3.Physiological adaptations

 Physiological Adaptations

Less obvious, but vital to survival, are problems related to temperature variation, changes in salinity, stresses resulting from discontinuous feeding, timing of spawning activity, variation in oxygen, and changes in pH. Each of these factors varies in importance depending on the nature of the particular coastal area.

· Temperature: Organisms exposed at low tide are subjected to a wider range of temperatures than they would be if continuously covered by water. Survival is enhanced by being physiologically able to withstand large temperature ranges (eurythermal) and by evaporating water to remove heat.

· Salinity: Organisms living in the intertidal region must withstand greater extremes of salinity than organisms from other environments; evaporation during warm summer days causes the tidal pools to become more salty, while precipitation decreases the salinity of a tide pool. Many organisms clamp up in order to maintain the salinity within narrow ranges.

· Oxygen: Exposed tide pools may become depleted of oxygen. Similar physiological and behavioral adaptations discussed above allow for survival during long periods without new seawater.

· pH: Sea water has a phenomenal ability to continually absorb acid without changing pH. This is particularly helpful to tide pool organisms stranded for long periods without new ocean water.

Last modified: Thursday, 28 June 2012, 5:19 AM