The Impact of Vessels on Humpback Whale Behavior: The Benefit of Added Whale Watching Guidelines

Abstract

The concurrent increase in marine tourism and vessel traffic around the world highlights the need for developing responsible whale watching guidelines. To determine the impact of vessel presence on humpback whale behaviors in Maui Nui, a land-based study was conducted from 2015 to 2018 in Maui, Hawai'i. Theodolite tracks were used to summarize humpback whale swim speed, respiration rate, dive time, and path directness to determine the potential impacts of various types of vessel presence on whale behavior. Vessel presence, proximity, and approach type in conjunction with biological parameters were used in a generalized additive modeling framework to explain changes in whale behaviors. The results presented here show increases in swim speed, respiration rate, and path directness in conjunction with decreasing dive times, which has been shown to be an energetically demanding avoidance strategy. These observations, in conjunction with increasing awareness on the implication of non-lethal effects of human disturbance and changing oceanic environments on humpback whales, highlights the need for a pre-cautionary approach to management. Stricter guidelines on whale watching will limit the level of disturbance to individual humpback whales in Hawai'i and ensure they maintain the fitness required to compensate for varying ecological and anthropogenic conditions.

Beluga (Delphinapterus leucas) response to personal watercraft and motorized whale watching vessels in the Churchill River estuary

“…SOR/ 2018-126, 2018). There is evidence that increased proximity of vessels to whales may result in increased negative behavioral reactions (Steckenreuter et al, 2012;Schaffar et al, 2013;Currie et al, 2021). With decreasing distance to vessels, southern resident killer whales showed increases in respiration interval and path deviation as well as exhibiting more surface behaviors (Noren et al, 2009;Williams et al, 2009).…”

“…Intensity of tourism, vessel type (Pirotta et al, 2015), vessel maneuvering (Filby et al, 2014;Argüelles et al, 2016;Arias et al, 2018), management regulations (Tosi and Ferreira, 2009) and vessel compliance to regulations has been shown to affect cetacean response to whale-watching (Corkeron, 1995;Stamation et al, 2010;Hoarau et al, 2020). Tourism should therefore be closely monitored as energetic costs associated with whale behavioral reactions can affect the fitness of individuals and thus survival of a population (Bejder et al, 2006b;Lusseau et al, 2006;Williams et al, 2006;Lusseau and Bejder, 2007;Christiansen et al, 2013a;Christiansen et al, 2013b;Christiansen et al, 2014;Currie et al, 2021).…”

“…Avoidance includes both vertical distancing by diving (Lusseau, 2003b;Stamation et al, 2010), and horizontal distancing by moving away from vessels (Steckenreuter et al, 2012). Horizontal avoidance of vessels by cetaceans includes more changes in travel direction (Lemon et al, 2006;Richter et al, 2006;Amrein et al, 2020), increased swimming speed (Magalhães et al, 2002;Scheidat et al, 2004;Avila et al, 2015) and combinations of these behaviors (Kruse, 1991;Williams et al, 2002;Bejder et al, 2006a;Williams et al, 2009;Stamation et al, 2010;Schuler et al, 2019;Currie et al, 2021;Santos-Carvallo et al, 2021). Attraction, interaction, positive reactions, and approach are terms that have been used to describe similar behaviors of cetaceans approaching vessels, traveling with vessels, and swimming around or underneath tourism vessels (Constantine, 2001;Gregory and Rowden, 2001;Arcangeli and Crosti, 2009;Stamation et al, 2010;Malcolm and Penner, 2011;Steckenreuter et al, 2012;Filby et al, 2014;Hoarau et al, 2020).…”

Seasonal and diel patterns in singing activity of humpback whales migrating through Bermuda

“…The presence of humpback whales, being continuously present from late December until mid-May (Figure 3), already coincides with the start of the current cruise season; should the new cruise season be rolled out, this temporal overlap will increase. Besides increased risks from ship strikes and behavioural disturbance from prolonged and more intense whale-watching, cruise and freight passages through Bermuda, growth in the tourism sector will further elevate ambient noise levels (e.g., through coastal infrastructure construction and increased vessel noise) which reduce humpback whales' communication space (Au and Green, 2000;Jones, 2011;Micheli et al, 2012;Dunlop, 2016;Lester et al, 2016;Cholewiak et al, 2018a;Gabriele et al, 2018;Sprogis et al, 2020;Currie et al, 2021). In response to elevated noise levels male humpback whales have been shown to cease their song (Sousa-Lima and Clark, 2008;Risch et al, 2012;Cerchio et al, 2014;Tsujii et al, 2018), lengthen their song cycle (Miller et al, 2000) and amplify their vocalisation display, exhibiting the Lombard effect (Guazzo et al, 2020).…”

“…Increased vessel traffic and marine tourism can have various negative impacts on humpback whales, from behavioural disturbance, increased stress levels and physical injuries, to disturbing their crucial auditory sensory system and communication (Au and Green, 2000;Cholewiak et al, 2018a;Fiori et al, 2020;Sprogis et al, 2020;Currie et al, 2021). Humpback whales produce low to mid frequency vocalisations (ranging from 0.01-28 kHz), but like all baleen whales most energy is produced in the lower frequencies (below 2 kHz), which can propagate across an entire ocean basin (Payne and Webb, 1971;Hannay et al, 2013;Cerchio et al, 2014;Huang et al, 2016;Cholewiak et al, 2018a;Davis et al, 2020).…”