Counting sperm whales and visualising their dive profiles using two-hydrophone recordings and an automated click detector algorithm in a longline depredation context

Pinson, Samuel; Richard, Gaëtan

doi:10.1101/2022.09.06.506716

Cited by 1 publication

(1 citation statement)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Whether and how whales may be engaging in foraging during other fishing activities, such as preying on the fish escaping the net during towing requires further research. Whale behavior during towing and in particular any interaction with the net could be studied using passive acoustic techniques [ 33 ], trawl cameras [ 34 ] and possibly drones [ 35 ].…”

Section: Discussionmentioning

confidence: 99%

Sperm and northern bottlenose whale interactions with deep-water trawlers in the western North Atlantic

Oyarbide,

Feyrer,

Gordon

2023

PLoS ONE

View full text Add to dashboard Cite

Commercial fisheries have increased in all the world’s oceans with diverse unintended impacts on marine ecosystems. As a result of resource overlap, interactions between cetaceans and fisheries are a common occurrence and, in many cases, can give rise to significant conservation issues. Research on the distribution and types of such interactions is important for efficient management. In this study, we describe the behaviors of two whale species: sperm whales (Physeter macrocephalus) and northern bottlenose whales (Hyperoodon ampullatus), interacting with benthic trawlers fishing off the eastern Grand Banks of the western North Atlantic in 2007. Whale interactions were only observed when vessels were targeting Greenland halibut (Reinhardtius hippoglossoides) in deep-water fishing areas and were most common during net hauling. Sperm whales and northern bottlenose whales appeared to engage in feeding behavior close to the surface during hauling, especially during the latter stages, suggesting they targeted fish escapees rather than discards. Using photo-identification methods, seven individual sperm whales were identified with multiple resights of six individuals being recorded over an almost two month period. The maximum distance between two resights was 234 km, suggesting individual sperm whales were repeatedly targeting and even following fishing vessels over multiple days and between fishing areas. By contrast, there were no photographic resights of individual northern bottlenose whales within this study, or with substantial photo-identification catalogues from other adjacent high density areas, suggesting that individuals of this species may be less likely to follow vessels or move between areas. This study documents the earliest confirmed records of northern bottlenose whales in this remote region. These interactions and high encounter rates may indicate that adjacent populations are recovering from the previous century of commercial whaling. Our study provides new insights and details on whale-fisheries interactions, which can inform future research and help managers understand the real and perceived impacts of depredation behaviour on fisheries and whales.

show abstract

Section: Discussionmentioning

confidence: 99%