SAV Growing Conditions
Underwater plants grow submerged in areas where the conditions are just right.
One key factor is sunlight because these plants need light to make food, so they grow in shallow, clear water where sunlight can reach the bottom.
Salinity, or how salty the water is, also matters because some plants prefer fresh water, while others thrive in salty or brackish water.
Water movement is important too—while some plants can handle strong currents, others need calm waters to stay rooted.
The bottom surface, or substrate, is another factor. These plants needs soft sand, mud, or other stable materials to anchor its roots.
Finally, temperature plays a role because each plant has a range of temperatures where it grows best. All these factors combine to determine where SAV can live and grow.
Water + Salt Affects What Plants Live Where
Salinity, or the saltiness of water, is a key factor shaping where aquatic plants grow, creating distinct zones that affect species diversity, or the variety in types of plants.
Salinity is measured in parts per thousand (ppt), creating zones classified as tidal fresh (0–0.5 ppt), oligohaline (0.5–5 ppt), mesohaline (5–18 ppt), and polyhaline (18–30 ppt).
Lower salinity zones, like tidal fresh and oligohaline areas, often have higher diversity, or more types of plants, because more species can survive in these conditions. In contrast, higher salinity zones, like polyhaline waters, have lower diversity species that are adapted to saltier environments.
Explore the map below to see how salinity impacts plant diversity across Delaware: