Mixture of metals relevant for Norwegian coastal water: uptake and effects in Salmo salar (copy)
In Kaldvellfjord a high concentration of metals is leaching from the rock deposition into the fjord. In water metal can be taken up by organism and cause toxic effects which can lead to the mortality. Fish is one of the most sensitive species and accumulation of pollutants in fish is assumed to be directly relevant for humans.
There is however not sufficient information available in the literature neither on metal uptake nor on its toxicity for fish in coastal water as the concentration is usually low. The knowledge about uptake and toxicity is very limited especially on the mixtures of metals. Such an information is however needed for risk assessment. Although there exists extensive literature on uptake and toxicity of metals in fresh water, the information could not be transferred to marine species. In marine conditions the bioavailability of metals,
higher pH as well as enriched concentration of ions (Ca, Mg, K) is different in comparison to freshwaters. Moreover, the physiology of organism and the uptake pathways are different for fish in fresh water and seawater. There is a strong need to perform a complex study using sensitive organisms of different trophic levels e.g. marine copepods and fish to obtain a broad overview on the uptake (toxicokinetics), toxicity (toxic effects) to estimate the risk in cases such as Kaldvellfjord. The information of mixture effects of metals in coastal water on fish can only be obtained by performing exposure experiments. This study is designed to
provide such information on the uptake of metals in fish (toxicokinetics) and induced toxic effects (toxicodynamics) of single and mixture exposure. Three selected metals (Al, Zn and Cu) among several metals leaching into the Kaldelvfjord are identified to be the main risk drivers. This is based on exposure study performed using the lower trophic marine organism the harpacticoid copepod T. battagliai. Obtained information of uptake and toxic effects are the basis to determine critical concentrations of metals at two different levels of salinity. The results with copepods were used to select the metals and their combinations. The second part will be based on the first part, using the water concentrations that was identified to give a measurable uptake in fish but at such levels adverse effects will be not observed. In total 511 Atlantic salmon smolts will be used, 35 fish in total for control before exposures, 133 fish for single dose response at high salinity, 133 fish for single dose response at low salinity and 210 fish for interaction effects of metals, respectively. This number of fish is a minimum to obtain required information for the selected number of metals, according to the OECD 203 Guidance and literature. Fish will be exposed to no effect concentrations of metals separately and in binary mixtures, where only sub lethal effects are expected. Results will generate knowledge an both the effects of salinity and interaction effects of trace metals on uptake and toxicity of trace metals in coastal water, information that are needed to perform risk assessments.
There is however not sufficient information available in the literature neither on metal uptake nor on its toxicity for fish in coastal water as the concentration is usually low. The knowledge about uptake and toxicity is very limited especially on the mixtures of metals. Such an information is however needed for risk assessment. Although there exists extensive literature on uptake and toxicity of metals in fresh water, the information could not be transferred to marine species. In marine conditions the bioavailability of metals,
higher pH as well as enriched concentration of ions (Ca, Mg, K) is different in comparison to freshwaters. Moreover, the physiology of organism and the uptake pathways are different for fish in fresh water and seawater. There is a strong need to perform a complex study using sensitive organisms of different trophic levels e.g. marine copepods and fish to obtain a broad overview on the uptake (toxicokinetics), toxicity (toxic effects) to estimate the risk in cases such as Kaldvellfjord. The information of mixture effects of metals in coastal water on fish can only be obtained by performing exposure experiments. This study is designed to
provide such information on the uptake of metals in fish (toxicokinetics) and induced toxic effects (toxicodynamics) of single and mixture exposure. Three selected metals (Al, Zn and Cu) among several metals leaching into the Kaldelvfjord are identified to be the main risk drivers. This is based on exposure study performed using the lower trophic marine organism the harpacticoid copepod T. battagliai. Obtained information of uptake and toxic effects are the basis to determine critical concentrations of metals at two different levels of salinity. The results with copepods were used to select the metals and their combinations. The second part will be based on the first part, using the water concentrations that was identified to give a measurable uptake in fish but at such levels adverse effects will be not observed. In total 511 Atlantic salmon smolts will be used, 35 fish in total for control before exposures, 133 fish for single dose response at high salinity, 133 fish for single dose response at low salinity and 210 fish for interaction effects of metals, respectively. This number of fish is a minimum to obtain required information for the selected number of metals, according to the OECD 203 Guidance and literature. Fish will be exposed to no effect concentrations of metals separately and in binary mixtures, where only sub lethal effects are expected. Results will generate knowledge an both the effects of salinity and interaction effects of trace metals on uptake and toxicity of trace metals in coastal water, information that are needed to perform risk assessments.