Detecting range shifts among Australian fishes in response to climate change

Abstract

Abstract. One of the most obvious and expected impacts of climate change is a shift in the distributional range of organisms, which could have considerable ecological and economic consequences. Australian waters are hotspots for climate-induced environmental changes; here, we review these potential changes and their apparent and potential implications for freshwater, estuarine and marine fish. Our meta-analysis detected ,300 papers globally on 'fish' and 'range shifts', with ,7% being from Australia. Of the Australian papers, only one study exhibited definitive evidence of climate-induced range shifts, with most studies focussing instead on future predictions. There was little consensus in the literature regarding the definition of 'range', largely because of populations having distributions that fluctuate regularly. For example, many marine populations have broad dispersal of offspring (causing vagrancy). Similarly, in freshwater and estuarine systems, regular environmental changes (e.g. seasonal, ENSO cycles -not related to climate change) cause expansion and contraction of populations, which confounds efforts to detect range 'shifts'. We found that increases in water temperature, reduced freshwater flows and changes in ocean currents are likely to be the key drivers of climateinduced range shifts in Australian fishes. Although large-scale frequent and rigorous direct surveys of fishes across their entire distributional ranges, especially at range edges, will be essential to detect range shifts of fishes in response to climate change, we suggest careful co-opting of fisheries, museum and other regional databases as a potential, but imperfect alternative.

Climate change impacts and adaptation of commercial marine fisheries in Australia: a review of the science

“…Similarly, NSW commercial fisheries data show that catch-per-unit-effort (CPUE) increased in proportion to freshwater flow for four commercial estuary species (dusky flathead, luderick G. tricuspidata, sand whiting S. ciliata and sea mullet) and decreased during drought (Gillson et al 2009). Booth et al (2011) find similar relationships, with increases in overall CPUE of the northern mud crab fishery interpreted as a response to sea temperature increases.…”

“…The ability to maintain viable catches is likely to be influenced not only by extreme weather but also distributional shifts of key commercial species away from the major ports/landing sites and economic zones (Booth et al 2011). Diminished access and property rights as distributions shift may become a significant issue in some regions, while other fishers may gain access to fish as they move .…”

“…These represent locations where significant changes for marine and estuarine species are occurring (Stuart-Smith et al 2009;Booth et al 2011). Temperate fish stocks off southeast Australia are likely to change as a result of climate change, particularly through the direct effects of exposure to increasing ocean temperature affecting species with limited thermal ranges, and indirectly through poleward movement of species Koehn et al 2011), habitat changes, and increasing disease outbreaks (Danovaro et al 2010).…”

Climate change and its implications for Australia's freshwater fish

“…A warmer climate may also facilitate increases in the range or abundance of some species in south-eastern Australia normally associated with warmer or more northern freshwaters Booth et al 2011). For example, the southerly range of golden perch (M. ambigua) is partly temperature-limited.…”

“….408C, Suppiah et al 2007) will increase the risk of the thermal tolerances of fish being exceeded in the small refuge-pool habitats typical throughout the south-west (Davies 2010), which could result in southerly contractions of the region's fish fauna (Booth et al 2011). Temperature is also a critical factor in the reproduction and growth of many freshwater fish species (e.g.…”