Abstract
Coastal and freshwater cetaceans are particularly vulnerable due to their proximity to human activity, localized distributions, and small home ranges. These species include Sotalia ...guianensis, found in the Atlantic and Caribbean coastal areas of central and South America, and Sotalia fluviatilis, distributed in the Amazon River and tributaries. We investigated the population structure and genetic diversity of these 2 species by analyses of mtDNA control region and 8–10 microsatellite loci. MtDNA analyses revealed strong regional structuring for S. guianensis (i.e., Colombian Caribbean vs. Brazilian Coast, FST = 0.807, ΦST = 0.878, P < 0.001) especially north and south of the Amazon River mouth. For S. fluviatilis, population structuring was detected between the western and eastern Amazon (i.e., Colombian Amazon vs. Brazilian Amazon, FST = 0.085, ΦST = 0.277, P < 0.001). Haplotype and nucleotide diversity were higher for S. fluviatilis. Population differentiation was supported by analysis of the microsatellite loci (S. guianensis, northern South America vs. southern South America FST = 0.275, Jost’s D = 0.476, P < 0.001; S. fluviatilis, western and eastern Amazon FST = 0.197, Jost’s D = 0.364, P < 0.001). Most estimated migration rates in both species overlapped with zero, suggesting no measurable migration between most of the sampling locations. However, for S. guianensis, there was measurable migration in neighboring sampling locations. These results indicate that the small home ranges of these species may act to restrict gene flow between populations separated by relatively short distances, increasing the risk of extirpation of some localized populations in the future if existing threats are not minimized.
On June 26, 2022, a dead killer whale (Orcinus orca) was found 48 km off the coast of Newport, Oregon, entangled in presumed recreational Dungeness crab (Metacarcinus magister) fishery gear: a crab ...pot and line. The Oregon Marine Mammal Stranding Network (OMMSN) was informed and promptly notified the U.S. National Oceanic and Atmospheric Administration (NOAA) Fisheries Service, leading to aerial and seaborne responses by the U.S. Coast Guard. Killer whales that inhabit the coastal waters of the Northeast Pacific are relatively well-documented from both traditional identification methods and genetic markers. Killer whale ecotypes are distinguishable using a fragment of the mitochondrial genome known as the control region or "D-loop". Although no tissue samples had been collected from the dead whale, we considered it likely that prolonged contact with the crabbing line would have inundated sections of the gear with recoverable DNA. Given the prolonged environmental exposure and decay of the body, we hypothesized that any usable genetic material would likely originate from the mitogenome as is common in these environments.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Antarctic humpback whales are recovering from near extirpation from commercial whaling. To understand the dynamics of this recovery and establish a baseline to monitor impacts of a rapidly changing ...environment, we investigated sex ratios and pregnancy rates of females within the Western Antarctic Peninsula (WAP) feeding population. DNA profiling of 577 tissue samples (2010–2016) identified 239 males and 268 females. Blubber progesterone levels indicated 63.5% of the females biopsied were pregnant. This proportion varied significantly across years, from 36% in 2010 to 86% in 2014. A comparison of samples collected in summer versus fall showed significant increases in the proportion of females present (50% to 59%) and pregnant (59% to 72%), consistent with demographic variation in migratory timing. We also found evidence of annual reproduction among females; 54.5% of females accompanied by a calf were pregnant. These high pregnancy rates are consistent with a population recovering from past exploitation, but appear inconsistent with recent estimates of WAP humpback population growth. Thus, our results will help to better understand population growth potential and set a current baseline from which to determine the impact of climate change and variability on fecundity and reproductive rates.
In coastal British Columbia, Canada, marine megafauna such as humpback whales (Megaptera novaeangliae) and fin whales (Balaenoptera physalus velifera) have been subject to a history of exploitation ...and near extirpation. While their populations have been in recovery, significant threats are posed to these vulnerable species by proposed natural resource ventures in this region, in addition to the compounding effects of anthropogenic climate change. Genetic tools play a vital role in informing conservation efforts, but the associated collection of tissue biopsy samples can be challenging for the investigators and disruptive to the ongoing behaviour of the targeted whales. Here, we evaluate a minimally intrusive approach based on collecting exhaled breath condensate, or respiratory 'blow' samples, from baleen whales using an unoccupied aerial system (UAS), within Gitga'at First Nation territory for conservation genetics. Minimal behavioural responses to the sampling technique were observed, with no response detected 87% of the time (of 112 UAS deployments). DNA from whale blow (n = 88 samples) was extracted, and DNA profiles consisting of 10 nuclear microsatellite loci, sex identification and mitochondrial (mt) DNA haplotypes were constructed. An average of 7.5 microsatellite loci per individual were successfully genotyped. The success rates for mtDNA and sex assignment were 80% and 89% respectively. Thus, this minimally intrusive sampling method can be used to describe genetic diversity and generate genetic profiles for individual identification. The results of this research demonstrate the potential of UAS-collected whale blow for conservation genetics from a remote location.
The utility of microsatellite markers for inferring population size and trend has not been rigorously examined, even though these markers are commonly used to monitor the demography of natural ...populations. We assessed the ability of a linkage disequilibrium estimator of effective population size (Ne) and a simple capture‐recapture estimator of abundance (N) to quantify the size and trend of stable or declining populations (true N = 100–10,000), using simulated Wright–Fisher populations. Neither method accurately or precisely estimated abundance at sample sizes of S = 30 individuals, regardless of true N. However, if larger samples of S = 60 or 120 individuals were collected, these methods provided useful insights into abundance and trends for populations of N = 100–500. At small population sizes (N = 100 or 250), precision of the Ne estimates was improved slightly more by a doubling of loci sampled than by a doubling of individuals sampled. In general, monitoring Ne proved a more robust means of identifying stable and declining populations than monitoring N over most of the parameter space we explored, and performance of the Ne estimator is further enhanced if the Ne/N ratio is low. However, at the largest population size (N = 10,000), N estimation outperformed Ne. Both methods generally required ≥ 5 generations to pass between sampling events to correctly identify population trend.
Obtaining the representative morphological data required for traditional taxonomy is difficult, and sometimes impossible, for cetaceans, especially large ones. As a result, three quarters of the 88 ...currently recognized extant species have no subspecies and 40 taxa likely have additional unnamed taxa. Conservation needs give urgency to improving taxonomy because unnamed taxa are unlikely to receive protection equivalent to that received by named taxa. Genetic data can improve efforts to delimit subspecies, but the markers and methods used have varied and the magnitude of genetic difference used to justify subspecies distinctions across studies has also varied. Here, we define the concepts of populations, subspecies, and species to establish a foundation for developing guidelines (data to include and analyses to conduct) and quantitative standards (the magnitude of differentiation expected at different taxonomic levels) for using genetic data to support taxonomic recognition. Our definition is particularly applicable to data‐poor groups because it allows for naming a subspecies when there is uncertainty about whether lineages have diverged sufficiently for species‐level recognition. This allows a species that lacks convincing data for lineage divergence to be recognized as a subspecies while sufficient data are accrued, which could take decades for some cetaceans.
In the context of a changing climate, understanding the environmental drivers of marine megafauna distribution is important for conservation success. The extent of humpback whale breeding habitats ...and the impact of temperature variation on their availability are both unknown. We used 19 years of dedicated survey data from seven countries and territories of Oceania (1,376 survey days), to investigate humpback whale breeding habitat diversity and adaptability to climate change. At a fine scale (1 km resolution), seabed topography was identified as an important influence on humpback whale distribution. The shallowest waters close to shore or in lagoons were favored, although humpback whales also showed flexible habitat use patterns with respect to shallow offshore features such as seamounts. At a coarse scale (1° resolution), humpback whale breeding habitats in Oceania spanned a thermal range of 22.3–27.8°C in August, with interannual variation up to 2.0°C. Within this range, both fine and coarse scale analyses of humpback whale distribution suggested local responses to temperature. Notably, the most detailed dataset was available from New Caledonia (774 survey days, 1996–2017), where encounter rates showed a negative relationship to sea surface temperature, but were not related to the El Niño Southern Oscillation or the Antarctic Oscillation from previous summer, a proxy for feeding conditions that may impact breeding patterns. Many breeding sites that are currently occupied are predicted to become unsuitably warm for this species (>28°C) by the end of the 21st century. Based on modeled ecological relationships, there are suitable habitats for relocation in archipelagos and seamounts of southern Oceania. Although distribution shifts might be restrained by philopatry, the apparent plasticity of humpback whale habitat use patterns and the extent of suitable habitats support an adaptive capacity to ocean warming in Oceania breeding grounds.
Exercise and weight loss diets are two independent non-pharmaceutical strategies used to improve several aspects of body composition and health. We plan to systematically review controlled clinical ...trials investigating weight loss diets alone compared to weight loss diets in conjunction with exercise on energy intake, body weight, body composition, cardiometabolic risk factors, sex hormones, and mental health.
PubMed/MEDLINE, EMBASE, ISI (Web of Science), Scopus, and Google Scholar will be searched to retrieve potential controlled clinical trials investigating the effects of exercise in conjunction with weight loss diets compared with weight loss diets alone on energy intake, body weight and composition (fat mass, fat-free mass), anthropometrics (waist circumference), cardiometabolic markers, sex hormones testosterone, estradiol, and sex hormone binding globulin (SHBG), liver and kidney enzymes (alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), uric acid, blood urea nitrogen (BUN), glomerular filtration rate (GFR), quality of life, and depression in adults. The weighted mean difference (WMD) and its corresponding 95% confidence intervals (CIs) will be derived using random effects model. Several subgroup analyses based on follow-up duration, the health status of the participants, the diet used for weight loss, the exercise protocol, participants' sex, and other possible variables will be conducted to explore possible sources of heterogeneity. Publication bias will be explored by inspecting funnel plots and by conducting asymmetry tests. Overall quality of the evidence will be assessed by using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool.
We envisage that this systematic review and meta-analysis will provide valuable information regarding the effectiveness of adding exercise to weight loss diets. No primary data is going to be collected; therefore, ethical approval is not required. The resulting manuscripts will be disseminated in peer-reviewed journals and at international and national conferences.
The study protocol is registered in the International Prospective Register of Systematic Reviews (PROSPERO, Registration ID: CRD42020173434 ).
Strandings of striped dolphins (SD) and short-finned pilot whales (PW) in Hokkaido, northern Japan, are rare but have recently increased, probably due to global warming. We quantified δ
13
C, δ
15
N, ...and δ
18
O in muscles of SD (n = 7) and PW (n = 3) stranded in Hokkaido and compared these values with those in muscles (red meat products) of hunted SD and PW in three areas of central and southern Japan. δ
18
O in stranded SD, except for the calf, decreased with increasing body length (BL), whereas δ
13
C increased, with no BL-related changes in δ
15
N. The variability of δ
18
O (range of maximum and minimum) was larger in the stranded SD (7.5 ‰) than of the hunted SD in three areas (0.9, 1.9, and 1.4 ‰), whereas that of δ
15
N was smaller in the stranded SD than in the hunted SD. Similarly, the variability of δ
18
O was larger in the stranded PW in Hokkaido (3.3 ‰) than in the hunted PW in central Japan (1.4 ‰). The larger variability of δ
18
O and smaller variability of δ
15
N in stranded SD imply long-term sojourning in coastal waters and feeding on small amounts of limited prey species at low trophic levels before death.
PDF
