What's one indirect consequence of building seawalls?

a. it rises the sea level, which infiltrates groundwater aquifers.
b. it causes an excess amount of fertilizer to become stuck in the sand.
c. it increases the frequency of algal blooms.
d. the shoreline habitat is destroyed through loss of sand.

The correct answer would be option D.

Explanation:

Sea walls are the structures or the boundaries that are built near the seashore to stops the erosion in coastline due to the waves that damage the shoreline region.

These structures are built of concrete as the main component and are generally very massive as their primary function is to restrict the effect of wave action. The negative consequence related to the building seawall is that it causes a disturbance in the habitat of the shoreline animals.

Thus, the correct answer is option D.

answer: c

explanation: