Tagging Response and Postspawning Movements of Pacific Herring, a Small Pelagic Forage Fish Sensitive to Handling

Abstract

Pacific Herring Clupea pallasii are an important forage fish in the northern Pacific Ocean and support commercial fisheries throughout the region, although numerous populations have experienced pronounced declines in abundance. Acoustic telemetry can enhance our understanding of the spatial and temporal distribution of depressed herring populations. However, herring are extremely sensitive to handling. During 2012-2013, we tagged 94 adult herring with acoustic transmitters on their spawning grounds in Prince William Sound, Alaska. The handling and tagging methods were specifically designed to minimize physical injuries and stress. Receiver arrays located near the spawning area (2012)(2013) and at the principal entrances into the sound from the Gulf of Alaska (2013) were used to track the postspawning movements of the fish. The herring responded well to the tagging procedures. Most were subsequently detected by the arrays, ranging from 88.0% in 2012 to 92.8% in 2013, when the entire tracking system was operational. Forty-three (67.2%) of the 64 fish detected during 2013 were recorded near entrances to the sound, representing minimum travel distances of 50-180 km. Initial movements during the spring and summer were generally to the southwest and mirrored the prevailing currents, but a number of fish were subsequently observed moving east, including one individual detected near the spawning area during the late fall and winter. Larger herring were more frequently detected near the entrances to the sound. Although it is possible that smaller fish exhibit different migratory patterns, the lower detection rate may also suggest that these individuals were adversely affected by the tagging. Our findings suggest that large-scale telemetry studies on pelagic forage fish such as herring are feasible. These data provide new insights into the migratory patterns of herring and present an opportunity to address ongoing questions related to the factors affecting the status and recovery of depressed populations.

Movement Patterns of Juvenile Sablefish within a Nursery Area in Southeast Alaska

“…Passive acoustic telemetry allows researchers to study long‐term movement monitoring, although not without caveats. Some disadvantages of using acoustic telemetry include the invasive nature of transmitter implantation, which may adversely affect the fish and its behavior (Eiler and Bishop ). Although it is sometimes apparent when a tag is expelled or mortality occurs, one may not be able to tell whether a tagged fish was consumed by a predator; however, methods to identify probable predation events by using predation tags are in development (Halfyard et al.…”

“…At least three receivers over the course of the study were encountered and had groundlines cut by fishing gear, but all receivers either were returned to researchers or were eventually recovered via grappling. Cost of acoustic telemetry, confinements of the study area, and limited battery life of the transmitters may further restrict study time and sample sizes (Eiler and Bishop ). For this study, the small size of the bay and the expected level of acoustic interference from vessel traffic restricted our sample size to 20 fish in each study year (Jonathan Mulock, Vemco, personal communication).…”

“…We monitored juvenile Sablefish movements using acoustic telemetry. Acoustic telemetry is a technique in which fish tagged with acoustic transmitters are detected by submerged hydrophones to provide detailed observations of distribution and movements (Eiler and Bishop ). Twenty juvenile Sablefish were captured for tagging on June 10, 2015, and twenty were captured on June 11 and 12, 2016.…”

Surgical Implantation of Acoustic Tags in American Shad to Resolve Riverine and Marine Restoration Challenges

“…Surgical implantation may place more acute stress on fish but can result in higher tag retention and multiple years of movement history. With reductions in tag size and battery size due to the miniaturization of components (Cooke et al 2013), expansive cooperative arrays to augment coastal tracking (Crossin et al 2017;Harcourt et al 2019), and analytical approaches that allow for many traditional inriver applications, the risks associated with surgical implantation of acoustic tags are often outweighed by the amount and types of information that can be gained, even for fragile species (Eiler and Bishop 2016). For alosines, surgical implantations should allow studies to follow individuals' and cohorts' migrations between freshwater and coastal environments over multiple years, providing information about marine movements, interannual survival, and in-river movements free of handling effects.…”

Acoustic‐telemetry payload control of an autonomous underwater vehicle for mapping tagged fish

“…Telemetry, specified for this paper as acoustic tag detection by a hydrophone distinct from telemetry as messages between a remote vehicle and user, has become an important tool for ecological and stock assessment research. Telemetry typically utilizes fixed arrays of moored omnidirectional hydrophones to detect passage or general area of space use (Heupel et al ; Reynolds et al ; Eiler and Bishop ) or if closely spaced to calculate sequential fine‐scale positions (tracks) by trilateration. (Cooke et al ; Espinoza et al ).…”