Final answer:
Coastal aquatic organisms must be adapted to survive in both low and high salinity environments due to seasonal changes in temperature, ocean currents, and tides.
Step-by-step explanation:
Coastal aquatic organisms must be adapted to survive in both low and high salinity environments due to the influence of seasonal changes in temperature, the varying salinity levels brought in by ocean currents, and the impact of high and low tides on salinity.
For example, estuarine plants called halophytes have adaptations to deal with the salt resulting from saltwater on their roots or from sea spray. Some can remove salt through filters in their roots, while others can pump oxygen into their roots. Animals, such as mussels and clams, have developed behaviors that allow them to function in this ever-changing environment, such as switching from aerobic to anaerobic respiration when exposed to low salinity.