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Two laboratory studies evaluated small Chinook salmon (Oncorhynchus tshawytscha) (36-99 mm fork length (FL), 0.7%-26.7% tag burden) survival, tag retention, and growth (n = 539) and critical swimming speed ([U.sub.crit]; n = 241). Fish were implanted with a new active acoustic tag and compared with untagged controls at 12 and 17 [degrees]C. Across studies, no temperature differences were detected. All control fish survived. All tagged fish [greater than or equal to] 58 mm FL survived and retained their tags. Regression models predicted [greater than or equal to] 98.6% survival and retention for tagged fish [greater than or equal to] 58.6 mm FL or [greater than or equal to] 1.9 g (4.2% tag burden). No growth differences among treatments were identified. Spline regression analysis indicated [U.sub.crit] was similar for control and tagged fish that measured [greater than or equal to] 57.3 mm FL. We recommend tagging salmon [greater than or equal to] 59 mm FL or [greater than or equal to] 1.9 g ([less than or equal to] 4.2% tag burden), although the guideline should be confirmed in a field setting. Study results represent an important step towards using the new active tag in acoustic telemetry field studies that estimate short-term (30-day) survival of small salmonids. Deux etudes en laboratoire ont permis d'evaluer la survie, la retention d'etiquettes et la croissance (n = 539), ainsi que la vitesse de nage critique ([U.sub.crit]; n = 241) de petits saumons chinooks (Oncorhynchus tshawytscha, longueur a la fourche (LF) : 36-99 mm; fardeau de l'etiquette : 0,7-26,7 %). Une nouvelle etiquette acoustique active a ete implantee dans des poissons, qui ont ete compares a des temoins non etiquetes a 12 et 17 [degrees]C. Aucune difference n'a ete relevee entre les etudes en ce qui concerne la temperature. Tous les poissons temoins ont survecu. Tous les poissons etiquetes de LF [greater than or equal to] 58 mm ont survecu et conserve leur etiquette. Des modeles de regression ont predit des taux de survie et de retention de [greater than or equal to] 98,6 % pour les poissons etiquetes de LF [greater than or equal to] 58,6 mm ou de masse [greater than or equal to] 1,9 g (fardeau de l'etiquette : 4,2 %). Aucune difference sur le plan de la croissance n'a ete relevee entre les traitements. L'analyse de regression par spline fait ressortir des [U.sub.crit] semblables pour les poissons temoins et les poissons etiquetes de LF [greater than or equal to] 57,3 mm. Nous recommandons l'etiquetage de saumons de LF [greater than or equal to] 59 mm ou de masse [greater than or equal to] 1,9 g (fardeau [less than or equal to] 4,2 %), cette directive devant toutefois etre confirmee sur le terrain. Les resultats des etudes constituent un pas important vers l'utilisation de la nouvelle etiquette active dans des etudes de telemetrie acoustique de terrain qui estiment la survie a court terme (30 jours) de petits salmonides. [Traduit par la Redaction], Introduction Advancements in active acoustic telemetry technology (reduced tag size, improved power outputs, signal strength, and battery life) have allowed researchers to push the limits of acceptable size-at-tagging guidelines for [...]

Fish that undertake juvenile migration pass through habitats that vary in mortality risk. The ability to identify regions of persistently low survival would improve fishery management. We conducted a field study combined with predictive modeling of survival in downstream migrating juvenile sea lamprey using a new micro-acoustic telemetry tag designed for implantation into small, slender-bodied fishes. Detection data were collected from eight receivers placed across a coastal riverine–wetland–lake complex. Juvenile sea lamprey initiated downstream movement near nautical twilight, stopped frequently, and were more likely to move during high river discharge. Estimated survival was highest in the riverine reach, declined through the river–wetland complex, and dropped precipitously in the drowned rivermouth lake. However, the high transmission rate and resulting short battery life of the microtransmitters (as configured) likely resulted in missed detections in the lower reaches. Simulation analyses suggested survival estimation could be improved by increasing the number of tagged lamprey and staggering release locations. We offer practical recommendations for the use of this new transmitter in field studies with small anguilliform fish. [ABSTRACT FROM AUTHOR]

The potential effects of underwater anthropogenic sound and substrate vibration from offshore renewable energy development on the behavior, fitness, and health of aquatic animals is a continuing concern with increased deployments and installation of these devices. Initial focus of related studies concerned offshore wind. However, over the past decade, marine energy devices, such as a tidal turbines and wave energy converters, have begun to emerge as additional, scalable renewable energy sources. Because marine energy converters (MECs) are not as well-known as other anthropogenic sources of potential disturbance, their general function and what is known about the sounds and substrate vibrations that they produce are introduced. While most previous studies focused on MECs and marine mammals, this paper considers the potential of MECs to cause acoustic disturbances affecting nearshore and tidal fishes and invertebrates. In particular, the focus is on particle motion and substrate vibration from MECs because these effects are the most likely to be detected by these animals. Finally, an analysis of major data gaps in understanding the acoustics of MECs and their potential impacts on fishes and aquatic invertebrates and recommendations for research needed over the next several years to improve understanding of these potential impacts are provided. [ABSTRACT FROM AUTHOR]