Líffræðifélag Íslands
Líffræðiráðstefnan 2015

Erindi/veggspjald / Talk/poster V47

Effect of heating up a stream on insect emergence

Aron D. Jónasson

Háskóli Íslands

Kynnir / Presenter: Gisli Mar Gislason

Tengiliður / Corresponding author: Gísli Már Gíslason (gmg@hi.is)

A cold stream (IS7) in Hengladalir east of Reykjavík was heated up by leading the stream water through a pipe into a heat exchanger in a nearby warm stream (IS8) and back to the lower reaches of the original stream. Emergence traps were placed in the unheated (7-10°C) and heated reaches (10-18°C) of the stream and in a warm stream (IS8) (19-22°C). This lead to changes in numbers of emerging insects, with a significant increase in total number of insects emerging from the heated stream and the warm stream. Of the total number of insects, Chironomidae were proportionally more numerous in the unheated reach compared with the heated reach, but blackflies (Simuliidae) and the predatory Limnophora riparia (Diptera) were both totally and proportionally more numerous in the heated reach. The fauna of the heated reach became more similar to the warm stream IS8.