| Photographs: | |
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| List: | Register of the National Estate |
| Class: | Natural |
| Legal Status: | Registered (21/03/1978) |
| Place ID: | 10802 |
| Place File No: | 5/14/193/0002 |
| Statement of Significance: |
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| Hamelin Pool is of international scientific importance. Stromatolites found here are of great importance as living fossils identical to fossils dated at 3.5 billion to 3.9 billion years bp. These fossils are one of the earliest known evidences of life on earth. Nowhere else on the globe do stromatolites show such diversity and abundance. The Basin of Hamelin Pool is one of the few in the world where salinities are almost twice that of normal sea water. The size, depth and geomorphological features combined with salinity make the basin environment unique in modern seas. The Faure Sill is a key element in the formation and maintenance of the hypersaline Hamelin Pool. Hamelin Pool and Faure Sill are also significant in the contribution they make to the internationally significant ecosystems of the Shark Bay region. The marine meadows of the Faure Sill support a rich and diverse assemblage of shell secreting organisms and provide important feeding grounds for the marine fauna of Shark Bay. As well as supporting the rare algal structures known as stromatolites Hamelin Pool also contains vast deposits of organic shell (coquinas), ooid shoals and lithified sediments which are either rare or of scientific importance. Although restricted in complexity the biota inhabiting the hypersaline environment of the pool is of special interest to marine biologists because of their physiological adaptations to high salinity. Hamelin Pool is a significant type locality for algal stromatolites today and is their principal remaining stronghold. These features have all but disappeared from the earth with few other living examples existing. Hamelin Pool and Faure Sill provide a rare environment and major field laboratory for education and scientific research in sedimentology, marine biology, physical oceanography and geochemistry. |
| Official Values: Not Available |
| Description: |
| Landlocked in the east, south and west, Hamelin Pool is a large, shallow marine basin partially separated from the rest of Shark Bay by an extensive sand and seagrass bank, the Faure Sill. This extremely shallow sill along the northern boundary of Hamelin Pool greatly restricts tidal flushing. Combined with low precipitation and high evaporation the restricted flushing results in increased salinities. The basin is one of the few areas in the world where marine waters are hypersaline, with salinities of 55 parts to 70 parts per thousand; almost twice the salinity of modern sea water. Hypersaline conditions in Hamelin Pool have led to the development of a number of unique geological and biological features. Outstanding among these are algal stromatolites, which are living fossils of comparable scientific importance and rarity to protected elements of the Australian fauna and flora. There also are restricted communities of marine organisms tolerant of hypersalinity, vast deposits of organic shells (coquinas), ooid shoals and lithified sediments. Stromatolites derive their name from their initial discovery as fossils. They are the oldest form of megascopic life, appearing in rocks up to 3.5 billion years old. Stromatolites form when sediment becomes trapped and calcified within a mat of blue-green algae, or cymobacteria. They take the form of elevated rock beds or columns in the intertidal and near-subtidal zone. Blue-green algae have wide ecological tolerances and have persisted without significant change for about 3.5 billion years. They have however declined in abundance since the early Palaeozoic. The explanation appears to be the evolution of organisms that can graze on the algae. Several fish species occur in Hamelin Pool and one species of bivalve is particularly abundant, but in general high salinity has produced an environment of notably low diversity with gastropods known to graze on blue-green algae absent. A key element in the formation and maintenance of the hypersaline environment has been the growth and shoaling of the Faure Sill. This structure is a barrier bank constructed during the past 5,000 years through the accumulation of skeletons of marine organisms living in seagrass meadows that flourish on the bank surface. Shoaling and growth have led to the restriction of tidal influx into Hamelin Pool. |
| History: Not Available |
| Condition and Integrity: |
| In good condition. |
| Location: |
| About 260,000ha, comprising the whole of Hamelin Pool to 40m above highwater, extending westward to Petit Point and the northern tip of Faure Island, northward to 25'45" S, and including contiguous saline coastal flats. |
| Bibliography: |
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BATHURST, R.C.G 1975 'CARBONATE SEDIMENTS AND THEIR DIAGENESIS', DEVELOPMENTS IN SEDIMENTOLOGY 12, ELSEVIER SCIENTIFIC PUB CO, NEW YORK. CONSERVATION THROUGH 1974 'CONSERVATION RESERVES IN WESTERN AUST RESERVES COMMITTEE -REPORT TO THE ENVIRONMENT PROTECTION AUTHORITY', EPA, PERTH. ENVIRONMENT PROTECTION 1975 'CONSERVATION RESERVES IN WESTERN AUST AUTHORITY AS RECOMMENDED BY THE EPA FOR CONSERVATION RESERVES IN W.A. SYSTEMS: 1,2,3,4,5,7,8,9,11,12' EPA, PERTH. ENVIRONMENT PROTECTION 1982 'STATUS OF RECOMMENDATIONS BY THE EPA AUTHORITY FOR CONSERVATION RESERVES IN WESTERN AUSTRALIA SYSTEMS: 1,2,3,4,5,7,8,9,10, 11,12' EPA, PERTH. ENVIRONMENT PROTECTION 1987 'IMPLICATIONS OF THE SHARK BY A REGION AUTHORITY PLAN FOR CONSERVATION IN SYSTEM 9 - REPORT AND RECOMMENDATIONS OF THE EPA' EPA BULLETIN 305, NOV, 1987, EPA, PERTH HALL, C.M. 1987 'SHARK BAY: THE PRESERVATION OF ITS WORLD HERITAGE VALUES: A REPORT TO THE AUSTRALIAN HERITAGE COMMISSION', DEPT GEOGRAPHY, UNIVERSITY OF W.A., NEDLANDS PLAYFORD, P.E. 1980 AUSTRALIA'S STOMATOLITE STRONGHOLD, 'NATURAL HISTORY' VOL 89, NO, 10:58-61. STATE PLANNING AUTHORITY 1987 'SHARK BAY REGIONAL PLAN' DEPARTMENT OF CONSERVATION AND LAND MANAGEMENT, PERTH WALTER, M.R. 1977 INTERPRETING STROMATOLITES, 'AMERICAN SCIENTIST', VOL 65:563-571. |
Report Produced: Fri Jul 30 02:08:44 2010