Why are some areas of the open ocean at the surface not very productive?

Why are some areas of the open ocean at the surface not very productive?

In surface waters away from coastlines, generally there is plenty of sun but not enough nutrients. So most of the ocean surface is not very productive. The water is too deep for storms to stir up nutrients from the bottom and there isn’t upwelling.

What limits productivity in the ocean?

Outside high-nutrient low-chlorophyll areas, productivity in most of the ocean (∼ 75%) is limited by the availability of inorganic nitrogen (Figure 1B), despite very low concentrations of iron and, in some cases, phosphate.

What limits productivity in tropical oceans and why?

Productivity is low and limited because of lack of nutrients. The sun is more directly over head > light penetrates deeper into tropical ocean than in temperate and polar waters.

What limits photosynthesis on the surface of the ocean?

Phytoplankton are dependent on sunlight and their CO2-fixation activity is therefore restricted to the upper, sunlit surface ocean (that is, the euphotic zone). CO2 usually does not limit phytoplankton growth due to its high concentration in seawater.

Why is the ocean productivity less?

In ocean, sunlight is the main limiting factor which decreases the rate of photosynthesis. Minerals and nutrients can also be a retarding factor based on location of the oceans.So, there will be less productivity than land which is 170 billion tons compared to 55 billion tons ion oceans.

What makes the ocean less productive?

(i) There is insufficient radiation as sunlight decreases with the increasing depth of the ocean. (ii) Oceans are nitrogen deficient which is an important nutrient for plants. (iii) Conditions oi high salinity which is not iavourable for all plants.

Why do open oceans produce the largest share of Earth’s biomass?

Open oceans produce the largest share of Earth’s biomass because the net primary productivity (NPP) of the ocean is… Both forest have the same gross primary productivity (GPP). Forest A has a net primary productivity of 1650 kcal/m^2/year, and forrest B has a net primary productivity of 1110 kcal/m^2/year.

Why are oceans less productive?

Where is ocean productivity highest?

Higher chlorophyll concentrations and in general higher productivity are observed on the equator, along the coasts (especially eastern margins), and in the high latitude ocean (Figure 4a and b).

What is the main reason for the low productivity of ocean as compared to land?

In ocean, there is insufficient radiation as sunlight decreases with the increasing depth which decreases the rate of photosynthesis. Decrease in rate of photosynthesis decreases the growth of aquatic plants and animals. Minerals and nutrients can also be a retarding factor based on location of the oceans.