Question

:how might a history of exposure to wide environmental fluctuation affect the physical tolerances of intertidal species compared to close relatives in sub tidal and oceanic environments .clue...think about chemical and physical conditions..?

Answer 1

The intertidal zone area is the link between the land and the sea. It has high and low tides. High tides have more waves with tremendous force, whereas low tides have fewer waves. The intertidal species are much more tolerant to various physical and chemical conditions in compare to species living at other oceanic environments. This adaptation occurs due to low and high tides. The conditions and comparisons to other oceanic levels are:

1) Light: The organisms in the intertidal zone face increased light during the low tides because they are exposed to the sun directly. On the other hand, high tide zone provides them less light due to the layers of interference. The organisms are able to survive in both conditions.

2) Temperature: High tides are responsible to increase the temperature and low tides are responsible to decrease the temperature up to 40 degree centigrade. The organisms in the intertidal zone are adopted to avoid desiccation, and maintain their internal temperature. In contrast, the maximum variance in the sheltered zones is from 18 degree to 23 degree centigrade.

3) Water movement: The rise and fall of tides varies from few centimetres to 15 meters at different regions of intertidal zones. The organisms experience a strong variation in the energy of waves. This variation is seldom experienced by the species in sheltered zone and bays.

4) Chemical conditions: Chemical conditions such as salinity, oxygen content, nutrient concentration, change with high and low tides depending on the sediments and circulation of air. Such changes are tolerated by the intertidal species. On the other side, species in sheltered zones are never exposed to such huge variations. So, adaptation is not required for them.

The following adaptations those are present in intertidal species but not present in sheltered zone species:

A) Vertical zonation

B) Desiccation tolerance

C) Crawling: To avoid extreme temperature, hiding in cool places.

D) Immune response: Recover from temperature stress infections.

E) Hard rock attachment