The impact of sewage discharge on nutrients and community production in a lagoon environment (Lagoon of Strunjan, Gulf of Trieste, northern Adriatic Sea) – a revisited experiment | Vpliv vnosa komunalnih odplak na hranila in produkcijo v lagunarnem okolju (Strunjanska laguna) – ponovni ogled poskusa

anglais. A specially constructed enclosure in the lagoon environment (Lagoon of Strunjan, Gulf of Trieste, northern Adriatic Sea) received sewage daily while another was kept clean and used as a reference. Nutrients and community production changes were monitored approximately bimonthly over a year. Nutrients introduced by the sewage discharges and diluted by tides were immobilized by enhanced community production, in particular benthic macroalgae. The dead organic matter afterwards settled and decomposed producing anoxic conditions and high levels of dissolved and suspended organic nutrients in the water and total nitrogen in the sediments. The daily mean gross community production showed no quantitative differences between the two enclosures during the study. Differences arose in the temporal succession of the studied events. An intensive nutrient recycling emerged from this study.

slovène. V posebej zgrajeni bazen v Strunjanski laguni smo dnevno uvajali komunalne odplake mesta Piran, medtem ko je drugi služil za primerjavo. V odbobju enega leta smo s približno dvomesečno frekvenco spremljali gibanja koncentracij hranil in produkcije. Vnešena hranila, redčena s plimovanjem, so povečala produkcijo predvsem bentoških makroalg. Odmrla organska snov se je nato posedla in razgrajevala ter povzročila nastanek anoksije in visokih koncentracij raztopljene in suspendirane organske snovi in celotnega dušika v sedimentu. Srednja dnevna bruto produkcija v celoletnem obdobju ni pokazala velikh razlik med bazenoma, medtem ko so bile lete opazne v časovnem poteku študiranih procesov. Iz poskusa je razvidno intenzivno kroženje vnešenih hranil.