Source of nutrients in Gulf of Mexico

http://water.usgs.gov/nawqa/sparrow/gulf_findings/primary_sources.html

Source of Nitrogen and Phosphorus in the Gulf of Mexico

Source Nitrogen (%) Phosphorus (%)

Corn and Soyabean crops 52 25
Other Crop 14 18
Pasture and range 5 37
Urban and population-related sources 9 12
Atmospheric deposition 16 -
Natural Land 4 8

Farmers use fertilzers to grow more crops and part of this is used to feed fish.
The fertilizer run off causes harmful algal bloom and this reduces fish population.

Instead if Nualgi is used the excesss fertilizer in water can be converted into fish feed via Diatom Algae and fisheries use of corn or soya meal as fish feed will reduce.

Diatoms are also source of biodiesel.

Thus many problems can be solved at one go.