SS1.01 Assessing Potential Environmental Impacts of Aquaculture
Date: Thursday, June 13, 2002
Time: 4:30:00 PM
Location: Lecture Theatre
BurfordMA, CSIRO Marine Research, Cleveland, Australia,
Costanzo, S, D, The University of Queensland, St Lucia, Australia,
Dennison, W, C, The University of Queensland, St Lucia, Australia,
Jackson, C, J, CSIRO Marine Research, Cleveland, Australia,
Jones, A, B, The University of Queensland, St Lucia, Australia,
McKinnon, A, D, Australian Institute of Marine Science, Townsville, Australia,
Preston, N, P, CSIRO Marine Research, Cleveland, Australia,
Trott, L, A, Australian Institute of Marine Science, Townsville, Australia,
Intensively farmed shrimp require the addition of high protein feeds to satisfy their nutritional requirements. Much of the feed is not assimilated by the animals but enters the pond system and may ultimately be discharged into adjacent waterways. A multidisciplinary study was conducted to link the source and fate of waste nutrients in discharge waters from two shrimp farms and downstream environments. The ponds were characterized as 'ultratrophic' systems with high carbon inputs, rapid growth and nutrient cycling by small phytoplankton and bacteria. Discharge waters resulted in elevated nutrient and chlorophyll a concentrations for 1 to 2 km downstream from the farms. The effect of the discharge water on bio-indicators and ecological processes downstream was highly variable, and in some cases was greater than that inferred by water quality measurements. Therefore, the use of process and bio-indicator measurements in monitoring programs has the potential to improve the assessment of impacts of shrimp farm discharges. Minimizing the impacts of shrimp aquaculture can be most effectively achieved by integrated waste management including improved feeds and feeding, and treatment methods.