Sex-specific vertical movements of spawning atlantic cod in coastal habitats inferred from acoustic telemetry.

Fish spawning location and behaviour can be challenging to detect, especially in deep water. Here we utilise two large acoustic telemetry datasets from western and mid Norway to study the vertical movement dimension of individual Atlantic cod Gadus morhua spawning behaviour in their natural habitats. The datasets comprise ~ 6 million depth detections from 644 sexed, mature cod, collected at seven different Norwegian coastal cod spawning grounds during 2017-2021.

Continuous sound from a marine vibrator causes behavioural responses of free-ranging, spawning Atlantic cod (Gadus morhua).

Marine vibrators are a new technology being developed for seismic surveys. These devices can transmit continuous instead of impulsive sound and operate over a narrower frequency band and at lower peak pressure than airguns, which is assumed to reduce their environmental impacts. We exposed spawning Atlantic cod (Gadus morhua) to sound produced by a prototype, but full-scale, marine vibrator, and monitored behavioural responses of tagged cod using acoustic telemetry.

Antarctic sea-ice low resonates in the ecophysiology of humpback whales.

The past six years have been marked by some of the most dramatic climatic events observed in the Antarctic region in recent history, commencing with the 2017 sea-ice extreme low. The Humpback Whale Sentinel Programme is a circum-polar biomonitoring program for long term surveillance of the Antarctic sea-ice ecosystem. It has previously signalled the extreme La Niña event of 2010/11, and it was therefore of interest to assess the capacity of existing biomonitoring measures under the program to detect the impacts of 2017 anomalous climatic events.

Use of unmanned aerial vehicles (UAVs) for mark-resight nesting population estimation of adult female green sea turtles at Raine Island.

Nester abundance is a key measure of the performance of the world's largest green turtle rookery at Raine Island, Australia, and has been estimated by mark-resight counts since 1984. Nesters are first marked by painting their carapace with a longitudinal white stripe. Painted and unpainted turtles are then counted by a surface observer on a small boat in waters adjacent to the reef.

Green turtle (Chelonia mydas) population demographics at three chemically distinct foraging areas in the northern Great Barrier Reef.

The catchments of the Great Barrier Reef (GBR) have experienced significant modifications in recent decades, leading to increases in sources of pollutants and declines in coastal water quality. As coastal waters of the GBR support some of the highest density green turtle (Chelonia mydas) foraging populations in the western Pacific Ocean, understanding the effects of contaminants on GBR green turtle populations is a priority. In 2012, elevated strandings of green turtles in the Upstart Bay region instigated the WWF's collaborative Rivers to Reef to Turtles (RRT) project to investigate if coastal pollutants are compromising green turtle health.