Vessel collision injuries on live humpback whales,Megaptera novaeangliae, in the southern Gulf of Maine

Abstract

North Atlantic humpback whales (Megaptera novaeangliae) in the Gulf of Maine overlap with both recreational and commercial vessel activity. Vessel strikes are one source of anthropogenic impact that has the potential to inhibit the recovery of this protected species. There are currently no regulations or guidelines specifically devised to reduce the likelihood of collisions for vessels transiting in the vicinity of humpback whales, except for vessels actively engaged in whale watching. To understand interactions between vessels and humpback whales better, we analyzed injuries on 624 individuals photographed in the southern Gulf of Maine from 2004 to 2013. Multiple reviewers evaluated 210,733 photos for five categories of injury consistent with a vessel strike. In total, 14.7% (n = 92) of individuals photographed showed injuries consistent with one or more vessel strikes. These results likely underestimate vessel collision rates and impacts because multiple events, events resulting in mortality, and those that involved only blunt force trauma could not be detected. Nevertheless, our results indicate that vessel strikes are underreported and that healing is dependent on the severity and location of the injury. We recommend that a management strategy be developed for all classes of vessels transiting in the vicinity of whales.

Pathology and causes of death in stranded humpback whales (Megaptera novaeangliae) from Brazil

“…Anthropogenic interactions such as vessel strikes and entanglement in fishing gear have been reported sporadically in some humpback whale populations [ 8 , 9 , 11 , 12 , 14 – 16 ]. In our study, vessel strike was the cause of death of 1/24 animals (animal no.11) while evidences of net markings, suggestive of entanglement, were observed in 4/24 individuals.…”

“…Most of the published pathology information for the species is limited to cases with prominent externally visible injuries such as those derived from entanglement in fishing gear, vessel strikes and predation by sharks [ 8 – 16 ]. Humpback whales typically strand as single individuals.…”

Satellite Telemetry Reveals Spatial Overlap Between Vessel High-Traffic Areas and Humpback Whales (Megaptera novaeangliae) Near the Mouth of the Chesapeake Bay

“…Ship strikes are a major cause of mortality for humpback whales worldwide (Bettridge et al, 2015;Hill et al, 2017). A database of global large whale ship strike records, compiled by Jensen and Silber (2004), found humpback whales to be the second most commonly struck species.…”

Boating- and Shipping-Related Environmental Impacts and Example Management Measures: A Review

“…Vessel collisions represent a key hazard to a broad range of aquatic vertebrates (e.g., turtles, dolphin, whales, and manatees (e.g., [54][55][56][57]). Such hazards will presumably continue as a consequence of continued vessel traffic expansion.…”

“…Additionally, smaller fauna is also at risk such as rays and swimming bird species [58,59]. Collisions often result in deep lacerations or anatomical injury from propeller-induced contact and/or internal injuries, or fatalities resulting from direct blows from vessel bows/hulls [55,56]. Vessel speed is one of the important factors that presumably determines the severity of a boat or ship collision but is also important regarding types of avoidance response and the efficacy of these strategies [59].…”