Consequences of spatial and temporal variation in reproduction cycle for the fishery of the New Zealand echinoid, Evechinus chloroticus Val.

Reproduction in the temperate commercial sea urchin Evechinus chloroticus (Valenciennes) at three sub-tidal locations in the Tory Channel, Marlborough Sounds New Zealand was monitored over 28 consecutive months during 1990–1992. Examination of oogenesis, spermatogenesis and monthly measurement of gonad index showed an annual reproductive cycle with gonads reaching a maximum size during the austral summer. Although the reproductive peak occurred in the summers, the duration of the reproductive season and the timing of spawning differed between years. The consequences of inter-annual and between-site variability in reproduction for the stewartship of this fishery are explored in the context of recent changes in fisheries management in New Zealand.