the function of the external ear canal in cetaceans is still under debate and its morphology is largely unknown. Immunohistochemical (IHC) analyses using antibodies specific for nervous tissue (anti-S100, anti-NSE, anti-NF, and anti-PGP 9.5), together with transmission electron microscopy (TEM) and various histological techniques, were carried out to investigate the peripheral nervous system of the ear canals of several species of toothed whales and terrestrial cetartiodactyla. this study highlights the innervation of the ear canal with the presence of lamellar corpuscles over its entire course, and their absence in all studied terrestrial mammals. Each corpuscle consisted of a central axon, surrounded by lamellae of Schwann receptor cells, surrounded by a thin cellular layer, as shown by IHC and TEM. These findings indicate that the corpuscles are mechanoreceptors that resemble the inner core of Pacinian corpuscles without capsule or outer core, and were labelled as simple lamellar corpuscles. They form part of a sensory system that may represent a unique phylogenetic feature of cetaceans, and an evolutionary adaptation to life in the marine environment. Although the exact function of the ear canal is not fully clear, we provide essential knowledge and a preliminary hypothetical deviation on its function as a unique sensory organ. The morphology of the external ear canal of toothed whales has received little attention in comparison to the middle and inner ear (e.g 1,2 .), and there is a debate on whether the canal still serves any function 3. The exact pathways for sound reception are not yet fully understood but it is known that echolocation signals are received through the mandibular fat bodies, while other sounds, such as those for communication, could be received through a lateral soft tissue pathway 3-5. However, whether the external ear canal forms a functional part of this or any other process is still a conundrum, and even basic knowledge on its morphology is largely incomplete. Very few papers describe the morphology of the ear canal in cetaceans and even fewer mention the presence of lamellar corpuscles, likely mechanoreceptors 6,7. Similar corpuscles have been mentioned in other tissues of cetaceans including the skin of the trunk, flippers, and fluke 8 , lips and eyelids 9 , inside the nasal sac system 10-12 , and associated with vibrissal crypts 13 , but their function is not clear. Moreover, there is a lack of information on the fine-scale morphology of these sensory nerve formations (SNF's) and their role in the external ear canal. To achieve a better understanding of the functionality of the ear canal in dolphins, we used several histological staining techniques, together with immunohistochemical labelling with four different antibodies specific for nervous tissue antigens. We also applied TEM to study the fine-scale morphology of the lamellar corpuscles, and did a preliminary quantitative study on their distribution along the ear canal. We compared the peripheral nervous system of the ear canals...

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The Shannon Estuary on the west coast of Ireland is one of Europe's premier deepwater berths catering for ships up to 200,000 deadweight tonnage. It is also Ireland's only designated candidate special area of conservation for bottlenose dolphins under the EU Habitats Directive. Long-term static acoustic monitoring was carried out at a number of intensive shipping sites. In 2012, noise monitoring took place over a 6-month period (at 1 site) as part of Ireland's requirements under the Marine Strategy Framework Directive (MSFD). This is the first assessment of the potential effect of vessel traffic on the behavior of this discrete dolphin population.

With the aim of classifying sperm whales, this report compares two methods that can use Gaussian functions, a radial basis function network, and support vector machines which were trained with two different approaches known as C-SVM and ν-SVM. The methods were tested on data recordings from seven different male sperm whales, six containing single click trains and the seventh containing a complete dive. Both types of classifiers could distinguish between the clicks of the seven different whales, but the SVM seemed to have better generalisation towards unknown data, at the cost of needing more information and slower performance

Statoil deployed three acoustic recorders from fall 2013 to 2014 in the Arctic region as part of a broad scientific campaign. One recorder was installed in the Barentsz Sea southeast of Spitsbergen. Two other recorders were installed in the Greenland Sea north-east of Greenland. All recorders were operating at a duty cycle of 2 min on and 30 min off, sampling at 39,062 Hz and recording in 24 bits. The Greenland recorders both captured air gun surveys performed during the summer months of 2013, allowing to estimate the transmission loss in the Arctic over long ranges. This paper presents "log(R)" transmission loss curves for these scenarios that can help assessing the acoustic shipping impact for future expeditions.