Behavioural avoidance of acidified water by juveniles of four commercial fish and prawn species with migratory life stages

Abstract

Impacts on aquatic ecosystems resulting from acute exposure to acid sulfate soil discharge are well documented. However, less is known about the long-term impacts of chronic acid sulfate discharge. Such discharge may create barriers to movement, potentially affecting migration of fish and invertebrate species, including commercial species. Avoidance of such discharges by adults may affect spawning migrations, while similar behaviour by juveniles may affect migration to nursery habitats. As a result, the capacity of fish to access important habitats beyond the discharge point may be reduced with potential consequences for stock size. This study examined the possible existence of acid sulfate avoidance behaviour in juveniles of 3 commercial fish species and 1 commercial prawn species. Schools of 10 individuals were given a simultaneous choice between 2 different water qualities in paired channels of a laboratory stream, i.e. preference-avoidance situation. All species avoided acidified water, indicating that chronic acid sulfate discharge has the potential to affect migration of these species in the field. The pH levels avoided in these experiments were well within the magnitude exhibited by natural systems. Thus, chronic acid sulfate discharge in the field could have a detrimental impact on commercial and recreational fisheries.

Sediment pollution impacts sensory ability and performance of settling coral-reef fish

“…The changes in behaviour seen in the reared post-settlement fish may be a similar response due to the acidity of red soil. Behavioural avoidance of acid sulfate soils has been shown in juveniles of various fishes when pH levels were well within the range exhibited in natural systems (Kroon 2005). Red soil in Okinawa is acidic, with a pH of ~5 (Mkadam et al 2006), and analysis of the rearing conditions used here showed that the pH decreased with both increasing concentration of red soil and time.…”

Reduced salinity, but not estuarine acidification, is a cause of immune-suppression in the Sydney rock oyster Saccostrea glomerata

“…The relatively small impact of the tested water quality variables on immune-gene expression in adult S. glomerata was unexpected and may reflect the fact that adult oysters are intertidal euryhaline organisms that have evolved mechanisms to cope with rapid changes in their environment. The juvenile finfish Pagrus auratus, Acanthopagrus australis and Macquaria novemaculeata and the marine invertebrate prawn Metapenaeus macleayi can predict acidity and avoid low concentrations of sulfuric acid (pH 6.6 to 5.0) when given a choice (Kroon 2005). Adult S. glomerata are sessile organisms that cannot escape ASS leachate, but are likely to close their shells in an attempt to avoid the acidity and heavy metal toxicity associated with ASS leachate.…”

Recovery of fish and crustacean communities during remediation of tidal wetlands affected by leachate from acid sulfate soils in north-eastern Australia

“…In eastern Australia, disturbance of acid sulfate soils has a well documented history of causing environmental problems including fish kills particularly in northern New South Wales Sammut et al 1996;Roach 1997;Kroon 2005;Kroon and Ansell 2006), south eastern Queensland (Preda and Cox 1998;Cook et al 2000), and at East Trinity, Cairns in north Queensland Hicks et al 1999;Cook et al 2000;Russell and Helmke 2002;Russell and McDougall 2003;Russell and Preston 2005;Russell 2006). The first records of fish kills in the vicinity of East Trinity were around 1972, not long after site reclamation works had commenced.…”