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Carroll E.L.,University of Auckland | Carroll E.L.,University of St. Andrews | Jackson J.A.,British Antarctic Survey | Paton D.,Blue Planet Marine | Smith T.D.,World Whaling History

Right whales (Eubalaena spp.) were the focus of worldwide whaling activities from the 16th to the 20th century. During the first part of the 19th century, the southern right whale (E. australis) was heavily exploited on whaling grounds around New Zealand (NZ) and east Australia (EA). Here we build upon previous estimates of the total catch of NZ and EA right whales by improving and combining estimates from four different fisheries. Two fisheries have previously been considered: shorebased whaling in bays and ship-based whaling offshore. These were both improved by comparison with primary sources and the American offshore whaling catch record was improved by using a sample of logbooks to produce a more accurate catch record in terms of location and species composition. Two fisheries had not been previously integrated into the NZ and EA catch series: ship-based whaling in bays and whaling in the 20th century. To investigate the previously unaddressed problem of offshore whalers operating in bays, we identified a subset of vessels likely to be operating in bays and read available extant logbooks. This allowed us to estimate the total likely catch from bay-whaling by offshore whalers from the number of vessels seasons and whales killed per season: it ranged from 2,989 to 4,652 whales. The revised total estimate of 53,000 to 58,000 southern right whales killed is a considerable increase on the previous estimate of 26,000, partly because it applies fishery-specific estimates of struck and loss rates. Over 80% of kills were taken between 1830 and 1849, indicating a brief and intensive fishery that resulted in the commercial extinction of southern right whales in NZ and EA in just two decades. This conforms to the global trend of increasingly intense and destructive southern right whale fisheries over time. © 2014 Carroll et al. Source

Torres L.G.,NIWA - National Institute of Water and Atmospheric Research | Smith T.D.,World Whaling History | Sutton P.,NIWA - National Institute of Water and Atmospheric Research | Macdiarmid A.,NIWA - National Institute of Water and Atmospheric Research | And 2 more authors.
Diversity and Distributions

Aim: Sufficient data to describe spatial distributions of rare and threatened populations are typically difficult to obtain. For example, there are minimal modern offshore sightings of the endangered southern right whale, limiting our knowledge of foraging grounds and habitat use patterns. Using historical exploitation data of southern right whales (SRW), we aim to better understand their seasonal offshore distribution patterns in relation to broad-scale oceanography, and to predict their exposure to shipping traffic and response to global climate change. Location: Australasian region between 130° W and 100° E, and 30° S and 55° S. Methods: We model 19th century whaling data with boosted regression trees to determine functional responses of whale distribution relative to environmental factors. Habitat suitability maps are generated and we validate these predictions with independent historical and recent sightings. We identify areas of increased risk of ship-strike by integrating predicted whale distribution maps with shipping traffic patterns. We implement predicted ocean temperatures for the 2090-2100 decade in our models to predict changes in whale distribution due to climate change. Results: Temperature in the upper 200 m, distance from the subtropical front, mixed layer depth, chlorophyll concentration and distance from ridges are the most consistent and influential predictors of whale distribution. Validation tests of predicted distributions determined generally high predictive capacity. We identify two areas of increased risk of vessel strikes and predict substantial shifts in habitat suitability and availability due to climate change. Main conclusions: Our results represent the first quantitative description of the offshore foraging habitat of SRW. Conservation applications include identifying areas and causes of threats to SRW, generating effective mitigation strategies, and directing population monitoring and research efforts. Our study demonstrates the benefits of incorporating unconventional datasets such as historical exploitation data into species distribution models to inform management and help combat biodiversity loss. © 2013 John Wiley & Sons Ltd. Source

Crawled News Article
Site: http://phys.org/biology-news/

The New Zealand southern right whale was particularly exploited in the nineteenth century when demand was high for oil extracted from its blubber. They were killed on the high seas and especially in sheltered bays where females were vulnerable while caring for their young calves. So it was easy for people to row out from the shore and kill them and for whale ships to hunt them on the open ocean. The term "right whale" was coined because they were so easy to hunt. This latest research used current estimates of abundance and population increase to reconstruct the population's trajectory over time. The findings suggest that between 29,000 and 47,000 whales were killed before the end of the nineteenth century. Numbers fell to roughly one hundred animals at the start of the twentieth century. Estimates vary as to how many may have been killed. This latest research suggests there were between 29,000 and 47,000 before the nineteenth century and that this fell to a paltry 100 animals between 1914 and 1926. Today levels stand at less than 12 per cent of pre-industrial levels. "We estimate that prior to whaling, southern right whales were very abundant in New Zealand waters and numbered between 28,000 and 33,000. If we assume most catches in the south-west Pacific were of New Zealand right whales, this number rises to 47,000. To put this in context, the estimated size of the current New Zealand population is less than 12% of these numbers. The road to recovery for this species is proving to be long - we estimate it will be at least 60 years before this population is restored to pre-hunting numbers." Emma Carroll of the University of St Andrews says: "The records of whale catches from the early nineteenth century are very patchy and we really needed to do a bit of detective work to get a good insight into the whaling history. We went back through early colonial New Zealand historical records, whaling logbooks and even had to cross-reference what ships had been seen where to get an understanding of the scale of operations during the winter in New Zealand. This has given a good insight into whaling history in New Zealand and made this population assessment possible." Historical whaling records used in this research were compiled by the World Whaling History Project, which summarised records American whaling logbook and New Zealand government records from 1800 to the present as part of the History of Marine Animal Populations and Census of Marine Life (CoML.org) initiatives. The research will be of vital importance in the planning of conservation strategies for this species and for the future protection of their habitats. More information: An integrated approach to historical population assessment of the great whales: case of the New Zealand southern right whale, Royal Society Open Science, rsos.royalsocietypublishing.org/lookup/doi/10.1098/rsos.150669

Monsarrat S.,CNRS Center of Evolutionary and Functional Ecology | Monsarrat S.,Marine Conservation Institute | Pennino M.G.,Federal University of Rio Grande do Norte | Smith T.D.,World Whaling History | And 4 more authors.
Conservation Biology

The North Atlantic right whale (NARW) (Eubalaena glacialis) is one of the world's most threatened whales. It came close to extinction after nearly a millennium of exploitation and currently persists as a population of only approximately 500 individuals. Setting appropriate conservation targets for this species requires an understanding of its historical population size, as a baseline for measuring levels of depletion and progress toward recovery. This is made difficult by the scarcity of records over this species’ long whaling history. We sought to estimate the preexploitation population size of the North Atlantic right whale and understand how this species was distributed across its range. We used a spatially explicit data set on historical catches of North Pacific right whales (NPRWs) (Eubalaena japonica) to model the relationship between right whale relative density and the environment during the summer feeding season. Assuming the 2 right whale species select similar environments, we projected this model to the North Atlantic to predict how the relative abundance of NARWs varied across their range. We calibrated these relative abundances with estimates of the NPRW total prewhaling population size to obtain high and low estimates for the overall NARW population size prior to exploitation. The model predicted 9,075–21,328 right whales in the North Atlantic. The current NARW population is thus <6% of the historical North Atlantic carrying capacity and has enormous potential for recovery. According to the model, in June–September NARWs concentrated in 2 main feeding areas: east of the Grand Banks of Newfoundland and in the Norwegian Sea. These 2 areas may become important in the future as feeding grounds and may already be used more regularly by this endangered species than is thought. © 2015 Society for Conservation Biology Source

Smith T.D.,World Whaling History | Reeves R.R.,Okapi Wildlife Associates | Josephson E.A.,Integrated Statistics | Lund J.N.,New Bedford Whaling Museum

American whalemen sailed out of ports on the east coast of the United States and in California from the 18th to early 20th centuries, searching for whales throughout the world's oceans. From an initial focus on sperm whales (Physeter macrocephalus) and right whales (Eubalaena spp.), the array of targeted whales expanded to include bowhead whales (Balaena mysticetus), humpback whales (Megaptera novaeangliae), and gray whales (Eschrichtius robustus). Extensive records of American whaling in the form of daily entries in whaling voyage logbooks contain a great deal of information about where and when the whalemen found whales. We plotted daily locations where the several species of whales were observed, both those caught and those sighted but not caught, on world maps to illustrate the spatial and temporal distribution of both American whaling activity and the whales. The patterns shown on the maps provide the basis for various inferences concerning the historical distribution of the target whales prior to and during this episode of global whaling. © 2012 Smith et al. Source

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