When I was growing up, my father would rent a small boat at the harbor so we could go
fishing one Sunday each month.
After returning home with the day's catch, we could clean the fish and bury the remains in
his vegetable garden, which was his pride and joy.
Fish remains provide an excellent fertilizer, indeed natural fish emulsion is very popular
with gardeners to this day.
The nutrients in the sea are recycled in a similar manner, much to the benefit of the
When organisms die, the remains decompose in
the mid and deep waters by bacterial activity (so-called decomposers).
The result is that the deep waters contain a vast reservoir of nutrients that can be
tapped by upwelling to return to the surface.
Let's examine this process by using the table
of chemical and temperature data above and the graph paper in your expedition worksheet.
Make plots of water depth against the concentration of:
1. Nitrogen (N) as Nitrate (NO3--)
2. Phosphorous (P) as Phosphate (PO4---)
3. Temperature (oC)
Make sure that understand the relationship of the nutrient distribution to the layering of the water masses.