Olis

Argumentative Essay- Martina Persini

"Eutrophication is the most damaging agricultural effect in water quality" Discuss this statement.

Eutrophication is a syndrome of ecosystem responses tohuman activities that fertilize water bodies with nitrogen (N) andphosphorus (P), often leading to changes in animal and plant populations and degradation of water and habitat quality. Nitrogen andphosphorus are essential components of structural proteins, enzymes, cell membranes, nucleic acids, and molecules that capture and utilize light and chemical energy to support life. The biologicallyavailable forms of N and P are present at low concentrations in pristine lakes, rivers, estuaries, and in vast regions of the upper ocean.

To begin with, the city of Puerto Madryn, located within asection of Nuevo Gulf (Patagonia, Argentina) known as Nueva Bay, can be regarded as an important centre of anthropogenic impact. Intertidal assemblages of macroalgae were studied in order to test thehypothesis that the seaweed flora impacted by raw sewage would show significant differences in structure compared to that of control localities, mainly due to the increase in biomass of ephemeraland opportunist chlorophytes. Three rocky shores showing similar characteristics were selected. One of these was located near the sewage outfall of the city of Puerto Madryn. Two control shores werechosen approximately 30 km northward and southward of the latter. Four seasonal surveys were performed between June 1998 and April 1999. Biomass data of 35 macroalgal species were analysed bynon-metric multidimensional scaling and the analysis of similarities permutation test. Species responsible for the differences between shores were identified by the similarity percentages routine. Themicroalgae assemblage of the impacted site was significantly different from those of the two control shores throughout the year. Ulva rigida, Corallina officinalis and Ralfsia sp. were the species mostly...