An untold story from Cyclone Larry: the success of good coastal planning

Most Australians knew the impact of Cyclone Larry through media stories and months of paying high banana prices. Thousands of north Queenslanders who lived in the cyclone path bore the immediate brunt and many suffered severe personal trauma, housing and business dislocation.

Another, smaller, group of people in the path of the Cyclone were those responsible for commercial, recreational and naval vessels in the ports and harbours from Cairns, just north of the eye of the Cyclone, to Cardwell in the south. Their story is largely untold. It concerns how they were able to protect themselves and their vessels by sheltering in mangrove creeks in Trinity Inlet and off other coastal rivers.

Given the huge demands on coastal space in Australia, the continued existence of such storm protection is not an accident, but rather the result of good planning based on sound scientific inputs, and the educated attitudes and expectations of local people - all developed well in advance of the cyclone itself.

Approximately 348,000 hectares of mangroves still remain along the Queensland coast, thanks to a long and varied history of protection, starting with 1914 legislation. Early laws were designed to ensure that oyster farmers had a ready supply of tough mangrove timber for stakes. More recently, the 1994 Queensland Fisheries Act is science-based and geared to conserve and protect biodiversity to support fisheries productivity.

Thus, while significant losses of mangroves have occurred in the past, almost all from urban, canal estate and port infrastructure development, the overall loss of mangroves has now slowed down to a trickle. Mangroves are provided two levels of protection: as protected plants that require a permit or notification before they can be damaged or removed, and, for those identified with high fisheries productivity (105,000 ha), protection in Fish Habitat Areas. On the east coast of Queensland, 47 per cent of mangroves are protected for fisheries habitats.

The result is that most Queensland coastal towns have estuaries with mangrove forests nearby. Cairns City, on the western bank of Trinity Inlet, is an excellent example. The inlet is almost totally protected by Fish Habitat Areas. It has about 3,600 ha mangroves (25 species of trees), 800 ha seagrass (eight species) in a wetland area of 7,400 ha - a beautiful, secluded, and sheltered mangrove-lined estuarine waterway just a five minute boat ride from any wharf in Cairns City.

The city has not expanded to the east to develop this waterway as port and city infrastructure because the legislated coastal management plans in place are supported at all levels of government - local, state and federal - especially to protect fishing as part of the Australian lifestyle.

In Queensland, 80 per cent of the value of fish caught commercially comes from fish that spend some part of their life cycles in an estuary. In addition to the Fish Habitat Areas, Trinity Inlet is also a multi-use marine park covered by a Trinity Inlet Management Plan (1999) - jointly agreed by the Cairns City Council, the Cairns Port Authority and the Queensland Government.

The Inlet’s additional role in cyclone protection is detailed in the “Maritime Cyclone Contingency Plan for the Port of Cairns”. This plan lists each of the Inlet’s normal anchorages, mooring piles, marinas and wharfs and, in the event of a cyclone, directs boats in each area to a section of the mangrove lined creeks in Trinity Inlet and describes the yellow/blue/red alert levels. Once located, the instructions allow the vessels to moor to the mangrove tree trunks and roots. When invoked, this contingency plan has the force of law. On arrival in the port, boats will be given a copy of the one-page Cyclone Contingency Plan.

Last March, just 60km from the center of cyclone Larry, the Trinity Inlet mangrove creeks were highly effective in protecting hundreds of vessels that normally berth in more open parts of the Inlet. In yachting newspapers, similar experiences were reported for Innisfail and Cardwell, nearer the cyclone centre.

Vessel protection is critical to the Cairns economy. First, the vessels were spared expensive damage. Additionally, the commercial vessels were able to return to business the day after the cyclone. Their work includes shipping services such as transporting pilots to and from ships navigating the sea lanes of the World Heritage listed Great Barrier Reef, and taking thousands of tourists daily to visit the Reef. The Cairns fleet undertakes over 11,000 ferry and vessel trips annually.

In Cyclone Larry, we witnessed how the results of the planning process helped determine the risk of loss of life and infrastructure in Trinity Inlet.

The mangroves and the mangrove-lined creeks remain in Trinity Inlet not by luck, but as the result of a successful outcome of a lot of work, science, negotiation, confrontation and whatever was needed to achieve a sensible coastal plan. A parallel and equally vital process, however, was that, thanks to active promotion of the Cyclone Contingency Plan, the Cairns boating community knew how to respond, were well prepared and knew where to get help.

Mangroves are important but it is good planning, plans and their proper implementation that finally save lives and property.