34 research outputs found
Body size data collected non-invasively from drone images indicate a morphologically distinct Chilean blue whale (Blaenoptera musculus) taxon
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Leslie, M. S., Perkins-Taylor, C. M., Durban, J. W., Moore, M. J., Miller, C. A., Chanarat, P., Bahamonde, P., Chiang, G., & Apprill, A. Body size data collected non-invasively from drone images indicate a morphologically distinct Chilean blue whale (Blaenoptera musculus) taxon. Endangered Species Research, 43, (2020): 291-304, https://doi.org/10.3354/esr01066.The blue whale Balaenoptera musculus (Linnaeus, 1758) was the target of intense commercial whaling in the 20th century, and current populations remain drastically below pre-whaling abundances. Reducing uncertainty in subspecific taxonomy would enable targeted conservation strategies for the recovery of unique intraspecific diversity. Currently, there are 2 named blue whale subspecies in the temperate to polar Southern Hemisphere: the Antarctic blue whale B. m. intermedia and the pygmy blue whale B. m. brevicauda. These subspecies have distinct morphologies, genetics, and acoustics. In 2019, the Society for Marine Mammalogy’s Committee on Taxonomy agreed that evidence supports a third (and presently unnamed) subspecies of Southern Hemisphere blue whale subspecies, the Chilean blue whale. Whaling data indicate that the Chilean blue whale is intermediate in body length between pygmy and Antarctic blue whales. We collected body size data from blue whales in the Gulfo Corcovado, Chile, during the austral summers of 2015 and 2017 using aerial photogrammetry from a remotely controlled drone to test the hypothesis that the Chilean blue whale is morphologically distinct from other Southern Hemisphere blue whale subspecies. We found the Chilean whale to be morphologically intermediate in both overall body length and relative tail length, thereby joining other diverse data in supporting the Chilean blue whale as a unique subspecific taxon. Additional photogrammetry studies of Antarctic, pygmy, and Chilean blue whales will help examine unique morphological variation within this species of conservation concern. To our knowledge, this is the first non-invasive small drone study to test a hypothesis for systematic biology.We are thankful to Foundation MERI (Melimoyu Ecosystem Research Institute) for logistical and funding support. Cruise support in 2017 was provided by the Dalio Foundation (now ‘OceanX’)
Photogrammetry of blue whales with an unmanned hexacopter
Author Posting. © Society for Marine Mammalogy, 2016. This article is posted here by permission of Society for Marine Mammalogy for personal use, not for redistribution. The definitive version was published in Marine Mammal Science 32 (2016):1510–1515, doi:10.1111/mms.12328.Baleen whales are the largest animals ever to live on earth, and many populations
were hunted close to extinction in the 20th century (Clapham et al. 1999). Their
recovery is now a key international conservation goal, and they are important in marine
ecosystems as massive consumers that can promote primary production through
nutrient cycling (Roman et al. 2014). However, although abundance has been
assessed to monitor the recovery of some large whale populations (e.g., Barlow et al.
2011, Laake et al. 2012) many populations are wide-ranging and pelagic, and this
inaccessibility has generally impeded quantitative assessments of recovery (Peel et al.
2015). To augment traditional abundance monitoring, we suggest that photogrammetric
measures of individual growth and body condition can also inform about population
status, enabling assessment of individual health as well as population numbers. Photogrammetry
from manned aircraft has used photographs taken from directly above
whales to estimate individual lengths (Gilpatrick and Perryman 2008) and monitor growth trends (Fearnbach et al. 2011), and shape profiles can be measured to assess
body condition to infer reproductive and nutritional status (e.g., Perryman and Lynn
2002, Miller et al. 2012). Recently, Durban et al. (2015) demonstrated the utility of
an unmanned hexacopter for collecting aerial photogrammetry images of killer
whales (Orcinus orca); this provided a noninvasive, cost-effective, and safe platform
that could be deployed from a boat to obtain vertical images of whales. Here we
describe the use of this small, unmanned aerial system (UAS) to measure length and
condition of blue whales (Balaenoptera musculus), the largest of all whales.MarÃa Francisca Cortés Solari;
Rafaela Landea Briones;
MERI Foundation;
Woods Hole Oceanographic Institution Acces
'Werner Buttner's Collages: From A to T (and Back Again)'
Contribution to a monograph on noted German collagist and painter Werner Buttner at Marlborough Contemporary Gallery, London
South American National Contributions to Knowledge of the Effects of Endocrine Disrupting Chemicals in Wild Animals: Current and Future Directions
Human pressure due to industrial and agricultural development has resulted in a biodiversity crisis. Environmental pollution is one of its drivers, including contamination of wildlife by chemicals emitted into the air, soil, and water. Chemicals released into the environment, even at low concentrations, may pose a negative effect on organisms. These chemicals might modify the synthesis, metabolism, and mode of action of hormones. This can lead to failures in reproduction, growth, and development of organisms potentially impacting their fitness. In this review, we focused on assessing the current knowledge on concentrations and possible effects of endocrine disruptor chemicals (metals, persistent organic pollutants, and others) in studies performed in South America, with findings at reproductive and thyroid levels. Our literature search revealed that most studies have focused on measuring the concentrations of compounds that act as endocrine disruptors in animals at the systemic level. However, few studies have evaluated the effects at a reproductive level, while information at thyroid disorders is scarce. Most studies have been conducted in fish by researchers from Brazil, Argentina, Chile, and Colombia. Comparison of results across studies is difficult due to the lack of standardization of units in the reported data. Future studies should prioritize research on emergent contaminants, evaluate effects on native species and the use of current available methods such as the OMICs. Additionally, there is a primary focus on organisms related to aquatic environments, and those inhabiting terrestrial environments are scarce or nonexistent. Finally, we highlight a lack of funding at a national level in the reviewed topic that may influence the observed low scientific productivity in several countries, which is often negatively associated with their percentage of protected areas
Gene expression patterns based upon k-means clustering.
<p>Data were used for the computation of expression trends in the set of 9,344 genes in male gonads across the annual cycle. K-means is an iterative procedure aimed to reduce the variance to a minimum within each cluster. A total of 18 different patterns of gene expression were determined. The tendency curve (centroid) is depicted by the solid line with the SE of the normalize intensity.</p
Normalized fold change levels ± standard error for <i>esr1</i>, <i>esrb</i>, <i>ar</i>, <i>cyp17α</i>, <i>cyp19α</i>, <i>spag</i>, <i>spata4</i>, <i>dmrt1</i>, <i>sox9</i>, <i>foxl2</i>, <i>hps90</i>, <i>hsp1</i>, <i>hsp70</i>, <i>nanos3</i>, <i>cdca8</i>, <i>surviving</i>, <i>fabp</i>, and <i>zp</i> analyzed using real-time PCR in male gonads over the different stages of testis development.
<p>Differences among treatment groups (p < 0.01) for each gene are denoted with different letters; outliers were included in the analysis.</p
The most significant Gene Ontology (GO) terms enriched in K-means clustering.
<p>The most significant Gene Ontology (GO) terms enriched in K-means clustering.</p
Processes activated in the transition from spawning to post-spawning.
<p>These processes are then suppressed as the testis enters recrudescence and begins a new maturation cycle. Blue colors genes represent a down-regulated gene and red colored figures represent an up-regulated gene.</p
A 3D Principal Component Analysis of male rainbow darter gene expression profiles in gonad tissue across the annual cycle.
<p>Different colors represent the different stages of gonad maturity, including post-spawning (green at bottom right), recrudescence (yellow to the right of the cluster at top left), developing (red top right), pre-spawning (blue in the centre of the cluster at top left) and spawning (purple top left).</p