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Apes the clarence river estuary restoration project in australia[1]

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The Clarence River Estuary in Australia contains endangered ecological communities and species. In the 1920s, a causeway was built across the estuary that blocked tidal flows, causing a buildup of sediments and nutrients. This led to algae blooms, higher water temperatures, and the death of seagrass beds. In 2008, a double-cell box culvert was installed in the causeway to restore tidal exchange and fish passage. This $420,000 project has successfully improved conditions in the estuary by reducing nutrients and temperatures and allowing the recovery of seagrass and fish populations.

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The Clarence River Estuary restoration project in Australia: the Shallow Channel Causeway
The Clarence River Estuary restoration project in Australia The Clarence River Estuary is located on one of the largest deltas on the east coast of Australia and is especially memorable for its marine biodiversity. The estuary itself contains several endangered ecological communities including saltmarsh and sub-tropical coastal flood plain forests and wetlands.Threatened species such as the black necked stork, mangrove honeyeater, osprey, and the black flying fox all call this estuary home. The Clarence River Estuary also plays a key role in the future of neighboring ecosystems by containing the nurseries of fish, crab, and prawn species, as well as being visited by migratory bird populations. The damage to the Clarence River Estuary originated in the 1920s when the Shallow Channel Causeway was built and worsened when it was reconstructed in the 1960s and made into a modern road without allowing the water to flow under it. This oversight blocked tidal flows which caused the buildup of sediments and nutrients. The buildup of nutrients in the now still waters caused algae blooms, which raised the water temperature. The raise in water temperature lead to algae bleaching, which in turn, lead to the death of sea grass beds that once served as vital marine habitats. Furthermore, fish populations where left isolated when their passages were blocked by the causeway. It wasn’t until 2008 that the group WetlandCare Australia was able to initiate the instillation of a double-cell box culvert intothe Shallow Channel Causeway. This method was chosen because it provided the largest volume of tidal exchange along with fish passages. The double-cell box cost $420,000 and was paid for by funds contributed by: the Recreational Fishing Community Grants Program; Clarence Valley Council, NSW Department of Primary Industries' 'Bringing Back the Fish' program; and Northern Rivers Catchment Management Authority. Installation of the culvert was managed by Clarence Valley Council. The culvert has been an agreed success, significantly improving the tidal flows and fish passages between the Shallow Channel and Oyster Channel. Sandbars and mud-flats that were fully-submerged before are now exposed at low tide, allowing for wading birds to return to the area. Baseline data shows nutrients and dissolved oxygen are returning to normal levels and the water temperature is stabilizing as well, so the sea grass beds are starting to recover. The area can now support a range of fish populations including whiting, flathead, yellow-finned bream, eel and mullet, which makes the area a substantial food resource for resident and migratory shore birds such as pelicans, oystercatchers, terns, egrets, sandpipers and spoonbills.
Works Cited Fixing Fish Habitat in the Clarence Estuary."Nsw.gov.au. NSW Department of Primary Industries.Web. 16 Jan. 2012. <http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0013/211702/CLARENCE---FIXING- FESHWATER-FISH-HABITAT.pdf>. Nellemann, C., and E. Corcoran. "Dead Planet, Living Planet: Biodiversity and Ecosystem Restoration for ... - Emily Corcoran, United Nations Environment Programme." Google Books.Web. 18 Jan. 2012. <http://books.google.com/books?id=irLBX-3nBEQC>. "Passage to the Sea- Fish Flow Restored at Clarence River's Shallow Channel." Wetland Care Australia.Web. 17 Jan. 2012. <wetland-restoration-and-rehabilitation/passage-to-the-sea>.

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Apes the clarence river estuary restoration project in australia[1]

  • 1. The Clarence River Estuary restoration project in Australia: the Shallow Channel Causeway
  • 2. The Clarence River Estuary restoration project in Australia The Clarence River Estuary is located on one of the largest deltas on the east coast of Australia and is especially memorable for its marine biodiversity. The estuary itself contains several endangered ecological communities including saltmarsh and sub-tropical coastal flood plain forests and wetlands.Threatened species such as the black necked stork, mangrove honeyeater, osprey, and the black flying fox all call this estuary home. The Clarence River Estuary also plays a key role in the future of neighboring ecosystems by containing the nurseries of fish, crab, and prawn species, as well as being visited by migratory bird populations. The damage to the Clarence River Estuary originated in the 1920s when the Shallow Channel Causeway was built and worsened when it was reconstructed in the 1960s and made into a modern road without allowing the water to flow under it. This oversight blocked tidal flows which caused the buildup of sediments and nutrients. The buildup of nutrients in the now still waters caused algae blooms, which raised the water temperature. The raise in water temperature lead to algae bleaching, which in turn, lead to the death of sea grass beds that once served as vital marine habitats. Furthermore, fish populations where left isolated when their passages were blocked by the causeway. It wasn’t until 2008 that the group WetlandCare Australia was able to initiate the instillation of a double-cell box culvert intothe Shallow Channel Causeway. This method was chosen because it provided the largest volume of tidal exchange along with fish passages. The double-cell box cost $420,000 and was paid for by funds contributed by: the Recreational Fishing Community Grants Program; Clarence Valley Council, NSW Department of Primary Industries' 'Bringing Back the Fish' program; and Northern Rivers Catchment Management Authority. Installation of the culvert was managed by Clarence Valley Council. The culvert has been an agreed success, significantly improving the tidal flows and fish passages between the Shallow Channel and Oyster Channel. Sandbars and mud-flats that were fully-submerged before are now exposed at low tide, allowing for wading birds to return to the area. Baseline data shows nutrients and dissolved oxygen are returning to normal levels and the water temperature is stabilizing as well, so the sea grass beds are starting to recover. The area can now support a range of fish populations including whiting, flathead, yellow-finned bream, eel and mullet, which makes the area a substantial food resource for resident and migratory shore birds such as pelicans, oystercatchers, terns, egrets, sandpipers and spoonbills.
  • 3. Works Cited Fixing Fish Habitat in the Clarence Estuary."Nsw.gov.au. NSW Department of Primary Industries.Web. 16 Jan. 2012. <http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0013/211702/CLARENCE---FIXING- FESHWATER-FISH-HABITAT.pdf>. Nellemann, C., and E. Corcoran. "Dead Planet, Living Planet: Biodiversity and Ecosystem Restoration for ... - Emily Corcoran, United Nations Environment Programme." Google Books.Web. 18 Jan. 2012. <http://books.google.com/books?id=irLBX-3nBEQC>. "Passage to the Sea- Fish Flow Restored at Clarence River's Shallow Channel." Wetland Care Australia.Web. 17 Jan. 2012. <wetland-restoration-and-rehabilitation/passage-to-the-sea>.