When fishing bites: Understanding angler responses to shark depredation

Highlights

• Shark depredation occurs in a range of recreational fisheries in the United States.

• Depredation is most common in the tuna, king mackerel, and snapper fisheries.

• Anglers and fishing guides have significantly different responses to depredation.

• Fishing guides have especially strong negative emotional responses to depredation.

• Perceiving sharks as threatening increases retaliation potential against sharks.

Abstract

Shark depredation, the full or partial removal of a hooked fish by a shark before it is landed, is anecdotally increasing in the United States. Perceptions of depredation by anglers and fishing guides may influence their behavior and have cascading effects on sharks and recreational fisheries. However, to date, these perceptions have not been broadly quantified. To better understand how anglers and guides respond to shark depredation in recreational fisheries, we used an online survey open to saltwater anglers in North America, distributed electronically via social media and online platforms. Of the 541 respondents, 77% had experienced depredation in nearshore and pelagic fisheries in the last five years, with depredation more commonly reported in the southeastern United States. Emotional responses to depredation were significantly different between anglers and guides, with the latter feeling more intense negative emotions. Behavioral changes in response to depredation, such as targeting and harvesting sharks, were driven largely by negative emotional responses and perceptions of sharks as threats to target species, while changes to protect target species varied with positive emotional responses and angler demographics. Guides were predominantly concerned about increased mortality to their target species and loss of trophy fish from the population. In fact, 87% of guides experienced depredation when fishing with clients and overwhelmingly reported that depredation has a negative effect on their livelihood. Overall, these results can be used to help inform strategies to reduce depredation while accounting for the values of stakeholder groups, particularly anglers and those advocating for shark conservation.

Introduction

Sharks are often perceived as a threat to human activities in saltwater, largely due to the nature of reporting on and popular media coverage of negative shark-human interactions (Neff, 2014, Neff, 2015, Panoch and Pearson, 2017). To date, most research has focused on the broader human perception of sharks (reviewed in Panoch and Pearson, 2017), as a threat or otherwise, rather than specific perceptions of stakeholder groups, like recreational anglers and fishing guides (see Press et al., 2016; Drymon and Scyphers, 2017 for exceptions). Despite this, shark interactions with these user groups are anecdotally increasing, particularly through depredation in recreational fisheries (see popular media for examples: Peralta, 2012; Memmott, 2013; Good Morning America, 2019; Miller, 2021). Shark depredation is the full or partial removal of a hooked fish before it is landed and can occur in recreational and commercial fisheries. How depredation affects various stakeholders (e.g., recreational anglers; professional guides) remains largely unstudied and unknown, despite anecdotal evidence that such events may powerfully shape angling behavior. Thus, there is a clear need for research on this issue.

Shark depredation is an understudied area of human-wildlife conflict, particularly with respect to recreational fisheries (Mitchell et al., 2018a, Mitchell et al., 2018b, Mitchell et al., 2019, Carlson et al., 2019). While depredation can be committed by other species, including marine mammals, seabirds, and other fish, sharks are an especially stigmatized group of potentially depredating species who could experience retaliation in response to depredation (Powell and Wells, 2011, Ferrari et al., 2015, Shideler et al., 2015). Depredation is a multifaceted issue that can affect the target species of the fishery, the depredating sharks, and the anglers. With increasing participation in saltwater recreational fisheries in the United States (U.S.) (Ihde et al., 2011, US DOI et al., 2018), their high economic value (Lovell et al., 2016, Lovell et al., 2020), and concerted management efforts to re-establish healthy shark populations (NMFS, 2006, Shiffman and Hammerschlag, 2016, Dulvy et al., 2017), understanding the ecological and social consequences of depredation in these fisheries is emerging as a pressing fisheries management need.

Depredation represents an unquantified source of mortality for target species in recreational fisheries that, if frequent, could have serious implications for stock assessments and species management (Sippel et al., 2017, Peterson and Hanselman, 2017, Tixier et al., 2020b). Some research also suggests that depredation could be a learned behavior in sharks, altering natural foraging behavior in response to the presence of fishing activity (Mitchell et al., 2020). Depredation could also result in financial loss for anglers, in the form of damaged fishing gear, losing trophy fish in a tournament, or the potential loss of return clients for charter fishing guides. Considering sharks are often a highly polarizing topic among anglers, with some seeing sharks as a threat to their catch and others valuing the importance of sharks to marine ecosystems (Press et al., 2016, Drymon and Scyphers, 2017), the potential for varied responses to depredation is high.

Angling allows participants across demographic groups to collect food while connecting more strongly with nature and each other, promoting improved psychological well-being (Toth and Brown, 1997, Freudenberg and Arlinghaus, 2010, Cooke et al., 2017, Wolsko et al., 2019). Recreational fishing efforts are currently increasing in the U.S. (Midway et al., 2021), even relative to commercial harvest (Ihde et al., 2011), with harvest from recreational fishing as the dominant source of fishing mortality for 17 of 22 species managed by the South Atlantic Fishery Management Council (Shertzer et al., 2019). Recreational angling also provides significant economic benefits to coastal communities in the U.S., supporting over 350,000 jobs and generating $7.9 - $49.6 billion of income and added economic value annually (Lovell et al., 2016, Lovell et al., 2020). Given the social and economic importance of recreational fisheries in the U.S., changes in recreational angler behavior have the potential for wide reaching economic effects across multiple industries, not just those tied directly to recreational fishing (Lovell et al., 2016).

Behavioral changes in response to shark depredation could have serious management and economic implications varying from redistributions of fishing effort, including location and target species, deciding not to hire a charter guide in the future due to a negative depredation experience, or targeting and harvesting sharks. Retaliation in response to shark depredation is of particular concern for larger bodied species that could be responsible for depredation, including but not limited to black tip (Carcharhinus limbatus), bull (Carcharhinus leucas), hammerhead (Sphyrna spp.), and white (Carcharodon carcharias) sharks, because they largely have k-selected life histories (Cortés, 2000). A fundamental lack of understanding of shark biology and ecological importance combined with fear was partially responsible for dramatic increases in recreational harvest of sharks in the U.S. through the 1970s and 1980s (Philpott, 2002, Babcock, 2008). Though targeted commercial harvest and incidental bycatch are largely responsible for the precipitous global declines in shark populations (Stevens et al., 2000, Pacoureau et al., 2021), recreational harvest can still impact shark populations (Young et al., 2014, Gallagher et al., 2016). In countries like the U.S., strict individual species or species complex management has helped to stabilize declining population trends and allowed some coastal species to show signs of recovery (Curtis et al., 2014, Peterson et al., 2017), but populations have not returned to historic levels of abundance (Jiao et al., 2009, Pacoureau et al., 2021). If shark depredation is perceived as a significant threat to anglers and guides, it could lead to unreported and/or illegal retaliatory harvest of sharks, in belief that shark populations are too abundant and mismanaged (Carlson et al., 2019). Calls for these kinds of actions are happening increasingly often on social media, with groups forming to lament the loss of depredated fish, display harvested sharks, and organize to petition regulatory changes from state and federal managers (Anonymous, 2020). Indeed, shark depredation was a main agenda item at management meetings on both the state and federal level in 2020 and 2021.¹ The need to quantify and better understand angler response to depredation is imperative as the potential for shark-angler conflict can only increase with continued successful shark management.

To date, depredation research has focused largely on quantifying depredation rates in commercial and recreational fisheries (Mitchell et al., 2018a, Mitchell et al., 2018b, Mitchell et al., 2019), while largely ignoring the social and behavioral human dimensions of this issue (Gillman et al., 2007, Iwane et al., 2021). The response of anglers to depredation could vary widely based on their potential employment as a fishing guide, previous experience on the water, motivations for fishing, perceptions of the health of their target species, and perceptions of the importance of sharks to marine ecosystems. To understand how anglers and fishing guides respond to depredation and how widespread this issue might be, we conducted an online survey targeting saltwater recreational anglers in North America. The goals of this survey were to: 1) develop a baseline understanding of which target species are being depredated most frequently; 2) quantify the emotional and behavioral responses of anglers and guides to depredation and determine how these responses may vary based on angler demographics, fishing experience, and motivations for fishing; 3) determine the role that pre-existing perceptions of sharks may play in angler and guide responses to depredation; and 4) understand how fishing guides perceive the effects of depredation on their industry.