Fishery independent survey of paua in PAU 2, between Tirua Point and Patea River, Taranaki
Project: Fishery independent survey of paua in PAU 2, between Tirua Point and Patea River, Taranaki
Project Code: PAU2004/03
Start Date: 1 October 2004
Completion Date: 30 September 2005
Vessel Use: Subject to tender
To estimate the relative abundance and size frequency distribution of paua (Haliotis iris) between Tirua Point and Patea River, Taranaki, using a fishery independent survey.
To assess the environmental effects of paua fishing between Tirua Point and Patea River, Taranaki.
To estimate the relative abundance and size frequency distribution of paua between Tirua Point and Patea River, Taranaki, using a fishery independent survey
To develop indicators to be used to assess the impact of paua fishing between Tirua Point and Patea River, Taranaki.
This project is subject to the outcome of consultation on proposed management measures.
Paua are relatively abundant throughout the Taranaki region and can be readily found in areas where suitable rocky reefs occur. The Taranaki coastline is characterised by very large reef platforms that extend considerable distances away from shore and in relatively shallow water. Large parts of these reefs are exposed during low tide, especially during very low ‘king tides’ every 1-2 months. Because of the extent and nature of the reef platforms, together with a general lack of offshore reefs, paua tend to be found very close to shore. These paua can be taken by hand gathering with relative ease during low tide.
Paua along the Taranaki coast generally grow to a maximum length of about 85−95 mm (compared to the current 125 mm MLS) and sexual maturity occurs at a much reduced size compared with most other paua populations. About 50% of Taranaki paua mature at about 60 mm and 95% at about 75 mm. These paua are commonly referred to as ‘stunted’. Stunted paua populations occur in many other areas, including north of Auckland, East Coast, eastern Tasman Bay, Bank Peninsula, and Karitane. The reasons why stunted populations do not reach the MLS is unknown, but may be related to environmental conditions such as food availability and quality, exposure, and populations density.
The recreational paua fishery is managed by two principle management tools: a national minimum legal size (MLS) of 125 mm shell length and a daily bag limit of ten paua per person. Despite the abundance of paua along the Taranaki coastline, recreational fishers are unable to lawfully harvest paua as a direct consequence of the failure of paua to reach the MLS. Some customary fishing occurs, but is restricted to those persons fishing under approved customary fishing authorisations to take paua less than the MLS.
No commercial fishing occurs in the area because of the 125 mm MLS for the commercial fishery.
Fisheries managers propose setting a lower MLS between Tirua Point and Patea River, Taranaki, to provide for a recreational paua fishery. The proposal also considers reviewing the amateur daily bag limit for the same area to mitigate the risk of overfishing on localised paua populations. Given the proposed change of management that will effectively open up a 'new' paua fishery, it is prudent to undertake a baseline survey of the paua population in the proposed management area, and to implement a regime to monitor for adverse effects of fishing.
The proposed survey will provide a baseline of paua abundance and size between Tirua Point and Patea River, Taranaki. This information is expected to be used in a stock assessment in the future. The methods for fishery independent paua surveys have been standardised and are available by request from the Chief Scientist, MFish. However, researchers will be expected to review the utility of these methods given that the Taranaki coastline is characterised by shallow water reef platforms.
Given that the Taranaki coastline is characterised by very large reef platforms that extend considerable distances away from shore, the water is relatively shallow and large parts of these reefs are exposed during low tides, recreational fishing is expected to have an impact on the inshore environment. The Ministry of Fisheries intends to monitor the expected increased activity on the reef so it can manage any adverse impacts.
All the objectives in this project are consistent with the Fisheries Resources goal in the Strategic Framework and Directions for Fisheries Research Contracted by the Ministry of Fisheries document.
Cost Recovery Information:
This project is 100% crown funded.
The project is estimated to cost between $50,000 — $100,000