The main difference between littoral limnetic zone is that littoral zone is a well-lit area that is shallow, close to the shore, and contains rooted plant growth, whereas limnetic zone is open and does not contain any rooted plant growth.
Littoral and limnetic zone are two types of primary lake zones whose main difference is the presence of rooted plants. The other primary lake zones include profundal, euphotic, and benthic zones.
Key Areas Covered
1. What is Littoral Zone
– Definition, Structure, Function
2. What is Limnetic Zone
– Definition, Structure, Function
3. Similarities Between Littoral and Limnetic Zone
– Outline of Common Features
4. Difference Between Littoral and Limnetic Zone
– Comparison of Key Differences
Key Terms
Limnetic Zone, Littoral Zone
What is Littoral Zone
The littoral zone is the shore area of a pond, lake, or sea. It contains an area of dry land that slopes to an open area of water. Generally, the littoral zone can be either narrow or very wide. Young ponds typically have narrow littoral zones. They also have steep sides. In addition, young ponds are oligotrophic. In contrast, old ponds that are eutrophic contain wide littoral zones. The sides of the shoreline slope. The littoral zone is shallow, and due to the process of runoff, this zone contains a lot of nutrients. However, the littoral zone is a non-point source of pollution.
Figure 1: Littoral Zone
Furthermore, the main feature of a littoral zone is the abundance of aquatic plant growth and algae growth. Additionally, cattails, crawfish, insects, snails, reeds, small fish, and zooplankton are the other inhabitants of the littoral zone. The sunlight does not penetrate all the way to the sediments. Generally, the euphotic zone of the lake is defined by the presence of a 1% sunlight level. There, the light level is too low for photosynthesis.
What is Limnetic Zone
The limnetic zone is the open water area of the lake or pond. It is a much larger section of water in oligotrophic ponds. In comparison, in eutrophic ponds, the limnetic zone is small. In addition, in the limnetic zone, there are two separate sections: open-water zone and deep-water zone. Usually, an open-water zone is the upper portion of the limnetic zone, and it is called a photic zone. The main characteristic feature of this zone is the penetration of sunlight through the water layer. Therefore, it is the warm water layer of the lake. Therefore, this zone contains thriving algae and other aquatic plants. In addition to that, this layer contains a dense fish population. Oxygen level is higher in this zone due to the contact with air.
Figure 2: Limnetic Zone
Moreover, the deep-water zone is the zone that occurs below the open-water zone, and it is called the aphotic zone. Usually, the deep-water zone does not contain a penetration of sunlight. It also does not contain a higher level of oxygen. Therefore, this zone does not show a higher growth of plants or a higher population of fish. However, the community of the limnetic zone is complex. Normally, zooplankton includes copepods, cladocerans, and rotifers.
Similarities Between Littoral and Limnetic Zone
- Littoral and limnetic zone are two types of primary lake zones.
- They occur in lakes and ponds, dividing the water column from top to bottom and side to side.
- The other zones include profundal, euphotic, and benthic zones.
Difference Between Littoral and Limnetic Zone
Definition
The littoral zone refers to the part of a sea, lake, or river that is close to the shore, while the limnetic zone refers to the open and well-lit area of a free-standing body of freshwater such as a lake or pond.
Occurrence
The littoral zone occurs at the shore, while the limnetic zone occurs before the shore.
Significance
The littoral zone is a well-lit area, while the limnetic zone is open.
Plant Growth
The littoral zone contains rooted plant growth, while the limnetic zone contains a thriving growth of algae and aquatic plants as well as a higher fish population.
Conclusion
In brief, littoral and limnetic zone are two types of primary lake zones. They occur in freestanding bodies of freshwater. Generally, the littoral zone is a part of the lake that is close to the shore. It is a well-lit area. In addition, it contains well-rooted plant growth. In comparison, the limnetic zone is the zone of the lake that occurs before the shore. However, it is open and does not contain rooted plant growth. Therefore, the main difference between littoral and limnetic zone is the type of plant growth.
References:
- Holz, J. Pond & Lake Zone Identification. Kasco Marine.
Image Courtesy:
- “Littoral Zones” By US gov– Own work (Public Domain) via Commons Wikimedia
- “Primary zones of a lake” By Geoff Ruth – Own Work (CC BY-SA 3.0) via Commons Wikimedia
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