Scientia Marina, Vol 82, No 2 (2018)

The abundance, diversity and distribution of small fishes in mangrove and non-mangrove estuaries in warm temperate South Africa

Steven McGregor
Department of Zoology, Nelson Mandela University, South Africa

Nadine A. Strydom
Department of Zoology, Nelson Mandela University, South Africa


Mangroves in tropical and subtropical regions have been well documented in terms of the advantages they provide and their role in structuring ichthyofaunal assemblages, but little is known about their warm temperate counterparts. The study aimed to investigate the importance of warm temperate mangroves by comparing the abundance, diversity and distribution of small fishes in mangrove and non-mangrove estuaries in warm temperate South Africa. A 50x2 m (12-mm mesh) seine net was used over three summer seasons to sample small fishes in the Gonubie, Qora, Nahoon and Xhora estuaries (the latter two being mangrove estuaries). Fish abundance and diversity showed little variation among estuaries, despite the presence of mangroves. Estuaries in warm temperate areas are not only at the edge of mangrove distribution, but also offer alternative habitats which lend similar advantages to fish survival. It appears that warm temperate ichthyofauna have not yet evolved a dependence on mangrove systems in terms of the food, refuge and other ecological services they provide. Understanding the function of habitats and their value in enhancing fish survival in estuarine nursery areas is essential for fish conservation.


ichthyofauna; estuary usage; juveniles; nursery; recruitment; refuge; pneumatophores

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Aburto-Oropeza O., Ezcurra E., Danemann G., et al. 2008. Mangroves in the Gulf of California increase fishery yields. Proc. Natl. Acad. Sci. U.S.A. 105: 10456-10459.

Adams J., Colloty B., Bate G. 2004. The distribution and state of mangroves along the coast of Transkei, Eastern Cape Province, South Africa. Wetlands Ecol. Manage. 12: 531-541.

Alongi D.M. 2002. Present state and future of the world’s mangrove forests. Environ. Conserv. 29: 331-349.

Beck M.W., Heck K.L., Able K.W., et al. 2001. The identification, conservation, and management of estuarine and marine nurseries for fish and invertebrates: A better understanding of the habitats that serve as nurseries for marine species and the factors that create site-specific variability in nursery quality will improve conservation and management of these areas. BioScience 51: 633-641.

Blaber S.J.M. 2007. Mangroves and fishes: Issues of diversity, dependence, and dogma. Bull. Mar. Sci. 80: 457-472.

Cameron A.C., Trivedi P.K. 1990. Regression-based tests for overdispersion in the Poisson model. J. Econometrics 46: 347-364.

Clarke K.R., Gorley R.M. 2006. PRIMER v6. PRIMER-E Ltd. Plymouth, UK.

Duarte C.M., Cebrian J. 1996. The fate of marine autotrophic production. Limnol. Oceanogr. 41: 1758-1766.

Duke N.C. 1993. Mangrove floristics and biogeography. Am. Geophys. Union, Washington D.C.

Ellison A.M., Farnsworth E.J. 1992. The ecology of Belizean mangrove-root fouling communities: patterns of epibiont distribution and abundance, and effects on root growth. Hydrobiologia 247: 87-98.

FAO. 2004. The state of world fisheries and aquaculture (SOFIA). FAO, Rome.

Gilman E.L., Ellison J., Duke N.C., et al. 2008. Threats to mangroves from climate change and adaptation options: A review. Aquat. Bot. 89: 237-250.

Gratwicke B., Speight M. 2005. The relationship between fish species richness, abundance and habitat complexity in a range of shallow tropical marine habitats. J. Fish Biol. 66: 650-667.

Hogarth P.J. 2015. The biology of mangroves and seagrasses. Oxford Univ. Press, Oxford.

Hoppe-Speer S.C., Adams J.B., Rajkaran A. 2015. Mangrove expansion and population structure at a planted site, East London, South Africa. South. Forests 77: 131-139.

Karosien? J., Kasperovi?ien? J. 2012. Peculiarities of epiphyton algal communities formation on different macrophyte species. Bot. Lithuanica 18: 154-163.

Kathiresan K. 2008. Threats to mangroves. Annamalai Univ., Cent. Adv. Study Mar. Biol., India, pp. 476-483.

Kristensen E., Bouillon S., Dittmar T., et al. 2008. Organic carbon dynamics in mangrove ecosystems: A review. Aquat. Bot. 89: 201-219.

Laegdsgaard P., Johnson C.R. 1995. Mangrove habitats as nurseries: Unique assemblages of juvenile fish in subtropical mangroves in eastern Australia. Mar. Ecol. Prog. Ser. 126: 67-81.

Laegdsgaard P., Johnson C. 2001. Why do juvenile fish utilise mangrove habitats? J. Exp. Mar. Biol. Ecol. 257: 229-253.

Lenanton R., Potter I. 1987. Contribution of estuaries to commercial fisheries in temperate Western Australia and the concept of estuarine dependence. Estuaries 10: 28.

Lugendo B.R., Pronker A., Cornelissen I., et al. 2005. Habitat utilisation by juveniles of commercially important fish species in a marine embayment in Zanzibar, Tanzania. Aquat. Living Resour. 18: 149-158.

Macnae W. 1963. Mangrove swamps in South Africa. J. Ecol. 51: 1-25.

Mahesh R., Saravanakumar A. 2015. Temporal and spatial variability of fin fish assemblage structure in relation to their environmental parameters in Pichavaram mangrove ecosystem, India. Indian J. Mar. Sci. 44: 910-923.

Manson F.J., Loneragan N.R., Skilleter G.A., et al. 2005. An evaluation of the evidence for linkages between mangroves and fisheries: A synthesis of the literature and identification of research directions. Oceanogr. Mar. Biol. 43: 483.

Mumby P.J., Edwards A.J., Arias-González J.E. et al. 2004. Mangroves enhance the biomass of coral reef fish communities in the Caribbean. Nature 427: 533-536.

Nagelkerken I., Kleijnen S., Klop T., et al. 2001. Dependence of Caribbean reef fishes on mangroves and seagrass beds as nursery habitats: A comparison of fish faunas between bays with and without mangroves/seagrass beds. Mar. Ecol. Prog. Ser. 214: 225-235.

Nagelkerken I., Roberts C., Van Der Velde G., et al. 2002. How important are mangroves and seagrass beds for coral-reef fish? The nursery hypothesis tested on an island scale. Mar. Ecol. Prog. Ser. 244: 299-305.

Nagelkerken I., Blaber S., Bouillon S., et al. 2008. The habitat function of mangroves for terrestrial and marine fauna: A review. Aquat. Bot. 89: 155-185.

Naylor R.L., Goldburg R.J., Primavera J.H., et al. 2000. Effect of aquaculture on world fish supplies. Nature 405: 1017-1024.

Oksanen J., Blanchet F.G., Friendly M., et al. 2017. VEGAN: Community Ecology Package. R package version 2.4-4.

Paterson A., Whitfield A. 1997. A stable carbon isotope study of the food-web in a freshwater-deprived South African estuary, with particular emphasis on the ichthyofauna. Est. Coast. Shelf Sci. 45: 705-715.

Paterson A., Whitfield A. 2000. Do shallow-water habitats function as refugia for juvenile fishes? Est. Coast. Shelf Sci. 51: 359-364.

Pattrick P., Strydom N. 2014. Recruitment of fish larvae and juveniles into two estuarine nursery areas with evidence of ebb tide use. Est. Coast. Shelf Sci. 149: 120-132.

Potter I.C., Tweedley J.R., Elliott M., et al. 2015. The ways in which fish use estuaries: A refinement and expansion of the guild approach. Fish Fish. 16: 230-239.

Quisthoudt K., Adams J., Rajkaran A., et al. 2013. Disentangling the effects of global climate and regional land-use change on the current and future distribution of mangroves in South Africa. Biodivers. Conserv. 22: 1369-1390.

Robertson A., Duke N. 1987. Mangroves as nursery sites: Comparisons of the abundance and species composition of fish and crustaceans in mangroves and other nearshore habitats in tropical Australia. Mar. Biol. 96: 193-205.

Rönnbäck P. 1999. The ecological basis for economic value of seafood production supported by mangrove ecosystems. Ecol. Econ. 29: 235-252.

Saintilan N., Wen L. 2012. Environmental predictors of estuarine fish landings along a temperate coastline. Est. Coast. Shelf Sci. 113: 221-230.

Saintilan N., Wilson N.C., Rogers K., et al. 2014. Mangrove expansion and salt marsh decline at mangrove poleward limits. Global Change Biol. 20: 147-157.

Sheaves M., Baker R., Nagelkerken I., et al. 2015. True value of estuarine and coastal nurseries for fish: Incorporating complexity and dynamics. Estuaries and Coasts 38: 401-414.

Short F., Dennison W., Capone D. 1990. Phosphorus-limited growth of the tropical seagrass Syringodium filiforme in carbonate sediments. Mar. Ecol. Prog. Ser. 60: 169-174.

Stevens P.W., Fox S.L., Montague C.L. 2006. The interplay between mangroves and saltmarshes at the transition between temperate and subtropical climate in Florida. Wetlands Ecol. Manage. 14: 435-444.

R Core Team. 2017. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.

van der Elst R., Wallace J. 1976. Identification of the juvenile mullet of the east coast of South Africa. J. Fish Biol. 9: 371-374.

Ward C., Steinke T.D. 1982. A note on the distribution and approximate areas of mangroves in South Africa. S. Afr. J. Bot. 1: 51-53.

Weerts S., Cyrus D. 2002. Occurrence of young and small-sized fishes in different habitats within a subtropical South African estuary and adjacent harbour. Mar. Freshw. Res. 53: 447-456.

Whitfield A.K. 1994a. Abundance of larval and 0+ juvenile marine fishes in the lower reaches of three southern African estuaries with differing freshwater inputs. Mar. Ecol. Prog. Ser. 105: 257-267.

Whitfield A.K. 1994b. An estuary-association classification for the fishes of southern Africa. S. Afr. J. Sci. 90: 411-417.

Whitfield A.K. 2017. The role of seagrass meadows, mangrove forests, salt marshes and reed beds as nursery areas and food sources for fishes in estuaries. Rev. Fish Biol. Fish. 27: 75-110.

Whitfield A.K., Baliwe N. 2013. A century of science in South African estuaries: Bibliography and review of research trends. SANCOR Occasional Report No. 7: 289 pp.

Wickham H. 2009. ggplot2: Elegant Graphics for Data Analysis. Springer-Verlag, New York.

Wiseman K., Burns M., Vernon C. 1993. Report No. 42: Nahoon (CSE 44), Qinira (CSE 45) and Gqunube (CSE 46). In: Morant P.D. (ed.), Estuaries of the Cape. Part II. Synopses of available information on individual systems. CSIR Res. Rep. 441: 1-136.

Wood S.N., Pya N., Saefken B. 2016. Smoothing parameter and model selection for general smooth models (with discussion). J. Am. Stat. Assoc. 111: 1548-1575.

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