south Donegal are now regarded by the International Commission for the Conservation of Atlantic Tuna (ICCAT) as an important area for Atlantic bluefin tuna and indications are that significant numbers arrive in the area over the period August to November each year. The Department of Agriculture Food and the Marine (DAFM) requested that the Marine Institute carry out a bluefin tagging programme in autumn 2016 to support the International Commission for the Conservation of Atlantic Tuna (ICCAT) Grand Bluefin Year Programme (GBYP) Atlantic research programme for Bluefin tuna

Atlantic Bluefin Tuna Tagging Programme in Ireland 2016

It is important that stock origin, habitat utilisation and large-scale movement patterns of Atlantic bluefin are characterised in detail to ensure that the population models and concepts used in Atlantic bluefin tuna stock assessment and Management Strategy Evaluation (MSE) are parameterised as accurately as possible. Investigation of the distribution and movements of Atlantic bluefin tuna in Irish waters is now a priority for Ireland. The ocean waters off south Donegal are now regarded by the International Commission for the Conservation of Atlantic Tuna (ICCAT) as an important area for Atlantic bluefin tuna and indications are that significant numbers arrive in the area over the period August to November each year. The Department of Agriculture Food and the Marine (DAFM) requested that the Marine Institute carry out a bluefin tagging programme in autumn 2016 to support the International Commission for the Conservation of Atlantic Tuna (ICCAT) Grand Bluefin Year Programme (GBYP) Atlantic research programme for Bluefin tuna

Global trends in aquatic animal tracking with acoustic telemetry

Acoustic telemetry (AT) is a rapidly evolving technique used to track the movements of aquatic animals. As the capacity of AT research expands it is important to optimize its relevance to management while still pursuing key ecological questions. A global review of AT literature revealed region-specific research priorities underscoring the breadth of how AT is applied, but collectively demonstrated a lack of management-driven objectives, particularly relating to fisheries, climate change, and protection of species. In addition to the need for more research with direct pertinence to management, AT research should prioritize ongoing efforts to create collaborative opportunities, establish long-term and ecosystem-based monitoring, and utilize technological advancements to bolster aquatic policy and ecological understanding worldwide

Influence of Environmental Variables on the Diel Movements of the Greenland Shark (Somniosus microcephalus) in the St. Lawrence Estuary

The geographic distribution of the Greenland Shark (Somniosus microcephalus) extends from the Arctic Ocean to the North Atlantic Ocean. However, little is known about the habitat of this species, as it is generally found at great depths or in the High Arctic. In the St. Lawrence Estuary, Greenland Sharks undertake diel vertical movements into shallow water (≤ 30 m), but the reasons for these movements are unknown. To test the hypothesis that environmental variables drive the movements of this shark in the St. Lawrence Estuary, eight Greenland Sharks were tagged with acoustic telemetry transmitters during the summer of 2005. Three environmental factors, temperature, light, and tides, were associated with their movements. Movement patterns indicate a preference for deep, cold water during daylight hours and shallow, warmer water during the night. Ascending into shallow water mostly coincided with darkness and high tide. This improved understanding of the spatio-temporal distributionof the Greenland Shark will allow for assessment of the risk to these sharks from commercial fisheries, as occurs in the Greenland Halibut (Reinhardtius hippoglossoides) longline fishery. In addition, temperature-driven behavioural patterns may change as the thermal structure of the water column shifts due to global warming

Session A8: An Evaluation of Fishway Passage for Alewife (Alosa pseudoharengus)

Abstract: Alewives (Alosa pseudoharengus) are anadromous fish that often encounter fishways when migrating upstream to their spawning habitat. In partnership with Ducks Unlimited Canada, we are quantifying attraction efficiency, passage efficiency and time of movement of alewife through fishways. To do this we tagged 790 fish with Passive Integrated Transponders (PIT) and tracked their movement through two Denil style fishways. Overall attraction efficiency to fishways was 44%, but passage efficiency was ≥74%. Tagged fish were most active at dawn and dusk. Tagged alewife detected at the base of the fishway were significantly longer than undetected individuals, and may have been experienced migrants. Our data suggest that quantification of the number of migrants that are motivated to attempt passage of fishways has implications for measures of true fishway attraction and passage efficiency for defining “effective fishways”

Diversity of behavioural patterns displayed by a summer feeding aggregation of Atlantic sturgeon in the intertidal region of Minas Basin, Bay of Fundy, Canada

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

Ocean tracking network Canada: A network approach to addressing critical issues in fisheries and resource management with implications for ocean governance

The Ocean Tracking Network (OTN) Canada is an integrative seven-year research program initiated in 2010 with academic, government, and industry partners. The team makes use of novel biotelemetry (primarily acoustic telemetry curtains), biologging, and oceanographic technologies to better understand changing ocean dynamics and their impact on ocean ecosystems, animal movements, and ecology and the dynamics of marine animal populations, many of which are commercially important. The network is organized around three ocean arenas (i.e., the Atlantic, Arctic, and Pacific) where specific research projects will occur. However, all projects will contribute toward addressing a single unifying national scale question-what are the movements of continental shelf marine animals, how do these movements affect species interactions, and what are the consequences of environmental variability/change and human activities on these species\u27 distributions and abundance? Taxa that will be tracked include diadromous (e.g., salmon, eels, sturgeon) and marine (e.g., sharks, capelin, cod) fishes and a variety of marine mammals (e.g., grey seals, killer whales). Some of the common activities that occur in all arenas include measurements of oceanographic characteristics and variability at various spatial and temporal scales, movements of key species at several trophic levels, and use of key acoustic bioprobes (animals that carry tags that record locations visited, ocean conditions, and interactions with other tagged animals) and roboprobes (remotely controlled autonomous vehicles such as gliders that measure physical, biological, and chemical conditions) to complement measurements from fixed OTN acoustic telemetry curtains. Ultimately, scientific information generated will inform resource management, help formulate new socioeconomic policies, and provide some impetus to the reformulation of governance practices and legal standards

Ocean predation and mortality of adult Atlantic salmon

Predation and mortality are often difficult to estimate in the ocean, which hampers the management and conservation of marine fishes. We used data from pop-up satellite archival tags to investigate the ocean predation and mortality of adult Atlantic salmon (Salmo salar) released from 12 rivers flowing into the North Atlantic Ocean. Data from 156 tagged fish revealed 22 definite predation events (14%) and 38 undetermined mortalities (24%). Endothermic fish were the most common predators (n = 13), with most of these predation events occurring in the Gulf of St. Lawrence and from the Bay of Biscay to the Irish Shelf. Predation by marine mammals, most likely large deep-diving toothed whales (n = 5), and large ectothermic fish (n = 4) were less frequent. Both the estimated predation rates (Zp) and total mortality rates (ZM) where higher for Atlantic salmon from Canada, Ireland, and Spain (Zp = 0.60– 1.32 y−1, ZM = 1.73–3.08 y−1) than from Denmark and Norway (Zp = 0–0.13 y−1, ZM = 0.19–1.03 y−1). This geographical variation in ocean mortality correlates with ongoing population declines, which are more profound for southern populations, indicating that low ocean survival of adults may act as an additional stressor to already vulnerable populations

Conducting and interpreting fish telemetry studies: considerations for researchers and resource managers

Telemetry is an increasingly common tool for studying the ecology of wild fish, with great potential to provide valuable information for management and conservation. For researchers to conduct a robust telemetry study, many essential considerations exist related to selecting the appropriate tag type, fish capture and tagging methods, tracking protocol, data processing and analyses, and interpretation of findings. For telemetry-derived knowledge to be relevant to managers and policy makers, the research approach must consider management information needs for decision-making, while end users require an understanding of telemetry technology (capabilities and limitations), its application to fisheries research and monitoring (study design), and proper interpretation of results and conclusions (considering the potential for biases and proper recognition of associated uncertainties). To help bridge this gap, we provide a set of considerations and a checklist for researchers to guide them in conducting reliable and management-relevant telemetry studies, and for managers to evaluate the reliability and relevance of telemetry studies so as to better integrate findings into management plans. These considerations include implicit assumptions, technical limitations, ethical and biological realities, analytical merits, and the relevance of study findings to decision-making processes