Migrating eels in a Canterbury river, New Zealand

Abstract

A fish trap in the upper reaches of the South Branch stream, Canterbury, New Zealand, caught eels from December 1957 to October 1964. The downstream migrations of immature and adult eels of both New Zealand freshwater species (short‐finned Anguilla australis and long‐finned A. dieffenbachii) were recorded. These migrations showed a seasonal and a lunar periodicity, and the larger runs were also influenced by rainfall, water volume, or the passage of a depression. Seasonal peaks were marked for mature eels of both species, and for immature A. australis, but not for immature A. dieffenbachii.