International Journal of Marine Science, 2016, Vol.6, No.9, 1-20
8
The Extracellular Polymeric Substance (EPS) produced under laboratory conditions by the strain isolated from a
microbial mat showed very high binding capacity for copper and iron salts (Xavier
et al
., 2009). Though this
finding was aimed at development of a low cost biosorbents, it could possibly be a threat to the marine microbes.
Marine and Environment substrata are often covered by microbial biofilms. The investigations of a study (Labare
et al
., 1997) from University of Maryland throws light to the toxic effects of bioconcentrated tributyl tin (TBT) on
oyster larvae. The study clearly depicts the impacts of bioconcentration of TBT in bacterial biofilms, while the
dissolved levels of TBT had no effect on the natural attachment and metamorphosis of the organism on bottom
sediments. So the role marine bacterial biofilms should be seriously taken into consideration when evaluating the
heavy metal toxicity in the marine environment.
5 Marine Pollution Monitoring
Environmental degradation of oceans and coastal areas should not be detrimental to human health, economic
development, climate issues and biodiversity.
The latest studies showed that Hg and POPs are present even in the upper trophic level of marine mammals like
polar bears (Ursus maritimus), Greenland sharks (Somniosus microcephalus) and seabirds (e.g. Letcher
et al
.,
2010). Letcher
et al.
(2010) also observed the presence of new pollutants such as polyfluorinated compounds
(PFCs) and brominated flame retardants (BFRs) in Arctic biota indicating the extend of marine pollution by toxic
and bioaccumulative pollutants."
5.1 Chemical monitoring
Chemical monitoring includes the quantitative analysis of pollutants in water and sediments. Instrumental
methods like Atomic absorption spectroscopy (AAS), atomic fluorescence spectroscopy (AFS) and Inductively
coupled plasma mass spectrometry (ICPMS) can be used for the detection of metals. Also the organic toxic
pollutants can be determined qualitatively and quantitatively by latest chromatographic techniques such as liquid
chromatography Quadrupole time-of-flight (LC-QTOF), Gas chromatography–mass spectrometry (GC-MS) etc.
The monitoring of concentration of pollutants in the abiotic environment may not be able to predict the actual
effects on the biota. Hence it is very significant to conduct biomonitoring.
5.2 Biomonitoring
Biomonitoring is a scientific technique for assessing environment including human exposures to natural and
synthetic chemicals, based on sampling and analysis of an individual organism’s tissues and fluids (Zhou et al,
2008). The biomonitoring methods commonly used for aquatic pollution include biota population, bacteria test,
acute toxicity assay, chronic toxicity assay, residue analysis etc The in-situ biomonitoring has been reviewed by
Hopkin (1993) as it follows:
a) Community effects: Presence or absence of species or changes in species composition in an ecosystem due to
the effect of pollution.
The log normal distribution of individuals per benthic species in the sediment samples is the simplest method for
analysing the impact of pollutants in marine ecosystem.
b) Bioconcentration of pollutants : determines the concentration of pollutants accumulated or concentrated in
organisms.
Bioaccumulation studies are mainly focused on the (1) lower trophic level organisms like molluscs as they are
filter feeders, food sources of vertebrates and (2) wide spread pollutants with longer residence time and lipophilic
nature are accumulated easily. In higher mammals it occurs through their diet.
c) Effects of pollutants: Marine ecosystem is vast and hence it is very difficult to relate effects with specific
pollutants. Addison (1996) suggested the use of three biochemical responses, measurement of energy partitioning
in molluscs and analysis of benthic community structure to determine the impact of marine pollution. The three
