This document provides an introduction to marine ecosystems. It discusses the key characteristics of marine ecosystems, including the biotic and abiotic components. It also describes several types of marine ecosystems in more detail, including oceans, estuaries, on-shore ecosystems, and coral reefs. For each ecosystem type, it outlines the defining features, environmental factors, and common plant and animal species found there. The goal is to study and understand these different marine environments and the life they support.

1. Shaik Umme Salma
Aquatic Envionment Management
COLLEGE OF FISHERIES,MANGLORE
MFK-1710

2. INTRODUCTION
• Life on earth is supported by the surrounding ecological conditions and the
natural resources.
• Continents and oceans are the two major divisions, comprising of all the life and
also the ecosystems throughout the world.

3. • About 75 % of the earth’ surface is covered with oceanic waters which has a very
rich wealth of marine life.
• The ocean is a major source of food, energy, and mineral resources.
• Aquatic Ecosystems are classified into two types as freshwater ecosystems and
marine ecosystems.

4. • Marine ecosystems also include the salt marshes and wetlands located along the
shores and river mouths.
• Within the coastal zone, several unique habitats like estuaries, tidal inlets, and
foreshore ecosystems are also included.
• The subject of Physical geography includes the study of all these ecosystems
• The following aspects are to be studied under marine ecosystems:
1. Characteristics of Marine Ecosystems
2. Oceans
3. Estuaries
4. On-shore ecosystems.
5. Coral reefs.

5. 1. CHARACTERISTICS OF MARINE ECOSYSTEMS
• Marine ecosystem is characterized by the many biotic and abiotic components.
• Biotic components are:
Organisms and their species
Predators, Parasites, Competitors and
Mates.

6. • The Abiotic Components (Physical and Chemical) are:
Temperature
Concentration of Nutrients
Sunlight
Turbulence
Salinity and density.
• The following are the properties affecting the life in the seas and oceans:
1. Quality of sea water
2. Skeleton shape and size of organisms
3. Buoyancy
4. Gravity

7. 5. Temperature of water
6. Density of water
7. Light penetration in water
8. Availability of Nutrients
9. Water turbulence and
10. Hydrostatic pressure.
• Marine environments have altogether different kinds of Physical conditions for
life to survive.

8. • Majority of marine plants are floating species and microscopic.
• Many marine animals are invertebrates. They do not have massive skeletons.
• For floating and swimming, marine life require little energy. Water which is a
fundamental constituent of all living organisms, is available in plenty within
these marine environments.

9. • It is a fact that 50% of the total solar radiation which penetrates into the sea
surface, gets disappeared rapidly within a few meters of depth.many of the
marine life depends on the availability of essential nutrients only.
• It is also to be noted that the zone just below the sea surface, experiences the
maximum environmental fluctuation.

10. 2. OCEANS
• The World Oceans are the huge volumes of sea water belonging to the
hydrosphere.
• Oceans cover more than 70 per cent of the earth's surface. About 97 per cent of
all the water available on the earth are in the oceans.

11. • When compared to land based terrestrial ecosystems, the marine ecosystems
have certain unique features.
They are:
• The oceanic systems are very deep in which life extends to all depths.
• The water masses of sea and oceans are continuous.
• The water is in continuous movement in both vertical and horizontal
dimensions.
• The water is salty with an average salt content of 35 g/litre.
• The concentration of dissolved nutrients is low.

12. • The Divisions of Marine environment included in the study of open sea are:
a) Pelagic environment,
b) Epipelagic environment,
c) Mesopelagic zone,
d) Bathypelagic zone,
e) Abyssopelagic zone, and
f) Benthic environment- sea bottom......

13. • There are two kinds of animals.
• 1. Stenothermal animals – the ones which live within 20°C
• 2. Eurythermal animals – the animals which can withstand the wide range of
temperature variations
• The surface temperature of the oceanic waters vary from about -2 °C near the
North and South poles to about 30 °C near the equator.

14. Based on the intensity of light the water body of marine ecosystems can be
differentiated into three zones.
They are:
• Euphotic zone -extends upto 100 m depth, illuminated zone production zone ,
rich with phytoplankton, primary consumers and secondary consumers.
• Disphotic zone - lies between 100 and 200 m depth, weakly lighted, secondary
consumers live with a few primary consumers, Rare plant life.

15. • Aphotic zone - above 200m depth , No light, no producers, no photosynthesis,
secondary consumers, feed on other animals also.
• Euphotic Zone is the uppermost layer of the world's oceans.

16. 3. ESTUARIES
• Estuaries are the coastal areas where the saline waters of the ocean meet with the
fresh water of the rivers.
• Estuarine habitats are usually very productive because of the accumulation of
nutrients from a large catchment of a river
• Estuarine waters are used for cooling of water in power generation plants
• These are the breeding habitat for a variety of Shrimp and Prawn species, oysters
and fishes.

17. • Structurally, they are deep funnel shaped mouths.
They are complex ecosystem comprising of three
zones as:
• Polyhaline zone(low salt)
• Mesohaline zone (medium salt) and
• Oligohaline zone(fully saline).

18. • It is called as Polyhaline zone. The
total dissolved salts of this zone may
range from 30 to 35 ppt.
• The middle estuary which is subject to
mixing of salt and freshwater is called
as the mesohaline zone.
• The salinities of this zone may be
around 15 ppt in the waters.
• The upper or fluvial estuary which is
characterized by the flow of
freshwater is known as oligohaline
zone.

19. • The level of salinity in such zone may be around 0 to 5 ppt.
• Ecologically, an estuary is an area of dynamic biogeochemical activity.
• Estuaries are critical for the survival of many species of birds, mammals, fish and
other wildlife
• The Biota of Estuaries are classified as
a) Producers
b) Zooplanktons
c) Benthic invertebrates

20. d) Fishes
e) Birds and wildlife
The Producers include:
Phytoplankton - diatoms, dinoflagellates, green algae.
Macroalgae - red algae, green algae, brown algae.
Microalgae - benthic diatoms.
SAV – seagrasses are common in estuaries.

21. 2. Zooplankton - grazing herbivores & carnivores. They include Copepods, larval
fish, fish eggs, chaetognaths.
• Larval invertebrates - oysters, clams, corals, etc
• jellyfish (small & large)
• ctenophores - very abundant in plankton of estuaries

22. • The benthic invertebrates include:
clams, oysters, mussels, snails (mollusks),polychaete worms,amphipods
• decapods - crabs, shrimp, lobsters

23. 4. ON-SHORE ECOSYSTEMS
• Marine Ecosystems are distributed as on-shore and off-shore ecosystems.
• The on-shore ecosystems are very typical ecosystems subjected to the everlasting
action of waves and tidal influences.
• The life of on-shore ecosystems are always under the dynamic impact of various
factors including human interventions. They are called as Foreshores.
• Foreshores are the lands bordering the seas and oceans. The geomorphology of
foreshores may vary from place to place and based on the slope of continental
margins.

24. • The abiotic factors controlling the fauna and flora of foreshores are:
1. Geomorphic factors- Width, length, Slope, thickness and Geology of the coastline.
2. Hydrographic factors- Water and its salinity.
3. Light
4. Temperature, Air, Wind and humidity.
5. Tides, Waves and mean sea level.
The notable fore-shore ecosystems are
a) Sandy foreshore,
b) Shingle foreshores,
c ) Lagoons,
d) Muddy foreshores

25. 5. CORAL REEFS
• Coral reefs are major geological structures built by biological activity.
• `Corals' can be seen along some of the beaches, looking as a piece of rock-like
material.
• The corals are the skeletons of many tiny sea animals living side by side. Each
one of these animals is known as a coral " polyp".
• A coral polyp is a soft, almost transparent animal which builds its own skeleton
outside its body. Since it has no backbone, it is an invertebrate.
• Corals which produce a hard skeleton are called stony corals.

26. • Corals belong to a large group of invertebrates which includes jelly fish, sea
anemones and hydroids

27. The types of corals are
A . STONY CORALS :
1. Stony corals
2. Finger corals
3. Fungus coral
4. Brain coral
5. Tube coral
6. Rose coral
7. Staghorn coral
8. Lettuce-leaf coral

28. B. SOFT CORALS :
1. Sea fan
2. Bushy soft coral
3. Sea feather
4. Black coral.
The live hard corals can be divided into
four major forms:
a. Branching
b. massive
c. Tabulate / flat
d. Others.

29. The best temperature for coral growth is 18°C
Factors influencing Coasts:
• Lithology/ rock types
• Geological Structures
• Processes
• Sea-level changes
• Human Impacts
• Ecosystem types

30. Lithology
• Hard rocks
• Granite, Basalt
• Rugged landscape
• Soft rocks
• Sands/ gravels
• Flatter landscape

31. GEOLOGICAL STRUCTURE
• Concordant Coast
• Discordant Coast

32. Human Impacts
• Modification by humans
• To protect settlements near the coast
• Mitigate problems of erosion
• Primary industries/ agriculture/ aquaculture
• Industries/ Tourism
• Mining
• Impacts of externality