Irish Whale and Dolphin Group

Kilrush, Ireland

Irish Whale and Dolphin Group

Kilrush, Ireland
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Ryan C.,Mayo Institute of Technology, Galway | Ryan C.,Irish Whale and Dolphin Group | McHugh B.,Marine Institute of Ireland | Trueman C.N.,University of Southampton | And 5 more authors.
Rapid Communications in Mass Spectrometry | Year: 2012

RATIONALE Stable isotope values (δ13C and δ15N) of darted skin and blubber biopsies can shed light on habitat use and diet of cetaceans, which are otherwise difficult to study. Non-dietary factors affect isotopic variability, chiefly the depletion of 13C due to the presence of 12C-rich lipids. The efficacy of post hoc lipid-correction models (normalization) must be tested. METHODS For tissues with high natural lipid content (e.g., whale skin and blubber), chemical lipid extraction or normalization is necessary. C:N ratios, δ13C values and δ15N values were determined for duplicate control and lipid-extracted skin and blubber of fin (Balaenoptera physalus), humpback (Megaptera novaeangliae) and minke whales (B. acutorostrata) by continuous-flow elemental analysis isotope ratio mass spectrometry (CF-EA-IRMS). Six different normalization models were tested to correct δ13C values for the presence of lipids. RESULTS Following lipid extraction, significant increases in δ13C values were observed for both tissues in the three species. Significant increases were also found for δ15N values in minke whale skin and fin whale blubber. In fin whale skin, the δ15N values decreased, with no change observed in humpback whale skin. Non-linear models generally out-performed linear models and the suitability of models varied by species and tissue, indicating the need for high model specificity, even among these closely related taxa. CONCLUSIONS Given the poor predictive power of the models to estimate lipid-free δ13C values, and the unpredictable changes in δ15N values due to lipid-extraction, we recommend against arithmetical normalization in accounting for lipid effects on δ13C values for balaenopterid skin or blubber samples. Rather, we recommend that duplicate analysis of lipid-extracted (δ13C values) and non-treated tissues (δ15N values) be used. Copyright © 2012 John Wiley & Sons, Ltd.

Lusher A.L.,Mayo Institute of Technology, Galway | Hernandez-Milian G.,University College Cork | O'Brien J.,Mayo Institute of Technology, Galway | O'Brien J.,Irish Whale and Dolphin Group | And 4 more authors.
Environmental Pollution | Year: 2015

When mammals strand, they present a unique opportunity to obtain insights into their ecology. In May 2013, three True's beaked whales (two adult females and a female calf) stranded on the north and west coasts of Ireland and the contents of their stomachs and intestines were analysed for anthropogenic debris. A method for identifying microplastics ingested by larger marine organisms was developed. Microplastics were identified throughout the digestive tract of the single whale that was examined for the presence of microplastics. The two adult females had macroplastic items in their stomachs. Food remains recovered from the adult whales consisted of mesopelagic fish (Benthosema glaciale, Nansenia spp., Chauliodius sloani) and cephalopods, although trophic transfer has been discussed, it was not possible to ascertain whether prey were the source of microplastics. This is the first study to directly identify microplastics <5 mm in a cetacean species. © 2015 Elsevier Ltd. All rights reserved.

Ryan C.,Mayo Institute of Technology, Galway | McHugh B.,Marine Institute of Ireland | Trueman C.N.,University of Southampton | Sabin R.,Natural History Museum in London | And 6 more authors.
Marine Ecology Progress Series | Year: 2013

Stable isotope analysis is a useful tool for investigating diet, migrations and niche in ecological communities by tracing energy through food-webs. In this study, the stable isotopic composition of carbon and nitrogen in keratin was measured at growth increments of baleen plates from 3 sympatric species of rorquals (Balaenoptera acutrostrata, B. physalus and Megaptera novaeangliae), which died between 1985 and 2010 in Irish and contiguous waters. Bivariate ellipses were used to plot isotopic niches and standard ellipse area parameters were estimated via Bayesian inference using the SIBER routine in the SIAR package in R. Evidence of resource partitioning was thus found among fin, humpback and minke whales using isotopic niches. Highest δ15N values were found in minke whales followed by humpback, and fin whales. Comparison between Northeast Atlantic (Irish/UK and Biscayan) and Mediterranean fin whale isotopic niches support the current International Whaling Commission stock assessment of an isolated Medi - terranean population. Significantly larger niche area and higher overall δ15N and δ13C values found in fin whales from Irish/UK waters compared to those sampled in adjacent regions (Bay of Biscay and Mediterranean) suggest inshore foraging that may be unique to fin whales in Ireland and the UK. Isotopic profiles support spatial overlap but different foraging strategies between fin whales sampled in Ireland/UK and the Bay of Biscay. Stable isotope analysis of baleen could provide an additional means for identifying ecological units, thus supporting more effective management for the conservation of baleen whales. © Inter-Research 2013.

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.

Ryan C.,Mayo Institute of Technology, Galway | Berrow S.D.,Mayo Institute of Technology, Galway | Berrow S.D.,Irish Whale and Dolphin Group | Mchugh B.,Marine Institute of Ireland | And 3 more authors.
Marine Mammal Science | Year: 2014

Over-exploitation of top predators and fish stocks has altered ecosystems towards less productive systems with fewer trophic levels. In the Celtic Sea (CS), discards and bycatch levels have prompted concern about some fisheries, while fin and humpback whales are recovering from centuries of over-exploitation. A lack of empirical evidence on the preferred diet of some predators such as whales in the CS has hindered the implementation of effective conservation measures using an ecosystem-based approach to fisheries management. Using a Bayesian framework (SIAR), stable carbon (δ13C) and nitrogen (δ15N) isotope mixing models were used to assign proportionate diet solutions to fin and humpback whales (skin biopsies) and putative prey items: herring (Clupea harengus), sprat (Sprattus sprattus), and krill (Meganyctiphanes norvegica and Nyctiphanes couchii) in the CS. Krill was the single most important prey item in the diet of fin whales, but one of the least important for humpback whales (albeit based on a small sample of humpback whale samples). Age 0 sprat and herring comprised a large proportion of the diet of both species, followed by older sprat (age 1-2) and older herring (age 2-4). An ecosystem based approach to fisheries management will be required in the CS if we seek effective conservation of both fin and humpback whales, and sustainable fisheries. © 2013 by the Society for Marine Mammalogy.

PubMed | Queen's University of Belfast, Irish Whale and Dolphin Group and Mayo Institute of Technology, Galway
Type: | Journal: Advances in experimental medicine and biology | Year: 2015

As part of the European Union Marine Strategy Framework Directive (MSFD), member states are required to address noise pollution in the marine environment under Descriptor 11. This study aimed to provide a practical desk-based application of Descriptor 11 assessment, focusing on the main contributors of ocean noise pollution in Irish waters, seismic surveying and shipping. To highlight specific geographical areas subject to elevated levels of noise pollution, the proportion of days over a calendar year that seismic air guns were operational was calculated and the vessel density per 50-km(2) grids was determined across Irelands exclusive economic zone (EEZ). Additionally, cetacean sighting data were used to determine the degree of spatial overlap between areas of elevated noise pollution and areas of cetacean abundance.

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.

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.

Lambert E.,University of Aberdeen | Pierce G.J.,University of Aberdeen | Pierce G.J.,University of Aveiro | Hall K.,University of Aberdeen | And 6 more authors.
Global Change Biology | Year: 2014

There is increasing evidence that the distributions of a large number of species are shifting with global climate change as they track changing surface temperatures that define their thermal niche. Modelling efforts to predict species distributions under future climates have increased with concern about the overall impact of these distribution shifts on species ecology, and especially where barriers to dispersal exist. Here we apply a bio-climatic envelope modelling technique to investigate the impacts of climate change on the geographic range of ten cetacean species in the eastern North Atlantic and to assess how such modelling can be used to inform conservation and management. The modelling process integrates elements of a species' habitat and thermal niche, and employs "hindcasting" of historical distribution changes in order to verify the accuracy of the modelled relationship between temperature and species range. If this ability is not verified, there is a risk that inappropriate or inaccurate models will be used to make future predictions of species distributions. Of the ten species investigated, we found that while the models for nine could successfully explain current spatial distribution, only four had a good ability to predict distribution changes over time in response to changes in water temperature. Applied to future climate scenarios, the four species-specific models with good predictive abilities indicated range expansion in one species and range contraction in three others, including the potential loss of up to 80% of suitable white-beaked dolphin habitat. Model predictions allow identification of affected areas and the likely time-scales over which impacts will occur. Thus, this work provides important information on both our ability to predict how individual species will respond to future climate change and the applicability of predictive distribution models as a tool to help construct viable conservation and management strategies. © 2014 John Wiley & Sons Ltd.

News Article | April 3, 2016

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.

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