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Managed and natural inundation: benefits for conservation of native fish in a semi‐arid wetland system
Author(s) -
Vilizzi L.,
McCarthy B. J.,
Scholz O.,
Sharpe C. P.,
Wood D. B.
Publication year - 2013
Publication title -
aquatic conservation: marine and freshwater ecosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 77
eISSN - 1099-0755
pISSN - 1052-7613
DOI - 10.1002/aqc.2281
Subject(s) - wetland , habitat , arid , floodplain , ephemeral key , channel (broadcasting) , environmental science , ecology , flooding (psychology) , hydrology (agriculture) , introduced species , natural (archaeology) , blackwater , geography , fishery , biology , geology , psychology , geotechnical engineering , archaeology , environmental engineering , electrical engineering , psychotherapist , engineering
Floodplain wetlands are areas of high biodiversity and conservation value, including those in semi‐arid regions. River regulation has resulted in disconnection from the main river channel of several ephemeral wetland systems, with profound modifications to their natural wetting/drying cycles that have contributed to the decline in diversity, distribution and abundance of native fish. From 2005 to 2011, a series of managed inundation events through pumping followed by natural inundation allowed assessment and comparison of the fish assemblage developing in Hattah Lakes, a semi‐arid wetland system of the regulated Murray River (Victoria, Australia). As a result of one‐way pumping from the main channel to Hattah Lakes, a ‘filtered’ fish assemblage consisting mainly of small‐bodied native species and very low numbers of non‐native species fully developed within 2 years. After disconnection from the main river channel in the absence of pumping, within‐system recruitment also occurred, but later drying of all water bodies caused the entire fish assemblage to perish. Conversely, following two‐way flooding by natural inundation a more diverse fish assemblage developed, including large‐bodied native species but also non‐native species, some of which were previously unrecorded. Managed inundation through pumping in Hattah Lakes represents a viable option for the creation of fish habitat, for promoting recruitment, and as a measure of rehabilitation. However, the absence of connectivity back to the main river channel means that future measures should be implemented to maintain a refuge water pool until the next inundation event. Long‐term monitoring is a key component of the integrated wetland conservation framework adopted by the Ramsar Wetland Convention, and this is especially relevant to the conservation of semi‐arid wetlands world‐wide including Hattah Lakes. Copyright © 2012 John Wiley & Sons, Ltd.