Lehnen, S. E. and D. G. Krementz. 2013. Use of aquaculture ponds and other habitats by migrating shorebirds along the lower Mississippi River. Environmental Management 52:417-426.
Populations of many shorebird species are declining and shorebirds may be especially vulnerable during migration. Shorebirds use a variety of habitats along interior migratory routes including managed moist soil units, natural wetlands and sand bars, and agricultural lands such as harvested rice fields. Less well known is shorebird usage of aquacultural facilities in the Lower Mississippi River Alluvial Valley (LMAV). We compared shorebird habitat use at drained aquacultural ponds, moist soil units, agricultural areas, and sand bars and other natural habitat, and a sewage treatment facility in the LMAV during fall 2009. Although 31,165 individuals of 28 shorebird species were observed, six species: Least Sandpiper (Calidris minutilla), Killdeer (Charadrius vociferous), Semipalamated Sandpiper (C. pusilla), Pectoral Sandpiper (C. melanotos), Black-necked Stilt (Himantopus himantopus), and Lesser Yellowlegs (Tringa flavipes), accounted for 92% of the observations. Waste management sludge (95.4 ± 23.7 birds/ha), drained aquacultural ponds (61.3 ± 9.1 birds/ha), and managed moist soil units on public lands (29.9 ± 7.1 birds/ha) had the highest densities of shorebirds. Together, drained aquaculture ponds and moist soil units supported the most non-Killdeer shorebirds in the LMAV, with an estimated 90% of non-Killdeer shorebirds in the LMAV using these areas during the 2009 fall migration period. There were an estimated 1,100 ha of aquaculture habitat available during fall 2009, which provided over half the estimated habitat requirement of 2,000 ha in the region. However, because of the decline in the aquaculture industry, fall habitat in the LMAV may be limited in the near future for shorebirds. This study illustrates the potential for freshwater aquaculture to create habitat for a declining taxa. Aquaculture is a rapidly growing industry worldwide; wildlife may be better managed by the identification of benefits as well as risks of aquacultural development and practices.