Spatial and temporal variation in the fish community of a South Island, New Zealand coastal lake

Communities in shallow coastal lakes are exposed to frequent environmental variation owing to their proximity to marine environments, and seasonal and daily variation in climate. Consequently, variability in these communities is likely to be considerable. The fish community of Lake Waihola, a shallow coastal South Island/New Zealand lake, was assessed by monthly day and night sampling by push net. A total of eight fish species were collected between January 1998 and January 1999. Common bully (Gobiomorphus cotidianus) comprised 78.92% of the total catch collected over the study period. Highest catches of common bully occurred in late summer and autumn, mostly at night. Juvenile perch (Perca fluviatilis) were also caught in high numbers for a short period in mid-summer, also mostly at night. Common smelt (Retropinna retropinna) and inanga (Galaxias maculatus) were collected in low numbers from late winter through to late autumn. Other species collected included shortfin eel (Anguilla australis), yellow-eyed mullet (Aldrichetta forsteri), lamprey (Geotria australis), and black flounder (Rhombosolea retiaria). Variation in abundance was attributed to life history an ontogenic shifts in habitat use, and changes in habitat structure related to the development of submerge macrophyte beds during warmer summer periods.