ScientistsinCanadasaybigoceanfishhavealmostdisappearedfromtheworldsincethestartofindustrialfishinginthenineteen-fifties.Thescientistsfoundthatpopulationoflargefishliketuna;swordfishandcodhavedroppedbyninetypercentinthepastfiftyyears. Thestudytooktenyears.Theresearchersgatheredrecordsfromfishingbusinessesandgovernmentsaroundtheworld.ThemagazineNaturepublishedthefindings. Thescientistssaythecommonmethodcalledlonglinefishingisespeciallydamagingtopopulationsoflargefish.Thismethodinvolvesmanyfishinglinesconnectedtooneboat.Thesewirescanbeclosetoone-hundredkilometerslong.Theyholdthousandsofsharpmetalhookstocatchfish. LonglinefishingisespeciallycommonintheJapanesefishingindustry.RecordsshowedthatJapaneseboatsusedtocatchabouttenfishforeveryone-hundredhooks.Thestudysayslonglinefishingboatsnowmightcatchonefishperhundredhooks. Thescientistssayindustrialfishingcandestroygroupsoffishmuchfasterthaninthepast.Thestudysuggeststhatwholepopulationscandisappearalmostcompletelyfromnewfishingareaswithintentofifteenyears. RansomMyersofDalhousieUniversityinNovaScotialedthestudywithBorisWormofDalhousieandtheUniversityofKielinGermany.MisterWormsaysthedestructioncouldleadtoacompletere-organizationofoceanlifesystems.MisterMeyerssaysthedecreasednumberoflargefishisnottheonlyworry.Hesaysevenpopulationsthatareabletoreproducedonotgetthechancetolivelongenoughtogrowasbigastheirancestors(祖先).Hesaysnotonlyaretherefewerbigfish,theyaresmallerthanthoseofthepast. Americangovernmentscientistssayevenwiththebesteffortstoprotectfishpopulations,decreasesaretobeexpected. 小题1:Whereisthepassageprobablytakenfrom? |
A.Astorybook. |
B.Abusinessmagazine. |
C.Anenvironmentreport. |
D.Aneconomicsurvey. |
小题2:Bigfishhavegraduallybeendisappearingespeciallybecause________.A.longlinefishingmethodisusedB.seawaterisgettingpollutedC.mankinddestroyst