欢迎来到天天文库
浏览记录
ID:68780421
大小:22.00 KB
页数:1页
时间:2021-10-20
《浮游生物(Plankton)》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、浮游生物(Plankton)Scatteredthroughtheseasoftheworldarebillionsoftonsofsmallplantsandanimalscalledplankton.mostoftheseplantsandanimalsaretoosmallforthehumaneyetosee.Theydriftaboutlazilywiththecurrents,providingabasicfoodformanylargeranimals.planktonhasbeendescribedastheequivale
2、ntofthegrassesthatgrowonthedrylandcontinents,andthecomparisonisanappropriateone.Inpotentialfoodvalue,however,planktonfaroutweighsthatofthelandgrasses.Onescientisthasestimatedthatwhilegrassesoftheworldproduceabout49billiontonsofvaluablecarbohydrateseachyear,thesea'splankton
3、generatesmorethantwiceasmuch.despiteitsenormousfoodpotential,littleeffectwasmadeuntilrecentlytofarmplanktonaswefarmgrassesonland.Nowmarinescientistshaveatlastbeguntostudythispossibility,especiallyasthesea'sresourcesloomevenmoreimportantasameansoffeedinganexpandingworldpopu
4、lation.Nooneyethasseriouslysuggestedthat"plankton-burgers"maysoonbecomepopulararoundtheworld.Asapossiblefarmedsupplementaryfoodsource,however,planktonisgainingconsiderableinterestamongmarinescientists.onetypeofplanktonthatseemstohavegreatharvestpossibilitiesisatinyshrimp-l
5、ikecreaturecalledkrill.Growingtotwoorthreeincheslong,krillprovidesthemajorfoodforthegreatbluewhale,thelargestanimaltoeverinhabittheearth.Realizingthatthiswhalemaygrowto100feetandweigh150tonsatmaturity,itisnotsurprisingthateachonedevoursmorethanonetonofkrilldaily.
此文档下载收益归作者所有