Sustainable Fisheries Management and the Welfare of Bycaught and Entangled Cetaceans

Abstract

The incidental capture of cetaceans and other protected marine wildlife in fishing gear has significant welfare implications. Many thousands of cetaceans are bycaught in fishing gear in European waters and hundreds of thousands die globally. We can expect many more to survive, but suffer from such interactions. As marine policy focuses on “population level” impact assessments and “sustainability” of fishing to preserve fish populations, the impacts to the bycaught individual, and their wider social group, are often largely underestimated, despite the large numbers affected. The wide range of recorded injuries, including abrasions, cuts, bruising, and broken bones, along with the potential for panic associated with forced submersion, indicate that the welfare of bycaught cetaceans is, individually and collectively, very poor. Commercial fishing is the last human activity targeting wildlife (fish) on a grand scale where slaughter includes incidental killing of other large sapient wildlife on such a regular basis. Here, we review the compelling evidence of the short and long term welfare impacts of bycatch, and the progress made toward implementation of measures to understand and solve this significant welfare issue. We argue that policy decisions surrounding fishing do not adequately consider cetacean bycatch, including welfare impacts. Ultimately, there are welfare issues in all bycatch situations and suffering cannot plausibly be reduced without preventing bycatch. The well-documented welfare implications provide a strong argument for zero tolerance of cetacean bycatch and provide a compelling case for immediate action in fisheries where bycatch is taking place. The only way to reduce the suffering of bycaught cetaceans is to decrease, or ideally eliminate, the number of animals caught in fishing gear. Uncertainties around the scale of bycatch should not delay management, even where individual bycatch estimates are considered “sustainable.” Lack of monitoring of sub-lethal impacts on populations may result in flawed impact assessments. We urge that animal welfare considerations should become an integral part of management decision-making in relation to bycatch globally. Enhanced, robust and transparent management systems are urgently required for the range of fisheries within which cetacean bycatch occurs, with the aim to better document and most importantly, work toward eliminating cetacean bycatch altogether.

Retrospective Study of Fishery Interactions in Stranded Cetaceans, Canary Islands

“…In addition, most fishery interaction findings (except gear cuts and impressions) are not pathognomonic (4,5). Nonetheless, fisheries are considered a major global threat to cetaceans (34). Bycatch especially affects the harbor porpoise (Phocoena phocoena), bottlenose dolphin, common dolphin, and striped dolphin [e.g., (1,35,36)].…”

“…Bycatch especially affects the harbor porpoise (Phocoena phocoena), bottlenose dolphin, common dolphin, and striped dolphin [e.g., (1,35,36)]. Furthermore, cases of chronic entanglements appear to be on the rise globally (8,10), and their effects in certain baleen populations such as the minke whale is concerning (34). In the Canary Islands, fishing is mainly artisanal and multispecific, and is characterized by the use of small vessels (≤15 m in total length) and various types of fishing gear.…”

Common and Antarctic Minke Whales: Conservation Status and Future Research Directions

“…It has been estimated that 70% of entanglement cases for this species are fatal (Lien, 1994). More recently, several studies have highlighted the long-term consequences of entanglement and animal welfare implications for individuals, often suffering serious health effects over many years, and urged policy and management action to be more inclusive of these issues (Cassoff et al, 2011;Moore and van der Hoop, 2012;Dolman and Moore, 2017;Dolman and Brakes, 2018).…”

Protein Identification of Spermatozoa and Seminal Plasma in Bottlenose Dolphin (Tursiops truncatus)

“…Cetaceans, aquatic mammals from the Cetacea infraorder, are considered essential for marine ecosystems (Bowen, 1997;Uhen, 2007). Their populations are under enormous anthropogenic pressure, especially as a result of commercial overfishing, incidental captures in fisheries, and habitat degradation (Reeves et al, 2003;Parsons et al, 2014;Dolman and Brakes, 2018). Indeed, many cetacean species are threatened or in danger of extinction (Davidson et al, 2012).…”