Climatic changes and 13‐year trends in stream macroinvertebrate assemblages in New South Wales, Australia

Abstract

Over the period from 1994 to 2007, air and water temperatures in the Australian state of New South Wales (NSW) increased while rainfall and river flows declined. Data on the occurrence of stream macroinvertebrate families in bioassessment samples collected in NSW during this period were examined to see whether a biological response to these climatic and hydrological trends could be discerned. Multiple logistic regression was used to test for long-term trends in the probability of detection of individual macroinvertebrate families within the samples, taking account of the latitude, longitude, altitude, hydraulic habitat, time of year and subsampling method associated with each sample. Of the 124 families and family groups tested, 33 had statistically significant increasing trends, 37 had significantly declining trends and 54 had no significant trend; however, many of the last group were seldom collected and their trend estimates had wide confidence limits. Significant relationships were found between the thermophily and rheophily of the families and the estimated strength and direction of their long-term trends, with families that favour colder waters and faster-flowing habitats more likely to have declined. Although many families showed trends of increasing detection within samples, such trends do not necessarily equate to increasing prevalence in the environment because the extent of wetted habitat has probably declined, especially flowing habitat. In addition, because of likely intrafamilial trait diversity, increasing or apparently increasing families may include species in decline. Many freshwater macroinvertebrate species in NSW may be threatened by anthropogenic climate change, exacerbated by water withdrawals. The thermal tolerances, rheophily and other pertinent traits of individual species need to be determined to identify those most at risk.

Temporal and altitudinal variations in benthic macroinvertebrate assemblages in an Andean river basin of Argentina

“…Additionally, knowledge of the environmental requirements and distribution ranges of the species in this kind of harsh environment is useful to identify biological variations when climate changes occur, and to distinguish bioindicator species of the health status of freshwater ecosystems. Several studies have demonstrated biological (composition, distribution, phenology) variations with climate change (Hassall et al, 2007;Chessman 2009). Because of this, features of individual species (like thermal tolerances, rheophily, habitat selection, among others) require to be determined to recognise those species most at risk of extinction.…”

Sensitivity of native and non-native mollusc species to changing river water temperature and salinity

“…Climate change may affect environmental conditions, and subsequently bioinvasions, by altering the pool of potential invaders and influencing the chance that non-native species will establish (Rahel and Olden 2008). Studies on the effects of climate change in lake and river systems have shown changes in freshwater species composition and diversity for fish (Buisson et al 2008;Daufresne and Boet 2007) and macroinvertebrates (Burgmer et al 2007;Chessman 2009;Daufresne et al 2004;Mouthon and Daufresne 2006). Abiotic changes in river systems typically include increases in water temperature, river dynamics and salinity (Gornitz 1991;Webb 1996).…”

The response of benthic macroinvertebrate communities to climate change: evidence from subtropical mountain streams in Central China

“…Several studies report on aspects of meteorological and hydrological fluctuations in freshwater ecosystems (ZHANG et al, 2005;JIANG et al, 2006;KEIL et al, 2008), but few have explicitly linked them to biological changes. However, in Europe, America, and Oceania, several studies have ascribed long-term shifts in freshwater communities to directional climatic changes (DAUFRESNE et al, 2004;Harper and PECKARSKY, 2006;Durance and ORMEROD, 2007;Haidekker and HERING, 2008;CHESSMAN, 2009). However, very little information is available on the effects of climate changes on freshwater macroinvertebrate communities in Asia (DUDGEON, 2007;VASS et al, 2009).…”