Changes in morphology and growth of the mudskipper (Periophthalmus argentilineatus) associated with coastal pollution
In this paper a comparison is made between the growth and morphology of barred mudskippers (Periophthalmus argentilineatus) from six mangrove forests along the coast of Tanzania. The fish populations from unpolluted sites consisted of different size classes, whereas only small sized fish were present in the polluted Mtoni mangroves. Age estimation based on the examination of otoliths revealed that the mudskippers followed similar growth patterns in all sites with limited pollution. However, the age estimates from the polluted Mtoni site revealed an abnormal growth pattern. The occurrence of unilateral anophthalmia in the Mtoni mudskippers suggested that these fish were affected by pollutants during early development. The study showed that the presence of urban and industrial wastes from Dar es Salaam city, as indicated by isotopic enrichment, correlated with abnormal growth and developmental effects in mudskippers. We hypothesize that pollution might also affect fish species that use the mangroves as a temporary habitat.
KeywordsPCBs Mangrove Forest Growth Zone Stable Nitrogen Opaque Zone
We gratefully acknowledge Richard Massinde from the Department of Zoology and Marine Biology, University of Dar es Salaam, for assistance during collection of samples in the field, and Ernst Thompson from the Department of Ichthyology and Fisheries Sciences, Rhodes University, for technical assistance in the processing of otoliths. This is Centre for Wetland Ecology publication number 412.
- Efron B (1982) The jackknife, the bootstrap, and other resampling plans. In: CBMS-NSF regional conference series in applied mathematics, monograph 38. Society for Industrial and Applied Mathematics, Philadelphia, 92 ppGoogle Scholar
- Engdahl S, Mamboya F, Mtolera M, Semesi AK, Björk M (1998) The brown macroalgae Padina boergesenii as an indicator of heavy metal contamination in the Zanzibar channel. Ambio 28:694–700Google Scholar
- Hyndes GA, Loneragan NR, Potter IC (1992) Influence of sectioning otoliths on marginal increment trends and age and growth-estimates for the flathead Platycephalus speculator. Fish B-NOAA 90:276–284Google Scholar
- Morales-Nin B (1992) Determination of growth in bony fishes from otolith microstructure. FAO Fisheries Techical Paper No. 322. FAO, Rome, 51 ppGoogle Scholar
- National Bureau of Statistics (2002) Tanzania: 2002 population and housing census. Dar es Salaam, TanzaniaGoogle Scholar
- Ricker WE (1975) Computation and interpretation of biological statistics of fish populations. Bulletin of the Fisheries Research Board of Canada 191. Department of the Environment, Fisheries and Marine Service, Ottawa, 382 ppGoogle Scholar
- Secor DH, Dean JM, Laban EH (1992) Manual for otolith removal and preparation for microsctructural examination. In: Stevenson DK, Campana SE (eds) Otolith microstructure examination and analysis. Canadian special publication of fisheries and aquatic sciences No. 117. Fisheries and Oceans Canada, Ottawa, pp 19–57Google Scholar
- Swedmark M, Granmo Å (1981) Effects of mixtures of heavy metals and a surfacant on the development of cod (Gadus morhua L.). Rapports et procès-verbaux des Réunions, Conseil international pour l’exploration de mer 178:95–103Google Scholar
- UNEP (2001) Eastern Africa atlas of coastal resources: Tanzania. United Nations Environment Programme, NairobiGoogle Scholar