hrvatski

Učinak višestrukih stresora na vodene kukce: što možemo naučiti iz laboratorijskog pokusa?

Antropogeni učinak i klimatske promjene utječu na bioraznolikost i prirodne resurse. Slatkovodni ekosustavi su vruće točke bioraznolikosti, izvor pitke vode i hrane za čovjeka te su posebno ranjivi na antropogene pritiske [1]. Zbog povećane urbanizacije i otpuštanja otpadnih voda, slatkovodni ekosustavi su kontaminirani različitim onečišćujućim tvarima poput farmaceutika, proizvoda za osobnu njegu, pesticida pa čak i hormona [2]. Iako su utjecaji pojedinačnih stresora na razini vrste ili populacije relativno dobro istraženi, utjecaj kombinacije različitih stresora znatno su slabije poznati. Različiti stresori mogu uzajamno djelovati na više različitih načina, aditivno, antagonistički, sinergistički, utječući pritom na slatkovodne ekosustave [1]. Ovim istraživanjem želimo ispitati pojedinačni i kombinirani učinak smjese onečišćujućih tvari i povišene temperature na vodene beskralježnjake. Proveli smo laboratorijski pokus s pojednostavljenom slatkovodnom hranidbenom mrežom koja je uključivala mahovine i ličinke tulara (Micropterna nycterobia, Trichoptera), te sljedeće tretmane: a) smjesa onečišćujućih tvari ; farmaceutici i endokrini disruptori, b) povišena temperatura, c) povišena temperatura i smjesa onečišćujućih tvari i d) kontrola. Uzorkovanje je organizirano u skladu sa stadijima životnog ciklusa tulara (ličinke, kukuljice i odrasli stadij). Jedinkama tulara izmjerena je masa i koncentracija proteina prema metodi po Bradfordu [3]. Prvi rezultati pokazuju da odrasli mužjaci i ženke emergiraju ranije u tretmanima s povišenom temperaturom neovisno o prisutnosti onečišćujućih tvari. Nadalje, povećana masa, a smanjena koncentracija proteina je primijećena kod ličinki i kukuljica u tretmanima koji sadrže onečišćujuće tvari. Nastavak istraživanja će uključivati analizu metabolita, lipida i određivanje masnih kiselina kako bi procijenili odgovor vodenih kukaca na odabrane višestruke stresore. Izvršit će se kvantifikacija onečišćujućih tvari u tkivima tulara i mahovina kako bi se procijenio bioakumulacijski potencijal odabranih spojeva pod različitim temperaturnim režimom vode. Anthropogenic impact and climate change leave a mark on biodiversity and natural resources. Freshwater ecosystems are biodiversity hotspots, a source of drinking water and food for humans, and as such are particularly vulnerable to environmental stressors [1]. Due to increased urbanization and wastewater discharges, freshwater ecosystems are contaminated with various pollutants such as pharmaceuticals, personal care products, pesticides and even hormones [2]. Although the effects of individual stressors on species or populations have been relatively well researched, the understanding of multiple stressors impacts is lacking. Different stressors can interact in many ways, additively, antagonistically, synergistically, thus affecting freshwater ecosystems [1]. The aim of the current study was to investigate the single and combined effects of emerging contaminants (ECs) and elevatedtemperatures on freshwater invertebrates. We conducted the microcosm experiment with a simplified freshwater food web containing moss and caddisfly larvae (Micropterna nycterobia, Trichoptera). Caddisfly larvae, water and moss were collected in spring from temporary river Krčić. After acclimatization, the individuals were assigned randomly to the aquariums according to treatment: a) mixture of ECs ; pharmaceuticals (PhACs) and endocrine disrupting compounds (EDCs), b) elevated temperature, c) elevated temperature and mixture of ECs, and d) control. Sampling included initial and several consecutive collections including all life stages (larvae, pupae and adult stage), in accordance with the life cycle of holometabolous caddisflies. We measured body weight of caddisflies and a total protein concentration using the Bradford method [3]. First results show that both male and female adults emerged earlier in treatments with increased water temperature irrespective of the presence of ECs. Furthermore, increased body weight, but decreased protein concentration was observed in larvae and pupae in treatments with ECs mixture. Further analyses that will be conducted include metabolite profiling, total lipid content and fatty acids composition in order to evaluate the response of non-model aquatic insects to selected stressors. Additionally, the quantification of ECs in caddisfly and moss tissues will be conducted in order to assess the bioaccumulation potential of the selected ECs under different water temperature regimes.

Klimatske promjene ; Onečišćujuće tvari ; Tulari

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