Answer:
Underwater plants will receive less light.
Step-by-step explanation:
When sea level rises the amount of solar energy in the aquatic environment is decreased and this makes underwater plants receive less light and their development is impaired. This is because, with less sunlight, aquatic plants are unable to photosynthesize and absorb the carbon needed for their metabolism, thus end up dying and diminishing the plant diversity of the sub-aquatic environment.
In addition, many underwater organisms (such as some fish) feed exclusively on these plants. If these plants fail to grow, these fish will be without food and will eventually die; This will also cause problems for the diversity of the underwater environment.