What limits primary productivity in the ocean?

What limits primary productivity in the ocean?

In the vast unproductive low- and mid-latitude ocean, warm and sunlit surface water is separated from cold, nutrient-rich interior water by a strong density difference that restricts mixing of water and thereby reduces nutrient supply, which becomes the limiting factor for productivity.

Why is productivity limited in tropical oceans?

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 factors limit primary productivity?

Production varies among ecosystems, as well as over time within ecosystems. Rates of production are determined by such factors as climate and nutrient supply. Precipitation is the dominant control worldwide, but nutrient availability often limits primary production in any particular, local system.

What is the limiting factor for primary productivity in the tropical waters?

At low latitudes the limiting factor for primary production is: sunlight. pressure.

What limits phytoplankton productivity in the tropical ocean?

They also require trace amounts of iron which limits phytoplankton growth in large areas of the ocean because iron concentrations are very low. Other factors influence phytoplankton growth rates, including water temperature and salinity, water depth, wind, and what kinds of predators are grazing on them.

Which factors limit the productivity of a marine ecosystem?

Factors that limit the productivity of estuary ecosystems include: The need to survive osmotic stress; The depletion of the oxygen in the sediments. Hunting sea otters disrupted the kelp forest ecological balance because: Sea otters eat sea urchins, which eat kelp.

What factor limits productivity in the ocean surrounding Antarctica?

This is primarily due to limitation of the micro-nutrient iron. If iron were more abundant in the Southern Ocean, then phytoplankton production would be even higher.

What is the main factor limiting productivity in polar oceans?

Arctic Ocean primary productivity is limited by light and inorganic nutrients. With sea ice cover declining in recent decades, nitrate limitation has been speculated to become more prominent.

What affects primary productivity in the ocean?

Reduction of sunlight by sea ice is a major limiting factor for primary productivity in the Arctic Ocean. In the Arctic Ocean, photosynthetic algae can be adapted to rather low light conditions. It is possible for photosynthesis to be inhibited if these algae are exposed to too much light.

What are some limiting factors in the ocean?

Nitrogen is a major limiting factor in the sea. 5. Nutrients. Macronutrients in marine ecosystems include carbon, nitrogen, phosphorus, silicon, sulfur, potassium, and sodium.

Which factors can limit phytoplankton productivity?

For photosynthetic organisms (like kelp or phytoplankton) are often limited by nutrients such as nitrogen or phosphorus. Organisms that eat other organisms are often limited by food availability or the abundance of predators that may eat them.

What limits the productivity of the ocean?

Because of the density difference between surface water and the deep sea across most of the ocean, ocean circulation can only very slowly reintroduce dissolved nutrients to the euphotic zone. By driving nutrients out of the sunlit, buoyant surface waters, ocean productivity effectively limits itself.

What is marine primary production?

Phytoplankton serve as the major primary producers in the marine ecosystem. These microscopic, single-celled plants, bacteria, algae and other organisms harvest sunlight through photosynthesis and store it as chemical energy before becoming food for tiny creatures called zooplankton.

What is ocean productivity?

Ocean productivity largely refers to the production of organic matter by “ phytoplankton ,” plants suspend- ed in the ocean, most of which are single-celled.

What is marine productivity?

Net marine primary productivity is the amount of organic material available to support the consumers (herbivores and carnivores) of the sea. The standing crop is the total biomass (weight) of vegetation.