Saltwater Oceans Compare and Contrast

SALTWATER OCEANS COMPARE and CONTRAST

To FRESHWATER LAKES AND RIVERS

COMPARE AND CONTRAST

In some respects, oceans and inland freshwater lakes are very different; in other respects, they are not as different as they may appear superficially. Similarly, while biological organisms that populate the oceans do differ from those that populate freshwater lakes, in many ways they may also be more similar than dissimilar.

While oceans are considered to be a saltwater environment, so-called "freshwater" also contains substantial amounts of salt and other minerals. That is because ocean water is significantly more salty than freshwater, but only relative to one another. A simple taste test between freshwater (including filtered and treated municipal drinking water) and distilled water illustrates the point. In comparison to distilled water, even freshwater that has been chemically treated and filtered still has a very noticeable flavor attributable to salts and other minerals that survive the filtration and chemical treatment processes. Without a specific comparison to distilled water, even a glass of freshwater with a few grains of table salt sprinkled into it does not taste particularly salty either.

The presence of salts and other dissolved minerals in ordinary freshwater drinking water is also evidenced by the fact that tap water often leaves significant rust, lime, carbon, and other deposits on porcelain surfaces despite being treated and filtered freshwater. Therefore, the primary difference between ocean saltwater and freshwater is not that only the former necessarily contains any salt or minerals; their difference is much more one of degree than the presence or complete absence of salts and other dissolved minerals. Actually, both ocean saltwater and fresh lake water contain some of the identical types of salts and mineral compositions; their main difference is that ocean saltwater is much more saturated with dissolved salts and minerals, whereas the typical saturation levels of those salts and minerals in lake water is so much less that it can be difficult to taste at all without a comparison to distilled water containing no dissolved impurities at all.

Just as the physical properties of ocean water and lake water differ from one another in some ways but relatively similar in others, that is also the case with much of the biological life in the respective environments. On one hand, many freshwater animals (such as beaver, muskrat, mink, and otter) typically live in lakes but also spend a significant amount of time on land. Meanwhile, ocean seals and penguins spend much more time in the water by comparison. Likewise, the organisms living in the ocean tend to grow much larger than their freshwater counterparts.