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Recently there has been controversy in Denmark regarding the porpoises in sea pens at the Fjord&Bælt center. As a scientist involved in studies with these animals, and with the conservation of wild animals and habitats close to my heart, I felt the need to speak/inform... THREAD
2/ First off – consider the context. Thousands of porpoises in EU waters alone (& hundreds of thousands of toothed whales globally) are killed as #bycatch *ANNUALLY*. Our oceans are polluted with noise (ADDs around fish farms, airguns to search for fossil fuels, sonars, etc.)…
3/ …& marine life is subjected to these disturbances. These activities are all legal + ongoing. I think it's important to consider this when arguing against keeping 3 captive porpoises which provide us with data that can help us understand and mitigate these #conservation issues
4/ The facebook page for @SeaShepherd calls all research at F&B “supposed research”. Similar rebuttals from @MC_org @DFEcoalition. I agree keeping animals in captivity is not a black/white issue, & so below are specific examples of how F&B studies contribute to conservation.
5/ The 3D echolocation beam pattern of the F&B porpoises can inform acoustic density estimations from #passiveacoustic monitoring, which is one of the primary methods for estimating wild population sizes & determining IUCN conservation statuses. https://asa.scitation.org/doi/10.1121/10.0001376
6/ … and knowledge on flexibility of their biosonar beam ( https://elifesciences.org/articles/05651 ) informs us of what echolocation can tell them. Knowledge of their sensory ecology helps us understand how they manage to still get entangled in nets, and can inform bycatch mitigation measures.
7/ Auditory studies on the F&B porpoises inform us of their hearing abilities and how the sensitivities of these can be modified depending on the acoustic situation ( https://royalsocietypublishing.org/doi/full/10.1098/rspb.2011.2465 )
8/ … which informs noise exposure criteria and appropriate frequency weighting techniques – totally relevant for policies and regulations of underwater noise. (e.g. https://www.sciencedirect.com/science/article/pii/S0025326X14007358 )
9/ Heart-rate biologging tags have been developed +deployed successfully in the field (on wild porpoises & pilot whales) thx to successful pilot trials on the F&B porpoises. ECG data tell us about bradycardia, tachycardia, drivers of dive response…. https://jeb.biologists.org/content/222/19/jeb208637
10/…& such baseline physiology is super important when measuring effects of #noisepollution on wild animals. In another study, the responses of ECG-tagged wild porpoises to acoustic deterrent devices was monitored (pub in progress, PhD thesis here: https://pure.au.dk/portal/da/publications/ecophysiology-of-echolocating-toothed-whales(2ddd69ee-f212-418b-9158-6de37eb2928f).html)
11/ …which adds a lot of context to likely habitat exclusion from ADDs shown in complementary noise mapping studies (e.g. https://www.sciencedirect.com/science/article/abs/pii/S0025326X18306064 ), by revealing the physiological stress they experiences when exposed to such sounds, as they regularly are in the wild.
12/… And not just loud ADDs, but even low levels of vessel noise have been identified as something that elicits strong behavioural responses - this study on the F&B porpoises suggests boat noise is a substantial source of disturbance: ( https://www.nature.com/articles/srep11083)
13/ ...& building on that, a F&B study revealed that since high pitch noise from vessels overlaps with their high pitch biosonar, this makes it harder for them to decode echo information. Yikes since echolocation key to livelihood
(pub in prog, see p314 https://www.wmmconference.org/wp-content/uploads/2020/02/WMMC-Book-of-Abstracts-3.pdf )
(pub in prog, see p314 https://www.wmmconference.org/wp-content/uploads/2020/02/WMMC-Book-of-Abstracts-3.pdf )
14/ Studies on acoustic communication between the porpoises at F&B ( https://www.tandfonline.com/doi/abs/10.1080/09524622.2011.9753630) laid the groundwork for identifying social interactions in wild porpoises ( https://www.nature.com/articles/s41598-018-28022-8 )...
15/ … which was crucial for interpreting acoustic data of a bycatch event recorded on active fishing gear. (pub in progress, see p.429 of https://www.wmmconference.org/wp-content/uploads/2020/02/WMMC-Book-of-Abstracts-3.pdf )
16/ Data from the F&B porpoises can also be used to validate metabolic expenditures of tagged wild animals. In this study, the field metabolic rate of porpoises (at F&B and in wild) was measured… https://jeb.biologists.org/content/221/23/jeb185827
17/ …and this aligned with reported high feeding rates of wild porpoises, emphasizing concerns about disturbances to their foraging arising from anthropogenic impacts on individuals and populations https://www.sciencedirect.com/science/article/pii/S0960982216303141
18/ Plus, #photogrammetry has been recently been used on F&B porpoises to create accurate, #openaccess 3D models, which are critical for investigating body condition, morphometrics, and bioenergetics https://onlinelibrary.wiley.com/doi/10.1111/mms.12759 & https://sketchfab.com/3d-models/model-75a-harbor-porpoise-eb02e57f17d741329a66844a3a8d2094
19/ ++ though less tangible, the studies conducted with these trained porpoises have in turn trained a huge swathe of biologists, filling their professional toolboxes with the analytical abilities necessary for investigating & quantifying anthropogenic disturbances, for example.
20/ I’m not comfortable with killer whales in captivity. I don’t feel supportive about keeping animals purely for display purposes (documentaries are plenty capable of engaging audiences). But these porpoises have contributed greatly to our understanding of conservation issues.
21/ Anyways, I hope these examples (+ many more, see https://twitter.com/NATsdu/status/1335884403768242178 ) contribute to the [mostly one-sided] discussion surrounding 3 porpoises at F&B. From echolocation to hearing, heart rate to foraging, these studies have been key to understanding/helping wild whales.
ps. above article from @NATsdu now also in English: https://www.sdu.dk/da/om_sdu/fakulteterne/naturvidenskab/nyheder-2020/2020_12_04_marsvin?fbclid=IwAR2TCaItxPJeqyJXRiczofSzLaEvBm_QEisao-aFHaOG2n2mPktQvu4xCuM
