Nanoplasti liikumine ahvena (Perca fluviatilis) toiduahelas
Laen...
Kuupäev
2021
Kättesaadavus
27.11.2021
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Alates 2013 aastast on mikroplastiteemaliste uuringute arv oluliselt suurenenud, kuid jätkuvalt ei ole mere – ja ookeanite kõrval piisavalt uuritud nanoplasti liikumist magevee toiduahelates. Mikro- ja nanoplasti suurus, mis on sarnane paljudele veeorganismidele, võimaldab sellel toiduahelasse sisenemise läbi filtraatorite ja detrivooride.
Uuringutel on oluline osa, mõistmaks mikro- ja nanoplasti mõju ja levikuvektoreid, koostamaks riskianalüüse reostuse ennetamiseks ja vähendamiseks.
Laboris läbi viidud toitumiskatsete eesmärk oli selgitada välja:
1) kas ja palju söövad kalavastsed plastist nanosfääre
2) kas ja mis määral liigub plastist nanosfääre eutroofsetele järvedele omases toiduahelas zooplankton-kalavastsed Zooplanktoni märgistamine näitas, et kõige rohkem sõid nanoplasti detrivooridest Chydorus spaericuse isendid, 30%, kes on kalavastsete üks olulisemaid toiduobjekte vesikirbuliste seas Eestis ja seetõttu oluline potentsiaalne nanoplasti toiduahelasse lülitaja. Nanoplasti leiti olulisel määral ka Bosmina longirostris ja Keratella cochlearis esindajatest, kes võivad samuti olla eutroofsetes veekogudes dominandid ja on Eestis olulised zooplanktoni liigid kalavastsete toiduna.
Tõestatud said hüpoteesid:
1) Ahvena (Perca fluviatilis) vastsete nanoplasti söömine sõltub osakeste kontsentratsioonist keskkonnas
2) nanoplasti osakeste söömine metazooplanktoni poolt on seotud osakeste suurusega
3) nanoplasti osakesed kanduvad toiduahelas läbi metazooplanktoni kalavastsete seedetrakti
Since 2013 the researches with matters of microplast are significally increased, however little is known about Nanoplastic movement through trophic exposure in the fresh water compared with seas and oceans. Size of micro– and nanoplast is similar resembling the size of many microorganisms which allows to plastics to enter food chain through filtrators and detrivores Significant part of researches is focusing to understand micro- and nanoplast impact and vectoral distribution for composeing more specific environmental risk analyses and pollution reduction plans. The goals of the feeding tests, performed in the laboratory, was to find out following: 1) whether and how much are fish larvae eating plastic nanospheres directly 2) whether and which quantities plastic nanospheres are moving in the food chain of eutrophic lakes from zooplankton to fish larvae Zooplankton labeling showed that most of the nanoplastic detrivors were eaten by Chydorus spaericus, 30% - which is one of the most important food objects of fish larvae in Estonia and therefore an important potential source of nanoplastics in the food chain. Nanoplastics were also found to a significant extent in representatives of Bosmina longirostris and Keratella cochlearis, which may also be dominant in eutrophic waters and are important zooplankton species in Estonia as food for fish larvae. The hypotheses were proved: 1) Ingesting nanoplastic particles by perch (Perca fluviatilis) larvae is depending on the concentration of particles in the environment 2) the ingestion of nanoplastic particles by metazooplankton is related to particle size 3) nanoplastic particles are transported in the food chain through the gastrointestinal tract of metazooplankton to fish larvae
Since 2013 the researches with matters of microplast are significally increased, however little is known about Nanoplastic movement through trophic exposure in the fresh water compared with seas and oceans. Size of micro– and nanoplast is similar resembling the size of many microorganisms which allows to plastics to enter food chain through filtrators and detrivores Significant part of researches is focusing to understand micro- and nanoplast impact and vectoral distribution for composeing more specific environmental risk analyses and pollution reduction plans. The goals of the feeding tests, performed in the laboratory, was to find out following: 1) whether and how much are fish larvae eating plastic nanospheres directly 2) whether and which quantities plastic nanospheres are moving in the food chain of eutrophic lakes from zooplankton to fish larvae Zooplankton labeling showed that most of the nanoplastic detrivors were eaten by Chydorus spaericus, 30% - which is one of the most important food objects of fish larvae in Estonia and therefore an important potential source of nanoplastics in the food chain. Nanoplastics were also found to a significant extent in representatives of Bosmina longirostris and Keratella cochlearis, which may also be dominant in eutrophic waters and are important zooplankton species in Estonia as food for fish larvae. The hypotheses were proved: 1) Ingesting nanoplastic particles by perch (Perca fluviatilis) larvae is depending on the concentration of particles in the environment 2) the ingestion of nanoplastic particles by metazooplankton is related to particle size 3) nanoplastic particles are transported in the food chain through the gastrointestinal tract of metazooplankton to fish larvae
Kirjeldus
Magistritöö
Kalandus- ja rakendusökoloogia õppekaval
Märksõnad
magistritööd, mikroplast, plastireostus, kala noorjärgud, mageveekalad