Science Centres: Fisheries

 

Shellfish gatherers, Akaroa Harbour. (Photo: Chris Woods, NIWA)

At least one in four New Zealanders engages in some form of marine recreational fishing, including gathering shellfish from the intertidal zone. MFish recently commissioned NIWA to study recreational shellfish harvesting around Banks Peninsula, in response to concerns that stocks were becoming depleted as harvesting pressure increased.

The study involved workshops with Banks Peninsula iwi to identify areas traditionally used for gathering kaimoana, document the main species involved, and highlight the stocks considered most at risk. Anecdotal, but richly detailed, reports by tribal elders left us in little doubt that the size and abundance of all intertidal shellfish around the Peninsula had declined noticeably over the last 40–60 years.

The University of Canterbury contributed to the study by compiling an exhaustive dossier of shellfish research around the Peninsula, using archival data from as far back as 1929. For species such as cockles in Christchurch’s Avon-Heathcote Estuary, this information is sufficient to identify trends in size and abundance, but for most stocks such data are limited or non-existent.

Our study concludes by recommending methods for a recreational survey to quantify the shellfish harvest at sites of concern. This would include diary and entry/exit intercept questionnaires, and a monitoring programme to compare harvest levels with shellfish population parameters. Stakeholders and tangata whenua would participate fully in the survey programme.