Answer: The kelp might not be able to replenish fast enough once depleted.
Explanation:The kelp is a brown algae that grows as a seaweed. Renewable resources are those resources which can be replenished once used. Non renewable resources are those resources which cannot be replenished once used. According to the given situation, although kelp can be used as renewable biofuel. But with the increase in demand in future, more quantity of the kelp will be required to produce the fuel. This will lead to the extinction of majority of colonies of species. The decrease in abundance of species may not be resustain in future.