Answer:
Both the biotic and abiotic components of an ecosystem play an important role in the biodiversity of the ecosystem.
In an aquatic ecosystem, crucial components which affect biodiversity are:
Temperature: In the oceans, there will be more biodiversity in areas where the water will be warmer as compared to areas where the water will be cooler.
Light: There will be more number of aquatic plants present in the areas of the river which can receive more sunlight. These plants will serve as a food source for other aquatic animals. Hence, biodiversity will be more in areas which will receive more light.
Preys: There will be more biodiversity in areas where aquatic preys, such as small fishes, will be in abundance.