Tufa stromatolite ecosystems on the South African south coast
- Perissinotto, Renzo, Bornman, Tommy G, Steyn, Paul-Pierre, Miranda, Nelson A F, Dorrington, Rosemary A, Matcher, Gwynneth F, Strydom, Nadine A, Peer, Nasreen
- Authors: Perissinotto, Renzo , Bornman, Tommy G , Steyn, Paul-Pierre , Miranda, Nelson A F , Dorrington, Rosemary A , Matcher, Gwynneth F , Strydom, Nadine A , Peer, Nasreen
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:6490 , http://hdl.handle.net/10962/d1014585 , http://dx.doi.org/10.1590/sajs.2014/20140011
- Description: Following the first description of living marine stromatolites along the South African east coast, new investigations along the south coast have revealed the occurrence of extensive fields of actively calcifying stromatolites. These stromatolites have been recorded at regular distances along a 200-km stretch of coastline, from Cape Recife in the east to the Storms River mouth in the west, with the highest density found between Schoenmakerskop and the Maitland River mouth. All active stromatolites are associated with freshwater seepage streams flowing from the dune cordon, which form rimstone dams and other accretions capable of retaining water in the supratidal platform. Resulting pools can reach a maximum depth of about 1 m and constitute a unique ecosystem in which freshwater and marine organisms alternate their dominance in response to vertical mixing and the balance between freshwater versus marine inflow. Although the factors controlling stromatolite growth are yet to be determined, nitrogen appears to be supplied mainly via the dune seeps. The epibenthic algal community within stromatolite pools is generally co-dominated by cyanobacteria and chlorophytes, with minimal diatom contribution.
- Full Text:
- Date Issued: 2014
- Authors: Perissinotto, Renzo , Bornman, Tommy G , Steyn, Paul-Pierre , Miranda, Nelson A F , Dorrington, Rosemary A , Matcher, Gwynneth F , Strydom, Nadine A , Peer, Nasreen
- Date: 2014
- Language: English
- Type: Article
- Identifier: vital:6490 , http://hdl.handle.net/10962/d1014585 , http://dx.doi.org/10.1590/sajs.2014/20140011
- Description: Following the first description of living marine stromatolites along the South African east coast, new investigations along the south coast have revealed the occurrence of extensive fields of actively calcifying stromatolites. These stromatolites have been recorded at regular distances along a 200-km stretch of coastline, from Cape Recife in the east to the Storms River mouth in the west, with the highest density found between Schoenmakerskop and the Maitland River mouth. All active stromatolites are associated with freshwater seepage streams flowing from the dune cordon, which form rimstone dams and other accretions capable of retaining water in the supratidal platform. Resulting pools can reach a maximum depth of about 1 m and constitute a unique ecosystem in which freshwater and marine organisms alternate their dominance in response to vertical mixing and the balance between freshwater versus marine inflow. Although the factors controlling stromatolite growth are yet to be determined, nitrogen appears to be supplied mainly via the dune seeps. The epibenthic algal community within stromatolite pools is generally co-dominated by cyanobacteria and chlorophytes, with minimal diatom contribution.
- Full Text:
- Date Issued: 2014
South African estuaries in the Anthropocene
- Authors: Perissinotto, Renzo
- Subjects: Estuaries -- South Africa , Geology, Stratigraphic -- Anthropocene , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20977 , vital:29424
- Description: In the new geological epoch of total human dominance of the planet, already widely referred to as the “Anthropocene”, estuaries are among the most vulnerable ecosystems to the changes that man’s activities have imposed on the coastal zone. For the non-specialist, an estuary is a “semi-enclosed coastal body of water, which has a permanent or temporary connection with the open sea, and within which sea water is diluted with fresh water from land drainage”.
- Full Text:
- Authors: Perissinotto, Renzo
- Subjects: Estuaries -- South Africa , Geology, Stratigraphic -- Anthropocene , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20977 , vital:29424
- Description: In the new geological epoch of total human dominance of the planet, already widely referred to as the “Anthropocene”, estuaries are among the most vulnerable ecosystems to the changes that man’s activities have imposed on the coastal zone. For the non-specialist, an estuary is a “semi-enclosed coastal body of water, which has a permanent or temporary connection with the open sea, and within which sea water is diluted with fresh water from land drainage”.
- Full Text:
- «
- ‹
- 1
- ›
- »