Pollution Status of Two River Estuaries in the Eastern Cape, South Africa, based on Benthic Meiofauna Analyses

T.K. Gyedu-Ababio

.

DOI: 10.4236/jwarp.2011.37057                

Abstract

The benthic meiofauna of the two river systems, the Swartkops and Gamtoos, in the Eastern Cape of South Africa has been studied extensively. Various biological indices and statistical packages were used to assess the biological status of the nematode communities in the two rivers. Nematode identification was done to the genus level. Various environmental conditions, including, concentrations of Zn, Mn, Fe, Cu and Pb, organic carbon and chlorophyll-a in the sediments, were investigated in relation to the nematode density, diversity and community structure. The results of the studies indicate that higher concentrations of heavy metals had a negative impact on the nematode density, diversity and community structure. Nematode genera such as Rhabditis, Monhystera and Theristus were found to be tolerant to pollution or indicators of pollution. The Swartkops River estuary was found to be polluted more severely than the Gamtoos. It was realised that some nematode genera such as Viscosia can establish themselves along the river estuaries, irrespective of the salinity gradient. The quantitative effects of individual metals on the structure of meiobenthic communities could not be differentiated from one another. Similarly, the effects of metals and organic carbon on the structuring of the nematode communities could not be distinguished from one another. It is suggested that more studies of this kind be carried out along the coast of Africa to establish the potential indicator value of nematodes on the African continent.

Keywords

Meiofauna, Nematodes, Heavy Metals, Pollution, Community Structure, Sediment

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	P. Morant and N. Quinn, “Influence of Man and Management of South African Estuaries,” In: B. R. Allanson and D. Baird, Eds., Estuaries of South Africa, Cambridge University Press, Cambridge, 1999, pp. 289-320.
[2]	A. Grant, J. G. Hateley and N. V. Jones, “Mapping the Ecological Impact of Heavy Metals on the Estuarine Polychaete Nereis Diversicolor Using Inherited Metal Tolerance,” Marine Pollution Bulletin, Vol. 20, No. 5, 1989, pp. 235-238. doi:10.1016/0025-326X(89)90438-4
[3]	P. J. Sommerfield, M. J. Gee and R. M. Warwick, “Benthic Community Structure in Relation to an Instantaneous Discharge of Waste Water from a Tin Mine,” Marine Pollution Bulletin, Vol. 28, No. 6, 1994, pp. 363-369. doi:10.1016/0025-326X(94)90273-9
[4]	S. Gascón, D. Boix, J. Sala and X. D. Quintana, “Nematode Assemblages and Their Responses to Disturbances: A Case Study from the Empordà Wetlands (Northeastern Iberian Peninsula),” Journal of the North Ame- rican Benthological Society, Vol. 25, No. 3, 2006, pp. 643-655. doi:10.1899/0887-3593(2006)25[643:NAATRT]2.0.CO;2
[5]	E. Abebe, I. Andrássy and W. Traunspurger, “Fresh Water Nematodes—Taxonomy and Assemblages,” Google Books.co.za., 2006.
[6]	N. Smol, K. A. Willems, J. C. R. Govaere and A. J. J. Sandee, “Composition, Distribution, Biomass of Meio- benthos in the Oosterschelde Estuary (SW Netherlands),” Hydrobiologia, Vol. 282-283, No. 1, 1994, pp. 197-217. doi:10.1007/BF00024631
[7]	F. Boufahja, A. Hedfi, J. Amorri, P. A?ssa, H. Beyrem and E. Mahmoudi, “An Assessment of the Impact of Chromium-Amended Sediment on a Marine Nematode Assemblage Using Microcosm Bioassays,” Biological Trace Element Research, Vol. 142, No. 2, 2010, pp. 242-255.
[8]	H. Beyrem, E. Mahmoudi, N. Essid, A. Hedfi, F. Boufahja and P. Aissa, “Individual and Combined Effects of Cadmium and Diesel on a Nematode Community in a Laboratory Microcosm Experiment,” Ecotoxicology and Environmental Safety, Vol. 68, No. 3, 2007, pp. 412-418. doi:10.1016/j.ecoenv.2006.12.007
[9]	E. Mahmoudi, N. Essid, H. Beyrem, A. Hedfi, F. Boufahja, P. Aissa and P. Vitiello, “Mussel-Farming Effects on Mediterranean Benthic Nematode Communities,” Nematology, Vol. 10, No. 3, 2008, pp. 323-333. doi:10.1163/156854108783900285
[10]	N. R. Millward and A. Grant, “Assessing the Impact of Copper on Nematode Communities from a Chronically Metal-Enriched Estuary Using Pollution-Induced Community Tolerance,” Marine Pollution Bulletin, Vol. 30, No. 11, 1995, pp. 701-706. doi:10.1016/0025-326X(95)00053-P
[11]	A. McLachlan, “Studies on the Psammolittoral Meiofauna of Algoa Bay. South Africa. II. The Distribution, Composition and Biomass of the Meiofauna and Macrofauna,” Zoology African, Vol. 12, 1977, pp. 33-60.
[12]	L. E. McGwynne, A. McLachlan and J. P. Furstenberg, “Wrack Breakdown on Sandy Beaches: Its Impact on Interstitial Meiofauna,” Marine Environmental Research, Vol. 25, No. 3, 1988, pp. 213-232. doi:10.1016/0141-1136(88)90004-9
[13]	J. P. Furstenberg and M. Vincx, “The New Chromadoropsis Species. (Nematoda, Desmoridae) from Southern Africa and the North Sea,” South African Journal of Zoology, Vol. 23, No. 3, 1988, pp. 215-223.
[14]	J. P. Furstenberg and M. Vincx, “Two New Species of the Family Microlaimidae (Nematoda: Order Chromadorida) from South Africa,” Cahiers de Biologie Marine, Vol. 33, 1992, pp. 245-251.
[15]	T. K. Gyedu-Ababio, J. P. Furstenberg, D. Baird and A. Vanreusel, “Nematodes as Indicators of Pollution: A Case Study from the Swartkops River Estuary, South Africa,” Hydrobiologia, Vol. 397, 1999, pp. 155-169. doi:10.1023/A:1003617825985
[16]	T. K. Gyedu-Ababio and D. Baird, “Response of Meiofauna & Nematodes to Increased Levels of Contamination in a Laboratory Experiment,” Ecotoxicology and Environmental Safety, Vol. 63, No. 3, 2006, pp. 443-450. doi:10.1016/j.ecoenv.2005.01.010
[17]	C. Heip, M. Vincx and G. Vranken, “The Ecology of Marine Nematodes,” Oceanogr. Mar. Biol. Ann. Rev, Vol. 23, 1985, pp. 399-489.
[18]	R. T. Lackey and B. E. May, “Use of Sugar Flotation and Dye to Sort Benthic Samples from Marine and Limnic Sediments,” Netherlands Journal of Sea Research, Vol. 7, 1971, pp. 233-243
[19]	H. M. Platt and R. M. Warwick, “Free Living Marine Nematodes, Part II: British Chromadorids,” Cambridge University Press, Cambridge, 1988.
[20]	R. Mantoura and C. Llewellyn, “The Rapid Determination of Algal Chlorophyll and Carotenoid Pigments and Their Breakdown Products in Natural Waters by Reverse-Phase High-Liquid Chromotography,” Analytica Chimica Acta, Vol. 151, 1983, pp. 297-314. doi:10.1016/S0003-2670(00)80092-6
[21]	S. Parker, “Determination of Soil Organic Content,” In: R. E. Carver, Ed., Procedures in Sediment Petrology, John Willey & Sons, New York, 1983, pp. 389-401.
[22]	B. Curtis, “PRIMER, Plymouth Routine in Marine Environmental Research. Non-Metric Multidimensional Scaling,” 1957.
[23]	T. Bongers, R. Alkemade and G. W. Yeates, “Interpretation of Disturbance-Induced Maturity Decrease in Marine Nematode Assemblages by Means of the Maturity Index,” Marine Ecology Progress Series, Vol. 76, 1991, pp. 135-142. doi:10.3354/meps076135
[24]	J. Mees and O. Hamerlyncl, “Introduction to Descriptive Multivariate Statistics,” Tutorial Handout, Marine Biology Section of the University of Gent, 1996, p. 18.
[25]	C. J. F. Ter Braak, “CANOCO-FORTRAN Program for Canonical Community Ordination by (Partial) Detrended (Canonical) Correspondence Analysis and Redundancy Analysis,” TNO Institute of Applied Computer Science, Statistical Department, Wageningen, 1987.
[26]	G. W. Bryan and W. J. Langston, “Bioavailability, Accumulation and Effects of Heavy Metals in Sediments with Special Reference to UK Estuaries: A Review,” Environmental Pollution, Vol. 76, No. 2, 1999, pp. 89-131. doi:10.1016/0269-7491(92)90099-V
[27]	R. J. Watling and H. R. Watling, “Metal Surveys in South African Estuaries. II. Gamtoos River. Report II. Zoology Department,” University of Port Elizabeth, Port Elizabeth, 1982.
[28]	R. J. Watling and H. R. Watling, “Metal Surveys in South African Estuaries. I. Swartkops River,” Water SA, Vol. 8, 1988, pp. 26-35.
[29]	T. M. Fenchel and R. J. Riedel, “The Sulphide System: A New Biotic Community underneath the Oxidised Layer of Marine Sand Bottoms,” Marine Biology, Vol. 7, No. 3, 1970, pp. 255-268. doi:10.1007/BF00367496
[30]	J. A. Ott, “Determination of Fauna Boundaries of Nematodes in an Intertidal Sand Flat,” Internationale Revue der gesamten Hydrobiologie und Hydrographie, Vol. 57, No. 4, 1972, pp. 645-663. doi:10.1002/iroh.19720570413
[31]	J. A. Ott and F. Schiemer, “Respiration and Anaerobiosis of Free Living Nematodes,” Oecologia, Vol. 2, 1973, pp. 251-291.
[32]	J. A. Ott and R. Novak, “Living at an Interface: Meiofauna at the Oxygen/Sulfide Boundary of Marine Sediments,” In: J. S. Ryland and P. A. Tyler, Eds., Reproduction, Genetics and Distribution of Marine Organisms, Olsen & Olsen, Fredensborg, 1989, pp. 415-422.
[33]	N. Smol, K. A. Willems, J. C. R. Govaere and A. J. J. Sandee, “Composition, Distribution, Biomass of Meiobenthos in the Oosterschelde Estuary (SW Netherlands),” Hydrobiologia, Vol. 282-283, No. 1, 1994, pp. 197-217. doi:10.1007/BF00024631
[34]	M. C. Austen, A. J. McEvoy and R. M. Warwick, “The Specificity of Meiobenthic Community Response to Different Pollutants: Results from Microcosm Experiments,” Marine Pollution Bulletin, Vol. 28, No. 9, 1994, pp. 557- 563. doi:10.1016/0025-326X(94)90075-2
[35]	M.C. Austen and P.J. Sommerfield, “A community level sediment bioassay applied to an estuarine heavy metal gradient,” Marine Environmental Research, Vol. 43, No. 4, 1997, pp. 315-328. doi:10.1016/S0141-1136(96)00094-3