Spatio-temporal patterns in fin whale <i>Balaenoptera physalus</i> habitat use in the northern Gulf of St. Lawrence

Significant ecosystem changes in the Gulf of St. Lawrence (GSL), Canada, have had far-reaching effects at all trophic levels. The abundance of fin whales Balaenoptera physalus has declined significantly in the northern GSL over the past decade. This study aimed to test the hypothesis that the observed decline was correlated to changing environmental conditions. Cetacean sightings data from 292 surveys, resulting in 2986 fin whale encounters from 2007 to 2013, were used to fit 2 separate generalised additive models in terms of (1) bathymetric and oceanographic variables (the proxy model) and (2) modelled krill biomass (the prey model). The concept of ‘handling time’ was introduced to correct for time off search effort, applicable to other studies relying on opportunistically sampled data. While a positive correlation between krill biomass and fin whale numbers was found, the performance of the proxy model (24.2% deviance explained) was overall better than the prey model (11.8%). Annual predictive maps derived from the final proxy model highlighted 2 key areas with recurrently high relative fin whale abundance and a significant overlap with shipping lanes. While both models provided evidence for an annual decline in relative fin whale abundance, static bathymetric features were the most important predictors of habitat use, and no correlation between dynamic variables and the decline was found. High resolution prey data and a better understanding of the feeding ecology of fin whales are proposed to further investigate the predator-prey relationship and decline of fin whales in the GSL

Fin whale survival and abundance in the Gulf of St. Lawrence, Canada

The fin whale Balaenoptera physalus, the second largest species in the animal kingdom to have lived on Earth, was heavily targeted during the industrial whaling era. North Atlantic whaling for this species ended in 1987 and it is unclear if the populations are recovering. The stock structure in the North Atlantic is still under debate, but several lines of evidence suggest that fin whales in the Gulf of St. Lawrence may form a discrete stock with limited exchange with the rest of the North Atlantic. We applied mark-recapture models to 21 yr of photo-identification data from the Jacques-Cartier Passage to estimate the abundance and, for the first time, a survival rate based on live re-sightings for this stock of fin whales. Using the Cormack-Jolly-Seber model, we estimated a unisex non-calf apparent survival rate of 0.955 (95% CI: 0.936 to 0.969) for the period 1990 to 2010, declining in the last 4 yr of the study. The reduced survivorship was likely caused by a lower site fidelity combined with a higher mortality. The POPAN model yielded a super-population estimate of 328 individuals (95% CI: 306 to 350) for the period 2004 to 2010, and confirmed the negative trend in apparent survival and annual abundance, indicating that the population has not increased since the last large-scale surveys from 1974 and 1997.Publisher PDFPeer reviewe

Examining the Skill Gap in Fashion Education

This research explores the importance of sewing skills within HE fashion education. Recent literature has identified significant discussion concerning a graduate skills gap at the onset of employment. Some industry specialists fear that educators are not doing enough to promote the technical side of fashion. As a consequence, there are concerns of a widening gap in the uptake of technical job roles within the fashion sector. This research investigates potential reasons why students might not make these career choices, focusing mainly on the teaching of construction skills through the development of a resource tool to enhance the curriculum to bridge this recognised gap. To contextualise the development of this project, literature has examined key areas of interest. These include studies relating to skill gaps, manufacture and production techniques as well as the relationship between technical skill and career interests. This research has applied a variety of methodologies, which have explored the skills required for fundamental sewing processes, the value of sewing from educational and industry perspectives and issues relating to the recognised skills gap and career choices. Methods have included object-based study, interviews with manufacturers and a focus group with second year BA (Hons) fashion design students undertaking pattern cutting and manufacture sessions. To evaluate the effectiveness of the resource tool of stitch and garment finishing techniques, questionnaires, observations and examinations were conducted with undergraduate students undertaking sewing sessions. This research has revealed that the resource tool was successful in engaging students with garment construction techniques, and that this was most beneficial when used in conjunction with other methods. During testing it was apparent that students preferred to work more creatively, using inventiveness over memory of previously taught sewing skills when producing samples. Interestingly, the research has also highlighted two distinctions; that further technical knowledge in sewing appears to, in some instances, have limited the creativity of students’ fashion design outcomes when advancing from a foundation to intermediate level of study. However, there is also evidence to suggest that further engagement with sewing had a positive influence on their understanding of garment construction informing feasible design. There appears to be minimal evidence that links strong sewing skill with the ambition to choose careers in the manufacturing sector. The conclusions from this research, including the testing results from the resource tool, support the development of a technical curriculum within the BA curriculum, and the development of a qualification level prior to BA

Direct estimation of genome mutation rates from pedigrees in free-ranging baleen whales

Current low germline mutation rate (&#x1d707;) estimates in baleen whales have greatly influenced research ranging from assessments of whaling impacts to evolutionary cancer biology. However, the reported rates were subject to methodological errors and uncertainty. We estimated &#x1d707; directly from pedigrees in natural populations of four baleen whale species and the results were similar to primates. The implications of revised &#x1d707; values include pre-exploitation population sizes at 14% of previous genetic diversity-based estimates and the conclusion that &#x1d707; in itself is insufficient to explain low cancer rates in gigantic mammals (i.e., Peto’s Paradox). We demonstrate the feasibility of estimating &#x1d707; from whole genome pedigree data in natural populations, which has wide-ranging implications for the many ecological and evolutionary inferences that rely on &#x1d707;

Universal baleen whale microsatellite panel for individual identification and power to detect parentage

Highly polymorphic single tandem repeat loci (STR, also known as microsatellite loci) remain a familiar, cost efficient class of markers for genetic analyses in ecology, behavior and conservation. We characterize a new universal set of ten STR loci (from 28 potential candidate loci) in seven baleen whale species, which are optimized for PCR amplification in two multiplex reactions along with a Y chromosome marker for sex determination. The optimized, universal set of STR loci provides an ideal starting point for new studies in baleen whales aimed at individual-based and population genetic studies, and facilitates data sharing among research groups. Data from the new STR loci were combined with genotypes from other published STR loci to assess the power to assign parentage (paternity) using exclusion in four species: fin whales, humpback whales, blue whales and bowhead whales. We argue that parentage studies should present a power analysis to demonstrate that the specific data are sufficiently informative to assign parentage with statistical rigor

Reintroducing extirpated herbivores could partially reverse the late Quaternary decline of large and grazing species

Aim Reinstating large, native herbivores is an essential component of ecological restoration efforts, as these taxa can be important drivers of ecological processes. However, many herbivore species have gone globally or regionally extinct during the last 50,000 years, leaving simplified herbivore assemblages and trophically downgraded ecosystems. Here, we discuss to what extent trophic rewilding can undo these changes by reinstating native herbivores. Location Global. Time period We report functional trait changes from the Late Pleistocene to the present, and estimated trait changes under future scenarios. Major taxa studied Wild, large (≥ 10 kg), terrestrial, mammalian herbivores. Methods We use a functional trait dataset containing all late Quaternary large herbivores ≥ 10 kg to look at changes in the body mass and diet composition of herbivore assemblages, a proxy for species’ ecological effects. First, we assess how these traits have changed from the Late Pleistocene to the present. Next, we quantify how the current body mass and diet composition would change if all extant, wild herbivores were restored to their native ranges (and if no functional replacements were used), exploring scenarios with different baselines. Results Defaunation has primarily removed large and grazing herbivores. Reinstating extant herbivores across their native ranges would reverse these changes, especially when reinstating them to their prehistoric distributions. It would partially restore herbivore body mass and diet composition to pre‐anthropogenic conditions. However, in the absence of complementary interventions (e.g., introducing functional replacements), many herbivore assemblages would remain down‐sized and browser dominated, relative to pre‐anthropogenic conditions. Main conclusions Many terrestrial herbivore assemblages—and hence ecosystems—would remain trophically downgraded, even after bringing back all extant, native herbivores. Therefore, complementary interventions would be required to achieve complete functional restoration. Nevertheless, our findings suggest that reintroducing the remaining native herbivores would diversify the herbivory and disturbances of herbivore assemblages

Body density of humpback whales (Megaptera novaengliae) in feeding aggregations estimated from hydrodynamic gliding performance

This study was funded by Strategic Environmental Research and Development Program (https://www.serdp-estcp.org; grant number RC-2337). In addition, the study was partly supported by Core Research for Evolutional Science and Technology by Japan Science and Technology Agency (http://www.jst.go.jp/kisoken/crest/en/index.html, grant number JPMJCR1685) and Bilateral Open Partnership Joint Research Projects by Japan Society for the Promotion of Science (http://www.jsps.go.jp/english/e-bilat/index.html; no specific grant number).Many baleen whales undertake annual fasting and feeding cycles, resulting in substantial changes in their body condition, an important factor affecting fitness. As a measure of lipid-store body condition, tissue density of a few deep diving marine mammals has been estimated using a hydrodynamic glide model of drag and buoyancy forces. Here, we applied the method to shallow-diving humpback whales (Megaptera novaeangliae) in North Atlantic and Antarctic feeding aggregations. High-resolution 3-axis acceleration, depth and speed data were collected from 24 whales. Measured values of acceleration during 5 s glides were fitted to a hydrodynamic glide model to estimate unknown parameters (tissue density, drag term and diving gas volume) in a Bayesian framework. Estimated species-average tissue density (1031.6 ± 2.1 kg m-3, ±95% credible interval) indicates that humpback whale tissue is typically negatively buoyant although there was a large inter-individual variation ranging from 1025.2 to 1043.1 kg m-3. The precision of the individual estimates was substantially finer than the variation across different individual whales, demonstrating a progressive decrease in tissue density throughout the feeding season and comparably high lipid-store in pregnant females. The drag term (CDAm-1) was estimated to be relatively high, indicating a large effect of lift-related induced drag for humpback whales. Our results show that tissue density of shallow diving baleen whales can be estimated using the hydrodynamic gliding model, although cross-validation with other techniques is an essential next step. This method for estimating body condition is likely to be broadly applicable across a range of aquatic animals and environments.Publisher PDFPeer reviewe

Introduced herbivores restore late pleistocene ecological functions

Large-bodied mammalian herbivores dominated Earth’s terrestrial ecosystems for several million years before undergoing substantial extinctions and declines during the Late Pleistocene (LP) due to prehistoric human impacts. The decline of large herbivores led to widespread ecological changes due to the loss of their ecological functions, as driven by their unique combinations of traits. However, recently, humans have significantly increased herbivore species richness through introductions in many parts of the world, potentially counteracting LP losses. Here, we assessed the extent to which introduced herbivore species restore lost—or contribute novel—functions relative to preextinction LP assemblages. We constructed multidimensional trait spaces using a trait database for all extant and extinct mammalian herbivores ≥10 kg known from the earliest LP (∼130,000 ybp) to the present day. Extinction-driven contractions of LP trait space have been offset through introductions by ∼39% globally. Analysis of trait space overlap reveals that assemblages with introduced species are overall more similar to those of the LP than native-only assemblages. This is because 64% of introduced species are more similar to extinct rather than extant species within their respective continents. Many introduced herbivores restore trait combinations that have the capacity to influence ecosystem processes, such as wildfire and shrub expansion in drylands. Although introduced species have long been a source of contention, our findings indicate that they may, in part, restore ecological functions reflective of the past several million years before widespread human-driven extinctions

Fin whale (Balaenoptera physalus) mitogenomics: A cautionary tale of defining sub-species from mitochondrial sequence monophyly

The advent of massive parallel sequencing technologies has resulted in an increase of studies based upon complete mitochondrial genome DNA sequences that revisit the taxonomic status within and among species. Spatially distinct monophyly in such mitogenomic genealogies, i.e., the sharing of a recent common ancestor among con-specific samples collected in the same region has been viewed as evidence for subspecies. Several recent studies in cetaceans have employed this criterion to suggest subsequent intraspecific taxonomic revisions. We reason that employing intra-specific, spatially distinct monophyly at non-recombining, clonally inherited genomes is an unsatisfactory criterion for defining subspecies based upon theoretical (genetic drift) and practical (sampling effort) arguments. This point was illustrated by a re-analysis of a global mitogenomic assessment of fin whales, Balaenoptera physalus spp., published by Archer et al. (2013), which proposed to further subdivide the Northern Hemisphere fin whale subspecies, B. p. physalus. The proposed revision was based upon the detection of spatially distinct monophyly among North Atlantic and North Pacific fin whales in a genealogy based upon complete mitochondrial genome DNA sequences. The extended analysis conducted in this study (1676 mitochondrial control region, 162 complete mitochondrial genome DNA sequences and 20 microsatellite loci genotyped in 380 samples) revealed that the apparent monophyly among North Atlantic fin whales reported by Archer et al. (2013) to be due to low sample sizes. In conclusion, defining sub-species from monophyly (i.e., the absence of para- or polyphyly) can lead to erroneous conclusions due to relatively 'trivial' aspects, such as sampling. Basic population genetic processes (i.e., genetic drift and migration) also affect the time to the most recent common ancestor and hence the probability that individuals in a sample are monophyletic

Baleen whale microsatellite panel for individual identification and parentage assignment in Mysticeti

Highly polymorphic single tandem repeat loci (STR, also known as microsatellite loci) remain a familiar, cost efficient class of genetic markers in genetic studies in ecology, behavior and conservation. Here we characterize a new, universal set of ten STR loci in seven species of baleen whales, optimized for PCR amplification in two multiplex reactions along with a Y chromosome marker for sex determination. The optimized, universal set of STR loci provides a convenient starting point for new genetic studies in baleen whales aimed at identifying individuals and populations. Data from the new STR loci were combined with genotypes from previously published STR loci to assess the power to assign parentage using paternity exclusion in four species: fin whale (Balaenoptera physalus), humpback whale (Megaptera novaeangliae), blue whale (B. musculus) and bowhead whale (Balaena mysticetus). Our results suggest that parentage studies should always be accompanied by a power analysis in order to ascertain that each individual specific study is based upon data with sufficient power to assign parentage with statistical rigor