Kusazindikira Sikuli Kosangalatsa: Kafukufuku Watsopano Wokhudza Mkhalidwe wa Nsomba Zosayesedwa Imatsimikizira Chiwopsezo Chapadziko Lonse Chodza Chifukwa Chosodza Mochulukira.

Wolemba Kenneth Stump, Wokondedwa wa Ocean Policy ku The Ocean Foundation

Kupha nsomba mopambanitsa (komanso kugwiritsa ntchito zida zowononga zophera nsomba) nthawi zambiri kumatchulidwa ngati chimodzi mwazinthu ziwiri zomwe zimawopseza kwambiri nyama za m'nyanja. Kupha nsomba mopitirira muyeso kumachitika pamene nsomba imachotsa nsomba kuchokera kwa anthu mofulumira kuposa momwe anthu angadzidziwire okha - m'mawu amodzi, nsomba zambiri zimachuluka. Ngati sichilamuliridwa mwachangu, kusodza kochulukira kumabweretsa kuwonongeka kwa nsomba ndi kugwa kwa usodzi. Asayansi ndi oyang’anira zausodzi amayesetsa kudziŵa kuchuluka kwa mitundu ina ya zamoyo zamtundu uliwonse kuti anene kuti si nsomba zochuluka.

Kwa masheya ophunzitsidwa bwino omwe adawunikidwa mwasayansi, ndizotheka kuwunika momwe zinthu zilili pokhudzana ndi kupha nsomba mopitilira muyeso zomwe zimachokera ku kuthekera kwa katundu woperekedwa kuti apange zokolola zokhazikika (MSY). Pogwiritsa ntchito miyeso yokhazikika yasodzi, Dr. Boris Worm et al. (2009) adapeza kuti 63% ya nsomba zomwe zimayesedwa padziko lonse lapansi zili ndi kukula kwake ("biomass," kutanthauza "B") pansi pamlingo womwe akuti umatulutsa MSY (B/Bmsy <1), pomwe kafukufuku wina wopangidwa ndi Bungwe la FAO (2010) linanena kuti 32% ya masheya omwe amawunikidwa padziko lonse lapansi ndi ochuluka kwambiri (B/Bmsy <0.5).

Mwachidule, nsomba zambiri zomwe zimayesedwa padziko lonse lapansi zimadyetsedwa mokwanira kapena mopambanitsa. Koma pafupifupi 20% yokha ya nsomba zapadziko lonse lapansi (zomwe zatsikirako) zimachokera ku mitundu yomwe idawunikidwa. Nanga bwanji za kuchuluka kwa nsomba zosawerengeka, zosawerengeka zomwe zimaphatikizira 80% kapena kuposerapo za nsomba zapanyanja padziko lonse lapansi chaka chilichonse?

Christopher Costello wa UC Santa Barbara ndi anzake angofalitsa kumene kafukufuku watsopano wokhudza momwe masheya osauka padziko lapansi alili pa intaneti ya Science (September 27, 2012). Pogwiritsa ntchito zolemba zomwe zilipo komanso njira zowunikira mosalunjika, olemba kafukufuku watsopanoyu apeza kuti zambiri mwa nsombazi zitha kutha kwambiri komanso kutsika kwambiri:

64% ya nsomba zomwe sizinayesedwe zimakhala ndi zotsalira za Bmsy (B/Bmsy <1), zomwe ndi zofanana ndi kuchepa kwa 60-70% pamagulu ambiri.
18% ya masheya osayesedwa akugwa (B / Bmsy <0.2) - mlingo wa kuchepa kwakukulu kotero kuti chiwerengero cha nsomba chikhoza kukhala gawo laling'ono chabe la kukula kwake kwachilengedwe, kosawerengeka.

Kuchepa kwa nsomba zambiri (kutsika kwa B/Bmsy) kumakhala ndi zotsatirapo pachitetezo cha chakudya: zokolola za nsomba zimakhala zocheperapo momwe zingathere ngati masheya ataloledwa kubwereranso pamlingo womwe ungatulutse MSY. Popeza ambiri mwa mausodzi osayesedwawa ali m'mayiko osauka komanso omwe akutukuka kumene, njira zoyendetsera zomanganso masheya zomwe zimadalira utsogoleri wamphamvu ndi kuyang'anira zowunikira sizingagwire ntchito. Koma Costello ndi ogwira nawo ntchito amakhalanso ndi chiyembekezo chakuti njira zatsopano zophatikizira ufulu wogwiritsa ntchito madera (TURFs), mabungwe asodzi, ndi malo otetezedwa osatenga m'madzi zitha kubwezeretsanso anthuwa kukhala athanzi, opindulitsa kwambiri - ngati achitapo kanthu mwachangu kuti athetse kuchepa kwachuma. .

Ku US, kusintha kwa malamulo a dziko lausodzi mu 1996 ndi 2006 kwachepetsa kupha nsomba mopitirira muyeso ndi pafupifupi theka kuchokera pamene bungwe la National Marine Fisheries Service linayamba kupereka malipoti a pachaka kumapeto kwa zaka za m'ma 1990, monga momwe tawonetsera mkuyu 1. Mu 2011, US. Usodzi wamalonda ndiwo wakhala ndi nsomba zambiri kwambiri m'zaka 17, zomwe zikusonyeza kuti zoyesayesa zoletsa kusodza mopambanitsa ndi kumanganso nsomba zomwe zasodza mochulukira zikuyamba kupindula m'madera ambiri (koma osati onse) mdziko muno.

Koma pafupifupi theka la masheya omwe amayendetsedwa m'madzi aku US akadali osayesedwa komanso kafukufuku wa Costello et al. amapeza kuti ena mwa masheya omwe alibe deta awa ali ndi mawonekedwe oyipa ngati omwe ali m'maiko omwe akutukuka kumene. Mwachitsanzo, nsomba zambiri za m'matanthwe monga gulu ku South Atlantic ndi Gulf of Mexico, mitundu yambiri ya shark, halibut ku New England, kutchula ochepa chabe, amadziwika kuti mbiri yakale yatha ngakhale kuti sanayesedwe.

Zotsatira za kusodza mopambanitsa sizimangokhala kutsika kwa mitundu ya nsomba. Kuchepa kwa mitundu yazamalonda motsatizana motsatizana kungayambitse mikwingwirima ya trophic yomwe imasintha kapangidwe kazakudya pakapita nthawi, ndikupanga zotsatira zosayembekezereka. Zotsatira zazachilengedwe zakusodza mopitilira muyeso sizimaganiziridwanso kwambiri pamawerengedwe wamba a nsomba mopitilira muyeso, koma kafukufuku wina waposachedwa ndi bungwe la NOAA la Northeast Fisheries Science Center adatsimikiza kuti dera la New England lakumana ndi kusodza kwachilengedwe chifukwa cha kufala kwa usodzi komanso kukolola kosankha kwa mitundu yomwe yakhala ikukula. kudapangitsa kusintha kwa kasamalidwe ka nsomba kuchokera ku kachitidwe komwe kamakhala ndi zamoyo zambiri monga cod kupita ku nsomba zotsika mtengo zamtundu wa pelagic monga herring ndi elasmobranch (shaki zing'onozing'ono ndi ma skate). Zotsatira zofananazo zawonedwanso m’zamoyo zina za m’nyanja zogwidwa kwambiri ndi nsomba, monga ku North Sea ku Ulaya kapena matanthwe a m’nyanja ya Caribbean.

Monga phunziro latsopano la Costello et al. zikusonyeza kuti mitundu yambirimbiri ya zamoyo ikukhudzidwa ndi usodzi padziko lonse ndipo zambiri zikuoneka kuti zikuchepa. Zotsatira zosayembekezereka za kufalikira kotereku kwa zamoyo zam'madzi sizidziwika bwino, koma kusadziwa sikuli kosangalatsa. Kupha nsomba mopambanitsa kumasokoneza chuma chambiri komanso usodzi wa m’deralo, koma zoyesayesa zochirikiza ulimi wa nsomba zakuthengo monga chakudya cha anthu zidzalephereka ngati tinyalanyaza ntchito zimene zamoyo zonsezi zimagwira m’chilengedwe. . Pamene asayansi a zausodzi ndi mameneja akulimbana ndi njira zothetsera vuto la kusodza mopambanitsa, ayenera kuganizira za chilengedwe m’kuŵerengera kwawo kwa kuchuluka kwa kusodza kumene kuli kochulukira. Zingatanthauze kugwira nsomba zocheperako, koma njira ina ikhoza kukhala osapha nsomba.

Sources:

Christopher Costello, Daniel Ovando, Ray Hilborn, Steven D. Gaines, Olivier Deschenes, ndi Sarah E. Lester (2012), Status and Solutions for the World's Unassessed Fisheries, Science Online, September 27, 2012.

NOAA Northeast Fisheries Science Center (2009), Ecosystem Status Report ya NE Continental Shelf Large Marine Ecosystem.

Boris Worm et al. (2009), Kumanganso Usodzi Padziko Lonse, Sayansi 325: 578-585.