Toxicity of Phenantherene Experiment

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Toxicity of Phenanthrene Experiment

Abstract

Phenanthrene (PAH) is one of the toxic contaminants that are abundant in the aquatic systems. Phenanthrene is a polycyclic aromatic hydrocarbon. There have been many experiments that have done to investigate the toxicity of any PAH compound. In a marine ecosystem, the effects of PAH is seen in growth, oxygen uptake, development, and reproduction. This compound greatly affects the life of aquatic animals. The paper seeks to study the toxicity of this compound in the aquatic ecosystem considering the three trophic levels in the ecosystem. The experiment involves exposing the organisms to Phenanthrene concentrations for three weeks.

Syanchoccous algae is a cyanobacteria that can be found in sea and freshwater ecosystems. It is produces about 25% of primary food to the marine environment. The species can bloom in waters with high nutrient value. It is known as blue algae. They need light for photosynthesis. The concentration of Phenanthrene in water is a potential risk to the algae. As the level of Phenanthrene increase in the water, it is taken up by the algae thus resulting to toxicity (Nour & Abdel 10)

Killifish embryos are very useful in understanding the toxicity of various compounds in the aquatic ecosystems. There are killifish in Qatar, and it is known as Arabian killifish (Riesch, Tobler, & Plath 5). It is mostly found in the Arabian Gulf. A fish embryo test is often developed. The experiment uses different killifish that are sexually mature. Different ages are used in the egg production. The eggs are placed in salty water to be fertilized. The embryos are observed using dissecting microscopes. The eggs that are exposed to PAH are often thickened, lack any heartbeat, experienced delayed hatching or had deformed tail.

 In the trophic level, the killifish is the secondary consumer in the aquatic ecosystem. Thus it is vital for the risk assessment in the environment (Riesch, Tobler, & Plath 7).  The suitable sample is the Killifish at their early stages of life to determine the quality of the water and check for chemicals. The killifish is obtained in a ration of male to female of 2:1 and kept in a breeding condition. The fish breed, reproduce and their eggs left to hatch.

PAHs are highly hydrophobic, and thus when it gets to the water column, it is impounded on the bed sediments in the organic matrix. This contaminates the sediment chronically. Copepods are the most abundant taxon in the deposit. They are essential in the aquatic food webs. Copepods are food for the small fish. The copepod is suitable for toxicity assessment as they can be found in large numbers yet they are small in size (Josh Butler, et al. 3). Similarly, they are intimately attached to the sediment, have a sessile lifestyle and can be clustered easily in the laboratory. Toxicity testing in the sediments helps in determining the effects of the PAH to the benthic organisms. Phenanthrene is highly concentrated in the estuarine sediments and is very toxic to the invertebrates that live in the sediments (Josh Butler, et al. 4).