Types and Characteristics of Estuarine Habitat
Table of Contents
- Definition of estuarine Habitat
- Types and characteristics of estuarine habitat
- Characteristics of estuarine habitat
- Distribution of plants and animals in the estuarine habitats.
- Food chain in estuarine habitats
- Factors affecting estuarine habitats
Definition of Estuarine habitat:
Definition: Estuarine Habitat is a body of water formed at the coast as a result of the action of tides which mix salt water from the sea with freshwater from the land. The mixing of salt water and freshwater result in the formation of brackish water. This brackish water is what is called Estuarine habitat.
READ ALSO – Types of Aquatic Habitats: Characteristics and Examples
Types and Characteristics of Estuarine Habitat
Estuarine habitat is found in the following bodies of water:
Types of Estuarine Habitat
1. Delta: A delta is where a river divides into many channels before entry into the ocean or sea. Brackish water or Estuary (delta) is formed at the mouth of a river as it enters the sea.
2. Lagoon: Lagoon is a body of ocean water that enters into the land through a canal and therefore has the opportunity of mixing with freshwater from rivers and streams.
3. Bay: Bay is a little or small portion of the sea water which enters into the land and mixes up with freshwater from rivers and streams. It should be noted that a lagoon is bigger than a bay and it may be long enough to join the sea at another end while Bay is very small and not long enough to rejoin the sea in another end.
Characteristics of Estuarine habitat
The following are the Characteristics of Estuarine Habitat:
- Fluctuation in salinity: Salinity fluctuate in this habitat. Salinity is lower at the mouth of a river and get higher towards the sea. Salinity is also affected by season. While raining season reduces salinity due to additional freshwater, dry season increases it.
- Turbidity: Turbidity of Estuarine habitat increases especially during the raining season when lots of debris are brought down by rivers to the habitat. This high turbidity also reduces the rate of photosynthesis and respiration by organisms.
- Shallowness of water: Unlike the sea water which is deep, the water in estuarine habitat is very shallow.
- Low species diversity: The estuarine habitat has low diversity of species compared to Marine habitat. Common plant species are phytoplankton, algae, Marsh vegetation etc. wild animal species are crabs, oysters, lobsters, fishes etc.
- Water is affected by tides: Sea water usually flows rapidly into Estuaries at high tides and rushes back into the ocean at low tides.
- High level of nutrients: Estuarine habitat contains abundant nutrients especially the organic detritus which form the bulk of producers in the habitat.
- Low oxygen content: Oxygen content of Estuarine habitat is generally very low and as a result, much of the microbiological activities are anaerobic.
The Distribution of plant and animals in a Estuarine Habitats
Plant species and their adaptive features
- Plankton’s (diatoms): They possess air spaces in their tissues, rhizoids or false feet for attachment to rock shores and air bladder for buoyancy.
- Algae: They possess chlorophyll for photosynthetic activities and small size or large surface area for floating.
- Red mangrove (rhizophora racemosa): It has silt roots which grows down from the stem into the soft mud and develop numerous rootlets which have air spaces for conducting air to the tissues of the roots. The roots also provide support and prevent plant from being washed away by the tides. Again the seed of red mangrove germinate while they are still on parents plants thereby preventing the seedlings from being carried away by water current.
- White mangrove (Avicennia nitida): It has pneumatophores or breathing roots for exchange of gases.
Animals species and their adaptive features in estuarine habitat
- Mosquito larvae and pupae: These organisms possess breathing trumpets for gaseous exchange.
- Crabs: They can burrow fast into the mud against predators, strong waves or tides.
- Water snails and shrimps: These animals can burrow into the mud when the tide is going out, thus escaping the periodic dilution of its external medium.
- Worms: They have strong protective and impermeable covering against high salinity.
- Mud skippers: These animals have fins adapted for crawling when on land and for swimming when in water.
- Fishes: Fishes like tilapia have fins for movement and swim bladder for buoyancy.
What are the Food Chains in Estuarine Habitat?
A typical food chain in an estuarine habitat may have up to three, four or five trophic levels. The factor phytoplankton such as diatoms and detritus form the the basic producers which support the food chain. Some examples of food chain in the Estuarine habitat are:
- Detritus – Worms – Snails – Birds
- Diatoms – Shrimps – Fishes
What are the factors affecting estuarine habitats?
The factors which affect historian habitat are common to aquatic habitats and this include temperature, wind, relative humidity, light and pH.
READ ALSO – Fresh Water Habitats: Types and Characteristics
Revision Questions for Students
- What is Estuarine Habitat?
- List and explain 5 types of Estuarine Habitat.
- Outline 5 characteristics of estuarine habitat.
- Mention any 5 animals species found in estuarine habitat.
- Mention any 5 plants species in estuarine habitat.