Downloaded by guest on September 24, 2021 www.pnas.org/cgi/doi/10.1073/pnas.1302602110 White . white marlin are actually Lowe’s species. know thatmanyofthefishtheyoncecalled thanks inlargeparttothosetests,scientists tests would establish its uniqueness. Today, covered, and decades more before genetic ,tobeofficiallyredis- georgii,alsoknownasthe forgotten. pear in1874,andthespecieswasallbut specimen, andLowehimself,woulddisap- Portugal, wherehehadachurch.Butthat specimen collectedoffthecoastofMadeira, immortalized byErnestHemingway. groupincludesthestoriedmarlins predatory fishwithaprominentbill.The species offish.Itwasabillfish:big,fast a four-linedescriptionofproposednew naturalist RichardThomasLowepublished In 1840,theEnglishchaplainandamateur Science Writer Mark Schrope prized whitemarlins—theirstocksmaybelowerthanwethought. Genetic testsshowwehavebeenmistakingalookalikebillfishforthe Fishy stocks numbers for marlin white It wouldtakepreciselyacenturyfor Lowe based his description on a single NEWS FEATURE

georgii sampleperished. his notebooks,andapparentlyonlyT. breria sank in the Bay of Biscay, and Lowe, Liverpool to the island, the steamship Madeira onoccasion.In1874,sailingfrom retreated toEngland.Buthereturned ligious schismontheislandandultimately tiple papersonfishandtheoddcrustacean. time forhissidepassion,publishingmul- gation onMadeira,buthefoundplentyof From 1826to1852,hehadhisowncongre- natural historyashewasaboutministering. ure outtheabundanceofeachspecies. lin population,asscientistsstruggletofig- dangerously dwindlingAtlanticwhitemar- to properlymanagewhatsomebelieveisa bating analreadycontentiousissue:How This caseofmistakenidentityisexacer- For acentury,allthatremainedwere Lowe wasalsoinvolvedforyearsinare- Lowe wasatleastaspassionateabout PNAS|March 12,2013|vol.110no.11 |4151–4153 Li-

Image courtesy of Guy Harvey. shrug andsay,‘That’spretty interesting’ other billfishresearchersand theywould difficult. “Wewouldhavediscussions with convincing thelargercommunity proved possibility ofanewspecies billfish.But er researchers also began considering the ers had candidatesamples. Elsewhere, oth- in additiontoroundedscalesandfins. distance betweentheanusandanalfins, included, relativetowhitemarlins,alarger ingly subtledefiningcharacteristicsthat on. Robinshadoutlinedsomechalleng- training sessions,buttherewaslittleto go talking ofthepossibilityduringobserver Observer Program(SFOP)inMiami,began ministration (NOAA)’sSoutheastFishery National OceanicandAtmosphericAd- ern Atlantic.DennisLee,theheadof roundscale mightalsobefoundinthewest- leagues inMiamibegantowonderifthe During the1990s,someofRobins’scol- Stark GeneticDifferences roundscales, anearlookalike. were callingthewhitemarlinactually were unawarethatmanyofthefishthey lurking in their own waters, and hence ers didn’trealizethatthesefishcouldbe lected intheeasternAtlantic,USresearch- turn out.SinceRobins’ssampleswerecol- experts. Notsofortheroundscale,itwould billfish species,mosteasilyidentifiedbythe same. initial descriptionhedecidedtheywerethe Comparing theirmorphologytoLowe’s whose presencehadbeenunsuspected.” alized that four of those were “of a species Europe tocollectfishsamples.Hesoonre- FL, hadtakenatripthepreviousdecadeto Robins, thenattheUniversityofMiami, reappearance came in1974 (2). Richard peculiar shapeandnature.”Thedefining had abody“clothedwithlargescalesof vague allusionstothefishthatLowesaid Within afewyears,theMiamiresearch- The Atlanticishometoonlyahandfulof

NEWS FEATURE and turn around,” says Lawrence Beer- kircher, the current head of SFOP. “I don’t think they really believed it.” It wasn’t until 2006 that the situation became indisputably clear. Beerkircher had sought the help of his former advisor, fish genetics specialist Mahmood Shivji, at Nova Southeastern University’s Guy Har- vey Research Institute, Dania Beach, FL. Shivji had developed techniques for rapidly identifying shark species based on small tis- sue samples, which, among other benefits, allowed identification of illegally caught species even after they had been chopped up. He had begun applying similar tech- niques to establishing genetic markers for various billfish species. Image courtesy of J. Foster/Guy Harvey Research Institute, Dania Beach, FL. When Shivji and colleagues analyzed Beerkircher’s samples, they were stunned. Photos of the two species side-by-side, white marlin (Top) and roundscale spearfish (Bottom). While the physical differences between the report in 2007 (5). The report highlighted based on only a nascent appreciation for species were subtle and missed by most, major uncertainties, both in absolute popu- roundscales. The picture soon turned more there was no mistaking the genetics. “They lation size and in the numbers of round- confusing. were not a little bit different from white scale fish misidentified as white marlin. After Shivji’s team established the round- marlin, they were really different,” says NOAA concluded that existing manage- scale genetics, they began working with Shivji of what proved to be roundscale ment efforts—controlling fishing seasons Beerkircher and others to figure out the ex- spearfish samples. They weren’t even in the and prohibiting certain practices that are tent of the species. In 2009 they published a same genus. The difference was so stark that more likely to snag white —were paper showing that, at least in the Sargasso it ruled out interbreeding (3). sufficient for preventing further declines. Sea region of the Atlantic, the roundscales Also, the distinctions weren’t mere The report also said that, despite the uncer- are fairly common (4). On average, round- academic minutiae. The discovery of the tainty, there appeared to be a slight uptick scales made up about a quarter of the catch- roundscale would significantly affect the in the population of white marlin, which es deemed white marlin from certain fish- already limited understanding of the had been plummeting since the 1960s. ing tournaments and longliners. This raised white marlin. “This completely messed up Eric Prince, a fisheries biologist at the new questions about the accuracy of the the white marlin stock assessments,” says NOAA National Marine Fisheries Service, population estimates of white marlin that Shivji. Miami, who took part in the reviews, says were used to review its threatened status. The white marlin is recognized as one of one of the greatest sources of uncertainty “You’ve got these big predators running the most overexploited pelagic fishes in the over white marlins is that most countries, around [being] mistaken for each other and Atlantic (4). In some countries subsistence unlike the United States, do not report their no one knows the status,” says Shivji. fishermen target them, but for the most white marlin bycatches, leaving huge gaps The confusion does not end there. There part white marlin are the unfortunate by- in the data. A variety of estimates put the seems to be substantial variability in the rel- catch of commercial fishermen known as total white marlin population size in the ative number of roundscales and marlins, longliners who drag kilometers-long fish- Atlantic Ocean at about 200,000 fish, but not just from one study area to another, ing lines with baited hooks intended for this is largely based on analyses from a de- but also from year to year. For several years other species like and . The cade ago that have neither been updated (6) now, John Graves, a fisheries biologist at white marlin are also prized by recreational nor corrected for possible roundscale mis- the Virginia Institute of Marine Science, sport fishermen, but regulations mostly call identifications. Gloucester Point, VA, and his colleagues, for them to be released alive, if possible, After the 2007 review, NOAA’s Endan- have found substantial variation in the when they’re caught. gered Species Division argued that because number of roundscales being caught at an of the uncertainties, NOAA should at least annual white tournament To List or Not to List retain the white marlin on its Species of in New Jersey. Some years there have been In 2001, scientists and environmentalists Concern list. This designation doesn’t pro- none and in others they’ve been plentiful. formally requested that the United States vide any special protection but can lead In some cases Graves discovered that it was consider listing the white marlin as ei- to more attention and research funding. roundscales winning the major prizes in ther threatened or endangered under the But in 2008, NOAA’s Office of Protected the tournament, which is allowed because Endangered Species Act. After a review, Resources, which had the final word, dis- the species are so outwardly hard to distin- NOAA rejected that petition, sparking a agreed and the white marlin was removed guish. legal challenge that led to another review. from the list. Researchers generally agree that this kind The second review resulted in a NOAA The arguments in those debates were of work has added to uncertainties over

4152 | www.pnas.org/cgi/doi/10.1073/pnas.1302602110 Schrope Downloaded by guest on September 24, 2021 Downloaded by guest on September 24, 2021 Schrope the white marlin threatened or endangered both petitionedthegovernmenttoconsider bers, aformerNOAAFisheriesscientist, versity (CBD),Tucson,AZ,andJimCham- really importantyearforthat.” to go,”saysPrince.“Thisisgoingbe a tic asawhole.“That’swherewereallyneed should giveaclearerpicturefortheAtlan- there, which,combinedwithearlierresults, the roundscaletowhitemarlinratioover fort willhelptheresearcherscalculate lect samples from their catches. This ef- fishermen there and asking them to col- are distributingDNAkitstocommercial samples fromthe eastern Atlantic. They Shivji isworkingwithPrincetogather Back toMadeira ters, butnodatayetexistfortheeast. cant roundscalepopulationsinwesternwa- yet surveyed?Researchhasshownsignifi- are roundscales inparts of theAtlantic not through worknowunderway. to getaclearerpicturemovingforward samples. Researchers are instead hoping is impossiblebecausetherearefewstored percentages havechangedoverthedecades But reliablyfiguringouthowthoserelative declines in the white marlinpopulation. identification, thiscouldpartiallyobscure marlins increases.Giventheongoingmis- percentage ofroundscalesrelativetowhite marlin’s currenthealthwouldbeifthe impact onourunderstandingofthewhite roundscale confusioncouldhaveamajor white marlinpopulations.Onewaythe Last year,theCenterforBiologicalDi- A keyopenquestionis:Howcommon Species Res9(2):81–90. Terapturus albidusandroundscale spearfish T. georgii. Endang tion onpopulationassessmentofoverfishedwhitemarlin 4 Beerkircher L,etal. (2009)Effectsofspeciesmisidentifica- logical andmolecularevidence.BullMarSci79:483–491. tion oftheroundscale spearfish,Tetrapturus georgii: morpho- 3 ShivjiMS,etal.(2006)Validity, identification,anddistribu- (National MarineFisheriesService,Seattle),pp.54–61. national Billfish Symposium, edsShomura RS, Williams F spearfish, Tetrapturus georgeii. Proceedings oftheInter- 2 Robins,CR(1974)Thevalidityandstatusoftheroundscale Proc ZoolSocLond 1840(8):36–39. 1 Lowe, RT (1841)Onnewspeciesoffishesfrom Madeira. lin tournamentsandgeneralrevenuefrom Some communitiesdependonwhitemar- ing mightcausemoreharmthangood. ward iscarefulmanagement.Hefearslist- is onasimilarpathtooblivion. about. Hebelievesthateventheroundscale it’s notjustthewhitemarlinhe’sconcerned wise we’regoingtolosethem,”hesays.And “We needtodosomethingpronto,other- possible atthistime.” ratio isimportant,NOAAdeemedit“not figuring outtheroundscaletowhitemarlin demonstrably shrinking.Whilenotingthat petitions, includingthatpopulationsizeis Chambers andtheCBDintheirseparate rejected variousargumentsputforthby based on available information. The agency that awhitemarlinlistingisn’twarranted al MarineFisheriesServiceagainconcluded the request. by the roundscale work as justification for sons, the CBD pointed to confusion created listing issueathirdtime.Amongotherrea- Prince, however,feelsthebestpathfor- Chambers isunhappywiththedecision. On January30thisyear,NOAA’sNation- PNAS|March 12,2013|vol.110no.11 |4153 February 15,2013. Meetings/Docs/2012_WHM_ASSESS_ENG.pdf. Accessed ment Meeting.Available athttp://www.iccat.es/Documents/ (2012)Reportofthe2012WhiteMarlineStock Assess- 6 InternationalCommissionfortheConservationofAtlantic Fisheries Service,SaintPetersburg, FL). vice, SoutheastRegionalOffice,December10,2007(NOAA Marlin Status Review. ReporttoNationalMarineFisheriesSer- 5 WhiteMarlinBiologicalReviewTeam (2007)Atlantic White years tosortout.’” marlin: “Mythoughtwas,‘It’sgoingtotake ences betweentheroundscaleandwhite when hefirstlearnedofthegeneticdiffer- spot onwithhisinitialreactionin2006 now, though,itseemsthatBeerkircherwas sual discoverymayfinallybeknown.For 2013, thesignificanceofLowe’salmostca- from Madeiraproceedsasplannedthrough Prince andShivji’sworktogathersamples standing ofroundscalepopulations.So,if mains oneofthebiggest gaps inourunder- off Madeirainthe1800s,thatregionre- cally, giventhatthespecieswasdiscovered significance, isgoingto continue.Ironi- growing appreciationfortheroundscale’s clear thatthedebate,fueledinpartby officially consideredoverexploited. men whoaremainlycatchingspeciesnot Prince says would heavily penalize fisher- lead towide-reachinglonglinebans,which gered. Thatstatuscouldconceivablyalso have toendifthefishwasdeemedendan- even withcatch-and-releasefishing,would sport fishermen;targetingthewhitemarlin, Given therecentNOAAposition,it’s

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