Waterbird use of different treatment stages in waste-stabilisation pond systems

Abstract

The significance of waste-stabilisation ponds (WSPs) to waterbirds has been well documented, but WSP differ depending on their place and purpose in the sewage-treatment system, and there is little information on how birds use these different types of pond. In mid-winter (July) 2012, waterbirds were counted on WSP at 18 sewage-treatment plants in the Goulburn Valley, Victoria. Winter-storage and maturation ponds supported greater abundance, density (birds ha⁻¹) and richness of waterbirds than aerated and anaerobic ponds. There were no significance differences in the number of species per hectare among types of pond. The abundance and density of diving waterfowl on maturation and winter-storage ponds was greater than on anaerobic and aerated ponds. A multivariate analysis revealed that waterbird community composition (based on both abundance and density) differed significantly between maturation ponds and anaerobic ponds (P <0.001) and also between winter-storage and anaerobic ponds (P <0.01). Comparing among types of WSPs, the waterbird communities of anaerobic ponds were the most distinct and winter-storage and maturation ponds the least different. Although the primary objective of a treatment plant is to treat sewage there is some design flexibility and, where possible, increasing the size or number of maturation and winter-storage ponds, or both, would generally benefit waterfowl.

Additional keywords:

• biodiversity
• conservation
• ecology
• sewage
• wildlife management