Final answer:
Subtidal pods on land are a concern because they indicate a change in land formation caused by rising sea levels and saltwater intrusion, which create areas for invasive vegetation to grow.
Step-by-step explanation:
Subtidal pods on land are a concern because they indicate a change in land formation. These pods are formed when sea levels rise and cause saltwater intrusion, leading to the deposition of sediment and creating new land areas. This expansion of land provides opportunities for invasive vegetation to grow, which can have negative effects on the native ecosystem.
Learn more about the impact of subtidal pods on land