Deteriorating freshwater quality and the increasing extinction rate of freshwater invertebrates are among the greatest environmental challenges currently facing New Zealand. More than 10% of endemic freshwater invertebrates in New Zealand are at risk of extinction due to poor water quality; indeed water quality is the leading contributor to the world’s endangered and threatened freshwater species. Furthermore, many freshwater invertebrate species have unknown conservation status due to insufficient data. Within the context of freshwater ecosystems, ponds (small water bodies) are an important habitat, providing ecosystems services for local biodiversity across a range of taxa (algae, macroinvertebrates, fish, amphibians, birds and mammals). In spite of this, research on pond macroinvertebrates, and how different land-use activities affect their biodiversity, has received almost no attention in New Zealand. This makes the ecological basis for conserving ponds weak. We conducted an assessment of macroinvertebrate diversity in 12 ponds across different land-use types (urban and rural) and seasons in the Auckland region. Macroinvertebrates were sampled using standard d-frame net sampling protocols and identified to family level. A total of 8,469 (3,414 winter, 5,055 summer) individuals belonging to 60 families were sampled. Winter samples had relatively higher species diversity (H'= 10.72) than summer samples (H'=9.99) (f=9.94, p=0.0001). Species diversity was also significantly different across land-use types (f=1.625, p=0.02). Shannon Weiner diversity index was highest (H' = 6.69) for ponds in rural areas and lowest (H'= 3.03) for ponds in large urban areas. We predict water quality to be higher in rural areas compared to urban areas, and our observed patterns in macroinvertebrate diversity across these land-use types correlate with this expectation.
Keywords: Pond, Macroinvertebrate, Land use, Water quality, Auckland