is a type of ocean pollution that is frequently caused by nutrient runoff from agriculture and from disposal of livestock and human waste, leading to the artificial enrichment of waters with a previous low nutrient level.

The right approach will be "Eutrophication".

Explanation:

The mechanism through which a reservoir, body of water, including stream is eutrophic, usually resulting from either the underlying and adjacent land's inorganic and organic overflow. Steadily increasing plants, as well as algae production that follows eutrophication, decreases the water is probably concentration of dissolved oxygen and induces other species to die prematurely off.

Place the point of the compass on point b and draw an arc that intersects  be¯¯¯¯¯  , using    ab    as the width for the opening of the compass.  hope it