To the Save the Smalltooth Sawfish Foundation:
The smalltooth sawfish is one of many members of a group called elasmobranches. This group is very powerful and very influential in the ocean. Elasmobranches represent creatures from all over the ocean food chain. Perhaps most impressive is that elasmobranches are actually the top of the ocean food chain. They are not only rays and scates, but they are sharks as well. The smalltooth sawfish is in fact a shark itself. Like I said, sharks are the top of the ocean food chain and play a very important role in our ecosystem. They are the clean up crew of the ocean. They clean dead, decaying materials from ocean reefs, make dinner out of rotting carcasses and basically nothing goes to waste with the sharks around. They are also the most feared creatures of the ocean with their bad reputations of thrashing and murdering innocent passer bys, but what exactly would our oceans be like if these creatures became extinct? With the disappearance of the sharks make the oceans an easier place to live or do we actually need a top to the food chain?
A food web is composed of four layers. The producers are the autotrophs located at the bottom levels. The primary consumer is the next level, followed by the secondary consumer and the third and final level being the tertiary consumer. These are the levels of our ecosystems. Each level is affected by the next. The smalltooth sawfish is a shark, but it is a small shark so it is located at the secondary consumer level. If the extinction of this species occurred it would not only affect the population of the primary consumers, but the tertiary consumers as well. Sharks make up the majority of these two top levels of the ocean food chain. If these elasmobranches became extinct it could cause overpopulation in fish. “Without them, numbers of mid-sized and smaller fish can quickly boom and then crash when their own food supply runs out” (Shark Finning). I propose an experiment to test the population of fish in waters where sharks are less abundant compared to where many sharks reside. I suspect that the number of fish in the waters where there are less sharks present will be greatly larger than those of waters that have high numbers of shark populations.
In order to test my hypothesis I have come up with an experiment. First we will look at some coasts that have a higher number of shark populations. I suggest we start with several waters of the coast of Australia. According to the website Shark Bay: Sea Week 2005, out of the 370 shark species present today, almost half of them mainly reside in Australian waters. By scuba diving with experts we can take an observation of the population of sharks. We can then observe the amount of fish. Are there many schools of fish? Are there a lot of solitary fish? What does the dispersment of fish look like? Next, we can travel to the Gulf of Mexico where there is also a larger shark population and observe the same data. Next, we will focus on areas where the shark populations have been observed as declining. Through the use of shark tagging, scientists have been able to figure out this type of data because it lets them know the most popular areas for sharks as well as when the sharks start to leave certain areas (Shark Bay). In Hawaiian waters the population of sharks has been observed to decrease in the last decade (Ichthyology). We will observe the same data for these fish and sharks as we did for the more populated areas. We can also look at areas near the Florida panhandle. This is an area that often has differences in the populations of sharks every year (Ichthyology). After observing this data we will look at our numbers and see if my hypothesis was correct.
I think that this experiment could not only teach us a little bit more about the importance of elasmobranches to the ocean’s eco system, but it could also show how every part of an ecosystem is important. One affects the other and so on. I think research like this could teach us just how important every piece to the ecosystem puzzle is.
Sources
Shark Bay: Seaweek 2005. ND. 5 May 2007.
www.mesa.edu.au/seaweek2005/
Knight, Peter. Shark Finning. Defenders Magazine. December 2002. 6 May 2007
Luer, Carl A. Sharks and Cancer. Florida Program for Shark Research. ND. 6 May
2007. http://flmnh.ufl.edu/fish/sharks/nsrc/sharksandcancer.html
