A review of the ecology and management of temporarily open/closed estuaries in South Africa, with particular emphasis on river flow and mouth state as primary drivers of these systems

African Journal of Marine Science

Volumn 34, Issue 2, 2012, Pages 163-180

  Whitfield, A K ^a   Bate, G C ^b   Adams, J B ^b   Cowley, P D ^a   Froneman, P W ^c   Gama, P T ^b   Strydom, N A ^b   Taljaard, S ^d   Theron, A K ^d   Turpie, J K ^a   van Niekerk, L ^d   Wooldridge, T H ^b  

^a SOUTH AFRICAN INSTITUTE FOR AQUATIC BIODIVERSITY   (South Africa)

^b NELSON MANDELA METROPOLITAN UNIVERSITY   (South Africa)

^c RHODES UNIVERSITY   (South Africa)

^d DSI CSIR Nanotechnology Innovation Centre   (South Africa)

Author keywords

birds; estuarine ecology; fish; hyperbenthos; macrophytes; microalgae; sediments; zoobenthos; zooplankton

Indexed keywords

ANTHROPOGENIC EFFECT; ESTUARINE ECOSYSTEM; HYDRODYNAMICS; LITERATURE REVIEW; MACROPHYTE; MICROALGA; RIVER FLOW; WETLAND MANAGEMENT; ZOOBENTHOS; ZOOPLANKTON;

SOUTH AFRICA;

EID: 84865264737     PISSN: 1814232X     EISSN: 18142338     Source Type: Journal    
DOI: 10.2989/1814232X.2012.675041     Document Type: Review

References (157)

1. Adams, JB and Bate, GC. 1994. The effect of salinity and inundation on the estuarine macrophyte Sarcocornia perennis (Mill.) A.J. Scott. Aquatic Botany, 47: 341-348.
2. Adams, JB and Bate, GC. 1995. The ecological implications of salinity and inundation tolerance in the estuarine halophyte, Spartina martima (Curtis) Fernald. Aquatic Botany, 52: 183-191.
3. Adams, JB and Bate, GC. 1996. "Understanding the freshwater requirements of estuarine plants". In Coastal management and habitat conservation, Edited by: Salman, AHPM, Langeveld, MJ and Bonazountas, M. 181-192. Leiden: EUCC.
4. Adams, JB, Bate, GC and O'Callaghan, M. 1999. "Primary producers". In Estuaries of South Africa, Edited by: Allanson, BR and Baird, D. 91-117. Cambridge: Cambridge University Press.
5. Adams, JB, Knoop, WT and Bate, GC. 1992. The distribution of estuarine macrophytes in relation to freshwater. Botanica Marina, 35: 215-226.
6. Allan, EL and Froneman, PW. 2008. Trophic interactions amongst the plankton in the temporarily open/closed East Kleinemonde Estuary South Africa. African Journal of Aquatic Science, 33: 167-174.
7. Allanson, BR. 2001. Some factors governing the water quality of microtidal estuaries in South Africa. Water SA, 27: 373-386.
8. Anandraj, A, Perissinotto, R and Nozias, C. 2007. A comparative study of microalgal production in a marine versus a river-dominated temporarily open/closed estuary, South Africa. Estuarine, Coastal and Shelf Science, 73: 768-780.
9. Anandraj, A, Perissinotto, R, Nozias, C and Stretch, D. 2008. The recovery of microalgal production and biomass in a South African temporarily open/closed estuary, following mouth breaching. Estuarine, Coastal and Shelf Science, 79: 599-606.
10. Baird, D, Reddering, JSV and Winter, PED. 1983. Hydrodynamics and sedimentation of the Bushmans River estuary, Eastern Cape. South African Journal of Science, 79: 154-155.
11. Bate, GC, Whitfield, AK, Adams, JB, Huizinga, P and Wooldridge, TH. 2002. The importance of the river-estuary interface zone in estuaries. Water SA, 28: 271-279.
12. Beck JS, Kemp A, Theron AK, Huizinga P, Basson GR 2004. Hydraulics of estuarine sediment dynamics in South Africa: implications for estuarine reserve determination and the develop ment of management guidelines. WRC Report No. 1257/1/04. Pretoria: Water Research Commission.
13. Becker, A, Cowley, PD, Whitfield, AK, Järnegren, J and Næsje, TF. 2011a. Diel fish movements in the littoral zone of a temporarily closed South African estuary. Journal of Experimental Marine Biology and Ecology, 406: 63-70.
14. Becker, A, Whitfield, AK, Cowley, PD, Järnegren, J and Næsje, TF. 2011b. An assessment of the size structure, distribution and behaviour of fish populations within a temporarily closed South African estuary using dual frequency identification sonar (DIDSON). Journal of Fish Biology, 79: 761-775.
15. Begg GW 1978. The estuaries of Natal. Pietermaritzburg: Natal Town and Regional Planning Report 41.
16. Bennett, BA, Hamman, KCD, Branch, GM and Thorne, S. 1985. Changes in the fish fauna of the Bot River estuary in relation to opening and closure of the estuary mouth. Transactions of the Royal Society of South Africa, 45: 449-464.
17. Bernard, ATF and Froneman, PW. 2005. Population dynamics of the caridean shrimp, Palaemon peringueyi, in a temperate temporarily open/closed South African estuary. Estuarine, Coastal and Shelf Science, 63: 73-81.
18. Berruti, A. 1983. The biomass, energy consumption and breeding of waterbirds relative to hydrological conditions at Lake St Lucia. Ostrich, 54: 65-82.
19. Bickerton IB, Badenhorst P 1987. Effects of a causeway on the Seekoei Estuary and possible remedial measures. CSIR Report T/SEA 8710. Stellenbosch: Council for Scientific and Industrial Research.
20. Burns ML, Heydorn AEF 1988. An evaluation of the effects of the construction of a viaduct across the tidal flats in the vicinity of the White Bridge, Knysna. CSIR Report EMA/C 8899. Stellenbosch: Council for Scientific and Industrial Research.
21. Burton, AJ. 1960. A quantitative assessment of the effect of factory effluent upon littoral and estuarine faunas at Umkomaas, Natal. South African Journal of Science, 56: 163-166.
22. Chuwen, BM, Steeg, DH and Potter, IC. 2009. Factors influencing the characteristics of the fish faunas in offshore, deeper waters of permanently-open, seasonally-open and normally-closed estuaries. Estuarine, Coastal and Shelf Science, 81: 279-295.
23. Colloty, BM, Adams, JB and Bate, GC. 2000. The use of a botanical importance rating to assess changes in the flora of the Swartkops Estuary over time. Water SA, 26: 171-180.
24. Cooper, JAG. 1989. Fairweather versus flood sedimentation in Mhlanga lagoon, Natal: implications for environmental manage ment. South African Journal of Geology, 92: 279-294.
25. Cooper JAG 1991. Sedimentary models and geomorphological classification of river-mouths on a subtropical, wave-dominated coast, South Africa. PhD thesis, University of Natal, Durban.
26. Cooper, JAG. 1993. Sedimentary processes in the river-dominated Mvoti estuary, South Africa. Geomorphology, 9: 271-300.
27. Cooper, JAG. 2001. Geomorphological variability among microtidal estuaries from the wave-dominated South African coast. Geomorphology, 40: 99-122.
28. Cowley, PD, Whitfield, AK and Bell, KNI. 2001. The surf zone ichthyoplankton adjacent to an intermittently open estuary, with evidence of recruitment during marine overwash events. Estuarine, Coastal and Shelf Science, 52: 339-348.
29. Davies, BR. 1982. Studies on the zoobenthos of some southern Cape coastal lakes. Spatial and temporal changes in the benthos of Swartvlei, South Africa, in relation to changes in the submerged littoral macrophyte community. Journal of the Limnological Society of Southern Africa, 8: 33-45.
30. Day, JH. 1981a. "Coastal hydrodynamics, sediment transport and inlet stability". In Estuarine ecology with particular reference to southern Africa, Edited by: Day, JH. 7-26. Cape Town: AA Balkema.
31. Day JH. 1981b. Estuarine ecology with particular reference to southern Africa. Cape Town: AA Balkema.
32. Day, JH and Grindley, JR. 1981. "The management of estuaries". In Estuarine ecology with particular reference to southern Africa, Edited by: Day, JH. 373-397. Cape Town: AA Balkema.
33. De Decker, HP and Bally, R. 1985. The benthic macrofauna of the Bot River Estuary, South Africa, with a note on its meiofauna. Transactions of the Royal Society of South Africa, 45: 379-396.
34. DWAF (Department of Water Affairs and Forestry). 1999. Water resource protection policy implementation. Resource directed measures for protection of water resources: estuarine ecosystems. Version 1.0. Pretoria: Department of Water Affairs and Forestry. Available at www.dwaf.gov.za/Documents/Policies/WRPP/default.htm [accessed 23 April 2012].
35. Dyer KR, Orth RJ. 1994. Changes in fluxes in estuaries: implications from science to management. Fredensborg: Olsen & Olsen.
36. Ellender, BR, Weyl, OLF, Shanyengange, MK and Cowley, PD. 2008. Juvenile population dynamics of Oreochromis mossambicus in an intermittently open estuary at the limit of its natural distributional range. African Zoology, 43: 277-283.
37. Emmerson, WD. 1989. The nutrient status of the Sundays River estuary, South Africa. Water Research, 23: 1059-1067.
38. Faith, JT. 2011. Ungulate community richness, grazer extinctions, and human subsistence behaviour in southern Africa's Cape Floral Region. Palaeogeography, Palaeoclimatology and Palaeoecology, 306: 219-227.
39. Ferreira, JG, Wolff, WJ, Simas, TC and Bricker, SB. 2005. Does biodiversity of estuarine phytoplankton depend on hydrology?. Ecological Modelling, 187: 513-523.
40. Forbes AT, Demetriades NT 2010. Estuaries of Durban, KwaZulu- Natal, South Africa. Report for the Environmental Management Department, 2nd edn. Durban: eThekwini Municipality.
41. Froneman, PW. 2002. Response of the plankton to three different hydrological phases of the temporarily open/closed Kasouga Estuary, South Africa. Estuarine, Coastal and Shelf Science, 55: 535-546.
42. Froneman, PW. 2004a. Food web dynamics in a temperate temporarily open/closed estuary (South Africa). Estuarine, Coastal and Shelf Science, 59: 87-95.
43. Froneman, PW. 2004b. Zooplankton community structure and biomass in a southern Africa temporarily open/closed estuary. Estuarine, Coastal and Shelf Science, 60: 125-132.
44. Froneman, PW. 2006. Population demographics of Palaemon peringueyi (Macpherson 1990) (Decapoda:Palaemonidae) in a small intermittently open Eastern Cape estuary. African Journal of Aquatic Science, 31: 197-203.
45. Froneman PW 2008. Appendix I. Specialist report: zooplankton and hyperbenthos. van Niekerk L, Bate GC, Whitfield AK, An intermediate ecological reserve determination study of the East Kleinemonde Estuary. WRC Report No. 1581/2/08. Pretoria: Water Research Commission.
46. Froneman, PW, Blake, J and Hulley, P. 2011. Aspects of the biology and population dynamics of piscivorous birds in the intermittently open Riet River estuary, Eastern Cape, South Africa. African Journal of Aquatic Science, 36: 101-107.
47. Fuggle, RF and Rabie, MA. 1992. Environmental management in South Africa, Cape Town: Juta & Co.
48. Gaigher, CM. 1984. The effects of bridge building on the bloodworm population in the Uilkraal River estuary. The Naturalist, 28: 16-18.
49. Gama PT 2008. Appendix F. Specialist Report: Microalgae. van Niekerk L, Bate GC, Whitfield AK, An intermediate ecological reserve determination study of the East Kleinemonde Estuary. WRC Report No. 1581/2/08. Pretoria: Water Research Commission.
50. Gama PT, Adams JB, Schael DM, Skinner T 2005. Phytoplankton chlorophyll a concentration and community structure of two temporarily open/closed estuaries. WRC Report No. 1255/1/05. Pretoria: Water Research Commission.
51. Haines, PE, Tomlinson, RB and Thom, BG. 2006. Morphometric assessment of intermittently open/closed coastal lagoons in New South Wales, Australia. Estuarine, Coastal and Shelf Science, 67: 321-332.
52. Harrison, TD and Cooper, JAG. 1991. Active migration of juvenile grey mullet (Teleostei: Mugilidae) into a small lagoonal system on the Natal coast. South African Journal of Science, 87: 395-396.
53. Harrison, TD and Whitfield, AK. 1995. Fish community structure in three temporarily open/closed estuaries on the Natal coast. Ichthyological Bulletin of the JLB Smith Institute of Ichthyology, 64: 1-80.
54. Harrison, TD and Whitfield, AK. 2006. Estuarine typology and the structuring of fish communities in South Africa. Environmental Biology of Fishes, 75: 269-293.
55. Hay D, Huizinga P, Mitchell S 2005. Managing sedimentary process in South African estuaries: a guide. WRC Report No. TT 241/04. Pretoria: Water Research Commission.
56. Hay D, McKenzie M 2005. Managing estuaries in South Africa: a step by step guide. WRC Report No. TT 243/04 1-33. Pretoria: Water Research Commission.
57. Heinecken TJE, Bickerton IB, Heydorn AEF 1983. A summary of studies of the pollution input by rivers and estuaries entering False Bay. CSIR Report T/SEA 8301. Stellenbosch: Council for Scientific and Industrial Research.
58. Henninger, T, Froneman, PW, Richoux, N and Hodgson, AN. 2009. Role of submerged macrophytes as a refuge and food source for the estuarine isopod, Exosphaeroma hylocoetes. Estuarine, Coastal and Shelf Science, 82: 285-293.
59. Heydorn, AEF. 1979. Overview of present knowledge on South African estuaries and requirements for their management. South African Journal of Science, 75: 544-546.
60. Heydorn AEF, Tinley KL 1980. Estuaries of the Cape. Part 1. Synopsis of the Cape coast-natural features, dynamics and utilization. CSIR Report No. 380. Stellenbosch: Council for Scientific and Industrial Research.
61. Heÿl, CW and Currie, MH. 1985. Variations in the use of the Bot River estuary by water-birds. Transactions of the Royal Society of South Africa, 45: 397-417.
62. Hockey, PAR and Turpie, JK. 1999. "Estuarine birds in South Africa". In Estuaries of South Africa, Edited by: Allanson, BR and Baird, D. 235-268. Cambridge: Cambridge University Press.
63. Howard-Williams, C and Liptrot, MR. 1980. Submerged macrophyte communities in a brackish South African estuarine-lake system. Aquatic Botany, 9: 101-116.
64. Huizinga, P and van Niekerk, L. 2001. The breaching of an estuary mouth. SA Water Bulletin, 27: 14
65. Huizinga P, van Niekerk L, Withers A 1997. Klein River estuary: the effects of high water levels during mouth breaching in 1996. CSIR Report ENV/S 97016. Stellenbosch: Council for Scientific and Industrial Research.
66. Human, L and Adams, JB. 2011. Reeds as indicators of nutrient enrichment in a small temporarily open/closed South African estuary. African Journal of Aquatic Science, 36: 167-179.
67. Huppert, DD, Johnson, RL, Leahy, J and Bell, K. 2003. Interactions between human communities and estuaries in the Pacific northwest: trends and implications for management. Estuaries, 26: 994-1009.
68. James, NC, Cowley, PD and Whitfield, AK. 2007. Abundance, recruitment and residency of two sparids in an intermittently open estuary in South Africa. African Journal of Marine Science, 29: 527-538.
69. James, NC, Cowley, PD, Whitfield, AK and Kaiser, H. 2008a. Choice chamber experiments to test the attraction of postflexion Rhabdosargus holubi larvae to water of estuarine and riverine origin. Estuarine, Coastal and Shelf Science, 77: 143-149.
70. James, NC, Hall, NG, Beckley, LE, Mann, BQ and Robertson, WD. 2008b. Status of the estuarine-dependent riverbream Acanthopagrus berda (Sparidae) harvested by the multi-sectoral fishery in Kosi Bay, South Africa. African Journal of Marine Science, 30: 45-53.
71. Kibirige, I and Perissinotto, R. 2003. The zooplankton community of the Mpenjati Estuary, a South African temporarily open/closed system. Estuarine, Coastal and Shelf Science, 58: 727-741.
72. Kibirige, I, Perissinotto, R and Thwala, XC. 2006. A comparative study of zooplankton dynamics in two subtropical temporarily-open/closed estuaries, South Africa. Marine Biology, 148: 1307-1324.
73. Lamberth, SJ, Drapeau, L and Branch, GM. 2009. The effects of altered freshwater inflows on catch rates of non-estuarine-dependent fish in a multispecies nearshore linefishery. Estuarine, Coastal and Shelf Science, 84: 527-538.
74. Lamberth, SJ and Turpie, JK. 2003. The role of estuaries in South African fisheries: economic importance and management implications. African Journal of Marine Science, 25: 131-157.
75. Lawrie, RA, Stretch, DD and Perissinotto, R. 2010. The effects of wastewater discharges on the functioning of a small temporarily open/closed estuary. Estuarine, Coastal and Shelf Science, 87: 237-245.
76. Lubke, RA and van Wijk, Y. 1988. "Estuarine plants". In A field guide to the Eastern Cape coast, Edited by: Lubke, RA, Gess, FW and Bruton, MN. 133-151. Grahamstown: Grahamstown Centre of the Wildlife Society of Southern Africa.
77. Lucas, LV, Koseff, JK, Cloern, JE, Monismith, SG and Thompson, JK. 1999. Processes governing phytoplankton blooms in estuaries. I: The local production-loss balance. Marine Ecology Progress Series, 187: 1-15.
78. Lukey, JR, Booth, AJ and Froneman, PW. 2006. Fish population size and movement patterns in a small intermittently open South African estuary. Estuarine, Coastal and Shelf Science, 67: 10-20.
79. MacClelland, JW and Valiela, I. 1998. Changes in food web structure under the influence of increased anthropogenic nitrogen inputs to estuaries. Marine Ecology Progress Series, 168: 259-271.
80. Martin, AP and Baird, D. 1987. Seasonal abundance of birds on the Swartkops Estuary, Port Elizabeth. Ostrich, 58: 122-134.
81. Martin, AP, von Korff, J and Watt, L. 2000. Abundance and distribution of waterbirds on the Knysna Estuary. Transactions of the Royal Society of South Africa, 55: 215-222.
82. Mbande, S, Froneman, W and Whitfield, AK. 2004. The primary carbon sources utilised by fishes in the Mngazi and Mngazana estuaries, South Africa: a preliminary assessment. African Journal of Aquatic Science, 29: 195-204.
83. Moldan, A, Chapman, P and Fourie, HO. 1979. Some ecological effects of the Venpet-Venoil collision. Marine Pollution Bulletin, 10: 60-63.
84. Morant, P and Quinn, N. 1999. "Influence of man and management of South African estuaries". In Estuaries of South Africa, Edited by: Allanson, BR and Baird, D. 289-321. Cambridge: Cambridge University Press.
85. Mundree, S, Perissinotto, R and Nozias, C. 2003. Seasonal variations in the vertical distribution of benthic microalgae in the upper sediment of the Mdloti Estuary, South Africa. Botanica Marina, 46: 323-331.
86. Nozais, C, Perissonotto, R and Mundree, S. 2001. Annual cycle of microalgal biomass in a South African temporarily-open estuary: nutrient versus light limitation. Marine Ecology Progress Series, 223: 39-48.
87. Painting, SJ, Devlin, MJ, Malcolm, SJ, Parker, ER, Mills, DK, Mills, C, Tett, P, Wither, A, Burt, J, Jones, R and Winpenny, K. 2007. Assessing the impact of nutrient enrichment in estuaries: susceptibility to eutrophication. Marine Pollution Bulletin, 55: 74-90.
88. Perissinotto R, Blair A, Connell A, Demetriades, NT, Forbes AT, Harrison TH, Lyer, K, Joubert M, Kibirige I, Mundree S, Simpson H Stretch, D, Thomas C, Thwala X, Zietsman I 2004. Contributions to information required for the implementation of resource directed measures for estuaries (Volume 2). Responses of the biological communities to flow variation and mouth state in two KwaZulu- Natal temporarily open/closed estuaries. WRC Report No. 1247/2/04. Pretoria: Water Research Commission.
89. Perissinotto, R, Nozias, C and Kibirige, I. 2002. Spatio-temporal dynamics of phytoplankton and microphytobenthos in a South African temporarily-open estuary. Estuarine, Coastal and Shelf Science, 54: 363-374.
90. Perissinotto, R, Nozias, C, Kibirige, I and Anandraj, A. 2003. Planktonic food webs and benthic-pelagic coupling in South African temporarily-open estuaries. Acta Oecologia, 24: 307-316.
91. Perissinotto, R, Stretch, DD, Whitfield, AK, Adams, JB, Forbes, AT and Demetriades, NT. 2010a. "Ecosystem functioning of temporarily open/closed estuaries in South Africa". In Estuaries: types, movement patterns and climatical impacts, Edited by: Crane, JR and Solomon, AE. 1-69. New York: Nova Science Publishers.
92. Perissinotto, R, Stretch, DD, Whitfield, AK, Adams, JB, Forbes, AT and Demetriades, NT. 2010b. Temporarily open/closed estuaries in South Africa, New York: Nova Science Publishers.
93. Perissinotto, R, Walker, DR, Webb, P, Wooldridge, TH and Bally, R. 2000. Relationships between zoo- and phytoplankton in a warm-temperate, semi-permanently closed estuary, South Africa. Estuarine, Coastal and Shelf Science, 51: 1-11.
94. Perry JE 1989. The impact of the September 1987 floods on the estuaries of Natal/Kwazulu; a hydro-photographic perspective. CSIR Report No. 640. Stellenbosch: Council for Scientific and Industrial Research.
95. Pradervand, P and Baird, D. 2002. Assessment of the recreational line- fishery in selected Eastern Cape estuaries: trends in catches and effort. South African Journal of Marine Science, 24: 87-101.
96. Reddy, P, James, NC, Cowley, PD and Whitfield, AK. 2011. Marine connectivity and fish length frequencies of selected species in two adjacent temporarily open/closed estuaries in the Eastern Cape Province, South Africa. African Zoology, 46: 239-245.
97. Riddin, T and Adams, JB. 2008. Influence of mouth status and water level on the macrophytes in a small temporarily open/ closed estuary. Estuarine, Coastal and Shelf Science, 79: 86-92.
98. Riddin, T and Adams, JB. 2009. The seed banks of two temporarily open/ closed estuaries in South Africa. Aquatic Botany, 90: 328-332.
99. Riddin, T and Adams, JB. 2010. The effect of a storm surge event on the macrophytes of a temporarily open/closed estuary, South Africa. Estuarine, Coastal and Shelf Science, 89: 119-123.
100. Roy, PS, Williams, RJ, Jones, AR, Yassini, I, Gibbs, PJ, Coates, B, West, RJ, Scanes, PR, Hudson, JP and Nichol, S. 2001. Structure and function of south-east Australian estuaries. Estuarine, Coastal and Shelf Science, 53: 351-384.
101. RSA (Republic of South Africa). 1935. National Sea-shore Act (Act No. 21 of 1935). Available at http://www.capetown.gov.za/en/SportRecreation/Documents/Sea_shore_Act_1935.pdf [accessed April 2012].
102. RSA (Republic of South Africa). 1998a. National Water Act (Act No.36 of 1998). Government Gazette, South Africa 398(19182).
103. RSA (Republic of South Africa). 1998b. National Environmental Management Act (Act No. 107 of 1998). Government Gazette, South Africa 401(19519).
104. RSA (Republic of South Africa). 2000. Local Government: Municipal Systems Act (Act No. 32 of 2000). Government Gazette, South Africa 425(21776).
105. RSA (Republic of South Africa). 2009. National Environmental Management: Integrated Coastal Management Act (Act. No. 24 of 2008). Government Gazette, South Africa 524(31884).
106. Russell, IA. 2003. Changes in the distribution of emergent aquatic plants in a brackish South African estuarine-lake system. African Journal of Aquatic Science, 28: 103-122.
107. Scharler, UM and Baird, D. 2003. The influence of catchment management on salinity, nutrient stochiometry and phytoplankton biomass of Eastern Cape estuaries, South Africa. Estuarine, Coastal and Shelf Science, 56: 735-748.
108. Scharler UM, Baird D, Winter PED 1997. Diversity and productivity of biotic communities in relation to freshwater inputs in three Eastern Cape estuaries. WRC Report No. 463/1/98. Pretoria: Water Research Commission.
109. Schlacher, TA and Wooldridge, TH. 1995. Small-scale distribution and variability of demersal zooplankton in a shallow, temperate estuary: tidal and depth effects on species-specific heterogeneity. Cahiers de Biologie Marine, 36: 211-227.
110. Scott, KMF. 1954. Notes on the birds of the Diep River and Rietvlei. Ostrich, 25: 25-31.
111. Skinner, T, Adams, JB and Gama, PT. 2006. The effect of mouth opening on biomass and community structure of microphytobenthos in a small oligotrophic estuary. Estuarine, Coastal and Shelf Science, 70: 161-168.
112. Slinger, JH, Taljaard, S and Largier, JL. 1994. "Changes in estuarine water quality in response to a freshwater flow event". In Changes in fluxes in estuaries: implications from science to management, Edited by: Dyer, KR and Orth, RJ. 51-56. Fredensborg: Olsen & Olsen.
113. Snow, GC and Adams, JB. 2007. Relating microalgal spatial patterns to flow, mouth and nutrient status in the temporarily open/closed Mngazi estuary, South Africa. Marine and Freshwater Research, 58: 1032-1043.
114. Snow, GC, Adams, JB and Bate, GC. 2000. Effect of river flow on estuarine microalgal biomass and distribution. Estuarine, Coastal and Shelf Science, 51: 255-266.
115. Snow, GC and Taljaard, S. 2007. Water quality in South African temporarily open/closed estuaries: a conceptual model. African Journal of Aquatic Science, 32: 99-111.
116. Steinke, TD. 1972. Further observations on the distribution of man- groves in the eastern Cape Province. Journal of South African Botany, 38: 165-178.
117. Stretch, DD and Parkinson, MG. 2006. The breaching of sand barriers at perched temporarily open/closed estuaries a model study. Coastal Engineering Journal, 48: 13-30.
118. Strydom, NA. 2003a. Occurrence of larval and early juvenile fishes in the surf zone adjacent to two intermittently open estuaries, South Africa. Environmental Biology of Fishes, 66: 349-359.
119. Strydom, NA. 2003b. An assessment of habitat use by larval fishes in a warm temperate estuarine creek using light traps. Estuaries, 26: 1310-1318.
120. Strydom, NA and d'Hotman, BD. 2005. Estuary-dependence of larval fishes in a non-estuary associated South African surf zone: evidence for continuity of surf assemblages. Estuarine, Coastal and Shelf Science, 63: 101-108.
121. Strydom, NA, Whitfield, A and Wooldridge, TH. 2003. The role of estuarine type in characterising early stage fish assemblages in warm temperate estuaries, South Africa. African Zoology, 38: 29-43.
122. Taljaard S, van Niekerk L. 2009 C.A.P.E. Estuaries Programme. Proposed generic framework for estuary management plans. Version 1.1. CSIR Report No. CSIR/NRE/CO/ER/2009/0128/A. Stellenbosch: Council for Scientific and Industrial Research.
123. Taljaard S, van Niekerk L, Huizinga P, Joubert W 2003. Resource monitoring procedures for estuaries: for application in the ecological reserve determination and implementation process. WRC Report No. 1308/1/03. Pretoria: Water Research Commission.
124. Taljaard, S, van Niekerk, L and Joubert, W. 2009. Extension of a qualitative model on nutrient cycling and transformation to include microtidal estuaries on wave-dominated coasts: Southern Hemisphere perspective. Estuarine, Coastal and Shelf Science, 85: 407-421.
125. Terörde AI 2008. Variation in the use of intermittently open estuaries by birds: a study of four estuaries in the Eastern Cape, South Africa. MSc thesis, University of Cape Town, South Africa.
126. Teske, PR and Wooldridge, TH. 2003. What limits the distribution of subtidal macrobenthos in permanently open and temporarily open/closed South African estuaries? Salinity vs sediment particle size. Estuarine, Coastal and Shelf Science, 57: 225-238.
127. Teske, PR and Wooldridge, TH. 2004. Affinities of some common estuarine macroinvertebrates to salinity and sediment type: empirical data from Eastern Cape estuaries, South Africa. African Zoology, 39: 183-192.
128. Theron AK 2007. Sediment dynamics. Whitfield A, Bate, G, A review of information on temporarily open/closed estuaries in the warm and cool temperate biogeographic regions of South Africa, with particular emphasis on the influence of river flow on these systems. WRC Report No. 1581/1/07. Pretoria: Water Research Commission.
129. Theron AK, Bornman TG 2008. Appendix D. Specialist Report: Coastal processes and sediment dynamics. van Niekerk L, Bate GC, Whitfield AK, An intermediate ecological reserve determination study of the East Kleinemonde Estuary. WRC Report No. 1581/2/08. Pretoria: Water Research Commission.
130. Thomas, CM, Perissinotto, R and Kibirige, I. 2005. Phytoplankton biomass and size structure in two South African eutrophic, temporarily open/closed estuaries. Estuarine, Coastal and Shelf Science, 65: 223-238.
131. van Ballegooyen RC, Taljaard S, van Niekerk L, Lamberth SJ, Theron AK, Weerts SP 2007. Freshwater flow dependency in South African marine ecosystems: A proposed assessment framework and initial assessment of South African marine ecosystems. WRC Report No. KV 191/07. Pretoria: Water Research Commission.
132. van der Elst RP, Birnie SL, Everett BI. 1999. Siyaya catchment demonstration project: an experiment in estuarine rehabilitation, Oceanographic Research Institute Special Publication No. 6.
133. van Niekerk L 2007. Hydrodynamics. In: Whitfield A, Bate, G, A review of information on temporarily open/closed estuaries in the warm and cool temperate biogeographic regions of South Africa, with particular emphasis on the influence of river flow on these systems. WRC Report No. 1581/1/07. Pretoria: Water Research Commission.
134. van Niekerk L, Bate GC, Whitfield AK. 2008. an intermediate ecological reserve determination study of the East Kleinemonde Estuary. WRC Report No. 1581/2/08. Pretoria: Water Research Commission.
135. van Niekerk L, Lamberth SJ, Cowley P, Huizinga P, Hutchings K, Mann B, Petersen C, Taljaard S 2011a. Key pressures on South Africa's estuaries. In: van Niekerk L, Turpie JK, National biodiversity assessment 2011: estuaries component. Council for Scientific and Industrial Research Report CSIR/NRE/ECOS/ ER/2011/0045/B to South African National Biodiversity Institute, Pretoria.
136. van Niekerk L, Petersen C, Daniels F, Maherry A, Malebu T 2011b. Section 3. Defining the estuarine functional zone. In: van Niekerk L, Turpie JK, National biodiversity assessment 2011: estuaries component. Council for Scientific and Industrial Research Report CSIR/NRE/ECOS/ER/2011/0045/B to South African National Biodiversity Institute, Pretoria.
137. van Niekerk L, Taljaard S 2007. C.A.P.E. Estuaries Programme. Proposed generic framework of estuarine management plans. Version 1. Report submitted to the C.A.P.E. Estuaries Programme. Available at http://fred.csir.co.za/extra/project/CAPE_Estuaries/.
138. van Niekerk, L, van der Merwe, JH and Huizinga, P. 2005. The hydro- dynamics of the Bot River estuary revisited. Water SA, 31: 73-86.
139. Vivier, L and Cyrus, DP. 2001. Juvenile fish recruitment through wave-overtopping into a closed subtropical estuary. African Journal of Aquatic Science, 26: 109-113.
140. Vorwerk PD 2007. Estuarine/marine interactions. In: Whitfield A, Bate G A review of information on temporarily open/closed estuaries in the warm and cool temperate biogeographic regions of South Africa, with particular emphasis on the influence of river flow on these systems. WRC Report No. 1581/1/07. Pretoria: Water Research Commission. pp 183-191.
141. Vorwerk, PD, Froneman, PW, Paterson, AW, Strydom, NA and Whitfield, AK. 2008. Biological responses to a resumption in river flow in a fresh water deprived, permanently open southern African estuary. Water SA, 34: 597-604.
142. Vromans DC 2011. Macrophyte phenology in a temporarily open/ closed estuary compared with a permanently open estuary. MSc thesis, Nelson Mandela Metropolitan University, South Africa.
143. Walker, DR, Perissonotto, R and Bally, RPA. 2001. Phytoplankton/ protozoan dynamics in the Nyara Estuary, a small temporarily open system in the Eastern Cape (South Africa). African Journal of Aquatic Science, 26: 31-38.
144. Whitfield, AK. 1980a. A quantitative study of the trophic relationships within the fish community of the Mhlanga Estuary, South Africa. Estuarine and Coastal Marine Science, 10: 417-435.
145. Whitfield, AK. 1980b. Factors influencing the recruitment of juvenile fishes into the Mhlanga Estuary. South African Journal of Zoology, 15: 166-169.
146. Whitfield, AK. 1984. The effects of prolonged aquatic macrophyte senescence on the biology of the dominant fish species in a southern African coastal lake. Estuarine, Coastal and Shelf Science, 18: 315-329.
147. Whitfield, AK. 1985. The role of zooplankton in the feeding ecology of fish fry from some southern African estuaries. South African Journal of Zoology, 20: 166-171.
148. Whitfield, AK. 1988. The role of tides in redistributing macrodetrital aggregates within the Swartvlei Estuary. Estuaries, 11: 152-159.
149. Whitfield, AK. 1989. Ichthyoplankton in a southern African surf zone: nursery area for the postlarvae of estuarine associated fish species?. Estuarine, Coastal and Shelf Science, 29: 533-547.
150. Whitfield, AK. 1998. Biology and ecology of fishes in southern African estuaries. Ichthyological Monographs of the JLB Smith Institute of Ichthyology, 2: 1-223.
151. Whitfield AK 2000. Available scientific information on individual South African estuarine systems. WRC Report No. 577/3/00. Pretoria: Water Research Commission.
152. Whitfield, AK, Adams, J B, Bate, GC, Bezuidenhout, K, Bornman, TG, Cowley, PD, Froneman, PW, Gama, PT, James, NC, Mackenzie, B, Riddin, T, Snow, GC, Strydom, NA, Taljaard, S, Terörde, AI, Theron, AK, Turpie, JK, van Niekerk, L, Vorwerk, PD and Wooldridge, TH. 2008. A multidisciplinary study of a small, temporarily open/closed South African estuary, with particular emphasis on the influence of mouth state on the ecology of the system. African Journal of Marine Science, 30: 453-473.
153. Whitfield AK, Bate GC 2007. A review of information on temporarily open/closed estuaries in the warm and cool temperate biogeo- graphic regions of South Africa, with particular emphasis on the influence of river flow on these systems. WRC Report No. 1581/1/07. Pretoria: Water Research Commission.
154. Wolanski, E. 2007. Estuarine ecohydrology, Amsterdam: Elsevier.
155. Wood AD 2010. A guide to the ecology of temporarily open/closed estuaries. Grahamstown and Pretoria: South African Institute for Aquatic Biodiversity and Water Research Commission.
156. Wooldridge, TH. 1991. Exchange of two species of decapod larvae across an estuarine mouth inlet and implications of anthropogenic changes in the frequency and duration of mouth closure. South African Journal of Science, 87: 519-525.
157. Wooldridge, TH. 1999. "Estuarine zooplankton community structure and dynamics". In Estuaries of South Africa, Edited by: Allanson, BR and Baird, D. 141-166. Cambridge: Cambridge University Press.