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

ABSTRACT

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.

KEYWORDS:

• Meiofauna abundance
• mangrove estuary
• benthic communities
• organic matter
• sediment grain size
• primary benthic productivity

Acknowledgements

We would like to thank the School of Science at the Auckland University of Technology (AUT) and the University of Auckland for proving technical support and the use of their lab and facilities. We are thankful to the lab technicians at AUT for their help with sample analyses, and to Dr Amrit Dancer-Brown and Carine Bourgeois for their help in the field.

Disclosure statement

No potential conflict of interest was reported by the author(s).