Right Whale Distribution Research Articles

Overview of catch history, historic abundance and distribution of right whales in the western North Atlantic and in Cintra Bay, West Africa

The catch history of the North Atlantic right whales (Eubalaena glacialis) in the western North Atlantic has been studied in a series ofprojects. Data from European archives on early Basque whaling, centred in the Strait of Belle Isle, showed that there were at least a fewthousand right whales in the northern part of the range in the sixteenth century. Data from shore whaling in the eastern United Statessupplemented by British customs data indicated that there were still more than a thousand right whales in the southern part of the range(i.e. south from Nova Scotia) in the late seventeenth century. Right whales were depleted throughout the western North Atlantic by themiddle of the eighteenth century, but small shore whaling enterprises persisted in some areas and pelagic whalers continued to kill rightwhales opportunistically. An increase in alongshore whaling occurred at Long Island (New York) beginning in the 1850s and in North andSouth Carolina, Georgia and northern Florida in the 1870s-1880s. By the start of the twentieth century only a few crews of shore whalersremained active in Long Island and North Carolina, and their whaling efforts were desultory. All evidence points to stock depletion as theprimary reason for the demise of organised whaling for right whales in eastern North America. Recent sightings indicate that some rightwhales travel from the Bay of Fundy and Scotian Shelf far to the north and east, at least occasionally reaching the historic Cape FarewellGround. Areas known to have been used regularly by right whales in the past (e.g. Gulf of St Lawrence, Delaware Bay) are now visitedseasonally by only a few individuals. Recent surveys of Cintra Bay, a historic right whale wintering ground in the eastern North Atlantic,provided no evidence of continued use by right whales.

Right whale occurrence in the coastal waters of Virginia, U.S.A.: Endangered species presence in a rapidly developing energy market

The endangered North Atlantic right whale is susceptible to increased risks associated with the developing energy market off the Virginia coast of the U.S.A., including increased noise exposure from shipping and energy exploration and extraction, and shipping activity. Primarily viewed as a migratory corridor between northern feeding and mating areas and the southern calving area, Virginia waters have not been intensely monitored for right whales. We conducted a 1 yr, continuous, passive acoustic survey from the Virginia coast to the continental shelf to better describe the seasonal occurrence and spatial distribution of right whales in this area. We found that whales were acoustically detected in every month of the year, with increased seasonal occurrences in fall and late winter/early spring, and not just during limited periods of the year. As industry activities continue to increase in the area, these new right whale occurrence data have implications for siting and permitting of offshore energy activities.

Modeling the distribution of the North Atlantic right whale Eubalaena glacialis off coastal Maine by areal co-kriging

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 24:21-31 (2014) - DOI: https://doi.org/10.3354/esr00579 Modeling the distribution of the North Atlantic right whale Eubalaena glacialis off coastal Maine by areal co-kriging Brooke Wikgren1,*, Hauke Kite-Powell2, Scott Kraus1 1New England Aquarium, John H. Prescott Marine Laboratory, Central Wharf, Boston, Massachusetts 02110, USA 2Woods Hole Oceanographic Institution, Marine Policy Center, MS 41, Woods Hole, Massachusetts 02543, USA *Corresponding author: bwikgren@neaq.org ABSTRACT: To enhance recovery of the Endangered North Atlantic right whale Eubalaena glacialis, mitigation strategies are needed to reduce the leading causes of injury and mortality of these animals, which include ship strikes and entanglement in fishing gear. Such efforts require information on the spatial and temporal distribution of right whales that can be analyzed against risk factors to identify solutions to protect whales while minimizing economic impacts to industry. Currently, no methods adequately make use of all available data to characterize right whale distribution, often leaving data gaps or misrepresenting whale activity in areas where we have limited systematic survey data. In response to this, an areal co-kriging interpolation technique was developed using ArcGIS 10.1 Geostatistical Analyst, utilizing all available right whale location data including systematic survey data, opportunistic sightings data, and satellite tag data. With many management plans shaped around specific geographic zones, this methodology was developed with the option to summarize information within user-defined polygons depending on the management regime. For this paper, whale distribution predictions were summarized to 524 irregularly shaped polygons off coastal Maine, representing lobster fishing zones at a 2 mo temporal scale. Results indicate that the predicted values fall within reasonable ranges, appropriately represent seasonal differences, and better represent right whale distribution patterns compared to other methods. KEY WORDS: Right whale · Spatial distribution · Conservation · Cetacean abundance · Endangered species · Habitat-based density model · Marine mammal · Modeling · Wildlife management Full text in pdf format Supplementary material PreviousNextCite this article as: Wikgren B, Kite-Powell H, Kraus S (2014) Modeling the distribution of the North Atlantic right whale Eubalaena glacialis off coastal Maine by areal co-kriging. Endang Species Res 24:21-31. https://doi.org/10.3354/esr00579 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 24, No. 1. Online publication date: April 09, 2014 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2014 Inter-Research.

Spatial variation in right whale food, Calanus finmarchicus, in the Bay of Fundy

We quantified small- and basin-scale variation in the energy available in right whale (Eubalaena glacialis) food, Calanus finmarchicus Copepodite-5 (C5), as a function of depth, tidal variation and circulation during the late-summer feeding period in the Grand Manan Basin of the Bay of Fundy. Food energy density (kJ m �3 ) is a function of C5 concentration (m �3 ) and individual C5 lipid energy content (J) that increases by 2 orders of magnitude from near the surface to ~18 kJ m �3 at ~160 m depth; this observation helps explain why right whales concentrate their foraging efforts at depth. Food energy density can vary by a factor of 4 over a tidal cycle and 3.5 over a hor- izontal distance of ~2 km in the deeper strata of the Basin. By tracing water mass trajectories, we show that it is the warmer, saltier and denser water that contains the highest food energy density that is tidally advected within the Basin. At the scale of the Basin (10s of kilometres) we observed maximum food energy densities of ~25 kJ m �3 in the 140 to 160 m depth stratum where the highest energy densities spatially coincide with the highest historical right whale concentrations. We con- cluded that the tidal variation and tidally driven circulation represents the simplest explanation for the distribution of food energy density and for the distribution of right whales in the Grand Manan Basin region and that Basin topography and water mass excursions associated with tidal currents facilitate the persistence of C5 aggregations in the dense deep water.

Seasonal and interannual correlations between right-whale distribution and calving success and chlorophyll concentrations in the Gulf of Maine, USA

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 394:289-302 (2009) - DOI: https://doi.org/10.3354/meps08267 Seasonal and interannual correlations between right-whale distribution and calving success and chlorophyll concentrations in the Gulf of Maine, USA Brittan L. Hlista1, Heidi M. Sosik1,*, Linda V. Martin Traykovski1, Robert D. Kenney2, Michael J. Moore1 1Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA 2Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island 02882-1197, USA *Corresponding author. Email: hsosik@whoi.edu ABSTRACT: The North Atlantic right whale Eubalaena glacialis is one of the most endangered species of large whales. Although human-caused mortality is the primary factor contributing to poor recovery of E. glacialis, variability in reproductive success may also play a role. The present study evaluates the idea that seasonal distributions and reproductive success in E. glacialis are linked to food availability or related environmental conditions that can be assessed by treating satellite-derived sea-surface chlorophyll (chl) concentration as a proxy. Sea-surface chl time series in the major high-use feeding habitats and whale-sightings data were compared. Whale transition between habitats reflects a pattern in the seasonal distribution of peak concentration in satellite-derived chl. A regionally and seasonally weighted chl index was calculated to reflect aspects of average potential food condition. We found a significant correlation between the number of whale calves born and the weighted chl averaged over the prior 2 yr. These findings are consistent with the view that food availability during and just before the gestation period may be a critical factor regulating reproductive success, with low food years contributing to delays in conception. Longer time series are necessary to examine the predictive relationship between weighted chl concentration and calf production. Although ecological interactions and whale reproductive biology are certainly more complex than can be encompassed by emphasizing only food availability, analysis of satellite-derived surface chl concentrations provides a practical means to monitor a level of ecosystem variability that affects right-whale distributions and productivity. KEY WORDS: Right whale · Eubalaena glacialis · Calving · Seasonal patterns · Ocean color · SeaWiFS · Chlorophyll · Remote sensing Full text in pdf format PreviousCite this article as: Hlista BL, Sosik HM, Martin Traykovski LV, Kenney RD, Moore MJ (2009) Seasonal and interannual correlations between right-whale distribution and calving success and chlorophyll concentrations in the Gulf of Maine, USA. Mar Ecol Prog Ser 394:289-302. https://doi.org/10.3354/meps08267 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 394. Online publication date: November 18, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.

Model-based estimates of right whale habitat use in the Gulf of Maine

Balancing human uses of the marine environment with the recovery of protected species requires accurate information on when and where species of interest are likely to be present. Here, we describe a system that can produce useful estimates of right whale Eubalaena glacialis presence and abundance on their feeding grounds in the Gulf of Maine. The foundation of our system is a coupled physical-biological model of the copepod Calanus finmarchicus, the preferred prey of right whales. From the modeled prey densities, we can estimate when whales will appear in the Great South Channel feeding ground. Based on our experience with the system, we consider how the relationship between right whales and copepods changes across spatial scales. The scale-dependent relationship between whales and copepods provides insight into how to improve future estimates of the distribution of right whales and other pelagic predators.

Probability and mitigation of vessel encounters with North Atlantic right whales

Successful mitigation of vessel-whale encounters requires quantitative estimates of vessel strikes, how strike rates change over time, where strikes are most likely to occur, and options for minimizing strikes. In addressing these issues, we first demonstrate a 3- to 4-fold increase in the number of reported large whale-vessel strikes worldwide from the early 1970s to the early 2000s, corresponding to a 3-fold increase in the number of vessels in the world fleet that is paralleled by an increase in vessel tonnage and speed. Second, we estimate a 50% chance of 14 or more annual ves- sel-strike reports worldwide between 1999 and 2002. For North Atlantic right whales Eubalaena glacialis, we estimate a 60% chance of observing at least 1 right whale death from vessel strike. Adjusting for undetermined causes of death and unobserved deaths, we estimate a 10-fold increase (from 1 to 10) in the expected annual number of fatal ship strikes. Third, we evaluate the eastern United States geographic distribution of right whales and vessels to calculate relative probabilities of vessel-whale encounters among 3 major right whale habitats. We determine that the Southern Calv- ing Ground poses the greatest threat of a vessel strike: 1.6- and 7-fold greater than in Cape Cod Bay and the Great South Channel, respectively. Finally, for the Great South Channel region we present a quantitatively determined vessel-traffic routing option that would achieve a 39% reduction in ves- sel-whale encounter probabilities. The methods employed in assessing encounter probabilities and vessel-routing options can be applied elsewhere to enhance the conservation of endangered and threatened species that suffer vessel-strike mortality.

Past and present distributions of southern right whales(Eubalaena australis)

During the 19th century, sail whalers hunted right whales throughout the southern oceans north of 50 degrees. This review seeks to document the recovery of southern right whales by comparing the northernmost recent sightings with older sightings that survive “fossilised” in historical records of the sail whaling era. Despite a steady expansion northwards in recent years, the present distribution of right whales is still far short of that recorded by sail whalers over a century ago.

Historical distribution of right whales in the North Pacific

AbstractFisheries records provide some of the only information on pre‐fishing distribution and abundance for species that were depleted before the advent of modern scientific investigations. This paper interprets records of the early history of whaling for North Pacific right whales (Eubalaena pacifica). The current population occupies only a fraction of its historical range. Historical distributions of several whale species have been inferred from charts prepared by Matthew Fontaine Maury in the early 1850s and Charles Haskins Townsend in the 1930s based on data from American whalers’ logbooks. In the North Pacific, Maury’s chart has been interpreted to show that right whales occurred continuously across the entire basin. However, we find plotting errors when we compare the North Pacific chart to the corresponding data worksheets prepared for Maury (the ‘Maury Abstracts’) and the chart appears to have misled historians and biologists. Although these charts and those in the North Atlantic are wrong, the Maury Abstracts themselves appear largely consistent with the original whaler logbooks. Our analysis shows that right whales were likely not distributed continuously across the North Pacific, but instead had a pronounced longitudinally bimodal distribution and were encountered infrequently in the central‐northern North Pacific. This work shows how valuable information can be obtained by examining original source material. The American whaling logbooks are extensive and have been largely overlooked in studies of whale populations.

NORTH ATLANTIC RIGHT WHALE DISTRIBUTION IN RELATION TO SEA‐SURFACE TEMPERATURE IN THE SOUTHEASTERN UNITED STATES CALVING GROUNDS

AbstractStandardized aerial surveys were used to document the winter (December–March) distribution of North Atlantic right whales in their calving area off the coasts of Georgia and northeastern Florida (1991–1998). Survey data were collected within four survey zones in and adjacent to federally designated critical habitat. These data, including whale‐sighting locations and sampling effort, were used to describe right whale distribution in relation to sea‐surface temperature (SST) from satellite‐derived images. Locations where whales were sighted (n= 609) had an overall mean SST of 14.3°C ± 2.1° (range 8°–22°C). Data from two survey zones having sufficient data (including the “early warning system” (EWS) zone and the Florida nearshore) were pooled by season and stratified by month to investigate changes in monthly ambient SST and fine‐scale distribution patterns of right whales in relation to SST within spatially explicit search areas. Using Monte Carlo techniques, SSTs and latitudes (means and standard deviations) of locations where whales were sighted were compared to a sampling distribution of each variable derived from daily‐search areas. Overall, results support a nonrandom distribution of right whales in relation to SST: during resident months (January and February), whales exhibited low variability in observed SST and a suggested southward shift in whale distribution toward warmer SSTs in the EWS zone; while in the relatively warmer and southernmost survey zone (Florida nearshore), right whales were concentrated in the northern, cooler portion. Our results support that warm Gulf Stream waters, generally found south and east of delineated critical habitat, represent a thermal limit for right whales and play an important role in their distribution within the calving grounds. These results affirm the inclusion of SST in a multivariate predictive model for right whale distribution in their southeastern habitat.

The distribution of right whales and Zooplankton in the Bay of Fundy, Canada

Temperature, salinity, density of Zooplankton patches, and the abundance of right whales (Eubalaena glacialis glacialis) were measured concurrently during summer and autumn of 1983 and 1984 over the Grand Manan Basin, outer Bay of Fundy. Right whales appeared to exploit patches of copepods at densities greater than about 820/m3 (170 mg m−3). Patches were composed primarily of stage V Calanus finmarchicus at depths ≥ 100 m during daylight hours. Patch densities were similar in 1983 and 1984. Potential right whale feeding areas increased in extent from late July to October, with at least two peaks of copepod biomass occurring in 1984. Right whales appear to exploit euphausiid patches in the bay only incidentally; the whales departed in 1984 when euphausiid biomass was at a maximum. The topography of the basin, prevailing summer currents, and orientation of transition zones from mixed to stratified water all combine to facilitate accumulation of copepods from the Scotian Shelf and Gulf of Maine in the central lower Bay of Fundy. This area provides an important feeding ground for this stenophagous whale species.