SAVING the North Coast's koalas is the aim of a project launched on Sunday for World Environment Day.

A secure future for koalas through the Koala Connections project will give koalas a better future by increasing the area, quality and connectivity of koala habitat.

The $3.5 million program will improve this habitat - to protect koalas and many other species of endangered fauna and flora - through tree planting, weed control, community engagement, invasive vertebrate pest management and fire management and planning.

"Coastal development in the Tweed and Byron shires has substantially reduced and fragmented available habitat for native fauna," Tweed mayor Barry Longland said.

Koala Connections will link core koala habitats, enhance endangered ecological communities, and improve connectivity for native flora and fauna between inland and coastal communities.

This applies particularly to koalas, creating numerous sub-populations and increasing the potential impact of threats such as feral and domestic animals and bushfires.

"Koala Connections will link core koala habitats, enhance endangered ecological communities, and improve connectivity for native flora and fauna between inland and coastal communities," Cr Longland said.

Tweed Shire Council and Byron Shire Council are working together on the Koala Connections project, which is being funded principally by a $2 million grant from the Federal Government's Clean Energy Future Biodiversity Fund.

The grant, from the Department of Sustainability, Environment, Water, Population and Communities, is complemented by cash and in-kind contributions of all project partners - including both councils, landholders and community groups.

That includes $100,000 over four years from Tweed Shire Council's Biodiversity Grant Program. Over four years, the project aims to plant 30,000 koala food trees, with 2000 mixed shrubs and understorey plants, to create 75 hectares of effective fauna and flora linkages.

About 25 hectares of riparian and rainforest plantings will comprise of 25,000 trees and shrubs and 6000 understorey plants to enhance endangered ecological communities.

The project is designed to enhance inland to coastal linkages over approximately 20,000 hectares, and improve ecosystem resilience and adaptation to climate change.

In addition to tree and shrub planting, weed control will help the habitat to restore itself. The goal is to see evidence of improved natural regeneration after five years, on 225 hectares of koala habitat and Endangered Ecological Communities (EEC) listed under the Environment Protection and Biodiversity Conservation Act (1999) and the NSW Threatened Species Conservation Act (1995).