What is the most productive zone in the Arctic?
The Arctic inflows shelves, i.e., the Chukchi and Barents Seas, experience the most variable ice-cover and PAR, the highest nutrient availability and enjoy thus the highest regional primary and secondary production in the AO, with about 50% of pan-arctic shelf primary production taking place in the Barents Sea ( …
Why the biologic productivity of the ocean is high in the Arctic Ocean?
In particular, the melting and retreat of sea ice during spring are strong drivers of primary production in the Arctic Ocean and its adjacent shelf seas due to enhanced light availability (Barber et al.
Why is surface productivity generally low in the tropics?
The overall pattern with latitude is clearly visible: low productivity in the tropics and subtropics, probably due to nutrient limitation brought about by strong, year-round thermocline and pycnocline.
Are tropical open ocean waters generally more or less productive than temperate and polar waters?
Tropical regions are always nutrient-limited and show low productivity. Polar regions are light limited in the winter and only display production during the late spring and summer months when light is available. Northern temperate regions have a spring bloom, and a smaller autumn bloom (PW).
Why is Antarctica so productive?
The Southern Ocean and Antarctica have high levels of primary productivity for three months of the year, based on the growth of phytoplankton. These microscopic plants are highly adapted to this unique environment and survive despite the lack of iron – a key nutrient – in these waters.
Why is productivity of tundra biome very low?
The tundra has some of the lowest net primary productivity of any ecosystems, due mainly to the cold and short growing season, and the infertile soils.
Why is the open ocean considered to be a biological desert?
Regions of ocean that contain low phytoplankton biomass indexed as chlorophyll-concentrations are called “ocean biological deserts”. The concept of ocean fertilisation is based on the effectiveness of the biological pump to sequester large amount of atmospheric carbon into deep layers of the oceans.
Why is productivity higher near the coasts?
The proximity to land and its nutrient sources, the interception of sinking organic matter by the shallow seafloor, and the propensity for coastal upwelling all result in highly productive ecosystems.
Why are tropical waters nutrient poor?
Nutrients are typically depleted in the surface waters due to photosynthesis and are abundant in deeper waters where they are replenished by the decay and biodegrading of organic matter that sunk into the ocean depths.
Why is the open ocean called a marine desert?
So-called “ocean deserts” or “dead zones” are oxygen-starved (or “hypoxic”) areas of the ocean. Furthermore, warmer upper layers of water stifle the process that brings nutrients up from colder, deeper parts of the ocean to feed a wide range of surface-dwelling marine wildlife.
What happens to the circulating water around Antarctica?
Once it surfaces, some of the water flows northward again and sinks north of the Subarctic Front. The remaining part flows toward Antarctica where it is transformed into the densest water in the ocean, sinking to the sea floor and flowing northward in the abyss as Antarctic Bottom Water.