Shark Population Lab Report

Melissa Ramessar

TA: John

August 20th 2015

Lab section M 13

The effect on decreasing numbers in the shark population

Summary

There is a rapid increase of rays, skates and numerous small pieces as a result of the decrease of sharks along the eastern seaboard. As a result of intense fishing of sharks in the northwest Atlantic over the past few decades, the shellfish populations such as scallops and Chesapeake bay oysters are decreasing. One of the contributions to the 73 million sharks killed each year is due to the supply of fins need to make the Chinese delicacy shark fin soup. According to Charles Peterson, a marine sciences biology and ecology professor at the University of North Carolina, between 1970 to 2005; there was a 97 percent decrease in the scalloped hammerhead and tiger sharks along the east coast. During that time, 14 different prey species’ populations increased. Moreover, overfishing is a contribution in the declining numbers of sharks. People are more open to trying different foods

According to Fredrick Humber, a marine sciences professor at University of South Alabama, the ocean-bottom sampling reveled that migrating rays are eating all adult scallops which prompted the state to close bay scallop fishery in 2004. In addition, because of the dense population of cownose rays, scientists are worried the rays will begin targeting other species. (Peterson 2015).

The information provided by the journal articles did contribute to the take home message. This topic has made me think differently because usually sharks are looked upon as the predator by humans; however, in this scenario they are the prey. The decreasing numbers of the sharks has also impacted the food chains. There is now more prey with fewer predators and there is a risk that a new predator may evolve targeting other species.