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Animal telemetry is the science of elucidating the movements and behavior of animals in relation to their environment or habitat. Here, we focus on telemetry of aquatic species (marine mammals, sharks, fish, sea birds and turtles) and so are concerned with animal movements and behavior as they move through and above the world's oceans, coastal rivers, estuaries and great lakes. Animal telemetry devices ("tags") yield detailed data regarding animal responses to the coupled ocean--atmosphere and physical environment through which they are moving. Animal telemetry has matured and we describe a developing US Animal Telemetry Network (ATN) observing system that monitors aquatic life on a range of temporal and spatial scales that will yield both short- and long-term benefits, ill oceanographic observing and knowledge gaps and advance many of the U.S. National Ocean Policy Priority Objectives. ATN has the potential to create a huge impact for the ocean observing activities undertaken by the U.S. Integrated Ocean Observing System (IOOS) and become a model for establishing additional national-level telemetry networks worldwide. Background: Telemetry can provide environmental, behavioral and physiological data in near-real time, or by use of archival tags in which the data are stored or later transmitted to satellites. Aquatic animal species tagged have ranged from 6-g salmon smolts to 150-ton whales. Detailed observations of animal movements and behavior in relation to critical habitats in their aquatic environment have significantly improved our understanding of ecosystem function and dynamics. These observations are critical for sustaining populations, conserving biodiversity and implementing ecosystem-based management through an increased understanding of ecosystem structures, functions, and processes, as well as their importance to ecosystem services and values. Sensors carried by tagged animals have come of age and deliver high-resolution physical oceanographic data at relatively low costs. Animals are particularly adept at helping scientists identify critical habitats, spawning locations, and important oceanographic features (e.g., fronts, eddies and upwelling areas). They also provide important insights into regions of the oceans that are difficult and expensive to monitor (e.g., offshore environments, Arctic). This paper focuses on how to integrate an operational ATN into U.S. IOOS. Results: The development of U.S. IOOS initially focused on the acquisition and integration of physical and chemical oceanographic data. With this system now operational, U.S. IOOS is ready to add the acquisition of relevant biological observations, and to enhance the acquisition of physical and chemical oceanographic observations via ATN platforms. Conclusion: A U.S. ATN observing system that monitors aquatic life on a range of temporal and spatial scales could yield both short- and long-term benefits, ill oceanographic observing and knowledge gaps, and advance many of the National Ocean Policy Priority Objectives. ATN has the potential to create a huge impact for the ocean observing activities undertaken by IOOS and become a model for establishing additional national-level telemetry networks worldwide. [ABSTRACT FROM AUTHOR]

Background: Motion detecting archival data loggers such as accelerometers have become increasingly important in animal biotelemetry and offer unique insights into animal behavior, energetics, and kinematics. However, challenges remain for successful deployment and interpretation of data from captive and wild animals. Accelerometer sensors require being packaged in an archival tag that has a firm attachment in a fixed (known) orientation to accurately measure the relevant motion of the animal. This requirement can lead to handling stress and attachment techniques that can affect the tagged animal's natural behavior and welfare, and lead to behavioral artifacts in the data. Accelerometer data also require careful interpretation to correctly identify behavioral events of interest such as foraging. For endothermic species, changes in stomach temperature can produce temperature signatures indicative of foraging events. In this paper, we present a novel method for recording foraging events in free-swimming white sharks. Methods: We used a combination of accelerometer loggers and pop-up archival transmitting (PAT) tags (MK10, Wildlife Computers) to examine the feeding and kinematics of white sharks (Carcharodon carcharias) in the wild. We validated feeding results using a captive juvenile white shark where controlled feeding experiments could be conducted in an aquarium setting at the Monterey Bay Aquarium. We fed data logger instrument packages to eight free-swimming white sharks. Deployment durations ended naturally when the package was regurgitated and ranged from 2 to 12 days. While inside the stomach, the orientation of the data logger package was arbitrary and resulted in slow shifting over time, a challenge for normal analysis routines. We present one of these datasets to illustrate a novel methodology for calibrating accelerometer orientation, and evaluate the utility of resulting data. Results: We obtained accurate accelerometer measurements including surge, heave, and sway from data loggers with shifting orientation through data post-processing. We measured consistent dips in stomach temperature followed by a steady prolonged heating during controlled feeding events in a captive white shark. Similar thermal signatures identified in wild white shark records confirmed feeding events while acceleration data characterized the associated prey capture behavior. Conclusions: We provided proof of concept for a novel and non-invasive technique for accelerometer data logger deployment extending the possibilities for their use in bio-logging. The placement of data-logging tags in the stomachs of endothermic white sharks produced high quality tri-axial acceleration data in addition to stomach temperature data capable of detecting feeding events. The technique has the potential for distinguishing between attempted and successful foraging events. This approach to accelerometer coordinate correction could be applied in other systems where logger orientation is unknown or changes after deployment. [ABSTRACT FROM AUTHOR]

Background: Many marine species are difficult to study because components of their lifecycles occur solely or partially outside of the observable realm of researchers. Advances in biologging tags have begun to give us glimpses into these unobservable states. However, many of these tags require rigid attachment to animals, which normally requires catching and restraining the animals. These methods become prohibitive with large, dangerous, or rare species, such as large predatory sharks, and can have significant consequences for individual survival and behavior. Therefore, there is a need for methods and hardware to non-invasively and rigidly attach biologging tags to large predatory sharks that presents limited effects on the animals and researchers. Here we test a clamp tag and methods to non-invasively and rigidly attach biologging tags to white sharks (Carcharodon carcharias) in Gansbaai, South Africa. Results: We developed stainless steel dorsal fin attachment clamps with abrasive pads for deployments of biologging devices on large marine organisms. We deployed 35 tags on 34 white sharks, which after modification, remained rigidly attached to the animals up to 93 h, even through significant dynamic motions, and released from the animals with little or no effect on the animals. Conclusion: These tags and attachments present a technique and hardware to equip large predatory sharks with biologging tags without the need to catch or restrain them, and with some additional modification, these tags may remain on the animals for long periods with potentially reduced risk for both researcher and animal. [ABSTRACT FROM AUTHOR]

Background: Bluefin tunas are highly prized pelagic fish species representing a significant economic resource to fisheries throughout the world. Atlantic bluefin tuna (Thunnus thynnus) populations have significantly declined due to overexploitation. As a consequence of their value and population decline, T. thynnus has been the focus of considerable research effort concerning many aspects of their life history. However, in-depth understanding of T. thynnus reproductive biology is still lacking. Knowledge of reproductive physiology is a very important tool for determining effective fisheries and aquaculture management. Transcriptome techniques are proving powerful and provide novel insights into physiological processes. Construction of a microarray from T. thynnus ESTs sourced from reproductive tissues has provided an ideal platform to study the reproductive physiology of bluefin tunas. The aim of this investigation was to compare transcription profiles from the ovaries and testes of mature T. thynnus to establish sex specific variations underlying their reproductive physiology. Results: Male and females T. thynnus gonad tissues were collected from the wild and histologically staged. Sub-samples of sexually mature tissues were also measured for their mRNA differential expression among the sexes using the custom microarray design BFT 4X44K. A total of 7068 ESTs were assessed for differential expression of which 1273 ESTs were significantly different (p<0.05) with >2 fold change in expression according to sex. Differential expression for 13 of these ESTs was validated with quantitative PCR. These include genes involved in egg envelope formation, hydration, and lipid transport/accumulation more highly expressed in ovaries compared with testis, while genes involved in meiosis, sperm motility and lipid metabolism were more highly expressed in testis compared with ovaries. Conclusions: This investigation has furthered our knowledge of bluefin tunas reproductive biology by using a contemporary transcriptome approach. Gene expression profiles in T. thynnus sexually mature testes and ovaries were characterized with reference to gametogenesis and potential alternative functions. This report is the first application of microarray technology for bluefin tunas and demonstrates the efficacy by which this technique may be used for further characterization of specific biological aspects for this valuable teleost fish. [ABSTRACT FROM AUTHOR]