{"id":5024,"date":"2023-01-23T20:12:15","date_gmt":"2023-01-24T03:12:15","guid":{"rendered":"https:\/\/blogs.oregonstate.edu\/gemmlab\/?p=5024"},"modified":"2023-01-23T20:12:15","modified_gmt":"2023-01-24T03:12:15","slug":"clicks-buzzes-and-rasps-how-the-mmpa-has-spurred-what-we-know-about-beaked-whale-acoustic-repertoire","status":"publish","type":"post","link":"https:\/\/blogs.oregonstate.edu\/gemmlab\/2023\/01\/23\/clicks-buzzes-and-rasps-how-the-mmpa-has-spurred-what-we-know-about-beaked-whale-acoustic-repertoire\/","title":{"rendered":"Clicks, buzzes, and rasps: How the MMPA has spurred what we know about beaked whale acoustic repertoire<\/strong>"},"content":{"rendered":"\n

By Marissa Garcia<\/em><\/a>, PhD Student, Cornell University, Department of Natural Resources and the Environment, <\/em>K. Lisa Yang Center for Conservation Bioacoustics<\/em><\/a><\/p>\n\n\n\n

In October 1972, the tides turned for U.S. environmental politics: the Marine Mammal Protection Act (MMPA) was passed. Its creation ushered in a new flavor of conservation and management. With phrases like \u201coptimum sustainable population\u201d baked into its statutory language, it marked among the first times that ecosystem-based management \u2014 an approach which directly calls upon knowledge of ecology to inform action \u2014 was required by law (Ray and Potter 2022). Transitioning from reductionist, species-siloed policies, the MMPA instead placed the interdependency<\/strong> of species at the core of ecosystem function and management. <\/p>\n\n\n\n

Beyond deepening the role of science on Capitol Hill, the MMPA\u2019s greatest influence may have been spurred by the language that prohibited \u201cthe taking and importation of marine mammals\u201d (16 U.S.C. 1361). Because the word \u201ctaking\u201d is multivalent, it carries on its back many interpretations. \u201cTaking\u201d a marine mammal is not limited to intentionally hunting or killing them, or even accidental bycatch. \u201cTaking\u201d also includes carelessly operating a boat when a marine mammal is present, feeding a marine mammal in the wild, or tagging a marine mammal without the appropriate scientific permit. \u201cTaking\u201d a marine mammal can also extend to the fatal consequences caused by noise pollution \u2014 not intent, but incident (16 U.S.C. 1362).<\/em><\/strong><\/p>\n\n\n\n

The latter circumstances remain reverberant for the U.S. Navy. To comply with the MMPA, they are granted \u201cincidental, but not intentional, taking of small numbers of marine mammals\u2026.[when] engag[ing] in a specified activity (other than commercial fishing)\u201d (87 FR 33113). So, if the sonar activities required for national security exercises adversely impact marine mammals, the Navy has a bit of leeway but is still expected to minimize this impact. To further mitigate this potential harm, the Navy thus invests heavily in marine mammal research. (If you are interested in learning more about how the Navy has influenced the trajectory of oceanographic research more broadly, you may find this book<\/a> interesting.) <\/p>\n\n\n\n

Beaked whales are an example of a marine mammal we know much about due to the MMPA\u2019s call for research when incidental take occurs. Three decades ago, many beaked whales stranded ashore following a series of U.S. Navy sonar exercises. Since then, the Navy has flooded research dollars toward better understanding beaked whale hearing, vocal behavior, and movements (e.g., Klinck et al. 2012). Through these efforts, a deluge of research charged with developing effective tools to acoustically monitor and conserve beaked whales has emerged.  <\/p>\n\n\n\n

These studies have laid the foundation for my Ph.D. research, which is dedicated to the Holistic Assessment of Living marine resources off Oregon (HALO) project<\/a>. Through both visual and acoustic surveys, the HALO project\u2019s mission is to understand how changes in ocean conditions \u2014 driven by global climate change \u2014 influence living marine resources in Oregon waters.\u00a0<\/p>\n\n\n\n

In my research specifically, I aim to learn more about beaked whales off the Oregon coast. Beaked whales represent nearly a fourth of cetacean species alive today, with at least 21 species recorded to date (Roman et al. 2013). Even so, 90% of beaked whales are considered data deficient: we lack enough information about them to confidently describe the state of their populations or decide upon effective conservation action.\u00a0<\/p>\n\n\n\n

Much remains to be learned about beaked whales, and I aim to do so by eavesdropping on them. By referring to the \u201cacoustic repertoire\u201d of beaked whales \u2014 that is, their vocalizations and corresponding behaviors \u2014 I aim to tease out their vocalizations from the broader ocean soundscape and understand how their presence in Oregon waters varies over time. <\/p>\n\n\n\n

Beaked whales are notoriously cryptic, elusive to many visual survey efforts like those aboard HALO cruises. In fact, some species have only been identified via carcasses that have washed ashore (Moore and Barlow 2013). Acoustic studies have elucidated ecological information (beaked whales forage at night at seamounts summits; Johnston et al. 2008) and have also introduced promising population-level monitoring efforts (beaked whales have been acoustically detected in areas with a historical scarcity of sightings; Kowarski et al. 2018). Their deep-diving nature often renders them inconspicuous, and they forage at depths between 1,000 and 2,000 m, on dives as long as 90 minutes (Moore and Barlow 2013; Klinck et al. 2012). Their echolocation clicks are produced at frequencies within the hearing range of killer whales, and previous studies have suggested that Blainville\u2019s beaked whales are only vocally active during deep foraging dives and not at the surface, possibly to prevent being acoustically detected by predatory killer whales. Researchers refer to this phenomenon as \u201cacoustic crypsis,\u201d or when vocally-active marine mammals are strategically silent to avoid being found by potential predators (Aguilar de Soto et al. 2012).<\/p>\n\n\n\n

We expect to see evidence of Blainville\u2019s beaked whales in Oregon waters, as well as Baird\u2019s, Cuvier\u2019s, Stejneger\u2019s, Hubb\u2019s, and other beaked whale species. Species-specific echolocation clicks were comprehensively described a decade ago in Baumann-Pickering et al. 2013 (Figure 1<\/strong>). While this study laid the groundwork for species-level beaked whale acoustic detection, much more work is still needed to describe their acoustic repertoire with higher resolution detail. For example, though Hubb\u2019s beaked whales live in Oregon waters, their vocal behavior remains scantly defined.<\/p>\n\n\n\n

\"\"
Figure 1: <\/strong>Baird\u2019s, Blainville\u2019s, Cuvier\u2019s, and Stejneger\u2019s beaked whales are among the most comprehensively acoustically described beaked whales inhabiting central Oregon waters, though more work would improve accuracy in species-specific acoustic detection. Credit: Marissa Garcia. Infographic draws upon beaked whale imagery from NOAA Fisheries and spectrograms and acoustical statistics published in Baumann-Pickering et al. 2013.<\/em><\/figcaption><\/figure>\n\n\n\n

The HALO project seeks to add a biological dimension to the historical oceanographic studies conducted along the Newport Hydrographic (NH) line ever since the 1960s (Figure 2<\/strong>). Rockhopper acoustic recording units<\/a> are deployed at sites NH 25, NH 45, and NH 65. The Rockhopper located at site NH 65 is actively recording on the seafloor about 2,800 m below the surface. Because beaked whales tend to be most vocally active at these deep depths, we will first dive into the acoustic data on NH 65, our deepest unit, in hopes of finding beaked whale recordings there. <\/strong><\/p>\n\n\n\n

\"\"<\/a>
Figure 2: <\/strong>The HALO project team conducts quarterly visual surveys along the NH line, spanning between NH 25 and NH 65. Rockhopper acoustic recording units continuously record at the NH 25, NH 45, and NH 65 sites. Credit: Leigh Torres.<\/em><\/figcaption><\/figure>\n\n\n\n

Beaked whales\u2019 acoustic repertoire can be broadly split into four primary categories: burst pulses (aka \u201csearch clicks\u201d), whistles, buzz clicks, and rasps.\u00a0Beaked whale search clicks, which are regarded as burst pulses when produced in succession, have distinct qualities: their upswept frequency modulation (meaning the frequency gets higher within the click), their long duration especially when compared to other delphinid clicks, and a consistent interpulse interval\u00a0 which is the time of silence between signals (Baumann-Pickering et al. 2013). Acoustic analysts can identify different species based on how the frequency changes in different burst pulse sequences (Baumann-Pickering et al. 2013; Figure 1<\/strong>). For this reason, when I conduct my HALO analyses, I intend to automatically detect beaked whale species using burst pulses, as they are the best documented beaked whale signal, with unique signatures for each species.\u00a0<\/p>\n\n\n\n

In the landscape of beaked whale acoustics, the acoustic repertoire of Blainville\u2019s beaked whales (Mesoplodon densirostris<\/em>) \u2014 a species of focus in my HALO analyses \u2014 is especially well defined. Blainville\u2019s beaked whale whistles have been recorded up to 900 m deep, representing the deepest whistle recorded for any marine mammal to date in the literature (Aguilar de Soto et al. 2012). While Blainville\u2019s beaked whales only spend 40% of their time at depths below 170 m, two key vocalizations occur at these depths: whistles and rasps. While they remain surprisingly silent near the surface, beaked whales produce whistles and rasps at depths up to 900 m. The beaked whales dive together in synchrony, and right before they separate from each other, they produce the most whistles and rasps, further indicating that these vocalizations are used to enhance foraging success (Aguilar de Soto et al. 2006). As beaked whales transition to foraging on their own, they predominantly produce frequently modulated clicks and buzzes. Beaked whales produce buzzes in the final stages of prey capture to receive up-to-date information about their prey\u2019s location. The buzzes\u2019 high repetition enables the whale to achieve 300+ updates on their intended prey\u2019s location in the last 3 m before seizing their feast (Johnson et al. 2006; Figure 3<\/strong>). <\/p>\n\n\n\n

\"\"
Figure 3: <\/strong>Blainville\u2019s beaked whales generally have four categories within their acoustic repertoire, including burst pulses, whistles, buzz clicks, and rasps. Credit: Marissa Garcia.<\/em><\/figcaption><\/figure>\n\n\n\n

All of this knowledge about beaked whale acoustics can be linked back to the MMPA, which has also achieved broader success. Since the MMPA\u2019s implementation, marine mammal population numbers have risen across the board. For marine mammal populations with sufficient data, approximately 65% of these stocks are increasing and 17% are stable (Roman et al. 2013). <\/p>\n\n\n\n

Nevertheless, perhaps much of the MMPA\u2019s true success lies in the research it has indirectly fueled, by virtue of the required compliance of governmental bodies such as the U.S. Navy. And the response has proven to be a boon to knowledge: if the U.S. Navy has been the benefactor of marine mammal research, beaked whale acoustics has certainly been the beneficiary. We hope the beaked whale acoustic analyses stemming from the HALO Project can further this expanse of what we know.<\/p>\n\n\n

Aguilar de Soto, N., Madsen, P. T., Tyack, P., Arranz, P., Marrero, J., Fais, A., Revelli, E., & Johnson, M. (2012). No shallow talk: Cryptic strategy in the vocal communication of Blainville’s beaked whales. Marine Mammal Science, 28(2), E75\u2013E92. https:\/\/doi.org\/10.1111\/j.1748-7692.2011.00495.x<\/a><\/p>\n\n\n\n

Baumann-Pickering, S., McDonald, M. A., Simonis, A. E., Solsona Berga, A., Merkens, K. P. B., Oleson, E. M., Roch, M. A., Wiggins, S. M., Rankin, S., Yack, T. M., & Hildebrand, J. A. (2013). Species-specific beaked whale echolocation signals. The Journal of the Acoustical Society of America, 134(3), 2293\u20132301. https:\/\/doi.org\/10.1121\/1.4817832<\/a><\/p>\n\n\n\n

Dawson, S., Barlow, J., & Ljungblad, D. (1998). SOUNDS RECORDED FROM BAIRD’S BEAKED WHALE, BERARDIUS BAIRDIL. Marine Mammal Science, 14(2), 335\u2013344. https:\/\/doi.org\/10.1111\/j.1748-7692.1998.tb00724.x<\/a><\/p>\n\n\n\n

Johnston, D. W., McDonald, M., Polovina, J., Domokos, R., Wiggins, S., & Hildebrand, J. (2008). Temporal patterns in the acoustic signals of beaked whales at Cross Seamount. Biology Letters (2005), 4(2), 208\u2013211. https:\/\/doi.org\/10.1098\/rsbl.2007.0614<\/a><\/p>\n\n\n\n

Johnson, M., Madsen, P. T., Zimmer, W. M. X., de Soto, N. A., & Tyack, P. L. (2004). Beaked whales echolocate on prey. Proceedings of the Royal Society. B, Biological Sciences, 271(Suppl 6), S383\u2013S386. https:\/\/doi.org\/10.1098\/rsbl.2004.0208<\/a><\/p>\n\n\n\n

Johnson, M., Madsen, P. T., Zimmer, W. M. X., de Soto, N. A., & Tyack, P. L. (2006). Foraging Blainville’s beaked whales (Mesoplodon densirostris) produce distinct click types matched to different phases of echolocation. Journal of Experimental Biology, 209(Pt 24), 5038\u20135050. https:\/\/doi.org\/10.1242\/jeb.02596<\/a><\/p>\n\n\n\n

Klinck, H., Mellinger, D. K., Klinck, K., Bogue, N. M., Luby, J. C., Jump, W. A., Shilling, G. B., Litchendorf, T., Wood, A. S., Schorr, G. S., & Baird, R. W. (2012). Near-real-time acoustic monitoring of beaked whales and other cetaceans using a Seaglider. PloS One, 7(5), e36128. https:\/\/doi.org\/10.1371\/annotation\/57ad0b82-87c4-472d-b90b-b9c6f84947f8<\/a><\/p>\n\n\n\n

Kowarski, K., Delarue, J., Martin, B., O’Brien, J., Meade, R., \u00d3 Cadhla, O., & Berrow, S. (2018). Signals from the deep: Spatial and temporal acoustic occurrence of beaked whales off western Ireland. PloS One, 13(6), e0199431\u2013e0199431. https:\/\/doi.org\/10.1371\/journal.pone.0199431<\/a><\/p>\n\n\n\n

Madsen, P. T.,  Johnson, M., de Soto, N. A., Zimmer, W. M. X., & Tyack, P. (2005). Biosonar performance of foraging beaked whales (Mesoplodon densirostris). Journal of Experimental Biology, 208(Pt 2), 181\u2013194. https:\/\/doi.org\/10.1242\/jeb.01327<\/a><\/p>\n\n\n\n

McCullough, J. L. K., Wren, J. L. K., Oleson, E. M., Allen, A. N., Siders, Z. A., & Norris, E. S. (2021). An Acoustic Survey of Beaked Whales and Kogia spp. in the Mariana Archipelago Using Drifting Recorders. Frontiers in Marine Science, 8. https:\/\/doi.org\/10.3389\/fmars.2021.664292<\/a><\/p>\n\n\n\n

Moore, J. E. & Barlow, J. P. (2013). Declining abundance of beaked whales (family Ziphiidae) in the California Current large marine ecosystem. PloS One, 8(1), e52770\u2013e52770. https:\/\/doi.org\/10.1371\/journal.pone.0052770<\/a><\/p>\n\n\n\n

Ray, G. C. & Potter, F. M. (2011). The Making of the Marine Mammal Protection Act of 1972. Aquatic Mammals, 37(4), 522.<\/p>\n\n\n\n

Roman, J., Altman, I., Dunphy-Daly, M. M., Campbell, C., Jasny, M., & Read, A. J. (2013). The Marine Mammal Protection Act at 40: status, recovery, and future of U.S. marine mammals. Annals of the New York Academy of Sciences, 1286(1), 29\u201349. https:\/\/doi.org\/10.1111\/nyas.12040<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

By Marissa Garcia, PhD Student, Cornell University, Department of Natural Resources and the Environment, K. Lisa Yang Center for Conservation Bioacoustics In October 1972, the tides turned for U.S. environmental politics: the Marine Mammal Protection Act (MMPA) was passed. Its creation ushered in a new flavor of conservation and management. With phrases like \u201coptimum sustainable … Continue reading Clicks, buzzes, and rasps: How the MMPA has spurred what we know about beaked whale acoustic repertoire<\/strong><\/span><\/a><\/p>\n","protected":false},"author":10751,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[188686,1310535],"tags":[173916,1310781,513,2251,1310782,1237662,148762,155,638026,5],"class_list":["post-5024","post","type-post","status-publish","format-standard","hentry","category-current-projects","category-oregon-whale-distribution","tag-acoustics","tag-beaked-whale","tag-marine-mammals","tag-marine-policy","tag-marissa-garcia","tag-mmpa","tag-oregon-coast","tag-oregon-state-university","tag-passive-acoustics","tag-science"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/posts\/5024","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/users\/10751"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/comments?post=5024"}],"version-history":[{"count":1,"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/posts\/5024\/revisions"}],"predecessor-version":[{"id":5026,"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/posts\/5024\/revisions\/5026"}],"wp:attachment":[{"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/media?parent=5024"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/categories?post=5024"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.oregonstate.edu\/gemmlab\/wp-json\/wp\/v2\/tags?post=5024"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}