Publication Date

4-2002

Series Number

133

Publisher

Department of Fisheries

City

Perth, Western Australia

ISBN

0 7309 8464 8

ISSN

1035 - 4549

Abstract

The concentrator ponds (CPs) of Dampier Salt, Port Hedland, cover an area in excess of 7 300 ha. Water is pumped from two adjacent, mangrove-lined estuaries at certain times of the year and small and larvae fishes are carried into the ponds, becoming trapped. A survey of the fish biota within the CPs was undertaken at four time periods between May 2000 and February 2001 to identify the species of fishes present and to estimate their abundances and distribution throughout the CPs. Further, the Artemia resources within the CPs were also assessed for identification of species and quality.

Forty two species of fishes were recorded from within the CPs, which included species with commercial, recreational and indigenous value, although the catches were dominated by fishes of low economic value. The total fish biomass within the system fluctuated between approximately 60 – 100 tonnes, a similar order of magnitude to the catch of the Pilbara inshore net fishery. The numbers and biomasses within the CPs varied overall and within CPs, most likely as a result of changing water conditions in the CPs, especially salinity, as a result of rainfall, evaporation and seasonal changes. The changes in biomass distribution are a result of fish growth, fish movement and mortality within the CPs at different time of the year and are a major consideration in maintaining the nutrient loading of the CPs to maintain efficient salt production. Artemia cysts from the CPs were identified as A.fransciana, the same species as in many other salt fields in Australia and other parts of the World. A preliminary assessment was performed and indicated that cyst quality was similar to cysts from other parts of Australia.

A discussion of the outcomes of the project presents a range of future options in regard to the commerical application of the results (Table 9). The application includes preventing the entry of fishes to the commercial aquaculture of certain species, or Artemia, and includes options for the development of indigenous involvement within the CPs. Initially, the harvesting of fishes within the CPs is possible and relatively simple to implement, especially as some species have a local indigenous value and the infrastructure is readily available. However, the development of a full-scale aquaculture facility should be considered for the long-term. Additional information that may be collected from the CPs for the better management of the CPs is provided for the managers of Dampier Salt.

Number of Pages

54

Keywords

Department of Primary Industries and Regional Development, Artemia, solar salt fields, fish mortality, Dampier salt

Disciplines

Aquaculture and Fisheries | Biodiversity | Environmental Monitoring | Natural Resources Management and Policy | Sustainability | Terrestrial and Aquatic Ecology

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