Biota, marine environment

In experimental studies of a marine environment of Narragansett Bay, Rhode Island, United States, it was shown that biodegradation by the surface microlayer biota accounted for at least 30% of the removal of di(2-ethylhexyl) phthalate (Davey et al., 1990). 

Malaysia has an extensive coastal line and the country is divided between the west and east by the South China Sea. The west coast of West Malaysia shares the Straits of Malacca with Sumatra Island. The Straits of Malacca, together with the Java Sea, South China Sea and the Gulf of Thailand, are part of the rich marine environment of the shallow Sunda Shelf. In recent years, the Straits of Malacca has become a very important shipping route connecting the oil rich West Asia to the Far East. Shipping accidents have occurred more frequently in these shallow and narrow channels (Chua et al., 2000). The South China Sea, on the other hand, is poorly understood in terms of its marine biota, ecology, and the human impacts upon it. However, it is anticipated that anthropogenic impacts, such as the over-exploitation of marine resources and pollutions, will threaten the sea (Morton and Blackmore, 2001). 

The use of bioindicators and biomonitors for gathering environmental information is currently widespread, although some abuse of these terms is customary. The terms bioindicator and biomonitor are commonly but incorrectly taken to be synonymous a bioindicator provides qualitative information on the quality of the environment, whereas a biomonitor supplies quantitative data on environmental contamination.14 This section focuses on the latter, since the trace metal content of biota has been commonly used in biomonitoring programs of metal pollution in the marine environment and is considered to provide a time-integrated measure of metal bioavailability.1,15,16... 

Figure 1 Diatoms are one of the most abundant biota containing siliceous skeletal material in the marine environment. Radiolaria, silicoflagellates, and siliceous sponges also deposit this amorphous phase for structural support. The diatoms in the figure (Corethron sp.) were collected from the Antarctic continental shelf, occurring as a monotypic assemblage in a large phytoplankton bloom. The siliceous frustules in this figure t3fpically are 100-...

The solubility of biogenic silica also is affected by its aluminum content. Van Bennekom et al. (1991) reported that the Al/Si atomic ratio in siliceous material collected from various marine environments varied from 0.6 X 10 to 7 X 10, with a corresponding change in silica solubility from 1,080 pM to 660 pM. The amount of aluminum incorporated into siliceous skeletons during growth appears to be dependent on the Al/Si ratio in the surrounding water as well as the particular species of siliceous biota. 

Freshwater and marine environments contain complex ecosystems such as ponds, rivers, lakes, and estuaries. Each of these ecosystems contains unique biota that may be represented by several thousand species. These biota, both flora and fauna, are often exposed to a variety of toxicants, including those that result from anthropogenic activities, and in some cases, toxicity and environmental damage can occur. The study of these adverse effects on freshwater and marine biota and on the ecosystems that contain them is called aquatic toxicology. 

An understanding of the biogeochemistry of organic matter In the contemporary marine environment Is important In order to facilitate a greater understanding of 1) the C, N, S and P cycle 11) Interactions between organic compounds and biota, e.g. chemotaxis 111) Interpretations of molecular paleontology In ancient sediments and petroleum formation Iv) the Inputs, fates and effects of pollutants as has been set forth In several reviews (1-6) ... 

Fent K, Flunn J (1991) Phenyltins in water, sediment and biota of freshwater marines. Environ Sci Technol 25, 958-963. 

The most intense period of eutrophication at the Romanian Black Sea shore were the 70ies and 80ies. The Danube river and coastal anthropogenic activities were the main sources of nutrients. Once the intensity of economic activities decreased (early 90ies), the marine environment is slowly evolving toward a normal status, some parameters of the marine biota (biomass and diversity) indicating the improving trend. 

These data and other data on mussels sampled elsewhere on the U.S. West Coast (33,34,35) clearly indicate that there is a low concentration of 10 9 g/g dry weight of fossil fuel or fossil fuel combustion product aromatics in one species of biota sampled in several locations of the coastal zone of the United States. In two cases to date, samples have shown elevated levels of aromatic hydrocarbons. These samples were taken near Boston and Biloxi, areas thought to be contaminated due to chronic release of these compounds to the marine environment. 

Since a number of investigators are employing continuous-flow oil delivery systems for determining effects of petroleum hydrocarbons on marine biota (9,22,23), it is important that the differences between hydrocarbon composition in these systems and hydrocarbon composition in the crude oils be measured and understood so that valid predictions of the effects of petroleum hydrocarbons in marine environments can be made. 

To ascertain the magnitude and the mechanism of a photochemical reaction, it is necessary to determine the rate of the process (see eq. 1). In classical photochemistry, reactions which are very slow are usually considered to be unimportant and hence of little interest. In the marine environment very slow reactions can be significant if they are the only operating mechanism for a particular process or if they compete favorably with other abiotic or biotic mechanisms contributing to the same process. Remineralization of organic matter, for example, is generally attributed solely to biological routes, and for those compounds readily utilized by the biota... 

Silicate is a very important nutrient in the ocean. Unlike other major nutrients such as phosphate and nitrate or ammonium, which are needed by almost all marine plankton, silicate is an essential chemical only for certain biota such as diatoms, radiolarian, sihcoflageUates, and siliceous sponges. However, this biology is one of the most important producers in marine. The estimation shows that diatoms contribute more than 40% of the entire primary production. Therefore, silicate cycling has received significant scientific attention in recent years and many scientists have studied silicate behavior in marine environments. Biogenic silicate is the amorphous content extracted by chemical methods, which is named as biogenic opal or opal in brief. The concentration of dissolved silicate in the world ocean is about 70.6 pmol/L and the net input of dissolved silicate from land to ocean is (6.1 2.0)x 10 mol (calculated by Si) every year, and the primary contribution (about 80%) comes from river. 

Rimkus G, Wolf M (1995) Nitro musk fragrances in biota from freshwater and marine environment. Chemosphere 30 641-651... 

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