In the “Next” section of the October 2011 issues of National Geographic magazine there was an article called Jellyfish currents. John Dabiri, a researcher at Caltech wanted to know if the amount of water jellyfish displace when moving affected the ecosystem. From his experiment he concluded that as jellyfish move hundreds of feet up to the surface every day they are dragging cold, nutrient-rich waters from the ocean deep up and then pulling warm water back down on their decent.
My reason for sharing this with you is because I think it highlights the fact that each species plays an integral part in the ecosystem and that in most cases we have no idea what it is. In this example someone took the time to ask a question about a specific species and its role in the larger ecosystem and the result was mind-blowing. I don’t think that most people would trumpet jellyfish as a critical component in the ocean environment or that they would believe that jellyfish combined other small organisms could rival tides in the impact they have on moving ocean water. This example leaves me wondering, how many species are there who have a profound impact on the environment, without us realizing it? My guess is all of them. This is why I am a conservationist, because we don’t know what the loss of one species will have on fragile ecosystems.
In the jellyfish example, the jellyfish’s action is not extraordinary. It is moving from the bottom of the ocean to the top to feed, which is required for the jellyfish to stay alive. While the intent for the jellyfish is to find food, the result is much further reaching; moving water and nutrients allows for other species to flourish. The absences of these creatures would be devastation for the ocean’s ecosystem, without jellyfish all of the surface species that require nutrients from the ocean floor and all of the deep species that require warmer water would not be able to exist.
On the flip side having too many of one species changes a positive impact into a negative one. For example elephants knock over trees. It’s natural and in ideal conditions it’s good for the environment. They get rid of weak or sick trees. They create areas for new trees to grow in the bush and the down trees create an ideal living space for other species. However, due to habitat loss and deforestation, there are more elephants than the land can support. In these places too many trees are being knocked down by the elephants and the result is that antelope species are not able to hide from predators and their numbers are dropping. In the short-term the easy prey will boost predator populations, but without a steady food source future generations will not be able to survive… all because of the number of trees that elephants knock down.
These two examples are supposed to show the delicate nature of two every different ecosystems. These are just two examples and we have them because someone was interested in the impact of a specific action on the environment. However there are far more instances where the organism or action has not been studied and therefore we have no idea what will happen without that species, or in the case of the elephants an imbalance between the number of species and the amount of habitat available to them. This unknown is the foundation of my belief that it is important to leave as much of the natural world intact as possible, because we just don’t know and extinction cannot be reversed.