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Lambert E.,University of Aberdeen | MacLeod C.D.,University of Aberdeen | Hall K.,University of Aberdeen | Brereton T.,MARINElife | And 6 more authors.
Endangered Species Research | Year: 2011

As with many other taxa, climate change is expected to result in geographic range shifts of cetacean species as they track changes in temperature to remain within their ecological niches. Such changes in geographic range could have implications for the conservation and management of cetaceans. Here, we propose a bioclimatic envelope modelling approach for providing quantitative predictions of how the ranges of cetacean species may respond to changing water temperatures. This combines predictions from habitat niche and 'thermal' niche models for an individual species to determine probable geographic range under specific climatic conditions. However, if this approach is to be used to inform conservation strategies, it is essential that the ability to predict responses to environmental change is validated beyond the period of data collection used to construct the models. Therefore, in addition to validation of modelled current range, we included a step to validate the models' ability to predict previous changes in range over time in response to climatic changes using independent data. We demonstrate this approach using common dolphin Delphinus delphis data from the Northeast Atlantic. The combined model was constructed with data collected between 1980 and 2007, and validated using independent distributional records collected between 1930 and 2006. The validated model was then applied to predict future range between 2010 and 2069, based on projected water temperatures. Thus, the modelling approach is shown to provide the type of information required to help ensure that conservation and management strategies remain effective in the face of a changing climate. © Inter-Research 2011. Source

News Article | April 3, 2016
Site: http://www.techtimes.com/rss/sections/science.xml

Experts say that killer whale, also known as Dopey Dick, is living off the west coast of Scotland. The orca became famous in November 1977 when it was first seen by locals in pursuit of a salmon prior to remaining five kilometers (3 miles) upriver of Loch Foyle for two days. Marine experts are tracking orcas, as they are the UK's only known resident population of killer whales in the west coast community of whales. Since 1994, the Hebridean Whale and Dolphin Trust has been continually monitoring the behavior of the west coast population of killer whales. Part of their documentation includes four males and four females that have never reproduced since their studies began. The orcas are not noted to interact with other orcas belonging in the north-east Atlantic community. Early this year, Lulu, one of the females was stranded near Tiree where it subsequently expired. The agency expressed that the discovering Dopey Dick as part of the west coast population is an important piece of information to understand the relative age of that particular orca population. Irish Whale and Dolphin Group sightings officer Padraig Whooley said that Dopey Dick's sighting puts the west coast community at the upper limits of the expected life expectancy of male orcas. "Adult males generally live to around 30 years, but with an upper range of 50 to 60 years," Whooley said. Based on Dopey Dick's initial sighting in 1977, he is believed to be an adult male back then. This present sighting places Dopey Dick to at least 50 years or older. A killer whale expert, Andy Foote shared that a photograph posted on Facebook showed Dopey Dick's white eye patch that sloped backwards is hard to miss. "I couldn't believe it - he was already a full-grown male back in 1977, when I was just five years old," Foote added. Dr. Conor Ryan of Hebridean Whale and Dolphin Trust said that Dopey Dick's sighting puts pressure on whale biologists to conduct more studies about this particular species before time runs out. He expresses concern that species like Comet may become extinct. "Since records began in the '80s, we haven't had any new animals join the population and we haven't had new calves either," said Ryan. "The population is declining because as the older animals die, they're not being replaced." Earlier this month, marine experts lauded the decision of Seaworld to finally stop breeding of orcas in captivity. The company also said that they are no longer training the orcas but instead showcase them in their natural setting. The decision came months after a trainer was attacked by a killer whale.

Whooley P.,Irish Whale and Dolphin Group | Berrow S.,Irish Whale and Dolphin Group | Barnes C.,West Marine
Marine Biodiversity Records | Year: 2011

Photo-identification of fin whales (Balaenoptera physalus L.) was carried out off the south coast of Ireland between 2003 and 2008. During 79 research trips, mainly on-board a whale watching vessel, 62 individual fin whales were identified using a variety of marks, including notches in the dorsal fin, blotches and scars. Forty (65%) of these whales were only seen once but eleven whales (18%) have been recorded within a year on up to four occasions within a season and eleven whales (18%) re-sighted between years with one recorded in four and one in five of the last seven years. Re-sighting rate varied depending on the marks used to identify whales but was 17.7% overall. The mean interval between the first and last reported sighting was 33.2 days, with a minimum of one day and a maximum interval of 165 days. The south coast of Ireland is an important site for fin whales and provides excellent research opportunities due to their close proximity to land. © 2011 Marine Biological Association of the United Kingdom. Source

Ryan C.,Irish Whale and Dolphin Group | Ryan C.,Mayo Institute of Technology, Galway | Holmes J.M.C.,National Museum of Ireland
Marine Biodiversity Records | Year: 2012

The stomach contents from a killer whale stranded in north-west Ireland were examined. Siphonostomatoid copepods Cecrops latreilli and bones consistent in shape and size with those from the ocean sunfish were found. While observations of free-ranging killer whales predating on sunfish exist from the Gulf of Guinea and the South Pacific, this is the first record for the North Atlantic and the first from stomach content analysis. © 2012 Marine Biological Association of the United Kingdom. Source

Beck S.,Mayo Institute of Technology, Galway | Foote A.D.,Copenhagen University | Kotter S.,Hebridean Whale and Dolphin Trust | Harries O.,Hebridean Whale and Dolphin Trust | And 4 more authors.
Journal of the Marine Biological Association of the United Kingdom | Year: 2014

An assemblage of killer whales that has been sighted in waters off the west coast of the British Isles and Ireland has previously been shown to be isolated from other North Atlantic killer whale communities based on association patterns. By applying a Bayesian formulation of the Jolly-Seber mark-recapture model to the photo-identification data compiled from opportunistic photographic encounters with this population of killer whales, we show that such sparse and opportunistically-collected data can still be valuable in estimating population dynamics of small, wide-ranging groups. Good quality photo-identification data was collected from 32 encounters over 19 years. Despite a cumulative total of 77 identifications from these encounters, just ten individuals were identified and the remaining 67 identifications were re-sights of these ten animals. There was no detected recruitment through births during the study and, as a result, the population appears to be in a slight decline. The demography of the population was highly skewed towards older individuals and had an unusually high ratio of adult males, and we suggest that demographic stochasticity due to a small population size may be further impacting the population growth rate. We recommend that this population be managed as a separate conservation unit from neighbouring killer whale populations. © 2013 Marine Biological Association of the United Kingdom . Source

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