Professor Loren McClenachen’s talk on the impact of the past in the study of marine ecology was an eye opening talk on the way we study natural ecosystems. Most of her talk centered on the decrease in ecological diversity among the reefs surrounding Florida and its southernmost islands.
One of the most interesting parts of the talk was when she discussed and showed evidence of the shrinking size of fish, especially trophy fish that swim around the reef. She showed pictures of the fish that she took while visiting a fishing boat and its captain. The fish that they had caught on a “good day” looked big to me, but when she showed the pictures of the fish from the 70s they looked even smaller, and as she moved farther back in years the quantity of fish and the size of each fish was bigger and bigger. This was especially startling. We obviously always think of the cost that our actions impose on the life that we can see but not the life that we can’t. While I am a fan of fishing, it was sad to watch what we as humans have done to an ecosystem that is so important and beautiful.
Another organism that we as a species have had an adverse effect on are sponges. Professor McClenachen talked at length about how the growth of the sponging industry in the early 20th century has greatly depleted the abundance and types of sponges that exist in our reefs. The industry started out being dominated by low tech spongers who used tools from the side of canoes to rake sponges off of the bottom of the sea floor. As technology improved, however, spongers who could afford to were able to use new SCUBA technology to dive down and take greater quantities of sponges off the seafloor. This caused massive competition in the industry and is the root of the cause for the depletion of the organism.
One of the major points of Professor McClenachen’s talk was the fact that we assume what we see as being “normal” when in reality we are only seeing a snapshot in time of what something looks like and how it should be. Her example to illustrate this was our study of these underwater ecosystems.
The study and mapping of coral reefs only began 240 years ago, and since then, we have seen a 52% reduction in the amount of coral at those reefs. While obviously this is not a good number, it is not as alarming as some may think. However, scientists now believe that the original amount of coral that we believed existed was much, much greater than what was there when we began studying it all those years ago. In reality, coral depletion is extremely high when we take into account how much coral there was on the Earth prior to onset of our study of the organism. This is a classic example of us, as a people, assuming that what we know is correct or natural. in reality, we must step back from what we know and take into account what was there before us. Not doing so can be harmful and can be conducive to us making false conclusions about important topics