Estuaries EXTRAORDINARY ECOSYSTEMS

Forest and Bird, Volume 17, Issue 3, 1 August 1986, Unnumbered Page

Estuaries EXTRAORDINARY ECOSYSTEMS

Wading and migratory birds, the most visible and spectacular dwellers of estuaries, command most of our attention when we visit these biologically-rich habitats. Next time you visit your local estuary, however, spare a thought for what it is that attracts the birds there, for they are simply a link in a complex food chain. Dr ow Geoffrey Hicks, Curator of Crustacea at the National Museum, has for the last five years studied part of Pauatahanui Inlet, just north of Wellington and the site of a Society reserve (see August 1985 Forest and Bird). In that time he has come up with figures which show that this inlet contains huge numbers of a creature found near the beginning of the food chain, the meiofaunal copepod crustacean Parastenhelia megarostrum, which impacts directly on birds at the top end of the = chain.

Table 1: Abundance and productivity of single species of copepods in various estuaries.

Location Average Density Production No. Animals per Grams of carbon square metre per square metre per year Dievengat Lagoon (Belgium) 31 700 0.11 Nanaimo Estuary (Canada) 6 300 0.07 Puget Sound (USA) 160 000 0.7 1.7 North Inlet (USA) 188 000 0.06 Pauatahanui Inlet (NZ) 263 000 0.9 3.6