Final answer:
Adaptations for organisms living in the intertidal zone include tough exoskeletons, cement-like secretions for attachment, and physiological adaptations in estuarine plants and animals to cope with variable salinity.
Step-by-step explanation:
The intertidal zone is a challenging environment where organisms must adapt to being dry for long periods, experiencing rapid changes in water coverage and temperature, and enduring the physical force of waves. Three notable adaptations to live in intertidal soft sediments include:
- Exoskeletons in crustaceans that provide protection from drying out (desiccation) and wave damage.
- Cement-like secretions by barnacles to anchor them firmly to surfaces, mitigating the impact of waves.
- Physiological adaptations in estuarine plants and animals like halophytes, which can tolerate salty conditions and animals that switch between aerobic and anaerobic respiration in response to changing salinity levels.
These adaptations enable the survival of diverse life forms in an ecosystem where the conditions fluctuate between aquatic and terrestrial.