Question

A pond serves as a good example for a ________ water ecosystem.
A.Fresh
B.Brackish
C.Marine
D.Sea

Answer 1

Ecosystems like forests, wetlands and grasslands are a critical part of the water cycle. All freshwater ecosystems ultimately depend on the continued healthy functioning of ecosystems, and recognizing the water cycle as a biophysical process is important to achieving sustainable water management.

Complete answer:

Wetlands, rivers, lakes are all aquatic ecosystems and elements of Earth’s dynamic processes which are essential to human economies and health. Aquatic ecosystems include microorganisms, invertebrates, insects, plants, and fish.
A pond or lake ecosystem includes biotic as well as abiotic components. Pond and lake are aquatic ecosystems within which, like other ecosystems, there are two main components i.e., the abiotic component of a pond consists of water, dissolved minerals, oxygen and CO2. Solar radiations are the most energy source of energy whereas, the biotic component includes producers, consumers, decomposers and transformers.
Pond and lake ecosystems are a main example of lentic ecosystems. Lentic refers to stationary or relatively still water, from the Latin lentus, which implies sluggish. A typical lake has distinct zones of biological communities linked to the organic structure of the lake. The coast is near the shore area where sunlight penetrates all of the sediment and allows aquatic plants (macrophytes) to grow. Light levels of about 1% or less of surface values usually define this depth. The first light level also defines the euphotic zone of the lake, which is that layer from the surface right down to the depth where light levels become too low for photosynthesizers. In most lakes, the sunlit euphotic zone occurs within the epilimnion. However, in unusually transparent lakes, photosynthesis may occur well below the thermocline into the perennially cold hypolimnion.
The limnetic zone is the open water area where light doesn't generally penetrate all the thanks to the underside. The underside sediment, referred to as the benthic zone, contains a surface layer abundant with organisms. This upper layer of sediments could also be mixed by the activity of the benthic organisms that live there, often to a depth of 2- 5 cm (several inches) in rich organic sediments. Most of the organisms within the benthic zone are invertebrates or small crustaceans.

Hence, the correct answer is option (A)

Note: Aquatic biodiversity could be a major concern in conservation and restoration projects, also as water resource management. The major issue of biological health of wetlands, rivers, and lakes has led to the thought of ‘ecosystem services’ as a method to quantify or assess the worth provided to society by different natural environments, including aquatic environments.