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A Ramsar wetland in crisis the Coorong, Lower Lakes and Murray Mouth, Australia

journal contribution
posted on 2011-01-01, 00:00 authored by R Kingsford, K Walker, Rebecca LesterRebecca Lester, W Young, Peter Fairweather, J Sammut, M Geddes
The state of global freshwater ecosystems is increasingly parlous with water resource development degrading high-conservation wetlands. Rehabilitation is challenging because necessary increases in environmental flows have concomitant social impacts, complicated because many rivers flow between jurisdictions or countries. Australia's MurrayDarling Basin is a large river basin with such problems encapsulated in the crisis of its Ramsar-listed terminal wetland, the Coorong, Lower Lakes and Murray Mouth. Prolonged drought and upstream diversion of water dropped water levels in the Lakes below sea level (20092010), exposing hazardous acid sulfate soils. Salinities increased dramatically (e.g. South Lagoon of Coorong>200gL-1, cf. modelled natural 80gL-1), reducing populations of waterbirds, fish, macroinvertebrates and littoral plants. Calcareous masses of estuarine tubeworms (Ficopomatus enigmaticus) killed freshwater turtles (Chelidae) and other fauna. Management primarily focussed on treating symptoms (e.g. acidification), rather than reduced flows, at considerable expense (≥AU$2 billion). We modelled a scenario that increased annual flows during low-flow periods from current levels up to one-third of what the natural flow would have been, potentially delivering substantial environmental benefits and avoiding future crises. Realisation of this outcome depends on increasing environmental flows and implementing sophisticated river management during dry periods, both highly contentious options.

History

Journal

Marine and freshwater research

Volume

62

Issue

3

Pagination

255 - 265

Publisher

CSIRO Publishing

Location

Collingwood, Vic.

ISSN

1323-1650

eISSN

1448-6059

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2011, CSIRO