Water Related Pollution

EUTROPHICATION

Eutrophication is the accumulation of nutrients in aquatic ecosystems. It alters the dynamics of a number of plant, animal and bacterial populations; thus, bringing about changes in community structure.

It is a form of water pollution and like all other forms of pollution is the result of human activities influencing ecological cycles.

An increase in chemical nutrients — compounds containing nitrogen or phosphorus in an ecosystem, and may occur on land or in water. However, the term is often used to mean the resultant increase in the ecosystem's primary productivity (excessive plant growth and decay), and further effects including lack of oxygen and severe reductions in water quality, fish, and other animal populations.

1. Fertilizer flows into water causing….

2. Increased plant growth on the surface of water, causing…..3. Decreased light in lower levels of water, causing…

4. Plants in lower levels of water to die, causing….5. Decay using up O2 and increasing CO2,causing…...

6. Death of fish and other animals.

STEPS OF EUTROPHICATION

The rise in eutrophic and hypoxic events has been attributed to the rapid increase in intensive agricultural practices, industrial activities, and population growth which together have increased nitrogen and phosphorus flows in the environment. The Millennium Ecosystem Assessment (MA) found that human activities have resulted in the near doubling of nitrogen and tripling of phosphorus flows to the environment when compared to natural values.

Sources of Eutrophication

Discharge of untreatedmunicipal sewage

(nitrates and phosphates)

Nitrogen compoundsproduced by cars

and factories

Natural runoff(nitrates andphosphates

Discharge ofdetergents

( phosphates)

Manure runofffrom feedlots

Inorganic fertilizer runoff(nitrates and phosphates)

Discharge of treated (nitrates,municipal sewage phosphates,

(primary and secondary ammonia)treatment:

nitrates and phosphates) Runoff from streets,lawns, and constructionLake ecosystem lots (nitrates andnutrient overload phosphates)

and breakdown ofchemical cycling

Dissolving of Runoff and erosionnitrogen oxides (from cultivation,

(from internal combustion mining, construction,engines and furnaces) and poor land use)

Overview of Cultural Eutrophication

Start with clear water stream or blue water lake.

Introduction of organic and/or inorganic nutrients.

The pathways of these two nutrient sources differ.

Follow organic pathway first; inorganic nutrient pathway second

Ecological effectsIncreased biomass of phytoplankton

Toxic or inedible phytoplankton species

Increases in blooms of gelatinous zooplankton

Increased biomass of benthic and epiphytic algae

Changes in macrophyte species composition

Decreases in water transparency (increased turbidity)

Colour, smell, and water treatment problems

Dissolved oxygen depletion

Increased incidences of fish kills

Loss of desirable fish species

Reductions in harvestable fish and shellfish

Decreases in perceived aesthetic value of the water