Spatial Pattern Analysis of Cruise Ship–Humpback Whale Interactions in and Near Glacier Bay National Park, Alaska

Abstract

Understanding interactions between large ships and large whales is important to estimate risks posed to whales by ships. The coastal waters of Alaska are a summer feeding area for humpback whales (Megaptera novaeangliae) as well as a prominent destination for large cruise ships. Lethal collisions between cruise ships and humpback whales have occurred throughout Alaska, including in Glacier Bay National Park (GBNP). Although the National Park Service (NPS) establishes quotas and operating requirements for cruise ships within GBNP in part to minimize ship-whale collisions, no study has quantified ship-whale interactions in the park or in state waters where ship traffic is unregulated. In 2008 and 2009, an observer was placed on ships during 49 different cruises that included entry into GBNP to record distance and bearing of whales that surfaced within 1 km of the ship's bow. A relative coordinate system was developed in ArcGIS to model the frequency of whale surface events using kernel density. A total of 514 whale surface events were recorded. Although ship-whale interactions were common within GBNP, whales frequently surfaced in front of the bow in waters immediately adjacent to the park (west Icy Strait) where cruise ship traffic is not regulated by the NPS. When ships transited at speeds >13 knots, whales frequently surfaced closer to the ship's midline and ship's bow in contrast to speeds slower than 13 knots. Our findings confirm that ship speed is an effective mitigation measure for protecting whales and should be applied to other areas where ship-whale interactions are common.

Risk of lethal vessel strikes to humpback and fin whales off the west coast of Vancouver Island, Canada

“…These species also spend extended periods of time at or near the surface, either feeding (Kot et al 2014, Constantine et al 2015 or recovering from the energetic demands of lunge-feeding at depth (Acevedo-Gutiérrez et al 2002, Goldbogen et al 2006, which increases their vulnerability (Laist et al 2001). Furthermore, most baleen whales exhibit a limited ability to manoeuvre away from close-approaching vessels, or do not attempt to avoid ships at all (Nowacek et al 2004, Harris et al 2012, McKenna et al 2015. This lack of avoidance behaviour may be caused by habituation to vessel noise (Nowacek et al 2004), failure to per-ceive the vessel as a threat, or unwillingness to cease important activities such as feeding (Panigada et al 2006, Silber et al 2010.…”

Factors affecting whale detection from large ships in Alaska with implications for whale avoidance

“…The current peak seasonal quota is 153 ship entries, and thus most days the daily maximum quota (2 ships per day) is met, although on a number of days either 1 or 0 ships enter the park. The shoulder season quota is 122 ship entries, although this quota is never met as Due to the large number of whales and narrow geography of the park, cruise ship routes overlap high-use whale habitat, resulting in a large number of ship−whale encounters (Gende et al 2011, Harris et al 2012. Lethal cruise ship−humpback whale collisions have been recorded both in the park and in nearby areas (Neilson et al 2012).…”

“…From 2008 to 2015, observers boarded cruise ships during 643 entries to record the frequency and proximity of surfacing events (encounters) of whales near the ships (see Gende et al 2011, Harris et al 2012; Fig. 1).…”

Disturbance of a rare seabird by ship-based tourism in a marine protected area

“…For our study, we built on successful methods developed by Jansen et al [32] and Harris et al [33], wherein an observer stood at the forward-most position on the bow of a cruise ship with rangefinder binoculars and, with unencumbered views of the waters in front and adjacent to the ship, recorded responses of murrelets to the ship as it traveled within the Park. Observations were made using a pair of rangefinder binoculars (Leica Vector IV, 7x 42mm, Heerbrugg, Switzerland; range up to 6 km +/- 1 m) mounted on a tripod (Manfrotto 3021BPRO, Upper Saddle River, NJ, USA) with an attached compass rose (compass rose only used in 2012).…”