|
Cape York Peninsula, located in North Queensland, is the largest region of wilderness area left on the east coast of Australia. It was the first part of Australia to be mentioned in recorded history. The earliest recorded visits were by Dutch and Spanish explorers during the 1600s. In 1605 Willem Jansz of Amsterdam sailed from Bantam in the Dutch East Indies (Indonesia) in search of New Guinea. He reached the Torres Strait a few weeks before Torres himself and unknowingly saw, and also named, part of the Australian coast -- Cape Keer-Weer, on the western side of Cape York Peninsula. The Spaniard Luis Vaez de Torres sailed between Australia and New Guinea in 1606, through the Straits that now bear his name. His discovery remained a secret for many years until 1762 when the British fleet occupied Spanish Manila in the Philippines and found a copy of Torres's chart. In 1770 James Cook proclaimed British sovereignty over the east coast of Terra Australis by raising the flag on Possession Island in the Torres Strait.
Despite this early beginning in history, the Cape remains a land of few people (18,000) and is a wilderness area of incredible contrasts. Between the breathtaking sandy beaches and lush rainforests, there are eucalypt forests and woodlands, arid grasslands, abundant river systems with crystal clear creeks and spectacular waterfalls; all supporting a variety of fauna and flora. The estuaries and tidal wetlands of Cape York Peninsula contain some of the most well developed mangrove habitats in Australia. Mangroves are crucial for the regulation of nutrient flow from land to sea. They are nurseries for a myriad of marine life forms, and the habitat of the saltwater crocodile (Crocodylus porosus), the world's largest crocodile.
 |
| View from tip of Cape York Peninsula - Jennifer Palmer |
Perched lakes and swamps occur on the eastern coastal dune fields. Perched lakes are formed in sandy depressions above the localised water table when the sand is cemented by humic substances leached from accumulating litter, producing an impervious layer of humicrete. The water in these habitats are usually stained brown due to the presence of tannins with a pH range from 3.9 to 6.8, and specific conductance from 62 to 338 mScm. Aquatic fauna found in these environs include Iriatherina werneri, Melanotaenia splendida inornata, Melanotaenia maccullochi, Pseudomugil gertrudae, Mogurnda mogurnda, Hypseleotris compressa and Ambassis spp. The freshwater crayfish Cherax quadricarinatus and freshwater shrimps Caridinides wilkinsi, and Caridina indistincta have also been collected in these acidic habitats.
The Cape occupies an area of around 115 350 km² and extends 800 kilometres from the tip to Cooktown. It is bounded by the Great Barrier Reef to the east, the Gulf of Carpentaria to the west; Torres Strait and Papua New Guinea to the north.
There are only two seasons on Cape York Peninsula the "wet" and the "dry". The wet is by far the most spectacular; from mid November thunderstorms herald the beginning of the monsoon season (November - April). The parched land is replenished and the once dry rivers and creeks again flow.
 |
| Cannibal Creek - Bruce Hansen |
The Peninsula Developmental Road is the principal means of access to the region; however, parts of this road are impassable during the wet season and the only way to visit the region is by aircraft. This is also the cyclone season, with the right conditions they can form anywhere out at sea and cross the coast in varying intensity. At the end of the wet season the south east trade winds return drying the land once more.
The Great Dividing Range bisects the region; westward flowing rivers including the Alice, Coleman, Edward, Holroyd, Kendall, Archer, Watson, Coen, Mission, Wenlock, Dulcie, Dulhunty and Skardon empty into the Gulf of Carpentaria; eastward flowing rivers empty into the Coral Sea (Macmillian and Pascoe), or Princess Charlotte Bay (Stewart, Annie, Morehead, Hann, Kennedy, Normanby and Jack rivers).
 |
| Wenlock River Crossing. The Wenlock River is reported to contain the richest known freshwater fish fauna in Australia, with the Jardine River not far behind it. photo: Bruce Hansen |
Many rivers in Cape York Peninsula are flood plain rivers, and during the wet season they break their banks to cover large areas of flat country. Floodplains are important areas for the growth of rainbowfishes and other aquatic biota. The floods covering floodplains in most areas are short lived. Flow in the river channel may persist for a long period, but the period of extensive flooding rarely exceeds two to three weeks. However, this may occur several times in the course of a good wet season, but is dependent upon cyclones, rain depressions and monsoonal development. Many species are dependent on flowing water or submerged vegetation, and the increased food supplies afforded by flooding, for breeding.
Eighty-eight freshwater fish species (including 15 vagrants from estuarine areas) were recognised in the CYPLUS survey. Several more have been added to that list since then. This represents approximately 40 per cent of Australia's known freshwater fish. The fish of Cape York Peninsula have much in common with New Guinea. For example, approximately three-quarters of the fish species known from the Jardine and Olive Rivers are also known from New Guinea. Cape York Peninsula is of national, regional and global significance both as an area of outstanding biodiversity, and as a largely intact land and biological bridge retaining valuable evidence of the bio-evolution and on-going 'fragmentation' of the biomes of the Australian Wet Tropics region and the island of New Guinea.
 |
| Cape York Peninsula - known Rainbowfish distribution sites. Absence of species from other areas reflects a lack of sampling, rather than absence as many suitable habitats have never been sampled. |
Rainbowfish species found in the Peninsula area include Iriatherina werneri, Melanotaenia maccullochi, M. nigrans, M. splendida splendida, M. s. inornata, M. trifasciata, Pseudomugil gertrudae, P. signifer, and P. tenellus. Pseudomugil inconspicuus and Pseudomugil cyanodorsalis may inhabit the estuaries and tidal wetlands on the western side of Cape York Peninsula.
Iriatherina werneri have a wide distribution across the Peninsula. They have been collected in the tributaries of the Jardine River and from the Olive River and other eastern peninsula habitats. They have been collected from the Edward River on the western side of Cape York Peninsula, and occur in other river systems on the western side of the Peninsula.
 |
| McIvor River Habitat - Jennifer Palmer |
Melanotaenia maccullochi are found in the Jardine River and its tributaries. They also occur at Cape Flattery, Cape Grenville, Shelburne Bay, and the Olive River. They probably occur elsewhere along the east coast of Cape York Peninsula that has suitable habitat.
Melanotaenia nigrans have a discontinuous distribution across the Peninsula. They inhabit a variety of freshwater environments but seem to prefer slow-flowing clear water streams, billabongs, and swamps with abundant aquatic vegetation.
Melanotaenia s. inornata occur in almost every kind of freshwater habitat on the Peninsula. They are frequently found in company with Melanotaenia nigrans and Melanotaenia trifasciata.
Melanotaenia s. splendida are found in streams east of the Great Dividing Range along the coast of Queensland from Gladstone north to Cape York Peninsula. Scrubby Creek, just south of the Lockhart River, appears to be the northernmost location for this species.
Melanotaenia trifasciata are most common in flowing waters or in streambeds where flow would be present for much of the year. They are rarely found in lagoons, and are never abundant in these habitats. Juveniles also are rarely seen in still water habitats, suggesting that flowing water or a clean substrate is essential for breeding in the wild. In these habitats, they predominate over Melanotaenia splendida inornata and Melanotaenia nigrans in both number and size. Although they live and thrive in aquariums, it appears as though in the wild, clear, flowing water is essential for their successful reproduction and growth.
Pseudomugil gertrudae have a wide distribution and are more frequently found in small creeks, lagoons, billabongs, swampy marshes, and rainforest streams, often associated with dense aquatic vegetation.
Pseudomugil tenellus have a patchy distribution and are mainly found in marshy swamps or slow flowing streams where there is an abundance of aquatic vegetation.
 |
| Burster Creek Habitat - Jennifer Palmer |
The aquatic flora of Cape York Peninsula is not dissimilar than that found in other tropical regions of the world. Although some endemic species are found, most species are cosmopolitan. Endemic species include Nymphoides, Nymphaea (waterlilies), Limnophila, and Aponogeton.
Floating species or bottom rooted water plants with floating leaves occur in most, if not all, of the water bodies of Cape York Peninsula. The following species appear to be constantly present: Azolla pinnata, Blyxa sp., Caldesia oligococca, Eriocaulon setaceum, Ludwigia perennis, Monochoria cyanea, Najas tenuifolia, Nelumbo nucifera, Nymphaea gigantea, N. violacea, Nymphoides indica and Utricularia sp. Bottom rooted emergent aquatic species generally grow in a mid-dense fringe around permanent water bodies. A few species appear to be constantly present in these communities, including Eleocharis sp., Oryza australiensis and O. rufipogon. The fringing flora of ephemeral water bodies is less diverse, with Eleocharis sp. commonly the most dominant. Other bottom rooted emergent aquatic species that have been recorded in the area are Centipeda sp., Cyperus spp., Eleocharis brassii, Ludwigia octovalvis, and Pseudopogonatherum sp.
Aquatic algal communities in the deeper water areas are dominated by Spirogyra sp. Extensive areas of floating grasses are also present, adjacent to deeper open water areas. Emergent communities at the margins include non-persistent species such as Cyperus aquaticus, Eriocaulon spectabile, Limnophila brownii, Nymphoides indica, Phyllanthus virgatus and persistent grasses such as Arundinella setosa, Eragrostis sp. aff. pubescens, E. interrupta, E. spartinoides, Pseudoraphis spinescens, and Triraphis mollis.
In addition to all the desirable rainbowfish species there are at least twelve genera (72 species) of mosquito that have been recorded from Cape York Peninsula, the most common genera being Aedes and Culex. So if you intend to visit this area make sure you bring plenty of mosquito repellent.
 |
| Jardine River Swamp - Bruce Hansen |
© Copyright Adrian R. Tappin
Updated 24 May, 2005.
|
|
