Influence of habitat on meiofaunal abundance and distribution in a New Zealand temperate estuary

Meiofaunal assemblages are often overlooked, yet they are important ecological components of estuarine ecosystems. To evaluate variations in meiofaunal communities in estuarine habitats, we conducted a comprehensive analysis of meiofaunal density, distribution and relationships with environmental parameters in a mangrove-dominated ecosystem at Mangawhai, Northern New Zealand, in summer (March) and winter (October), 2013. Five habitat types were studied including mangrove stands, pneumatophore zones, sandflats, mudflats and saltmarshes. In addition, data were recorded for sediment grain size, organic content, and primary benthic productivity (chlorophyll a). Twelve major taxa were identified, with meiofaunal densities ranging between 269 and 8090 ind. 10 cm(-2). Highest abundances were found in fine-grained organic-rich sediments compared to coarse-grained organically poor sediments; the former were generally associated with mangroves stands and pneumatophore zones. Nematodes dominated all observed habitats. Foraminifera ranked second in fine-grained organically rich sediments, whereas copepods ranked second in coarser-grained sediments. Results suggest that meiofaunal taxonomic abundance and distribution are highly sensitive to local physical and biological parameters (e.g. sediment grain size, organic content, benthic primary productivity). The findings revealed that environmental characteristics have an important influence within this temperate estuary.

Automated summary

Meiofaunal assemblages, often overlooked, play important roles in estuarine ecosystems. Variations in meiofaunal communities in different habitats are influenced by environmental parameters such as sediment characteristics and benthic primary productivity. Environmental characteristics have a significant impact on meiofaunal taxonomic abundance and distribution within temperate estuaries.