Because of their wide geographic distribution, position in the trophic chain, rapid turnover, huge biomass and role in ocean biogeochemical cycles, copepods are regarded as important marine test species. Tigriopus brevicornis Muller, 1776 is a shallow water benthic marine species (Crustacea, Copepoda Harpacticoida). The toxicity of essential and non-essential metals (Ag, Cd, Cu, Hg, Ni and Zn) to Tigriopus brevicornis was determined by 96-h LC50 testing. Comparative crustacean 96-h LC50 data in the literature show that Tigriopus brevicornis is a sensitive species suggesting that copepods are good indicators of minimal lethal concentrations of metals. Groups of 1000 to 1500 adult copepods were exposed for 1 to 14 days to metals at concentrations in water, 3 for each metal, considered realistic in comparison with those encountered in polluted environments and far below lethal concentrations, in order to avoid protein metabolism disturbance. The response of Tigriopus brevicornis in terms of MT induction has been examined in specimens exposed to metals. The induction of these proteins and their implication in detoxificatory mechanisms and trophic transfer are discussed.

Influence of different essential and non-essential metals on MTLP levels in the Copepod Tigriopus brevicornis.

http://www.pfigueiredo.org/ecotox_Gurzau.pdf

Essential metals--case study on iron.

Influences of sex and seasons on levels of heavy metals in tissues of green tiger shrimp (Penaeus semisulcatus de Hann, 1844)

Lack of readily available information on the status and distribution of inland water taxa in western Africa explains why biodiversity is often poorly represented within the development planning process. In response to this need for information, a regional assessment of the status and distribution of 1,395 taxa of freshwater fishes, molluscs, odonates, crabs, and selected families of aquatic plants from across western Africa was conducted. It is hoped that these findings and the data compiled here can now be made available to the relevant decision makers and stakeholders in a format that can be easily understood and readily integrated within the decision-making process.

http://africhthy.org/sites/africhthy.org/files/2011.pdf

The Status and Distribution of Freshwater Biodiversity in Central Africa

The upper catchment of the Olifants River, from its origin near Bethal to its confluence with the Wilge River, north of Witbank, and its tributaries are being subjected to increasing afforestation, mining, power generation, irrigation, domestic and industrial activities. These activities have a profound effect on the water quality. The major point sources of pollution in the study area include mines, industries and very importantly, combined sewage purification works that are located alongside the river. In addition to oxidizable material, these sources contain detergents, nutrients and metals. It was therefore necessary to determine the extent to which these activities affect the water quality of the system. The bioaccumulation of zinc (Zn), copper(Cu), manganese (Mn), lead (Pb), chromium (Cr), nickel (Ni), aluminium (Al) and iron (Fe) in the skin, muscle, liver and gill tissues of Clarias gariepinus and Labeo umbratus from the Upper Olifants River and Klein Olifants River was investigated over the period February 1994 to May 1995. The highest concentrations of these metals were found in the gill and liver tissues of both species, with lower concentrations in the skin and muscle tissues. Bioaccumulation patterns were found to vary according to the species of the fish, mainly according to their different feeding habits and the routes of metal uptake. It also varied as a function of the different localities. Accumulation was size specific, with higher concentrations of metals found in smaller fish.

/pdf/metal-concentrations-in-clarias-gariepinus-and-labeo-mg7qpzjvmw.pdf

Metal concentrations in Clarias gariepinus and Labeo umbratus from the Olifants and Klein Olifants River, Mpumalanga, South Africa: zinc, copper, manganese, lead, chromium, nickel, aluminium and iron

Manganese concentrations in water and sediments of the Bronkhorstspruit River, Nooitgedacht Dam and especially in the Natalspruit River, did not fall within stated limits for the protection of aquatic life. Tissue manganese concentrations in Potamonautes warreni from the Natalspruit River were generally higher than those in the tissues of crabs from the other two aquatic ecosystems. The highest mean manganese tissue concentration in crabs from the three systems was detected in the carapace (587± 445 µg g-1 wet weight). It appears that the carapace in these animals acts as a sink in which manganese can be deposited, thus also playing an important role in the detoxification of manganese in these crustaceans. No seasonal or sex-related variation was detected. Body size of the crabs, however, seems to be an important influencing factor in manganese bioaccumulation. A significant increase in carapace manganese concentrations was detected with an increase in body size. However, muscle manganese concentrations were higher in the smaller groups. The concentration factors (BF) calculated for the different tissues with respect to the water were highest in the carapace and ranged from 280.9 to 742.8. The BF with respect to the sediment was comparatively low for all the tissues (0.1 to 0.7). As the manganese concentration in the tissues reflects to some extent the degree of manganese contamination of the surrounding aquatic environment, it appears that P. warreni may be useful as a potential biomonitor of manganese pollution.

Bioaccumulation of manganese in selected tissues of the freshwater crab, Potamonautes warreni (Calman), from industrial and mine-polluted freshwater ecosystems

The copper concentration detected in the water and sediments of the Natalspruit River, Bronkhorstspruit River and Nooitgedacht Dam exceeded certain stated limits for the protection of aquatic life. Despite considerable individual variation, the general ranking of copper concentrations in the various tissues was carapace < muscle < gonads < midgut gland < gills. Seasonal variation was detected in the bioaccumulation of copper in crabs sampled from the Natalspruit River. However, this phenomenon did not occur in crabs from the other two water bodies. A significant increase in copper concentrations was detected with a decrease in size, indicating that the size of the crabs is an important influencing factor in the bioaccumulation of copper. It was also found that more copper accumulated in the ovary than in the testis per unit weight. The bioaccumulation factors (BF) calculated for the different tissues with respect to the water were highest in the gills and midgut gland (785,00 – 1257,50 and 432,00 – 1340,00, respectively). The BF with respect to the copper concentration in the sediments was comparatively low for all the tissues (<0,10 – 2,74). It appears that  P. warreni  is able to regulate the copper concentrations in its various tissues and is therefore not a suitable indicator of the presence of copper in the aquatic environment.

/pdf/bioacciimulation-of-copper-in-the-tissues-of-potamonautes-2cdvjz9ioa.pdf

Bioacciimulation of copper in the tissues of Potamonautes warreni (Calman) (Crustacea, Decapoda, Branchiura), from industrial, mine and sewage-polluted freshwater ecosystems

Bioaccumulation of zinc and lead in selected tissues and organs of the freshwater crab, Potamonautes warreni

An investigation was made into the bioaccumulation of iron in the organs and tissues of the freshwater crab Potamonautes warreni (Calman) from 3 metal-polluted aquatic ecosystems. Differences in water and sediment iron concentrations were related to environmentally induced factors. The highest ion concentrations in the crab occurred in the gills, suggesting this organ to be the prime site for the absorption and/ or loss of iron to/from the aquatic environment. Although no seasonal or gender-related tendency in iron concentrations in the various organs and tissues was detected, there appears to be an inverse relationship in the capacity of the crab to bioaccumulate iron with size. A brief discussion is given on the physical and chemical conditions which prevailed at the 3 sampling sites

Bioaccumulation of iron in the freshwater crab (Potamonautes warreni) from three industrial, mine and sewage polluted freshwater ecosystems in the Transvaal

An investigation was made into the nickel concentrations of the water and sediments of the Natalspruit and Bronkhorstspruit Rivers (Gauteng) and Nooitgedacht Dam (North West Province), as well as nickel concentrations in tissues of the freshwater crab Potamonautes warreni from these three water systems. Water nickel concentrations were relatively constant, while large fluctuations were detected in the sediment nickel concentrations. The highest water and sediment nickel concentrations were measured at the Natalspruit River. The highest mean tissue concentration of nickel in P. warreni sampled from the three aquatic systems was detected in the carapace, indicating that this tissue might be used as a sink for nickel, for disposing of excessive amounts during the moult-cycle. No seasonal variation was detected. Sex also does not seem to be a variation factor in the bioaccumulation of nickel except in the mature gonads. P. warreni collected from the three different sampling sites showed a general increase in tissue nickel concentrations with a decrease in size. Significant correlations were observed between the midgut gland nickel concentrations and the concentration of this metal in the water (r = 0,63) and sediment (r = 0,77), as well as between the muscle nickel concentration and the water and sediment nickel concentrations (r = 0,63 and r = 0,77, respectively). These phenomena, as well as the fact that P. warreni is able to accumulate relatively high levels of nickel in various tissues, suggest that this freshwater crab is a potential indicator of nickel pollution in aquatic ecosystems.

V.E. Steenkamp

Papers

Bioaccumulation of manganese in selected tissues of the freshwater crab, Potamonautes warreni (Calman), from industrial and mine-polluted freshwater ecosystems

Bioacciimulation of copper in the tissues of Potamonautes warreni (Calman) (Crustacea, Decapoda, Branchiura), from industrial, mine and sewage-polluted freshwater ecosystems

Bioaccumulation of zinc and lead in selected tissues and organs of the freshwater crab, Potamonautes warreni

Bioaccumulation of iron in the freshwater crab (Potamonautes warreni) from three industrial, mine and sewage polluted freshwater ecosystems in the Transvaal

Accumulation of nickel in three freshwater crab populations