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.María Francisca Cortés Solari; Rafaela Landea Briones; MERI Foundation; Woods Hole Oceanographic Institution Acces

Remembering the Sea: Personal and Communal Recollections of Maritime Life in Jizan and the Farasan Islands, Saudi Arabia

This is the final version of the article. Available from the publisher via the DOI in this record.People create narratives of their maritime past through the remembering and forgetting of seafaring experiences, and through the retention and disposal of maritime artefacts that function mnemonically to evoke or suppress those experiences. The sustenance and reproduction of the resulting narratives depends further on effective media of intergenerational transmission; otherwise, they are lost. Rapid socio-economic transformation across Saudi Arabia in the age of oil has disrupted longstanding seafaring economies in the Red Sea archipelago of the Farasan Islands, and the nearby mainland port of Jizan. Vestiges of wooden boatbuilding activity are few; long-distance dhow trade with South Asia, the Arabian-Persian Gulf and East Africa has ceased; and a once substantial pearling and nacre (mother of pearl) collection industry has dwindled to a tiny group of hobbyists: no youth dive today. This widespread withdrawal from seafaring activity among many people in these formerly maritime-oriented communities has diminished the salience of such activity in cultural memory, and has set in motion narrative creation processes, through which memories are filtered and selected, and objects preserved, discarded, or lost. This paper is a product of the encounter of the authors with keepers of maritime memories and objects in the Farasan Islands and Jizan. An older generation of men recall memories of their experiences as boat builders, captains, seafarers, pearl divers and fishermen. Their recounted memories are inscribed, and Arabic seafaring terms recorded. The extent of the retention of maritime material cultural items as memorials is also assessed, and the rôle of individual, communal and state actors in that retention is considered. Through this reflection, it becomes clear that the extra-biological memory and archive of the region’s maritime past is sparse; that intergenerational transmission is failing; that the participation of state agencies in maritime heritage creation is highly limited; and that, as a result, memories current among the older generation have limited prospect of survival. These memories, recorded and interpreted here, identify the Farasan Islands as a former centre of the pearling industry in the Red Sea, and identify them and Jizan as open to far-reaching maritime-mediated cultural influences in an era before the imposition of the attributes of the modern nation-state.This study was funded by the Golden Web Foundation (UK registered charity number 1100608), with additional support from the Seven Pillars of Wisdom Trust (UK registered charity number 208669)

RENEWAL: REpurposing study to find NEW compounds with Activity for Lewy body dementia—an international Delphi consensus

Drug repositioning and repurposing has proved useful in identifying new treatments for many diseases, which can then rapidly be brought into clinical practice. Currently, there are few effective pharmacological treatments for Lewy body dementia (which includes both dementia with Lewy bodies and Parkinson’s disease dementia) apart from cholinesterase inhibitors. We reviewed several promising compounds that might potentially be disease-modifying agents for Lewy body dementia and then undertook an International Delphi consensus study to prioritise compounds. We identified ambroxol as the top ranked agent for repurposing and identified a further six agents from the classes of tyrosine kinase inhibitors, GLP-1 receptor agonists, and angiotensin receptor blockers that were rated by the majority of our expert panel as justifying a clinical trial. It would now be timely to take forward all these compounds to Phase II or III clinical trials in Lewy body dementia

An accurate and adaptable photogrammetric approach for estimating the mass and body condition of pinnipeds using an unmanned aerial system

<div><p>Measurements of body size and mass are fundamental to pinniped population management and research. Manual measurements tend to be accurate but are invasive and logistically challenging to obtain. Ground-based photogrammetric techniques are less invasive, but inherent limitations make them impractical for many field applications. The recent proliferation of unmanned aerial systems (UAS) in wildlife monitoring has provided a promising new platform for the photogrammetry of free-ranging pinnipeds. Leopard seals (<i>Hydrurga leptonyx</i>) are an apex predator in coastal Antarctica whose body condition could be a valuable indicator of ecosystem health. We aerially surveyed leopard seals of known body size and mass to test the precision and accuracy of photogrammetry from a small UAS. Flights were conducted in January and February of 2013 and 2014 and 50 photogrammetric samples were obtained from 15 unrestrained seals. UAS-derived measurements of standard length were accurate to within 2.01 ± 1.06%, and paired comparisons with ground measurements were statistically indistinguishable. An allometric linear mixed effects model predicted leopard seal mass within 19.40 kg (4.4% error for a 440 kg seal). Photogrammetric measurements from a single, vertical image obtained using UAS provide a noninvasive approach for estimating the mass and body condition of pinnipeds that may be widely applicable.</p></div

Comparison table of the most informative model from each model family.

<p>Comparison table of the most informative model from each model family.</p

Photogrammetric measurements.

<p>An example measured leopard seal with labeled photogrammetric measurements.</p

Aerial versus ground precision.

<p>Observer-derived variances compared between ground-based SL (n = 9) and aerial PSL (n = 9) measurements. Residuals were calculated by summing the absolute difference between each measurement and the mean value for a given animal. Leven’s Test F_1,9 = 2.439, p = 0.14.</p

Measurement accuracy comparisons.

<p>Measurement accuracy comparisons.</p