New publication, Using gliders to explore fin whale habitat in coastal and offshore waters
My co-authors and I are pleased to share our latest publication from our use of gliders to explore whale habitat: _Remote sensing and mapping habitat features pertinent to fin whale life histories in coastal and offshore waters of Vancouver Island, British Columbia_ Journal of Experimental Marine Biology and Ecology 537, 151511 Abstract: Current knowledge of the population size and movement of fin whales in the northeast Pacific is lacking, but is critical in implementing effective management actions. Here we used ocean gliders to survey the deep-coastal and offshore waters of Vancouver Island to add to what is known about fin whale habitat use in the Canadian Pacific. Passive acoustic recordings were made continuously, from which fin whale vocalizations were used as a proxy to presence. Oceanographic and preyscape variables were also taken to better delineate habitat units in horizontal and vertical space. Comparisons were made between on-shelf and shelf-break zones, and measures taken in- and out-side submarine canyons. Temporal comparisons between winter and spring were also possible. An on-shelf and shelf-break divide was seen, with cooler, fresher waters present closer to the coast for both deployments. The spring deployment showed fin whale acoustic presence focused around topographical features, including the shelf-break and canyons. The most prevalent cue was their 40-Hz call, which suggests foraging. Echosounder readings suggested denser aggregations of larger bodied zooplankton prey were present at canyon heads and along the shelf break. During the winter, calls in the acoustic record were more numerous than in the spring, and dominated by the 20-Hz call. A proportion of the recordings also showed 'song' patterning, which suggests breeding activity. Interpolated surfaces were used to examine the spatiotemporal relationships between the high-resolution habitat point data and presence of far-propagating fin whale calls. The predicted use of habitat by fin whales, as represented by their calls, was examined through Random Forest machine learning models using oceanographic and preyscape measures as input variables from these interpolations. Distance from the shelf break and preyscape variables were determined important in predicting whale habitat use in the spring, with model accuracy exceeding 80%. Call presence showed a much weaker relationship to environmental var-iables for the winter recordings with reduced accuracy of model predictions (13%). An understanding of habitat selection by fin whales may also aid in determining the importance of habitat units and areas that may critical to life history functions. The paper is free to read/download from JEMBE online at https://authors.elsevier.com/a/1cThA51aUfmHA [1] until March 16, 2021 Please feel free to contact me if you have questions, or for a PDF after that time Best, Rianna Burnham, PhD Links: ------ [1] https://authors.elsevier.com/a/1cThA51aUfmHA
My co-authors and I are pleased to share our latest publication: Burnham, R.E., Duffus, D.A., Malcolm, C.D., Towards an enhanced management of recreational whale watching: The use of ecological and behavioural data to support evidence based management actions
Biological Conservation 255, 109009
Abstract: Recognition of the potential disturbance from whale-based tourism has stimulated the discussion of whether whale watching remains 'no take'. Here we use observations and passive acoustic surveillance of tourism activities of foraging gray whales (_Eschrichtius robustus [1]_) on the west coast of Vancouver Island to better understand the pressures on whales that are repeatedly subject to aerial and vessel-based viewing. Pressure from the fleet was greatest for low prey years, whereby fewer whales were subject to a greater number of encounters with whale watching vessels. The pressure on operators for close encounters was also greater during these years. The acoustic recordings found that whale watching vessels shaped the soundscape, with a distinct diurnal pattern. Acoustic reactions by the whales were also noted. Cow-calf pairs showed increased calling rate in the presence of vessels in the feeding bay, with calling rate of single foraging whales increasing as ve! ssel number, particularly those engaged in whale watching, increased. These responses have implications for energetics, communication success. The implications of acoustic disturbance from whale watching has yet to be well defined, but it is only one of many stressors that gray whales are subject to. The results of this study lead us to argue for greater evidence-based management of whale watching; restrictions on encounters; noise emission limitations; requiems for the whales, and a greater interpretative component for passengers. The aggregate and cumulative effects [2] of disturbance should also be emphasized in vessel-whale interaction guidelines, with the most vulnerable individuals removed from the viewing resource altogether.
The paper is free to read/download online at https://authors.elsevier.com/a/1ccjs1R%7EeL7Ye [3] until April 11, 2021
Please feel free to contact me if you have questions, or for a PDF after that time
Best,
Rianna Burnham, PhD
Links: ------ [1] https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/es... [2] https://www.sciencedirect.com/topics/earth-and-planetary-sciences/cumulative... [3] https://authors.elsevier.com/a/1ccjs1R%7EeL7Ye
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