Fertilizers are commonly used substances that aid in the growth of many different fruit and vegetable species. Unfortunately, these substances are often toxic, or create undesirable organic reactions. People often consider the harmful effects of toxic substances on terrestrial species. However, what many people do not realize is that terrestrial fertilizers can also be very damaging to marine ecosystems.
Fertilizers reach marine ecosystems through runoff. When it rains, the growth aids in the soil drift. These substances eventually make their way into rivers and streams. From there, they flow through the water and are eventually carried to the ocean.
Once they reach the ocean, the many nutrients, including high levels of nitrogen, that the fertilizers are carrying are released into the water. Normally, marine ecosystems do contain some of these nutrients. They help marine plants, including algae, grow. However, when such strong levels of the nutrients are released, some algae species explode in growth. These growth explosions are known as red or brown tides, depending on the type of algae affected.
As the algae blooms, it releases harmful toxins. In normal levels, these toxins would not have much effect on marine creatures. However, in such large amounts, these toxins can easily poison many different types of marine life. In addition, algae require a great deal of oxygen in order to grow. Because of this, the water may become oxygen deprived, suffocating other marine creatures. Sometimes, the algae and its toxins are so overwhelming that an ecosystem is essentially shut down. Whole areas may become dead spots, places where normal marine life can no longer thrive or live at all.
These harmful algae blooms may eventually die down. However, even when the algae’s effect decreases, it can still take many years for a particular ecosystem to return to its former, healthy self. These lasting, damaging effects can also harm neighboring ecosystems that rely on the various fish and crustaceans to survive.
Today, many studies are being conducted that test the actual effects of fertilizer runoff and pollution on marine ecosystems. As the evidence piles up, more and more scientists believe that toxic runoff is a real problem. It is also thought that some kind of regulations will need to be put into practice in order to protect marine life in the future.
Images via eutrophication&hypoxia