DrMyersandDrWormarguethattheirworkgivesacorrectbaseline,whichfuturemanagementeffortsmusttakeintoaccount.Theybelievethedatasupportanideacurrentamongmarinebiologists,thatofthe"shiftingbaseline".Thenotionisthatpeoplehavefailedtodetectthemassivechangeswhichhavehappenedintheoceanbecausetheyhavebeenlookingbackonlyarelativelyshorttimeintothepast.Thatmattersbecausetheorysuggeststhatthemaximumsustainableyieldthatcanbecroppedfromafisherycomeswhenthebiomassofatargetspeciesisabout50%ofitsoriginallevels.Mostfisheriesarewellbelowthat,whichisabadwaytodobusiness.

　　答：本题句疑问点在currunt的词性、作用及thatof上.搜索发现没有打错,没有漏打.

　　句法分析：

　　主语：They

　　谓语：believe

　　宾语：省略了that的一个从句：

　　thedatasupportanideacurrentamongmarinebiologists,thatofthe"shiftingcaseline".

　　从句句法分析：

　　主语：thedata

　　谓语：support

　　宾语：anidea

　　定语：amongmarinebiologists

　　插入语：thatofthe"shiftingcaseline".

　　其中that是替代词=theidea,而that(theidea)与the"shiftingcaseline"是又是同位关系,类似于：thecityofBeijing.

　　其中current疑为currently之笔误,是副词修饰后面的介词短语among...的,目前海洋生物学家所持有的（观点）

　　但网上搜索,currentamong.比currentlyamong用得更普遍!看来current象straight一样,也可以当副词用,修饰介词短语了.