Describe any five salient features of a Marine Ecosystem.

The marine ecosystem is very different from fresh water ecosystem. It covers almost seventy percent of the earth’s surface. The silent features of marine ecosystem are:

• Salinity: The.salinity of sea is fairly constant with sodium chloride being the chief salt component.
• Light: It is definitely a limiting factor in the ocean as it contributes greatly to production and distribution of life inside sea.
• Temperature: It also remains constant like salinity. The annual variation in the temperature is not more than 6°C.
• Concentration of Nutrients: There is a scarcity of nutrients in the marine environment.
• Dissolved Gases: The marine environment is a huge reservoir of dissolved gases which regulate the composition of air.
• Alkalinity: The presence of cations is more than anions in the marine water hence it is alkaline in nature.
• Pressure: The pressure of water increases with the increase in depth of ocean. This has a direct effect on the distribution of organisms.
• Continuity: Though the temperature and salinity are different yet all the water bodies are connected to each other.
• Depth: The depth of sea varies therefore the presence of organisms also varies.
• Currents: Water flow continuously by the means of water currents. They may be wind driven or may arise from deeper currents.
• Waves and Tides: Waves and tides are the movement of water currents under the influence of moon and sun.
• Circulation of Nutrients in Coastal Zone: By up welling and out wellings the circulations of nutrients from bottom to upper surface take place.

The marine zone is divided into two different zone:

1. Benthic zone which resembles an inverted hat: The upper portion is called as supra littoral zone, then littoral and then sublittoral zone.
2. Pelagic zone which consists of water in sea basin. The zone is divided into neritic zone and the deep, open sea of oceanic zone.

The life in an ocean is widespread. Almost all types of lives are found in all layers of oceans. On the basis of depth difference the ocean is divided into littoral, neritic, pelagic and benthis zones.

The littoral zone is the shore reason of marine ecosystem. It is also the zone of higher productivity. The animals population is of snails, clams, crustaceans, etc. The neritic oceanic zone consist of high productivity zone owing to factors such as penetration of light, depth. etc. The pelagic zonehas 90% of the total ocean surface. It has comparatively less species of organisms