Acoustically Detected Year‐Round Presence of Right Whales in an Urbanized Migration Corridor

Abstract

Species' conservation relies on understanding their seasonal habitats and migration routes. North Atlantic right whales (Eubalaena glacialis), listed as endangered under the U.S. Endangered Species Act, migrate from the southeastern U.S. coast to Cape Cod Bay, Massachusetts, a federally designated critical habitat, from February through May to feed. The whales then continue north across the Gulf of Maine to northern waters (e.g., Bay of Fundy). To enter Cape Cod Bay, right whales must traverse an area of dense shipping and fishing activity in Massachusetts Bay, where there are no mandatory regulations for the protection of right whales or management of their habitat. We used passive acoustic recordings of right whales collected in Massachusetts Bay from May 2007 through October 2010 to determine the annual spatial and temporal distribution of the whales and their calling activity. We detected right whales in the bay throughout the year, in contrast to results from visual surveys. Right whales were detected on at least 24% of days in each month, with the exception of June 2007, in which there were no detections. Averaged over all years, right whale calls were most abundant from February through May. During this period, calls were most frequent between 17:00 and 20:00 local time; no diel pattern was apparent in other months. The spatial distribution of the approximate locations of calling whales suggests they may use Massachusetts Bay as a conduit to Cape Cod Bay in the spring and as they move between the Gulf of Maine and waters to the south in September through December. Although it is unclear how dependent right whales are on the bay, the discovery of their widespread presence in Massachusetts Bay throughout the year suggests this region may need to be managed to reduce the probability of collisions with ships and entanglement in fishing gear.

North Atlantic right whale occurrence near wind energy areas along the mid-Atlantic US coast: implications for management

“…Although right whales were detected between November and April, our results did not reveal a bi-modal pattern of occurrence, which one would expect if whales were migrating through the area twice: once during their southward autumn− winter migration, and again during their northward winter−spring migration (as described by Morano et al 2012). In contrast, our results show that right whales occurred in the North Carolina and Georgia sites outside of the previously documented migratory period (Winn et al 1986, Kenney et al 2001.…”

“…Monitoring efforts conducted over multiple years would not only reveal further information about right whale spatial and temporal patterns (e.g. Morano et al 2012), but could also address questions regarding demography, abundance, and habitat use. Given how little is known about right whales in the midAtlantic migratory corridor, we recommend longterm monitoring efforts be conducted along the North Carolina and Georgia coasts in the midAtlantic US.…”

“…Although this migration pattern explains the distribution of much of the right whale population, recent acoustic studies have detected right whales at times of the year when their occurrence in a region was not previously expected. For instance, Morano et al (2012) and Whitt et al (2013) documented right whale occurrence yearround in Massachusetts Bay and off the New Jersey coast, respectively, while Mellinger et al (2007) detected right whale calls on the Scotian Shelf in late December, when much of the population would be predicted to have left for more southerly areas. Similarly, the aerial survey study by Cole et al (2013) documented right whales in the central Gulf of Maine between November and January.…”

North Atlantic right whale Eubalaena glacialis occurrence in offshore wind energy areas near Massachusetts and Rhode Island, USA

“…A computer data-logging system automatically recorded survey parameters (latitude, longitude, heading, altitude) at frequent intervals (every 2−5 s) (Taylor et al 2014). Sighting locations were recorded when the detection was abeam of the aircraft, and distance in n miles from the transect line was estimated in the following classes: within 1/8; 1/8 to 1/4; 1/4 to 1/2; 1/2 to 1; 1 to 2; 2 to 4; and > 4, via calibrated markings on the wing struts (Mbugua 1996, Ridgway 2010. Survey, environmental, and sighting data were recorded via digital voice re cor der and manually transcribed post-flight.…”

Passive acoustic monitoring on the North Atlantic right whale calving grounds

“…, Spaulding et al 2010. Archival PAM has been used to effectively detect and monitor temporal changes in occurrence of N orth Atlantic right whales and N orth Pacific right whales Eubalaena japonica on their foraging grounds (Mellinger et al 2004, 2007a, Munger et al 2008, Morano et al 2012, Mussoline et al 2012, and near real-time monitoring and reporting have been used effectively for ship strike mitigation on the North Atlantic right whale foraging grounds (Spaulding et al 2010).…”