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Mangrove Restoration

Queensland’s mangroves have the highest biodiversity in Australia and are classified as marine plants, protected under the State’s Fisheries Act 1994.

Development pressures, particularly along coastal regions have historically seen coastal environments, including mangroves destroyed for urban development. Although this trend has slowed in recent times, clearing of mangrove communities still occurs.

 

 

To minimise long-term impacts from clearing of mangroves, a condition of development may require rehabilitation of disturbed areas. However, restoration of mangrove communities poses challenges particularly in terms plant procurement, seasonality and timing and making sure your safety spotter is constantly watching for crocodiles.

Biotropica Australia is well-positioned to undertake this kind of work; our experienced ecologists regularly conduct assessments across the coastal environments of the Far North, which often result in the preparation of management plans, in many cases provisioning rehabilitation works to minimise impacts to the environment.

Biotropica has been involved in a number of mangrove restoration projects in the Cairns Region, in which we designed and implemented mangrove restoration works in accordance with the Accepted Development Requirements for fisheries development. Works involved the salvage of mangrove hypocotyls from nearby creeks and man-made drainage channels which would otherwise be routinely removed by council infrastructure maintenance activities. Hypocotyls, of mostly Rhizophora spp. (stilt mangroves) and Bruguiera spp. (orange mangroves), were collected carefully by hand from a location close to the recipient site, transported and replanted to ensure the highest chances of success. These two genera were used as both inhabited the recipient site prior to clearing and were available in high numbers to salvage.

Notification to the Department of Agriculture and Fisheries (DAF) was required prior to salvage of marine plants and post-works as part on the conditions of the Accepted Development Requirements. Removal of hypocotyls for replanting within the development site was authorised under the Cairns Marine Plant Management Strategy, which is also endorsed by DAF.

Within several weeks, the first new leaves had emerged, and as the planting was timed to coincide with approaching wet season rains, no watering was required; consistent falls post planting provided the optimal conditions for the hypocotyls to establish. Regular monitoring allowed us to document the progress of the planting (i.e., survival and growth) as well as identify any potential threats within the site which may have required management. A year after planting, survival rates are high and each site is continuing along a positive trajectory.

If you would like to discuss how Biotropica can assist you in your next restoration project, or on any other matter discussed above, contact Biotropica to talk to one of our ecologists.