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Behaviors of Grey Seals (<I>Halichoerus Grypus</I>)

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Behaviors of Grey Seals (<I>Halichoerus Grypus</I>) Tourism in Marine Environments, Vol. 15, No. 3–4, pp. 159-171 1544-273X/20 $60.00 + .00 Printed in the USA. All rights reserved. DOI: https://doi.org/10.3727/154427320X15945013137030 Copyright © 2020 Cognizant, LLC. E-ISSN 2169-0197 www.cognizantcommunication.com BEHAVIORS OF GREY SEALS (HALICHOERUS GRYPUS) ADDRESSED TOWARDS HUMAN SWIMMERS DURING EXPERIMENTAL OPEN WATER ENCOUNTERS OFF HELIGOLAND (GERMAN BIGHT, NORTH SEA) MICHAEL SCHEER Independent Scholar, Bremen, Germany Risks arising for humans during swim encounters with seals are poorly understood. This study was initiated to examine behaviors of unhabituated grey seals addressed towards humans during experi- mental, noncommercial seal-swim activities off Heligoland. In total, 26 in-water encounters were conducted. Behavioral classes and the number of seals simultaneously approaching swimmers were time sampled. A set of risky and nonrisky interactive behaviors was continuously sampled. Seals spent approximately the same amount of time interacting with swimmers (53%) as they did ignoring them (47%). Seals displayed higher rates of nonrisky behaviors than risky ones, but risky behaviors occurred during 73% of all seal-swims. Seals remained ≤20 m near swimmers for 51% and ≤1 m for 13% of the time. A mean number of 0.65 and 0.18 seals approached swimmers per minute within a range of ≤20 m and ≤1 m, respectively. Behavioral classes, interactive behaviors, and the number of seals approaching ≤20 m did not vary significantly throughout seal-swims but the number of seals approaching ≤1 m moderately decreased. Due to high rates of risky behaviors, it is recommended to promote public awareness on site and to regulate seal-swims before commercial operations emerge. Key words: Grey seals; Halichoerus grypus; Tourism; Swim-with seals; Behavior Introduction approaches, swim-with-seals activities in wild settings have become a popular and growing segment of this Pinniped-focused tourism is part of the marine industry (Constantine, 1999; Curtin & Garrod, 2008; wildlife tourism industry that has increased rapidly Kirkwood et al., 2003; Muir, Barnes, & Reid, 2006; (Cowling, Kirkwood, Boren, & Scarpaci, 2014; Newsome & Rodger, 2008; Scarpaci, Nugegoda, & O’Connor, Campbell, Cortez & Knowles, 2009; Corkeron, 2005). Past research has demonstrated Stafford-Bell, Scarr & Scarpaci, 2012; Strong negative impacts of land- and boat-based approaches & Morris, 2010). Next to land- and boat-based by tourists for seals during commercial activities Address correspondence to Michael Scheer, Brunnenstrasse 15-16, 28203 Bremen, Germany. Tel: +49(0)173 238 61 56; E-mail: [email protected] Delivered 159by Ingenta IP: 80.134.236.247 On: Sat, 17 Oct 2020 11:41:13 Article(s) and/or figure(s) cannot be used for resale. Please use proper citation format when citing this article including the DOI, publisher reference, volume number and page location. 160 SCHEER (e.g., Boren, Gemmell, & Barton, 2002; Cassini, Salgado Kent, & Robinson, 2017; Stafford-Bell et 2001; Henry & Hammill, 2001; Holcomb, Young, al., 2012). During one extreme case, a diver was & Gerber, 2009; Kovacs & Inness, 1990). However, drowned by a leopard seal (Hydrurga leptonyx) seal-swim activities remain understudied (Curtin & (Muir et al., 2006). Muir et al. (2006) pointed out Garrod, 2008; Kirkwood et al., 2003). that people who want to encounter free-ranging Commercial swim-with programs targeting wild seals are at risk, and they need appropriate infor- pinnipeds have become critical, and research is mation about potential hazards. needed on behavioral responses initiated by the From a management perspective, understand- animals. Although swimmers often try to attract or ing close encounters with seals can inform recom- to closely approach seals in the water (Boren, Gem- mendations to reduce the likelihood of aggressive mell, & Barton, 2009), it generally depends on the and dangerous interactions. Kirkwood et al. (2003) animals to initiate or terminate contact, or to avoid stated that commercial seal-swim activities in humans and stay out of sight. However, the level of wild settings are one of the most critical areas habituation, swimmer behavior during encounters, where research is needed to foster regulations. It as well as the presence or absence of guidelines was proposed that baseline and longitudinal stud- and guides may influence the nature of encoun- ies be conducted before commercial programs are ters. During commercial and unguided swim-with implemented and to introduce species-specific activities with habituated animals, Australian fur regulations (Curtin & Garrod, 2008; Kirkwood et seals (Arctocephalus pusillus doriferus) were al., 2003; Öqvist, Granquist, Burns, & Angerbjörn, found to increase haul-out events in response to 2018). While the responses of animals being habit- human swimmers (Stafford-Bell et al., 2012) and uated to commercial swim activities have been New Zealand fur seals (Arctocephalus forsteri) studied for some pinniped species and regions interacted with swimmers but mostly ignored them (Boren et al., 2009; Cowling et al., 2014; Dans et (Cowling et al., 2014). Boren et al. (2009) showed al., 2017; Osterrieder et al., 2017; Scarpaci et al., that the presence of guides during commercial 2005; Stafford-Bell et al., 2012), behavioral studies swims reduces the number of avoidance responses on in-water encounters with unhabituated animals among New Zealand fur seals because guides man- are absent. Such insights are essential to outline aged inappropriate swimmer behaviors. In many and understand natural responses before commer- areas where seal swims occur, there are no regu- cial operations are established. lations or guidelines present (Öqvist, Granquist, In the North Sea, growing populations of grey Burns, & Angerbjörn, 2018). seals (Halichoerus grypus) are increasingly inter- Next to negative impacts for seals, humans can acting with humans. For example, at the South experience health risks as well. As pointed out by Devon coastline (UK), 70,000 tourists are annually Moscardo, Taverner, and Woods (2006), the poten- engaged in watching and swimming with grey seals tial effects of wildlife on tourist safety remain (Curtin, Richards, & Westcott, 2009), and such understudied. Swimmers and divers often are in activities represent a significant economic potential close contact with the animals in their open water (Bosetti & Pearce, 2003). The most economically environments and thus are exposed to unpredict- productive seal watching sites are those that can able behaviors. Seals were reported to address be easily approached, are close to human popula- inquisitive behaviors towards swimmers such as tion centers, and have spatial and temporal predict- encircling, close approaches, mimicking of human ability for viewing the animals (Curtin & Garrod, postures, and establishing physical contact in a 2008; Kirkwood et al., 2003). The island of Heli- neutral way. However, behaviors of the seals also goland has several ferry and flight connections to included potentially threatening displays: they the mainland and provides a sound and relatively were shown to chase, duck, pull, and bite swim- cheap touristic infrastructure. However, there is a mers and divers, and they showed threat and sexual lack of regulations regarding human contact with behaviors (Boren, 2001; Constantine, 1999; Dans, pinnipeds. From 2008 to 2011, more than 300,000 Crespo, & Coscarella, 2017; Kirkwood et al., 2003; tourists annually visited the island and about 50% Martinez, 2003; Muir et al., 2006; Osterrieder, of them came to Dune islet (Gemeinde Heligoland, Delivered by Ingenta IP: 80.134.236.247 On: Sat, 17 Oct 2020 11:41:13 Article(s) and/or figure(s) cannot be used for resale. Please use proper citation format when citing this article including the DOI, publisher reference, volume number and page location. GREY SEAL BEHAVIOR TOWARD SWIMMERS 161 2011). Grey seals on Dune islet have become a by them during their 20–30 min swims (personal popular wildlife attraction in recent years with observation). Though scratches were reported to the animals being annually confronted with land- happen incidentally by seals during rapid underwa- based approaches mainly during the pupping sea- ter approaches, swimmers chose to wear wetsuits son in wintertime. Habituation effects are unknown to protect themselves. Regulations, guidelines, or because residency and migration patterns remain educational signs do not exist on site to this date. unstudied so far for local animals. Thus, there is a growing concern among wildlife For breeding, females at UK breeding sites managers about the potential negative impacts for typically return to the site where they were born human bathers, snorkelers, and divers. (Pomeroy, Anderson, Twiss, & McConnell, 1994). Behaviors displayed by seals and addressed By extrapolating this to Dune islet, the chance of towards swimmers and divers during open water successive contacts with humans across seasons encounters have received little attention by research- is quite probable. For the summer months, an ers. Thus, their structure and function mostly unknown fraction of tourists uses local beaches for remain unclear. Furthermore, seal-swim activities recreational activities such as bathing, diving, and with unhabituated animals remain understudied so snorkeling. Consequently, humans have had occa- far. This study was conducted to experimentally sional and incidental contact with grey seals. How- investigate responses of grey seals during
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