I was thinking of a follow-up post about jellyfish or jellyfish stings until I encountered this article about the growth of jellyfish population in oceans and how it is an indication that something has changed and how it poses as a threat to marine ecosystems. Usually, when someone mentions “species population” and “environmental degradation” we immediately think of words such as “pollution”, “global warming”, and “endangered species”. However, changes in the environment and ecosystems, or environmental degradation is not only hinted by a decline in a certain species’ population. A drastic increase or sightings of a certain species in one area (where it is uncommon) could also mean the same thing.
Phytoplanktons - I’m sure a lot of you have heard of this one, particularly in Ecology class. Anyway, phytoplanktons are best known to be one of the reasons for eutrophication (increase in primary productivity in lakes resulting in lack of oxygen needed by fishes to survive) in lakes and rivers. Eutrophication promotes excessive plant growth and decay and is likely to cause severe reductions in water quality. Enhanced growth of choking aquatic vegetation or phytoplankton disrupts the normal function of the marine ecosystem, causing a variety of problems. You won’t be able to see phytoplanktons directly, but a good sign of high density of their species in a body of water would be the water’s color itself. A bright green color would indicate that there are a lot of phytoplanktons in the water.
Crabs and other Crustaceans - 40 million years ago when the waters in the polar regions froze and lowered the temperature of the water around them, crabs and other marine predators were driven away. Now, with global warming becoming an issue and the temperature level of the waters around the poles increasing, those same predators are going back and would most likely be feeding on the defenseless marine creatures in their new territory. This would throw the ecosystem out of whack and would have a great impact on species diversity.
Jellyfish - Now for the article itself. According to Jacqueline Goy of the Oceanographic Institute of Paris, “Jellyfish are an excellent bellwether for the environment”. Why? This was answered by Ricardo Aguilar, the research director for Oceana, an international conservation organization. According to him, “Jellyfish have come to occupy the place of many other species; when vertebrates, such as fish, disappear, then invertebrates - especially jellyfish - appear. The collapse of fish populations boost this process in two important ways, he added. When predators such as tuna, sharks, and turtles vanish, not only do fewer jellyfish get eaten, they have less competition for food.” This not only poses a threat on the direct environment but also on humans as well. Just imagine encountering an army of those things while swimming. You’ll be covered in jellyfish stings and that would most likely prove fatal.
