How do ocean currents and water masses differ in their impacts on marine life and coastal environment? Give suitable examples.

Ocean Streams are water currents flowing linearly along a fixed path. E.g.: Canary, Kurosiwo, North Atlantic Drift etc. Water Masses, on the other hand, are large volumes of water comparable to seas or oceans characterised by a gradual change in temperature and salinity. 

Impacts of ocean Currents on marine life and Coastal Environment:

1. Distribution of nutrients, oxygen and plankton.

2. Aquatic animals often follow ocean currents in their migratory cycle.

3. Mixing of cold and warm currents lead to nutrient rich waters, thus provisioning fish rich water regions.

4. Maintain heat balance by transporting heat away from lower latitudes to higher ones.

5. Produce an oceanic effect on coastal areas preventing extreme temperatures. E.g.: land and sea breeze.

6. Ocean Currents control moisture distribution and precipitation. E.g.: Cold canary current has contributed to the dry Sahara Desert in Africa. 

Impacts of water masses on marine life and Coastal Environment:

1. It is a zone of uniform temperature and salinity gradient: Help maintain homeostasis in aquatic animals.

2. Diversity of aquatic species is due to differences in the temperature, salinity and thus composition of different water masses.

3. Upwelling pushes nutrient rich waters to near the surfaces.

4. Downwelling helps in dissolved oxygen reaching the depths.

5. The upwelling and downwelling help prevent creation of hypoxic zones in water bodies.

6. Water masses are associated with weather phenomena like cyclones, troughs, etc.

The role of ocean currents and water masses are critical yet complex. Anthropogenic activities are changing the way these systems work, which has been characterised by changing climatic behaviour in the form of increased intensity and frequency of cyclones, rainfall etc.