Ucwaningo olusha luveze umthelela obalulekile wemvelo wokudonsa ngamanetha phansi, indlela yokudoba evame ukubandakanya ukuhudula amagiya asindayo uwele phansi olwandle. Yize lo mkhuba kade ugxekwa ngemiphumela yawo elimazayo ezindaweni ezihlala olwandle, ucwaningo lwakamuva lluveza ukuthi luphinde ludlale indima enkulu ekusheshiseni ukuguquka kwesimo sezulu kanye nokwenza i-asidi yolwandle. Olwenziwa ithimba lamazwe ngamazwe lososayensi, ucwaningo luthole ukuthi ukudoba okuphansi kukhipha amanani ashaqisayo e-CO2 egciniwe ezinhlakeni zasolwandle, okunikela kakhulu kumazinga we-CO2 womkhathi.
Abacwaningi basebenzise indlela enezici eziningi yokuhlola umthelela wokudoba ngaphansi. Basebenzise idatha yesathelayithi evela ku-Global Fishing Watch ukukala ukushuba kanye nezinga lemisebenzi yokudoba ngamanethi, izilinganiso ze-sediment stock carbon ezisuka ocwaningweni lwangaphambilini, kanye namamodeli omjikelezo we-carbon. ukulingisa ezokuthutha nesiphetho se-CO2 eyenziwe nge-trawling ngokuhamba kwesikhathi. Okutholakele kwabo kuyethusa: phakathi kuka-1996 no-2020, imisebenzi yokudonsa ngamanethi ilinganiselwa ukuthi ikhiphe ama-petagrams (Pg) angu-8.5-9.2 e-CO2 emkhathini, okulingana nokuphuma konyaka okuqhathaniswa no-9-11% wezinto ezikhishwayo emhlabeni. kusukela ekushintsheni kokusetshenziswa komhlaba ngo-2020 kuphela.
Esinye sezambulo ezihlaba umxhwele kakhulu izinga elisheshayo lapho i-CO2 ekhishwa ngokudonsa ngamanethi ingena emkhathini. Ucwaningo luthole ukuthi ama-55-60% ale CO2 adluliswa olwandle aye emkhathini phakathi neminyaka engu-7-9 nje kuphela, kuyilapho u-40-45% osele uhlala uncibilikile emanzini olwandle, okunomthelela ekwenzeni i-acidity yolwandle. Amamodeli omjikelezo wekhabhoni aphinde aveza ukuthi ngisho nezifunda ezingenawo amanethi aqinile, njengeSouth China Sea kanye neNorwegian Sea, zingathinteka yi-CO2 ethuthwa isuka kwezinye izindawo.
Okutholakele kusikisela ukuthi ukwehlisa imizamo yokudonsa phansi kungasebenza njengesu elisebenzayo lokunciphisa isimo sezulu. Uma kubhekwa ukuthi imithelela ye-CO2 yomkhathi yokudonsa ngamanethi iyisikhathi esifushane uma kuqhathaniswa neminye imithombo yekhabhoni, ukusebenzisa izinqubomgomo zokukhawulela ukudotshwa ngamanethi kungaholela ekwehliseni okukhulu kokukhishwa kwekhabhoni. Ucwaningo lugcizelela ukubaluleka kokuvikela izinsalela zasolwandle, hhayi nje kuphela kwezinhlobonhlobo zezinto eziphilayo kodwa futhi nendima yazo ebalulekile ekulawuleni isimo sezulu sethu ngokugcina inani elikhulu lekhabhoni.
Isifinyezo Ngu: Aeneas Koosis | Isifundo Soqobo Ngu: Atwood, TB, Romanou, A., DeVries, T., Lerner, PE, Mayorga, JS, Bradley, D., Cabral, RB, Schmidt, GA, & Sala, E. (2024) | Kushicilelwe: Julayi 23, 2024
Isikhathi Sokufunda Esilinganisiwe: Amaminithi angu-2
Ucwaningo olusha lwembula ukuthi ukudotshwa ngamanethi okuphansi, umkhuba ovamile wokudoba, kukhipha amanani amakhulu e-CO2 ezinhlakeni zasolwandle, okungase kusheshise ukushintsha kwesimo sezulu kanye ne-acidification yolwandle.
I-bottom trawling, indlela yokudoba ebandakanya ukuhudula igiya elisindayo uwele phansi olwandle, sekunesikhathi eside igxekwa ngomthelela wayo olimazayo ezindaweni ezihlala olwandle. Lolu cwaningo luthole ukuthi lo mkhuba nawo unomthelela omkhulu esimweni sethu sezulu. Ucwaningo, olwenziwa ithimba lamazwe ngamazwe lososayensi, luthole ukuthi ukudotshwa ngamanetha okuphansi kukhipha amanani ashaqisayo e-CO2 egciniwe kusuka ezinhlakeni zasolwandle, okunomthelela emazingeni e-CO2 osemkhathini kanye ne-acidification yolwandle.
Abacwaningi basebenzise inhlanganisela yezindlela ukuphenya umthelela wokudonsa ngamanethi ngaphansi. Bahlole idatha yesathelayithi evela ku-Global Fishing Watch ukuze balinganisele ukushuba kanye nezinga lokudonsa ngamanethi phansi. Baphinde bahlaziya izilinganiso zesitoko se-sediment carbon stock ocwaningweni lwangaphambilini. Ekugcineni, basebenzise amamodeli omjikelezo wekhabhoni ukuze balingise ezokuthutha kanye nesiphetho sokukhishwa kwe-CO2 eyenziwe nge-trawling ngokuhamba kwesikhathi.
Bathole ukuthi phakathi kuka-1996 no-2020, imisebenzi yokudonsa ngamanethi ilinganiselwa ukuthi ikhiphe i-8.5-9.2 Pg (ama-petagram) e-CO2 emangalisayo emkhathini. Lokhu kulingana nokukhishwa kwaminyaka yonke kwe-0.34-0.37 Pg CO2, eqathaniswa no-9-11% wezinto ezikhishwa emhlabeni wonke ezivela ekushintsheni kokusetshenziswa komhlaba ngo-2020 kuphela.
Okunye okutholwe okugqama kakhulu isivinini esisheshayo lapho i-CO2 eyenziwe nge-trawling ingena khona emkhathini. Ucwaningo luthole ukuthi u-55-60% we-CO2 ekhishwa ngokudotshwa ngamanethi idluliswa isuka olwandle iye emkhathini phakathi neminyaka eyi-7-9 kuphela. Ama-40-45% asele e-CO2 akhishwe ngokudotshwa ngamanethi ahlala encibilikile emanzini olwandle, okunomthelela ekwenzeni i-acidity yolwandle.
Amamodeli omjikelezo wekhabhoni avumele ithimba ukuthi lilandelele ukunyakaza kwe-CO2 ngokusebenzisa imisinga yolwandle, izinqubo zebhayoloji, kanye nokushintshisana kwegesi yolwandle yolwandle. Lokhu kuveze ukuthi ngisho nezindawo ezingenawo amanethi aqinile, njengeSouth China Sea kanye neNorwegian Sea, zingase zithinteke yiCO2 ethuthwa isuka kwezinye izifunda.
Okutholakele kusikisela ukuthi ukunciphisa imizamo yokudonsa phansi kungaba isu elisebenzayo lokunciphisa isimo sezulu. Ngenxa yokuthi imithelela ye-CO2 yasemkhathini yokudonsa ngamanethi ihlala isikhathi esifushane uma iqhathaniswa neminye imithombo yekhabhoni, izinqubomgomo ezikhawulela ukudotshwa ngamanethi zingaholela ekwehlisweni okukhulu kokukhishwa kwekhabhoni.
Lolu cwaningo lugcizelela ukubaluleka kokuvikela izinsalela zasolwandle njengamadamu ekhabhoni abalulekile. Ngaphezu kwendima yazo ekusekeleni izinhlobonhlobo zezinto eziphilayo, izinsalela zasolwandle zidlala indima ebalulekile ekulawuleni isimo sezulu ngokugcina inani elikhulu le-organic carbon. Ababhali bayaqaphela ukuthi izilinganiso zabo cishe zinokonga, njengoba ukulinganiselwa kwedatha kanye negebe lolwazi kubavimbele ekubaleni ngokugcwele izinga lomhlaba jikelele lokudotshwa ngamanethi. Bafuna olunye ucwaningo ukuze sithuthukise ukuqonda kwethu umthelela we-trawling esitokisini se-sedimentary carbon kanye nezinqubo eziqhuba ukukhishwa kwe-CO2.
Ababhali batusa ngokuqinile ukuthi abameli nabakhi bezinqubomgomo babeke phambili ukuvikelwa kwenhlabathi yasolwandle njengengxenye ebalulekile yakho kokubili ukongiwa kolwandle kanye nemizamo yokunciphisa ukuguquguquka kwesimo sezulu . Ngokusebenzisana ukuze sinciphise imikhuba yokudoba elimazayo efana nokudoba ngamanethi angaphansi, singakwazi ukuvikela ukuphila olwandle lwethu kuyilapho sisiza ekuvikeleni isimo sezulu esizinzile ezizukulwaneni ezizayo.
Hlangana Nombhali: Aeneas Koosis
U-Aeneas Koosis ungusosayensi wokudla kanye nommeli wokudla komphakathi, oneziqu zeDairy Chemistry kanye nePlant Protein Chemistry. Njengamanje usebenzela ukuthola iziqu ze-PhD Kwezokudla, egxile ekuthuthukiseni impilo yomphakathi ngokuthuthuka okuphusile ekwakhiweni kwesitolo segrosa kanye nezindlela zokusebenza.
Izingcaphuno:
Atwood, TB, Romanou, A., DeVries, T., Lerner, PE, Mayorga, JS, Bradley, D., Cabral, RB, Schmidt, GA, & Sala, E. (2024). Ukukhishwa kwe-CO2 yase-atmospheric kanye ne-acidification yolwandle kusukela ekudonsa phansi. I-Frontiers in Marine Science, 10, 1125137. https://doi.org/10.3389/fmars.2023.1125137
Qaphela: Lokhu okuqukethwe bekushicilelwe ekuqaleni ngoFaunalyTics.org futhi kungahle kungabonisi imibono ye Humane Foundation.
