The importance of water-level fluctuation for the conservation of shallow water benthic macroinvertebrates: an example in the Andean zone of Chile

Abstract

Many researchers have shown the importance of water chemistry and benthic habitat characteristics for the conservation of the freshwater macroinvertebrate biodiversity. However, few authors have examined the physical eVect of extreme water-level Xuctuations in lakes. The present study set out to determine, through a comparative study between a regulated lake (Laja Lake, LL) and an unregulated lake (Icalma Lake, IL) of the Andean zone of southern Chile, how man-made disturbances of the natural hydrological regime aVect the structure of the benthic macroinvertebrate community. The results showed LL had very low values for species richness, density and biomass in comparison with IL, and the community was composed mainly of few individuals belonging to opportunistic taxa such as Chironomidae and Naididae. We suggest that the low values in the regulated lake are potentially explained by littoral zone factors driven by the water-level Xuctuations such as: desiccation, freezing of the biota, removal of organic particles from the sediment and absence of aquatic macrophytes.

The impact of water-level regulation on littoral macroinvertebrate assemblages in boreal lakes

“…Existing knowledge of the effects on macroinvertebrate communities is largely based on a few case studies (e.g. Furey et al, 2006;Valdovinos et al, 2007); more general patterns in structural responses of communities to water-level regulation, based on multi-lake comparisons, have not been well documented (but see Smith et al, 1987). Also, relatively little is still known about the causes for the detected responses.…”

Native and exotic fishes in a Patagonian reservoir with rainbow trout cage culture: spatial and trophic resource use

“…<4.5 m, compared to Valdovinos et al, 2007;Zohary and Ostrovsky, 2011;Eloranta et al, 2016), is expected to reduce occupation of the littoral zone by native species in the presence of the introduced rainbow trout (Hanisch et al, 2012;Otturi et al, 2016). However, the abundant large rocks and semisubmerged coastal trees present in the Alicurá reservoir seem to provide the necessary structure and refugia for native species, as revealed by the observation of P. trucha less than 10 cm in length using the shallow littoral in protected bays, along with G. maculatus and juvenile ERT (D. Nabaes Jodar, unpublished data).…”

Macroinvertebrate community succession in the Three-Gorges Reservoir ten years after impoundment

“…Moderate fluctuation can be beneficial to the development of macroinvertebrate communities, whereas intense and sustaining fluctuation may reduce diversity and even destroy the structure of a macroinvertebrate community (Valdovinos et al, 2007;Aroviita and H€ am€ al€ ainen, 2008;Bond et al, 2008). Water-level fluctuations of the TGR are mainly of two kinds: periodic variation caused by reservoir regulation; and drastic fluctuation within a short time caused by flooding (Figs.…”