Light - marine ecosystems, Biology

Assignment Help:

Light - Marine Ecosystems

Light is a limiting factor in the ocean as it contributes significantly to organic production and distribution of marine life. The ocean is divisible on the basis of the light penetration into two horizontal zones:

1. The lighted photic or euphotic zone extending from the sea surface up to a depth of 200 metres, where sufficient light reaches to support photosynthesis. This photic zone, also called the epipelagic one, is characterised by sharp gradients or light, temperature and salinity. The amount of light reaching the lower level of this zone rarely exceeds 0.0001% of what is received at the surface. Below this is the

2. Aphotic or lightless zone which distinguishable into three further sub-zones

  • Mesopelagic which extends from 200 metres to 1.0(10 metres. This zone is in semi-darkness as very little light penetrates it. Here temperature gradient is more even and gradual, without much seasonal variation. Further this zone contains a minimum of oxygen and a maximum of nitrates and phosphates. Next is the
  • Bathypelagic zone which extends from 1,000 metres to 2,000 metres and where darkness IS virtually complete, tor humans though some fishes and crustacean do respond to dim light. The third and the lower most zone is the
  • Abyssopelagic zone where permanent darkness prevails and where temperature is uniform at 3°C and hydrostatic pressure is enormous.

Related Discussions:- Light - marine ecosystems

Phospholipids exhibit important biological functions, Phospholipids exhibi...

Phospholipids exhibit  important biological functions. They are: a)  increase  the rate of fatty acid oxidation b)  act as inorganic ion carrier across the membrane c) hel

What is the main risk factor for lung cancer, Q. What is the main risk fact...

Q. What is the main risk factor for lung cancer? The major risk factor for lung cancer is tobacco smoking. In The large number of cases of this kind of cancer is due to the inc

Determine the synaptic process, Since neurotransmitters are not consumed in...

Since neurotransmitters are not consumed in the synaptic process, what are the mechanisms to decrease their concentrations in the synaptic cleft after they have been used? As t

Explain ketoconazole, Explain Ketoconazole It is now seldom used. The ...

Explain Ketoconazole It is now seldom used. The other azoles have fewer adverse effects and are usually preferred. Ketoconazole remains an option for treatment of infections w

Morula in humans, Which one of the following statements about morula in hum...

Which one of the following statements about morula in humans is correct? 1. It has almost equal quantity of cytoplasm as an uncleaved zygote but much more DNA 2. It has far l

Plant physiology, application of apical dominace in horticulture and agricu...

application of apical dominace in horticulture and agriculture short notes

Determine the concept of numeric pyramid, In a numeric pyramid to which tro...

In a numeric pyramid to which trophic level does the base always refer? What about the top level? In a numeric pyramid the base corresponds to the first trophic level, i.e., to

What are cell movements, Cell movements are movements performed by cell str...

Cell movements are movements performed by cell structures, like the movements of cilia and flagella, the pseudopod movements (in amoeba, macrophages, etc.), the cyclosis of the cyt

Endocrine glands - placenta, PLACEN T A - Placenta is the intimate...

PLACEN T A - Placenta is the intimate connection between the foehls and the uterine wall of the mother to exchange the materials. Placenta is a tempormy endocrine gland

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd