The lower Daintree River estuary is home to an amazing diversity of life-forms both marine and terrestrial, with more than 150 fish species and over 100 crustaceans. The lower estuary is an important fuel-stop for visiting migratory waders and is home to numerous resident birds including up to eight kingfisher types. In any case it is one of the most beautiful eco-systems in Australia - not to be missed!

"The Daintree River (16.291 S 145.451 E) drains wooded coastal ranges surrounding a small coastal plain before discharging in the Coral Sea off the north east coastline of Australia. In contrast to most other river catchments to the south, much of the Daintree hinterland (1,308 km ) is pristine, with small amounts of sugar cane agriculture (~48 km ) and cattle grazing (~45km ). The remainder is covered in luxuriant and largely pristine tropical rainforest, recognised worldwide as a core section of Australia’s Wet Tropics World Heritage Area, adjacent to the Great Barrier Reef World Heritage Area. The Daintree is not quite a wilderness but the influences of local human impacts on this largely pristine region are minimal.

The special location of the Daintree with it’s unique combination of influencing factors makes the estuary a special place also for mangroves. A chief defining feature is the high biodiversity. There are 30 mangrove species in this single estuary making it perhaps the most species-rich mangrove estuary in the world. The estuary certainly has more species than anywhere else in Australia which has 38 in total. Australian mangroves are recognised as the wildest and best preserved in the world, with more than half the world’s 72 species represented. Daintree mangroves therefore offer a unique opportunity to learn about the factors influencing ecosystem function and evolutionary processes, as well as to gain greater understanding of human impacts.

Numerous factors affect the distribution of mangrove plants. Mangrove species are dispersed by water-buoyant propagules (fruits, seed and hypocotyls), allowing them to take advantage of estuarine, coastal and ocean currents both to replenish existing stands and to establish new ones. The ability to accomplish this differs for each species. Similarly, each species differs in establishment success and growth development rates, and each has unique tolerance limits and growth responses. Such attributes are responsible for the characteristic distributional ranges of each species, like those upriver, where each responds to the environmental, physical and biotic settings they occupy. In practice, species are distributed by the interplay of different factors along key environmental gradients which overall may be considered at four geographic scales - global, regional, estuarine and intertidal. The distribution of Daintree mangroves upriver and uptidal profile are accordingly influenced chiefly by a number of key factors namely: availability of propagules; rainfall; salinity; catchment size and tidal range"

Credits

Intorduction by Lee Lafferty of Daintree River And Reef Cruise Centre. Article courtesy of Norm Duke, Centre for Marine Studies, University of Queensland.