Intensive Mangrove Planting at the Lang Lang Cliffs (Project 7085)

Intensive Mangrove Planting at the Lang Lang Cliffs (Project 7085)

This was a partnership project between the Western Port Seagrass Partnership, the Port Phillip and Westernport CMA and the National Heritage Trust.

Seeds that germinated in trays of seagrass. Photo: T.Ealey, WPSP

Seedlings grown in containers in greenhouse. Photo: T.Ealey, WPSP

Following on from the encouraging results from the mangrove planting activities of project 4.09, this project focused on planting mangroves along the eroding coastline to the south of the Lang Lang River.

A key element of this project was to perfect improved techniques for transplanting and staking seedlings obtained from donor sites and for planting out our better quality greenhouse container grown stock. It also focused more effort on direct seed planting techniques.

A considerable amount of valuable practical information was gained from this project that will be used to ensure greater effectiveness of future mangrove planting activities. Experience to date has shown that the green house grown stock and fresh seeds provide the best return for effort.

Two year old seedlings planted in May 2005, have developed cable roots and pneumatophores, providing good anchorage . Photo: T. Ealey WPSP.

Seedling grown from direct planted seed. Photo: T. Ealey, WPSP

Seeds grow at a much faster rate than transplants and do not require expensive and time consuming staking. About 5,400 seedlings and 5000 seeds were planted and replaced (where lost) over the 2006/2007 period. There were significant losses but at the end of the project 1,666 plants had survived and 816 seeds had germinated with fully functioning leaves. The longer the seedlings hold on, the greater their chances of reaching maturity. The current survival rate is acceptable given natural seed survival rates, the early stages of technique development and the inhospitable nature of the environment which to date has prevented natural mangrove colonisation.

Further losses are expected due to the ravages of frost and storm events, but the WPSP is confident that enough mangroves will hold on to establish a viable and self sustaining mangrove stand. Thickening up of stands over time will also help provide the density of plants required for effective shoreline erosion protection.

Final report for project 7085 – PDF