Ecosystems where the area is submerged under water at least part of the year are called:

A wetland is an ecosystem in which water either covers the soil or is present at or near the surface for at least part of the year. Water may flow through freshwater wetlands or stay in place. Wetlands are often nutrient-rich, highly productive, and serve as breeding grounds for many organisms.

Explanation:

. fibrinogen is soluble in water and is found in high concentrations in the blood, where it waits until needed to form a clot