Answer:
5 kelps per square meters
Step-by-step explanation:
The population density would be 5 kelps per square meters.
The population density for an organism is defined as the total number of the organism living per unit particular area at a specific time.
Mathematically, the population density for an organisms is expressed as:
Number of organisms/Land area
In this case:
Number of kelp = 2000
Area of land = 400 square meters
Hence, population density of kelp = 2000/400
= 5 kelps per square meters