32607 Document Published / External 30990 PSD- Cetacean Research Program (CRP) Publications Portfolio Project Completed 2017-02-23 False killer whales (Pseudorca crassidens) feed primarily on several species of large pelagic fish, species that are also targeted by the Hawaii-permitted commercial deep-set longline fishery. False killer whales have been known to approach fishing lines in an attempt to procure bait or catch from the lines, a behavior known as depredation. This behavior can lead to the hooking or entanglement of an animal, which currently exceeds sustainable levels for pelagic false killer whales in Hawaii. Passive acoustic monitoring (PAM) was used to record false killer whales near longline fishing gear to investigate the timing, rate, and spatial extent of false killer whale occurrence. Acoustic data were collected using small autonomous recorders modified for deployment on the mainline of longline fishing gear. A total of 90 fishing sets were acoustically monitored in 2013 and 2014 on a chartered longline vessel using up to five acoustic recorders deployed throughout the fishing gear. Of the 102 odontocete click and/or whistle bouts detected on 55 sets, 26 bouts detected on 19 different fishing sets were classified as false killer whales with high or medium confidence based on either whistle classification, click classification, or both. The timing of false killer whale acoustic presence near the gear was related to the timing of fishing activities, with 57% of the false killer whale bouts occurring while gear was being hauled, with 50% of those bouts occurring during the first third of the haul. During three fishing sets, false killer whales were detected on more than one recorder, and in all cases the whales were recorded on instruments farther from the fishing vessel as the haul proceeded. Only three of the 19 sets with acoustically-confirmed false killer whale presence showed signs of bait or catch damage by marine mammals, which may relate to the difficulty of reporting depredation. PAM has proven to be a relatively inexpensive and efficient method for monitoring the Hawaii longline fishery for interactions with false killer whales. Bayless, A.R., E.M. Oleson, S. Baumann-Pickering, A.E. Simonis, J. Marchetti, S. Martin, S.M. Wiggins. 2017. Acoustically monitoring the Hawai'i longline fishery for interactions with false killer whales. Fisheries Research 190:122-131. doi:10.1016/j.fishres.2017.02.006. 10.1016/j.fishres.2017.02.006 Theme WAIVER Theme acoustic monitoring Theme cetacean-fishery interactions Theme false killer whale Pacific Islands Fisheries Science Center Honolulu HI USA Journal article Acrobat Portable Document Format Published Author 2016 Person Bayless, Ali R ali.bayless@noaa.gov 1845 Wasp Blvd. Honolulu HI 96818 USA (808)725-5728 email Point of Contact 2016 Person Bayless, Ali R ali.bayless@noaa.gov 1845 Wasp Blvd. Honolulu HI 96818 USA (808)725-5728 email Confidential Requestor will be asked to submit a request by email to Erin Oleson (erin.oleson@noaa.gov). Requestor will be asked to submit a request by email to Erin Oleson (erin.oleson@noaa.gov). Requestors must supply harddrive or other compatible media with sufficient volume to duplicate requested data. Location data are confidential. For acoustic data without associated location data, requestor will be asked to submit a request by email to Erin Oleson (erin.oleson@noaa.gov) Requestor will be asked to submit a request by email to Erin Oleson (erin.oleson@noaa.gov). None None http://dx.doi.org/10.1016/j.fishres.2017.02.006 Link to journal article. Acoustic data is offloaded and converted into longterm spectral averages that are reviewed for any gaps or errors. This data is then run through classification software to determine species identification with certainty. For classification that requires an analyst decision, two analysts are used and results are compared for validity. 25341 Data Set Cross Reference Data used in the analyses. gov.noaa.nmfs.inport:32607 Ali Bayless 2016-04-29T17:34:32 SysAdmin InPortAdmin 2022-08-09T17:11:15 2022-05-04 Pacific Islands Fisheries Science Center PIFSC 1845 Wasp Blvd. Honolulu HI 96818 USA 808-725-5300 https://www.pifsc.noaa.gov 8:00 a.m. - 4:30 p.m. 1001 Public No 2022-05-04 1 Year 2023-05-04