I n contrast to the other salts, the nitrates and phosphates vary in concentration due to biological activity. In surface waters, where plants are actively in the process of photosynthesis, the nitrates and phosphates can be in short supply, limiting the amount of biological activity that can take place. T emperature Temperature is a very important physical parameter in the marine environment. It limits the distribution and ranges of ocean life by affecting the density, salinity, and concentration of dissolved gasses in the oceans, as well as influencing the metabolic rates and reproductive cycles of marine organisms. The seasonal range of temperature in the ocean is affected by latitude , depth, and proximity to the shore.
Marine temperatures change gradually because of the heat capacity of water.
In the abyssal zone, water temperatures are remarkably stable and remain virtually constant throughout the year. Similarly, in equatorial and polar marine regions, ocean temperatures change very little with season. Because the surface of the ocean is heated by sunlight, the depths are cooler. There is a minimum of vertical mixing, because the warm water cannot displace the dense, colder deep water. Temperature Anomalies T he waters of the ocean are in constant motion.