The objective with setting a Minimum Legal Size (MLS) is to protect the spawning biomass so that all paua have at least two years of spawning before they reach the MLS and can be harvested. All paua fisheries in New Zealand (including the Chatham Islands) have a MLS of 125mm. Unfortunately the work that supports this was based in Kaikoura so the MLS in Kaikoura might not be ideally suited to other regions. Generally in the cooler water temperature regions (lower South Island) the paua are larger when they reach maturity and the MLS needs to be increased whereas in the Northern paua fisheries the paua might never reach the MLS. Compounded with this is the habitat variations that can occur over very short distances along the coastline resulting in a variation of the length at maturity.

Ultimately future research will give us a better understanding of “length at maturity” so that the MLS can be varied and enforced at a scale similar to our Micro Management Zones (each Quota Management Area is divided into approximately 100 zones).

Varying the MLS achieves two things – it will ensure sustainability (i.e. we could manipulate the MLS to ensure 3 years spawning before they can be harvested) while at the same time allowing the productivity of the fishery to be better utilised.

In the Tasmanian Abalone Fishery ( Australia) they already have 5 different MLS.