Effects of Overfishing Bluefin Tuna

Technological advancements have allowed fishermen to determine the species' migratory patterns making it easier for them to capture the fish at high volume. Another advantage that fishing boats have over the Bluefin tuna is their utilization of a fishing method called Purse Seine fishing (Clark, 1979). In this method, a net that can be as large as 2 square kilometers is spread over an area of water. After the net is in place, bait is spread throughout the area in an effort to attract Bluefin, or whatever fish is being sought out. Using systematic pull levers, the bottom of the net is tightened and all fish in the area are unable to escape. This leads to a different topic that must be lightly touched upon: bycatch. When the nets are drawn in, every organism in the area is caught. That includes, turtles, sharks, dolphins, anything. These different organisms are usually thrown out because most fishing boats are only permitted to catch certain fish. All of these other organisms, some of which are also endangered, are completely wasted. If the Purse Seine method is used to its full potential, in a way that conservation ignorant fishing organizations would want it to be used, the net has the potential to capture an entire school of the Bluefin, killing off an entire population in that area. .
             Harvesting a whole population of Bluefin endemic to a certain area reduces the overall biodiversity of that specific area but it also reduces the biodiversity within Bluefin tuna populations globally because it diminishes their gene pool. Certain harvested populations might have had a unique allele that was potentially beneficial. Losing that population means the allele is gone, leaving the species at higher levels of risk because of an increase in susceptibility to certain diseases, and an inability to adapt to changing environmental landscapes. Furthermore, Bluefin tuna play a specific role in the marine ecosystem in which many different organisms depend on them.