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Filatova OA, Fedutin ID, Pridorozhnaya TP, Hoyt E. Bottom-feeding gray whales Eschrichtius robustus demonstrate a finer scale of site fidelity than pelagic-feeding humpback whales Megaptera novaeangliae on an Arctic feeding ground. Polar Biol. [DOI: 10.1007/s00300-022-03048-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ashe E, Hammond PS. Effect of matching uncertainty on population parameter estimation in mark-recapture analysis of photo-identification data. Mamm Biol 2022. [DOI: 10.1007/s42991-022-00236-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AbstractQuantifying and dealing with uncertainty are key aspects of ecological studies. Population parameter estimation from mark-recapture analyses of photo-identification data hinges on correctly matching individuals from photographs and assumes that identifications are detected with certainty, marks are not lost over time, and that individuals are recognised when they are resighted. Matching photographs is an inherently subjective process. Traditionally, two photographs are not considered a “match” unless the photo reviewer is 100% certain. This decision may carry implications with respect to sample size and the bias and precision of the resultant parameter estimates. Here, we present results from a photo-identification experiment on Pacific white-sided dolphins to assign one of three levels of certainty that a pair of photographs represented a match. We then illustrate how estimates of abundance and survival varied as a function of the matching certainty threshold used. As expected, requiring 100% certainty of a match resulted in fewer matches, which in turn led to higher estimates of abundance and lower estimates of survival than if a lower threshold were used to determine a match. The tradition to score two photographs as a match only when the photo reviewer is 100% certain stems from a desire to be conservative, but potential over-estimation of abundance means that there may be applications (e.g., assessing sustainability of bycatch) in which it is not precautionary. We recommend exploring the consequences of matching uncertainty and incorporating that uncertainty into the resulting estimates of abundance and survival.
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Delarue JJY, Moors-Murphy H, Kowarski KA, Davis GE, Urazghildiiev IR, Martin SB. Acoustic occurrence of baleen whales, particularly blue, fin, and humpback whales, off eastern Canada, 2015–2017. ENDANGER SPECIES RES 2022. [DOI: 10.3354/esr01176] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Keen EM, Pilkington J, O’Mahony É, Thompson KL, Hendricks B, Robinson N, Dundas A, Nichol L, Alidina HM, Meuter H, Picard CR, Wray J. Fin whales of the Great Bear Rainforest: Balaenoptera physalus velifera in a Canadian Pacific fjord system. PLoS One 2021; 16:e0256815. [PMID: 34478477 PMCID: PMC8415578 DOI: 10.1371/journal.pone.0256815] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/17/2021] [Indexed: 11/19/2022] Open
Abstract
Fin whales (Balaenoptera physalus) are widely considered an offshore and oceanic species, but certain populations also use coastal areas and semi-enclosed seas. Based upon fifteen years of study, we report that Canadian Pacific fin whales (B. p. velifera) have returned to the Kitimat Fjord System (KFS) in the Great Bear Rainforest, and have established a seasonally resident population in its intracoastal waters. This is the only fjord system along this coast or elsewhere in which fin whales are known to occur regularly with strong site fidelity. The KFS was also the only Canadian Pacific fjord system in which fin whales were commonly found and killed during commercial whaling, pointing to its long-term importance. Traditional knowledge, whaling records, and citizen science databases suggest that fin whales were extirpated from this area prior to their return in 2005-2006. Visual surveys and mark-recapture analysis documented their repopulation of the area, with 100-120 whales using the fjord system in recent years, as well as the establishment of a seasonally resident population with annual return rates higher than 70%. Line transect surveys identified the central and outer channels of the KFS as the primary fin whale habitat, with the greatest densities occurring in Squally Channel and Caamaño Sound. Fin whales were observed in the KFS in most months of the year. Vessel- and shore-based surveys (27,311 km and 6,572 hours of effort, respectively) indicated regular fin whale presence (2,542 detections), including mother-calf pairs, from June to October and peak abundance in late August-early September. Seasonal patterns were variable year-to-year, and several lines of evidence indicated that fin whales arrived and departed from the KFS repeatedly throughout the summer and fall. Additionally, we report on the population's social network and morphometrics. These findings offer insights into the dynamics of population recovery in an area where several marine shipping projects are proposed. The fin whales of the Great Bear Rainforest represent a rare exception to general patterns in this species' natural history, and we highlight the importance of their conservation.
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Affiliation(s)
- Eric M. Keen
- North Coast Cetacean Society, Alert Bay, British Columbia, Canada
- Environmental Studies, Sewanee: The University of the South, Sewanee, TN, United States of America
- Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - James Pilkington
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Éadin O’Mahony
- North Coast Cetacean Society, Alert Bay, British Columbia, Canada
- Scottish Oceans Institute, University of St Andrews, St Andrews, United Kingdom
| | - Kim-Ly Thompson
- Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - Benjamin Hendricks
- North Coast Cetacean Society, Alert Bay, British Columbia, Canada
- SoundSpace Analytics, Cumberland, British Columbia, Canada
| | - Nicole Robinson
- Gitga’at Oceans and Lands Department, Hartley Bay, British Columbia, Canada
| | - Archie Dundas
- Gitga’at Oceans and Lands Department, Hartley Bay, British Columbia, Canada
| | - Linda Nichol
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | | | - Hermann Meuter
- Pacific Whale Society, Hartley Bay, British Columbia, Canada
| | - Chris R. Picard
- Gitga’at Oceans and Lands Department, Hartley Bay, British Columbia, Canada
| | - Janie Wray
- North Coast Cetacean Society, Alert Bay, British Columbia, Canada
- Pacific Orca Society, Alert Bay, British Columbia, Canada
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Jory C, Lesage V, Leclerc A, Giard J, Iverson S, Bérubé M, Michaud R, Nozais C. Individual and population dietary specialization decline in fin whales during a period of ecosystem shift. Sci Rep 2021; 11:17181. [PMID: 34433851 PMCID: PMC8387503 DOI: 10.1038/s41598-021-96283-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/28/2021] [Indexed: 11/25/2022] Open
Abstract
This study sought to estimate the effect of an anthropogenic and climate-driven change in prey availability on the degree of individual and population specialization of a large marine predator, the fin whale (Balaenoptera physalus). We examined skin biopsies from 99 fin whales sampled in the St. Lawrence Estuary (Canada) over a nine year period (1998–2006) during which environmental change was documented. We analyzed stable isotope ratios in skin and fatty acid signatures in blubber samples of whales, as well as in seven potential prey species, and diet was quantitatively assessed using Bayesian isotopic models. An abrupt change in fin whale dietary niche coincided with a decrease in biomass of their predominant prey, Arctic krill (Thysanoessa spp.). This dietary niche widening toward generalist diets occurred in nearly 60% of sampled individuals. The fin whale population, typically composed of specialists of either krill or lipid-rich pelagic fishes, shifted toward one composed either of krill specialists or true generalists feeding on various zooplankton and fish prey. This change likely reduced intraspecific competition. In the context of the current “Atlantification” of northern water masses, our findings emphasize the importance of considering individual-specific foraging tactics and not only population or group average responses when assessing population resilience or when implementing conservation measures.
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Affiliation(s)
- Cabrol Jory
- Maurice Lamontagne Institute, Fisheries and Oceans Canada, Mont-Joli, QC, Canada.
| | - Véronique Lesage
- Maurice Lamontagne Institute, Fisheries and Oceans Canada, Mont-Joli, QC, Canada.,Département de Biologie, Chimie et Géographie, Québec-Océan, Université du Québec à Rimouski, Rimouski, QC, Canada
| | - Alexandra Leclerc
- Maurice Lamontagne Institute, Fisheries and Oceans Canada, Mont-Joli, QC, Canada.,Département de Biologie, Chimie et Géographie, Québec-Océan, Université du Québec à Rimouski, Rimouski, QC, Canada
| | - Janie Giard
- Groupe de Recherche et d'Éducation sur les Mammifères Marins, Tadoussac, QC, Canada
| | - Sara Iverson
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Martine Bérubé
- Marine Evolution and Conservation, Groningen Institute of Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.,Centre for Coastal Studies, Provincetown, MA, USA
| | - Robert Michaud
- Groupe de Recherche et d'Éducation sur les Mammifères Marins, Tadoussac, QC, Canada
| | - Christian Nozais
- Département de Biologie, Chimie et Géographie, Québec-Océan, Université du Québec à Rimouski, Rimouski, QC, Canada
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Ramp C, Gaspard D, Gavrilchuk K, Unger M, Schleimer A, Delarue J, Landry S, Sears R. Up in the air: drone images reveal underestimation of entanglement rates in large rorqual whales. ENDANGER SPECIES RES 2021. [DOI: 10.3354/esr01084] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Entanglement in fishing gear is a significant threat to many cetaceans. For the 2 largest species, the blue whale Balaenoptera musculus and the fin whale B. physalus, reports of entangled individuals are rare, leading to the assumption that entanglements are not common. Studies of interaction with fisheries in other species often rely on the presence of scars from previous entanglements. Here, scar detection rates were first examined in humpback Megaptera novaeangliae, fin and blue whales using standard vessel-based photo-identification photographs collected between 2009 and 2016 in the Gulf of St. Lawrence, Canada. We then examined aerial images of fin whales collected with a drone in 2018 and 2019 and compared both methods. Entanglement rates were 6.5% for fin and 13.1% for blue whales using photo-identification images of individuals. Prominent scarring was observed around the tail and caudal peduncle, visible only when animals lifted those body sections above water when diving. For the small subset of pictures which captured the entire caudal peduncle, entanglement rates ranged between 60% for blue and 80% for fin whales. This result was similar to the 85% entanglement rate estimated in humpback whales. The assessment of aerial-based photography yielded an entanglement rate of 44.1 to 54.7% in fin whales. Scars were always around the peduncle, often the tail, rarely the dorsal fin and never around the pectoral fins, while the mouth cannot be examined from above. Thus, in species that do not regularly expose their tail or peduncle, aerial imagery is the preferred method to quantify entanglement rates by assessment of scars.
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Affiliation(s)
- C Ramp
- Mingan Island Cetacean Study, St Lambert, J4P 1T3, QC, Canada
- Sea Mammal Research Unit, University of St Andrews, Fife KY16 8LB, UK
| | - D Gaspard
- Mingan Island Cetacean Study, St Lambert, J4P 1T3, QC, Canada
| | - K Gavrilchuk
- Mingan Island Cetacean Study, St Lambert, J4P 1T3, QC, Canada
| | - M Unger
- Mingan Island Cetacean Study, St Lambert, J4P 1T3, QC, Canada
| | - A Schleimer
- Mingan Island Cetacean Study, St Lambert, J4P 1T3, QC, Canada
- Sea Mammal Research Unit, University of St Andrews, Fife KY16 8LB, UK
- Marine Evolution and Conservation, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC, Groningen, The Netherlands
| | - J Delarue
- Mingan Island Cetacean Study, St Lambert, J4P 1T3, QC, Canada
| | - S Landry
- Center for Coastal Studies, Provincetown, 02657, MA, USA
| | - R Sears
- Mingan Island Cetacean Study, St Lambert, J4P 1T3, QC, Canada
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Schleimer A, Ramp C, Delarue J, Carpentier A, Bérubé M, Palsbøll PJ, Sears R, Hammond PS. Decline in abundance and apparent survival rates of fin whales ( Balaenoptera physalus) in the northern Gulf of St. Lawrence. Ecol Evol 2019; 9:4231-4244. [PMID: 31016001 PMCID: PMC6468087 DOI: 10.1002/ece3.5055] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 02/16/2019] [Accepted: 02/25/2019] [Indexed: 11/06/2022] Open
Abstract
Estimates of abundance and survivorship provide quantifiable measures to monitor populations and to define and understand their conservation status. This study investigated changes in abundance and survival rates of fin whales (Balaenoptera physalus) in the northern Gulf of St. Lawrence in the context of anthropogenic pressures and changing environmental conditions. A long-term data set, consisting of 35 years of photo-identification surveys and comprising more than 5,000 identifications of 507 individuals, formed the basis of this mark-recapture study. Based on model selection using corrected Akaike Information Criterion, the most parsimonious Cormack-Jolly-Seber model included a linear temporal trend in noncalf apparent survival rates with a sharp decline in the last 5 years of the study and a median survival rate of 0.946 (95% confidence interval (CI) 0.910-0.967). To account for capture heterogeneity due to divergent patterns of site fidelity, agglomerative hierarchical cluster analysis was employed to categorize individuals based on their annual and survey site fidelity indices. However, the negative trend in survivorship remained and was corroborated by a significant decline in the estimated super-population size from 335 (95% CI 321-348) individuals in 2004-2010 to 291 (95% CI 270-312) individuals in 2010-2016. Concurrently, a negative trend was estimated in recruitment to the population, supported by a sharp decrease in the number of observed calves. Ship strikes and changes in prey availability are potential drivers of the observed decline in fin whale abundance. The combination of clustering methods with mark-recapture represents a flexible way to investigate the effects of site fidelity on demographic variables and is broadly applicable to other individual-based studies.
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Affiliation(s)
- Anna Schleimer
- Sea Mammal Research Unit, Scottish Oceans InstituteUniversity of St AndrewsFifeUK
- Marine Evolution and Conservation, Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- Mingan Island Cetacean StudySt LambertQuébecCanada
| | - Christian Ramp
- Sea Mammal Research Unit, Scottish Oceans InstituteUniversity of St AndrewsFifeUK
- Mingan Island Cetacean StudySt LambertQuébecCanada
| | | | | | - Martine Bérubé
- Marine Evolution and Conservation, Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- Center for Coastal StudiesProvincetownMassachusetts
| | - Per J. Palsbøll
- Marine Evolution and Conservation, Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
- Center for Coastal StudiesProvincetownMassachusetts
| | | | - Philip S. Hammond
- Sea Mammal Research Unit, Scottish Oceans InstituteUniversity of St AndrewsFifeUK
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Affiliation(s)
- Mònica Arso Civil
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews Fife KY16 8LB UK
| | - Barbara Cheney
- Lighthouse Field Station Institute of Biological and Environmental Sciences University of Aberdeen Cromarty IV11 8YL UK
| | - Nicola J. Quick
- Duke University Marine Laboratory Nicholas School of the Environment Beaufort North Carolina 28516 USA
| | - Paul M. Thompson
- Lighthouse Field Station Institute of Biological and Environmental Sciences University of Aberdeen Cromarty IV11 8YL UK
| | - Philip S. Hammond
- Sea Mammal Research Unit Scottish Oceans Institute University of St Andrews Fife KY16 8LB UK
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Ramp C, Delarue J, Palsbøll PJ, Sears R, Hammond PS. Adapting to a warmer ocean--seasonal shift of baleen whale movements over three decades. PLoS One 2015; 10:e0121374. [PMID: 25785462 PMCID: PMC4364899 DOI: 10.1371/journal.pone.0121374] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 02/11/2015] [Indexed: 11/19/2022] Open
Abstract
Global warming poses particular challenges to migratory species, which face changes to the multiple environments occupied during migration. For many species, the timing of migration between summer and winter grounds and also within-season movements are crucial to maximise exploitation of temporarily abundant prey resources in feeding areas, themselves adapting to the warming planet. We investigated the temporal variation in the occurrence of fin (Balaenoptera physalus) and humpback whales (Megaptera novaeangliae) in a North Atlantic summer feeding ground, the Gulf of St. Lawrence (Canada), from 1984 to 2010 using a long-term study of individually identifiable animals. These two sympatric species both shifted their date of arrival at a previously undocumented rate of more than 1 day per year earlier over the study period thus maintaining the approximate 2-week difference in arrival of the two species and enabling the maintenance of temporal niche separation. However, the departure date of both species also shifted earlier but at different rates resulting in increasing temporal overlap over the study period indicating that this separation may be starting to erode. Our analysis revealed that the trend in arrival was strongly related to earlier ice break-up and rising sea surface temperature, likely triggering earlier primary production. The observed changes in phenology in response to ocean warming are a remarkable example of phenotypic plasticity and may partly explain how baleen whales were able to survive a number of changes in climate over the last several million years. However, it is questionable whether the observed rate of change in timing can be maintained. Substantial modification to the distribution or annual life cycle of these species might be required to keep up with the ongoing warming of the oceans.
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Affiliation(s)
- Christian Ramp
- Mingan Island Cetacean Study, St. Lambert, Quebec, Canada
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, United Kingdom
- * E-mail:
| | - Julien Delarue
- Mingan Island Cetacean Study, St. Lambert, Quebec, Canada
| | - Per J. Palsbøll
- Marine Evolution and Conservation, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - Richard Sears
- Mingan Island Cetacean Study, St. Lambert, Quebec, Canada
| | - Philip S. Hammond
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews, United Kingdom
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