scholarly journals A note on the distribution and abundance of blue whales (Balaenoptera musculus) in the Central and Northeast North Atlantic

2009 ◽  
Vol 7 ◽  
pp. 19 ◽  
Author(s):  
Daniel G Pike ◽  
Gísli A Víkingsson ◽  
Thorvaldur Gunnlaugsson ◽  
Nils Øien
Keyword(s):  
North Atlantic ◽  
Line Transect ◽  
Positive Trend ◽  
Standard Line ◽  
Balaenoptera Musculus ◽  
Species Identity ◽  
Detection Function ◽  
Significant Positive Trend ◽  
Northeast Atlantic ◽  
Blue Whales

The distribution and abundance of blue whales (Balaenoptera musculus) was assessed from ship surveys conducted in the Central and Northeast Atlantic in 1987, 1989, 1995 and 2001. Blue whales were most commonly sighted off western Iceland, and to a lesser extent northeast of Iceland. They were very rare or absent in the Northeast Atlantic. Sightings were combined over all surveys to estimate the detection function using standard line transect methodology, with the addition of a covariate to account for differences between surveys. Total abundance was highest in 1995 (979, 95% CI 137-2,542) and lowest in 1987 (222, 95% CI 115-440). Uncertainty in species identity had little effect on estimates of abundance. There was a significant positive trend in abundance northeast of Iceland and in the total survey area.

More than two decades of Faroe Bank Channel overflow: Stable, but warming

2020 ◽  
Author(s):  
Karin Margretha Húsgarð Larsen ◽  
Bogi Hansen ◽  
Hjálmar Hátún ◽  
Svein Østerhus
Keyword(s):  
North Atlantic ◽  
Bottom Water ◽  
Linear Trend ◽  
Volume Transport ◽  
Meridional Overturning Circulation ◽  
Positive Trend ◽  
Bottom Temperature ◽  
Bottom Water Temperature ◽  
Significant Positive Trend ◽  
Meridional Overturning

<p>Since November 1995, we have monitored the volume transport of Faroe Bank Channel overflow (FBC-overflow) and since 2001, the bottom temperature at the sill of the channel. The FBC-overflow is the coldest and densest overflow component and contributes approximately one third of the total overflow. Together with water that it entrains en route, it is therefore one of the main sources for North Atlantic Deep Water and the lower limb of the Atlantic Meridional Overturning Circulation (AMOC). In spite of reported AMOC weakening, the FBC-overflow has shown no signs of reduced volume transport. In contrast, a linear trend analysis indicated a weak (but non-significant) positive trend in volume transport of +5% from 1996 to 2018. The bottom water at the sill of the channel is the coldest component of the FBC-overflow and the densest overflow component overall. Since high-quality monitoring of the bottom water temperature began in summer 2001, the bottom water has warmed by approximately 0.2 °C with most of the warming occurring in two periods: 2004-2007 and 2015-2019. During the period, salinity has also been changing and the combined temperature/salinity effect on the density of the FBC-overflow will be discussed.</p>

scholarly journals Blue whale (Balaenoptera musculus musculus) genome: population structure and history in the North Atlantic

2021 ◽  
Author(s):  
Sushma Jossey ◽  
Oliver Haddrath ◽  
Livia Loureiro ◽  
Burton Lim ◽  
Jacqueline Miller ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
North Atlantic ◽  
Conservation Strategies ◽  
Balaenoptera Musculus ◽  
Blue Whale ◽  
Genetic Diversity And Structure ◽  
Population Structuring ◽  
The Impact ◽  
Blue Whales

Knowledge of genetic diversity and structure is essential for developing conservation strategies for endangered species. The advances in museum genomics can assist in better understanding the effects of over-hunting on the genome by comparing historical to present-day samples. Blue whales were hunted to the point of near extinction in the mid-twentieth century. Herein, we use whole genome sequencing to elucidate the poorly understood population structure of North Atlantic (NA) blue whales (Balaenoptera musculus musculus). We generated a de novo genome assembly of 2.49 Mbp for a NA blue whale (N50 of 1.46 Mb) to analyze 19 whole genomic sequences and 28 complete mitochondrial genomes. We included present-day and historical samples (earliest from 1900) from the Atlantic and Antarctica to understand the impact of whaling on the genetic diversity. We found low population structuring, but high genetic diversity, suggesting a single, panmictic population in the NA. We identified gene flow from fin whale to blue whales, accounting for ~3.5% of the genome. Introgression between blue and fin whales was observed in all the present-day samples but were lacking in some whales sampled early in the 20th century, which suggests increasing disruption in mate choice concomitant with decline in blue whale population. We also assembled and analyzed the transcriptome and revealed positive selection of oncogenes, which may be involved in reduced cancer rates in this largest of mammals ever known. Our sequencing and population structuring studies provide a genomic framework to guide ongoing conservation strategies for this iconic species.

A Review of the Morid Fish Genus Halargyreus with First Records from the Western North Atlantic

1968 ◽  
Vol 25 (5) ◽  
pp. 877-901 ◽  
Author(s):  
Wilfred Templeman
Keyword(s):  
New Zealand ◽  
North Atlantic ◽  
The Other ◽  
Nominal Species ◽  
Meristic Characters ◽  
Western Atlantic ◽  
North Central ◽  
Northeast Atlantic ◽  
The North

Three specimens of Halargyreus johnsonii taken on the southwestern and southeastern slopes of the Grand Bank in 1959 and 1964 are apparently the first records of this species and genus from the western Atlantic. These specimens are compared with the holotypes of H. johnsonii Günther and of H. brevipes Vaillant and with the syntypes of H. affinis Collett and also with specimens identified as H. affinis from the north-central and northeast Atlantic and with specimens of H. johnsonii from Madeira and New Zealand. These three nominal species are also compared. Is it concluded that for the present all North Atlantic specimens may be referred to H. johnsonii and that the other two species names should be considered as junior synonyms of H. johnsonii.The New Zealand specimens of Halargyreus, described by Günther (1887, Challenger Rept., 22(Zoology), p. 1–268) as H. johnsonii, have higher numbers for some meristic characters than Atlantic specimens of H. johnsonii but these differences are not too great to be possibly due to environmental differences. Pending the study of additional specimens in better condition, these New Zealand specimens are tentatively allowed to remain as H. johnsonii.

scholarly journals Performance of Parametric Model for Line Transect Data

2020 ◽  
pp. 1-7
Author(s):  
Noryanti Muhammad ◽  
Gamil A.A. Saeed ◽  
Wan Nur Syahidah Wan Yusoff
Keyword(s):  
Simulation Study ◽  
Present Model ◽  
Parametric Model ◽  
Line Transect ◽  
Population Abundance ◽  
Line Transect Sampling ◽  
Detection Function ◽  
Transect Sampling ◽  
Proposed Model ◽  
Shoulder Condition

One of the most important sides of life is wildlife. There is growing research interest in monitoring wildlife. Line transect sampling is one of the techniques widely used for estimating the density of objects especially for animals and plants. In this research, a parametric estimator for estimation of the population abundance is developed. A new parametric model for perpendicular distances for detection function is utilised to develop the estimator. In this paper, the performance of the parametric model which was developed using a simulation study is presented. The detection function has non-increasing curve and a perfect probability at zero. Theoretically, the parametric model which has been developed is guar-anteed to satisfy the shoulder condition assumption. A simulation study is presented to validate the present model. Relative mean error (RME) and Relative Bias (RB) are used to compare the estimator with well-known existing estimators. The results of the simulation study are discussed, and the performance of the proposed model shows promising statistical properties which outperformed the existing models. Keywords: detection function, line transect data, parametric model

scholarly journals Blue whales (Balaenoptera musculus) optimize foraging efficiency by balancing oxygen use and energy gain as a function of prey density

2015 ◽  
Vol 1 (9) ◽  
pp. e1500469 ◽  
Author(s):  
Elliott Lee Hazen ◽  
Ari Seth Friedlaender ◽  
Jeremy Arthur Goldbogen
Keyword(s):  
Energy Intake ◽  
Prey Density ◽  
Prey Capture ◽  
Energy Gain ◽  
Foraging Strategies ◽  
Foraging Efficiency ◽  
Energetic Efficiency ◽  
Breath Hold ◽  
Balaenoptera Musculus ◽  
Blue Whales

Terrestrial predators can modulate the energy used for prey capture to maximize efficiency, but diving animals face the conflicting metabolic demands of energy intake and the minimization of oxygen depletion during a breath hold. It is thought that diving predators optimize their foraging success when oxygen use and energy gain act as competing currencies, but this hypothesis has not been rigorously tested because it has been difficult to measure the quality of prey that is targeted by free-ranging animals. We used high-resolution multisensor digital tags attached to foraging blue whales (Balaenoptera musculus) with concurrent acoustic prey measurements to quantify foraging performance across depth and prey density gradients. We parameterized two competing physiological models to estimate energy gain and expenditure based on foraging decisions. Our analyses show that at low prey densities, blue whale feeding rates and energy intake were low to minimize oxygen use, but at higher prey densities feeding frequency increased to maximize energy intake. Contrary to previous paradigms, we demonstrate that blue whales are not indiscriminate grazers but instead switch foraging strategies in response to variation in prey density and depth to maximize energetic efficiency.

scholarly journals From conservation genetics to conservation genomics: a genome-wide assessment of blue whales ( Balaenoptera musculus ) in Australian feeding aggregations

2018 ◽  
Vol 5 (1) ◽  
pp. 170925 ◽  
Author(s):  
Catherine R. M. Attard ◽  
Luciano B. Beheregaray ◽  
Jonathan Sandoval-Castillo ◽  
K. Curt S. Jenner ◽  
Peter C. Gill ◽  
...  
Keyword(s):  
Population Structure ◽  
Adaptive Divergence ◽  
Balaenoptera Musculus ◽  
Blue Whale ◽  
Conservation Genomics ◽  
Next Generation Sequencing Technology ◽  
Genome Wide ◽  
A Genome ◽  
Wide Range ◽  
Blue Whales

Genetic datasets of tens of markers have been superseded through next-generation sequencing technology with genome-wide datasets of thousands of markers. Genomic datasets improve our power to detect low population structure and identify adaptive divergence. The increased population-level knowledge can inform the conservation management of endangered species, such as the blue whale ( Balaenoptera musculus ). In Australia, there are two known feeding aggregations of the pygmy blue whale ( B. m. brevicauda ) which have shown no evidence of genetic structure based on a small dataset of 10 microsatellites and mtDNA. Here, we develop and implement a high-resolution dataset of 8294 genome-wide filtered single nucleotide polymorphisms, the first of its kind for blue whales. We use these data to assess whether the Australian feeding aggregations constitute one population and to test for the first time whether there is adaptive divergence between the feeding aggregations. We found no evidence of neutral population structure and negligible evidence of adaptive divergence. We propose that individuals likely travel widely between feeding areas and to breeding areas, which would require them to be adapted to a wide range of environmental conditions. This has important implications for their conservation as this blue whale population is likely vulnerable to a range of anthropogenic threats both off Australia and elsewhere.

scholarly journals The Greening and Wetting of the Sahel Have Leveled off since about 1999 in Relation to SST

2020 ◽  
Vol 12 (17) ◽  
pp. 2723
Author(s):  
Tiexi Chen ◽  
Shengjie Zhou ◽  
Chuanzhuang Liang ◽  
Daniel Fiifi Tawia Hagan ◽  
Ning Zeng ◽  
...  
Keyword(s):  
Piecewise Linear ◽  
Vegetation Indices ◽  
Positive Trend ◽  
Causality Analysis ◽  
Area Index ◽  
Piecewise Linear Regression ◽  
Significant Positive Trend ◽  
Tropical Oceans ◽  
Regression Approach

The Sahel, a semi-arid climatic zone with highly seasonal and erratic rainfall, experienced severe droughts in the 1970s and 1980s. Based on remote sensing vegetation indices since early 1980, a clear greening trend is found, which can be attributed to the recovery of contemporaneous precipitation. Here, we present an analysis using long-term leaf area index (LAI), precipitation, and sea surface temperature (SST) records to investigate their trends and relationships. LAI and precipitation show a significant positive trend between 1982 and 2016, at 1.72 × 10 −3 yr −1 (p < 0.01) and 4.63 mm yr−1 (p < 0.01), respectively. However, a piecewise linear regression approach indicates that the trends in both LAI and precipitation are not continuous throughout the 35 year period. In fact, both the greening and wetting of the Sahel have been leveled off (pause of rapid growth) since about 1999. The trends of LAI and precipitation between 1982 and 1999 and 1999–2016 are 4.25 × 10 − 3 yr −1 to − 0.27 × 10 −3 yr −1, and 9.72 mm yr −1 to 2.17 mm yr −1, respectively. These declines in trends are further investigated using an SST index, which is composed of the SSTs of the Mediterranean Sea, the subtropical North Atlantic, and the global tropical oceans. Causality analysis based on information flow theory affirms this precipitation stabilization between 2003 and 2014. Our results highlight that both the greening and the wetting of the Sahel have been leveled off, a feature that was previously hidden in the apparent long-lasting greening and wetting records since the extreme low values in the 1980s.

A Review of the Morid Fish Genus Lepidion of the North Atlantic With First Records of Lepidion eques from the Western North Atlantic

1970 ◽  
Vol 27 (3) ◽  
pp. 457-498 ◽  
Author(s):  
Wilfred Templeman
Keyword(s):  
North Atlantic ◽  
Sexual Maturity ◽  
Head Length ◽  
Western Atlantic ◽  
Morphometric Characters ◽  
Northeast Atlantic ◽  
West Greenland ◽  
Biological Station ◽  
The North ◽  
The North Atlantic

Seventeen specimens of Lepidion eques (Günther) taken by the Fisheries Research Board of Canada St. John's, Nfld., Biological Station are apparently the first records of the species from the western Atlantic west of West Greenland. Comparison with specimens from the northeast Atlantic shows some differences in averages of meristic and morphometric characters, but with overlapping ranges in these characters.Comparison of these North Atlantic L. eques with the Mediterranean Lepidion lepidion (Risso) revealed that although closely related, these species are separable on the bases of the smaller orbit diameter in relation to the head length and especially by the relatively larger postorbital length in L. lepidion. Lepidion guentheri (Giglioli) is distinctly different from these two species in some meristic and many morphometric characters. Lectotypes of L. eques and L. guentheri are designated. Various incorrect or doubtful records of Lepidion are discussed. Two giant lepidions reported recently from the northeast Atlantic as L. guentheri are tentatively assigned to Lepidion schmidti Svetovidov, a species hitherto known only from Japan.The distributions of the North Atlantic species of Lepidion are discussed and information is provided on sexual maturity.

Patient-Reported Fatigue Scores in Cancer Patients with Chemotherapy-Induced Anemia Treated with Erythropoietic-Stimulating Agents (ESAs).

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1304-1304
Author(s):  
Tanya Burton ◽  
David Hoaglin ◽  
Kay Larholt ◽  
Elizabeth Apgar ◽  
Chris Pashos ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Repeated Measures ◽  
Prospective Observational Study ◽  
Positive Trend ◽  
Significant Positive Trend ◽  
Repeated Measures Analysis ◽  
Patient Reported ◽  
Clinical Trial Evidence ◽  
Outcomes Study ◽  
Trial Evidence

Abstract Background: Clinical trial evidence has demonstrated greater anemia-related fatigue at lower hemoglobin (Hb) levels in ESA-treated patients with chemotherapy-induced anemia (CIA). To understand these patient-reported outcomes (PROs), during ESA treatment in a real-world setting, data were analyzed from the Dosing and Outcomes Study of Erythropoiesis-Stimulating Therapies (D.O.S.E.) Registry, an ongoing, prospective, observational study. Methods: Patients included for analysis were required to have a baseline Hb prior to ESA administration and at least two ESA administrations. PROs were measured using the Functional Assessment of Cancer Therapy: Fatigue subscale (FACT-F), a 13-question measure of anemia-associated fatigue with lower scores indicating greater fatigue in patients with CIA. Patients were to have completed up to three FACT-F questionnaires within seven days of a post-baseline Hb level. If multiple Hb values were identified, the Hb value closest to the FACT-F assessment was reported. The association between FACT-F scores and Hb levels was tested in a repeated-measures analysis. Mean FACT-F scores were calculated for specified Hb ranges. Results: 740 CIA patients from 63 sites were identified between 12/03 and 7/08. 1088 concurrent FACT-F and Hb level assessments were available during ESA treatment. Mean FACT-F scores were lower when patients had lower Hb levels (table). The association between FACT-F scores and Hb levels showed a significant positive trend (p&lt;.0001). Hb ≤ 8.0 g/dL 8.01–9.0 g/dL 9.01–10.0 g/dL 10.01–11.0 g/dL 11.01–12.0 g/dL n (concurrent FACT-F and Hb assessments) 19 63 212 336 458 Mean FACT-F score (SD) 21.26 (11.01) 22.95 (12.44) 25.64 (12.40) 26.84 (11.70) 29.34 (12.04) Conclusions: This analysis of FACT-F assessments in CIA patients suggests that lower Hb levels were associated with greater anemia-related fatigue. These findings are consistent with clinical trial evidence and provide observational PRO data to patients and providers regarding anemia-related fatigue during ESA treatment.

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