Love Rimurimu - Kākāriki (Worser Bay)

Restoration Project

Love Rimurimu - Kākāriki (Worser Bay)

Restoration Objective:

By improving conditions and restoring sites in the harbour with juvenile and adult seaweeds, we hope to set up the right environment for regeneration- helping nature to be a self-sustaining and healthy ecosystem again. These sites will take up carbon, restore habitat and strengthen our marine ecosystem - making it more resilient into the future. Our journey starts with collaboration, learning and innovating.

Site Selection Criteria:

The Kākāriki Hutia (Worser Bay) site has been visited regularly by community and school groups as part of the Love Rimurimu project and is closely connected to local community groups. Similar to other sites around Motu Kairangi, Macrocystis pyrifera typically grows at Kākāriki with Ecklonia radiata, Carpophyllum flexuosum, Carpophyllum maschalocarpum and *Undaria pinnatifida* (invasive kelp). The substrate is a mix of boulders and bedrock, intermixed with patches of sand and cobbles. Macrocystis is patchy but once grew at this site in much more abundance.

Cause Of Decline:

Cause of decline: a combination of sedimentation in the harbour, global sea temperatures rising, and overfishing of top predators which has led to an ecosystem imbalance and overabundance of Kina (Sea urchins- which graze heavily on Macrocystis pyrifera).

Key Reasons For Decline:

Climate Change

Imbalance

Sedimentation

Overgrazing

Increased turbidity

Ocean warming

Organisation:

Love Rimurimu

New Zealand

Site Observations:

Observation Date

7th Sep 2023 – 12th Jun 2024

Action Summary:

Trial plant out area was 0.07Ha approx. Methods to come

Lessons Learned:

Some preliminary observations:

  1. Observations indicated that factors such as weather on plant out day (UV exposure), time in transit (from lab to sea), and cluster location (those in less UV exposed areas seemed to do better) may lead to a better intial start for sporophytes.
  2. Grazing is the main threat to kelpling survivorship initially. However, this has not necessarily been kina (sea urchin) grazing and is more likely to be gastropod grazing.
  3. High percentage of kelpling loss intially which stabilises after about a month.
  4. Kelplings that were attached to larger rocks (cobbles) when planted out fared better than those attached to smaller ones (pebbles). Preliminary observatiosn suggest this may be a result of water movement and storm surge events.
  5. A whanau-based approach (out planting sporophytes in clusters close to existing Macrocystis) appears to be effective and will continue to be trialled.
  6. In less than 1 year we have seen sporophytes grow from leass than 5 cm (when out planted) to over 5 meters.
  7. The most successful cluster is in a a slightly deeper area with more consistent water flow and but less surge. It is on a semi isolated bommie surround , mostly by sandy areas and is slightly further away from the shoreline and is therefore exposed to less tidal movement.
  • Note that our sporophytes were grown in a laboratory, and planted out attached to rocks by freedivers. All monitoring and filed work has been conducted using freediving techniques.

Project Outcomes:

This project has had constant community involvement and been a collaboration between many different groups leading to positive social outcomes and more publicity for our kelp forests.

Nature of Disturbance:

Key Reasons For Decline:

Unspecified

Indicator Data:

Transplant Info:
Life Stage:Juveniles
Source:Culture
  • Terms of Use
  • Privacy Policy
  • Contact
  • Cookie Settings
    • © 2024 Kelp Forest Alliance. All Rights Reserved
    Powered ByShapeable Logo