CORE Metadata, citation and similar papers at core.ac.uk Provided by NSU Works Nova Southeastern University NSUWorks Oceanography Faculty Articles Department of Marine and Environmental Sciences 10-1-2004 Evidence of Shark Predation and Scavenging on Fishes Equipped with Pop-up Satellite Archival Tags David W. Kerstetter Virginia Institute of Marine Science, [email protected] J. Polovina National Marine Fisheries Service - Honolulu John E. Graves Virginia Institute of Marine Science Find out more information about Nova Southeastern University and the Oceanographic Center. Follow this and additional works at: http://nsuworks.nova.edu/occ_facarticles Part of the Marine Biology Commons, and the Oceanography and Atmospheric Sciences and Meteorology Commons NSUWorks Citation David W. Kerstetter, J. Polovina, and John E. Graves. 2004. Evidence of Shark Predation and Scavenging on Fishes Equipped with Pop- up Satellite Archival Tags .Fishery Bulletin , (4) : 750 -756. http://nsuworks.nova.edu/occ_facarticles/542. This Article is brought to you for free and open access by the Department of Marine and Environmental Sciences at NSUWorks. It has been accepted for inclusion in Oceanography Faculty Articles by an authorized administrator of NSUWorks. For more information, please contact [email protected]. Nova Southeastern University NSUWorks Oceanography Faculty Articles Oceanographic Center Faculty Publications 10-1-2004 Evidence of Shark Predation and Scavenging on Fishes Equipped with Pop-up Satellite Archival Tags David W. Kerstetter J. Polovina John E. Graves Find out more information about Nova Southeastern University and the Oceanographic Center. Follow this and additional works at: http://nsuworks.nova.edu/occ_facarticles Part of the Marine Biology Commons, and the Oceanography and Atmospheric Sciences and Meteorology Commons This Article is brought to you for free and open access by the Oceanographic Center Faculty Publications at NSUWorks. It has been accepted for inclusion in Oceanography Faculty Articles by an authorized administrator of NSUWorks. 750 Evidence of shark predation and scavenging on almost swallowi ng a free-floating PSAT off the Dominican Republic in fishes equipped with pop-up satellite archival tags Muy 2002 (Graves, personal obser v.). Alternately, the tag could be ingested David W. Kco:t e tter incidentally with part of the tngged fish , as described by Jolley and Irby School 01 Marine xience (979) who reported that a n acoustic Virginia Institute of M,mne S(lence College of William and Mary tag on a sailfish (lstiofJhorll s pLotyp. GIouc~ler POint. Virgima 23062 tcrus) was eaten a long with the fish E nvol ~rHS b.I~ fi: VI01S Mu by an undetermined species ofshnrk. In this note, we present data from PSATs deployed on two white marlin Jeffery J. Poloyina in t he western North Atla ntic Ocean POK ilk Islands Fisheries xlence Cenler and on nn opah (Lampris gul/alus) NaTional Manne Fishenes ServICE' in the central Paci fic; the data from Honolulu, Hawaii 96822 these tags indicate that the tags were consumed by sharks. John E. Graves School of Manne SClefI<e Materials and methods Virginia Institute of M.:mne Science College of Wi" i;tm and Mary GIooc~I~ POlnl Virgiolcl 23062 White marlin 1 IWM1 ) A:t approximately 10:00 am local time on I September 2002, a wh ite marlin was obser ved on pelagic longline gear set dul"ing the ni ght near the Over the past few years, pop-up sat­ have developed mecha nisms t hat reo southenste r·n edge of Georges Ba nk. e ll ite u l'chival tags ( PSA'l's) have lease tags from dead or dying fi s h The fish , which had been caught been used to investigate the behav­ before the struct ural integrity of the on n s lightly offset, s t ra ig ht·shank ior, movements, thermal biology, tag is compromised at de pth. These J ·style hook (size 9/0 ). wns manu· find poslrcicasc mortality of a w ide mecha ni s ms include both mechani­ ally guided with the leader a long­ range of la rge, highly mig ratory s pe­ cal devices that sever the monofila­ side the vessel. A PTT-lOO H R model cies including blucfin luna <Block c t ment tethe r that a u aches the tag to PSAT ( j\·l icrowave Telemetry, I nc ., al.. 2001), swordfish (Sedberry li nd the fi sh upon reaching a given depth Columbia, M D) was attached to the I ~ocfc r . 2001 ), blue marlin (Graves oL a nd internal softwn re s ubroutines dorsal musculature approx imately 5 aI., 2002 ), striped marlin (Dome ie r that acti vate the normnl e lectronic em be low the base of the dors a l fi n and Dewa r, 2003), a nd white s harks release mecha nism if the t ag either wi th [l lurge nylon a nchor acconling (Bousta ny e t aI., 2002 ). PS AT tag renches a cer tain depth or maintains to the pl"Oced ure a nd tether desig n technology has im proved rapidly, o cons tant depth for a I>redeter mined described in Kers tetter et al. (2003). and current tag models ure cn pable length of time. The tag was activated s hortly after of collecting, processing, a nd stor­ Despite t he addition of t hese reo the white marlin was firs t identifi ed. ing lorge amounts of information on lease mechanisms t o PS ATs, some although a pproxi mately one hour is light level, temperature. and pressure tags s till fa il to trans mit data. Such required foll owing activation for this (depth) for a predetermined leng th of failure could result from any of the tag model to begin collecting dnta. time before the release of these tags followi ng events or condit ions: me­ The tag was programmed to record frolll a nima ls. After release, the tags chanical failure of a cr iticnl tng com· point mensurements of temperature. float to the s urface, and transmit the pone nt; destruction by fishing crews li ght, and pres su re (depth) in four­ sto"ed da ta to passing satell ites of the unaware of or not IHlrt icil>ating in minute time inter vals nnd to deltlch Argos system. lhe p.·esent research : excessive e pi . from t he tlnimnl tlfte l" 10 duys. Afte r A problem noted by severo I au · faunal g rowth t hat makes the tag re lease from the fi s h. the positively t hors using ea rl y PSAT models was negatively buoyant or prevents t he buoyant tag was expected to fl oat to t he occasio nal occu r rence of tags lag from noating with the a ntenna the strr face and transmit stored and that did not transmit data. Cleorl y. in a verLi cal position ; or fouling of real·time data. For both white marlin a tag uUached to a moribund fish the tag on the fish, fi shing gear. or thllt would sink to a depth exceeding flotsa m. Another cause of failure is MnnU IICrl pt l!'ubrniued 27 April 2003 the pressure limit of t he tng cas ing that the tags cou ld be lost as are· to the Scientific Editor's Offke. wou ld be des t royed. To preve nt the suIt of ingestion. For example, a free· Mal1 UIICript npprm·ed for publ ication loss of tags due to mortality events, swimmi ng white marlin ('/'etraplllrlls 7 June 2004 by the Scientific Ed,tor. tag manufacturers a nd resen rchers albidus) was observed mouthing a nd fish. Bull . 102 :750- 756 (2004 ). NOTE Kerstetter et at: Shark predation and scavenging on fishes equipped with sa tellite archival tags 751 Table 1 Cornp" I'i ~O Il of depth s n nd tern perntu r e ~ recurded by t.h reI.' pop-up satellite (lI'ch i \';11 t;lg~ (PSA 'l's) bl.'fol'(l n lid ;1he r t he tags were ingested by an oq:,an ism. Before ingestion Aftel' ingestion Depth Depth Temp. Tl.'rn p Depth Depth Temp Temp rnnge Illl.'all ra ngl.' nll.' an ra nge mean range mean Anirnnl ( m) ( SD> ( C, (SO) " ( Ill ) ( SD ) t·C) ( SD ) " Wi'll I 14;'.2 1,15.2 11.6-11 1 1.7 17!) 0-564.9 130.0 12.1-26.5 24.1 2755 ( ~O . OO ) f ~ 0 . 0 7j t~237. 50 ) b:0.84 ) W;\12 0-26,9 5.9 19.8 -27.8 2,1.7 207 0 - 699.=1 13 1.0 18.9 - 29.5 27.3 1683 ( ~ ' I A4 J I ~ 0.9 ]) 1:!: 162.611 (:!:1.20 ) 32- 456 221.81 8_·-,J - .6 Hi68 360 0 -52<1 170.56 26.2-30.6 28.64 168 1~92 .2 0 J (:= ,1. 211 1:!: 1=13.83) (:!:0.67) ttlgs, mlllllllUrll stra ight-line distances were calculated the dorsal musculaLuI'e wi t h a Wildli fe Compute rs tita­ bet ween the point of release nnd t he firs t clearly trans ­ nium a nchor. The tag was I)rogl'ammed to record t he mitted location of t he t ag follow ing its re lease (pop-of 0 tempera ture a nd depth occ upied by t he fi sh in binned (Argos location codeS 0-3). histograms. a nd the m inimu m a nd maximum teml)era­ At the time of taggi ng. the longl ine hook used to Cal)­ Lur'es a nd depths fo r 12-hour time periods. Howeve r, tUl'e t he fi sh was not vi sible in the mouth of t he whi te t hes e 12-houl' bins e ncompassed bot h day a nd nig ht marl in.