Abstract
The North Atlantic right whale (Eubalaena glacialis) remains one of the most endangered large whales in the world with an estimated population size of about 400 individuals at the end of 2018 (Pace et al. 2017; Hayes et al. 2019). Despite decades of protection, a combination of anthropogenic impacts and a low calving rate continue to impede recovery of the species (Kraus et al. 2016; Corkeron et al. 2018; Hayes et al. 2019). The most pressing threats to right whale survival include entanglement in fishing gear and collisions with vessels, which combined are responsible for a minimum of 86 mortalities and serious injuries in the U.S. and Canada between 2000 and 2017 (Waring et al. 2004; Waring et al. 2009; Waring et al. 2013; Hayes et al. 2019) representing approximately 20% of the extant population. In 2008, the National Marine Fisheries Service (NMFS) implemented a seasonal, mandatory vessel speed rule in certain areas along the U.S. East Coast to reduce the risk of vessel collisions with right whales. We conducted a review of the speed rule to evaluate how effective it is at reducing the incidence of right whale mortality and serious injury due to vessel strikes and where it could be improved. While it is not possible to determine a direct causal link, the number of documented vessel strike mortalities and serious injuries decreased from 12 during the 10 years prior to the rule’s implementation to 8 in the 10 years since implementation. This overall decline demonstrates progress but also indicates additional action is warranted to further reduce the threat of vessel collisions. The level of mariner compliance with the speed rule increased to its highest level (81%) during 2018-2019. In most Seasonal Management Areas (SMAs) more than 85% of vessels subject to the rule maintained speeds under 10 knots, but in some portions of SMAs mariner compliance is low, with rates below 25% for the largest commercial vessels outside four ports in the southeast. Evaluations of vessel traffic in active SMAs revealed a reduction in vessel speeds over time, even during periods when SMAs were inactive. An assessment of the voluntary Dynamic Management Area (DMA) program found limited mariner cooperation that fell well short of levels reached in mandatory SMAs. An examination of AIS-equipped small vessel traffic (< 65 ft in length) in SMAs, not subject to the rule, found the densest activity in the Mid-Atlantic where less than 50% of transit distance was below 10 knots. Off New England, small vessel traffic was sparser with 83% of transit distance under 10 knots. Our investigation of navigational safety revealed no indication of impacts from implementation of the speed rule. Finally, an economic impact assessment was conducted to evaluate the cost of compliance to the regulated community. The yearly cost to industry is estimated to be $28.3 to $39.4 million annually, with the majority of the cost (58 -70%) borne by the container ship sector. Findings from this review include recommendations for further action, including addressing low compliance in some SMA port entrance areas and insufficient cooperation with voluntary DMAs. More attention is needed to further investigate the impact of non-lethal vessel collision injuries to i right whales, assess conservation concerns with small vessel traffic and strengthen our ability to enforce the speed regulations