The Potential Impact of Mineral Prospecting on Streams ...
Jan 7, 2014 12:35:14 GMT 12
Post by RKC on Jan 7, 2014 12:35:14 GMT 12
G'day,
The Potential Impact of Mineral Prospecting on Streams in Victorian National Parks.
There have been no specific studies examining the impact of prospecting on the ecology of streams, however there have been a number of studies evaluating the impact of eductor dredging (ENRC 1994)(including one conducted in dredged streams draining into Lake Eildon (Doeg 1985). That investigation did not find evidence that eductor dredging had seriously altered invertebrate communities in any of the streams sampled. However Hall (1988) noted that the Eildon study had not included sampling in summer or autumn,the seasons of intensive dredging, nor from slow water areas where most suspended sediment would settle out. In addition the study simply sampled rivers where dredging was known to have occurred, but it was not known whether the sites actually sampled had been subject to dredging. Nevertheless the dredging that occurred in the four rivers did not have a widespread substantial impact on aquatic invertebrate communities.
Studies of dredging in North America have detected impacts on both fish and invertebrates(e.g.Griffith and Andrews 1981,Harvey 1986). Where the area dredged was relatively small, and unimpacted areas which could act as sources of colonists were close,most studies have found a recovery of the invertebrate fauna within a few weeks to months. Dredging has been found to kill a substantial proportion of fish eggs and fish larvae entrained in the operation, but the impact on fish populations is not known.
www.veac.vic.gov.au/documents/Consultancy%20report.pdf
Regards,
Rob (RKC)
The Potential Impact of Mineral Prospecting on Streams in Victorian National Parks.
There have been no specific studies examining the impact of prospecting on the ecology of streams, however there have been a number of studies evaluating the impact of eductor dredging (ENRC 1994)(including one conducted in dredged streams draining into Lake Eildon (Doeg 1985). That investigation did not find evidence that eductor dredging had seriously altered invertebrate communities in any of the streams sampled. However Hall (1988) noted that the Eildon study had not included sampling in summer or autumn,the seasons of intensive dredging, nor from slow water areas where most suspended sediment would settle out. In addition the study simply sampled rivers where dredging was known to have occurred, but it was not known whether the sites actually sampled had been subject to dredging. Nevertheless the dredging that occurred in the four rivers did not have a widespread substantial impact on aquatic invertebrate communities.
Studies of dredging in North America have detected impacts on both fish and invertebrates(e.g.Griffith and Andrews 1981,Harvey 1986). Where the area dredged was relatively small, and unimpacted areas which could act as sources of colonists were close,most studies have found a recovery of the invertebrate fauna within a few weeks to months. Dredging has been found to kill a substantial proportion of fish eggs and fish larvae entrained in the operation, but the impact on fish populations is not known.
www.veac.vic.gov.au/documents/Consultancy%20report.pdf
Regards,
Rob (RKC)