Overfishing

1. What is overfishing?

http://www.sea-way.org/

          Overfishing is simply overfishing. There is no other explanation for it. It is as simple as it sounds. To break it down for the incompetent, overfishing is simply fishing too much. The ocean is vast, and so is the human race. Seafood makes up such a huge economic market that there is a major demand for it which results in overfishing. Fisherman are sent out by major fishing companies to catch fish such as tuna and cod, two species of fish that are being overfished. Because these fish are in such huge demand in the fishing industry, there isn't enough time for them to reproduce and their populations can't catch up; as a result, overfishing occurs. Catching as many fish at a time may seem idealistic, but it has huge impacts on marine ecosystems. Overfishing is a major environmental problem that should be dealt with if the human race wants to continue to enjoy a nice sushi dinner, or a greasy batch of fish and chips.

2. What causes overfishing?

http://en.wikipedia.org/wiki/Overfishing

          As stated earlier, overfishing occurs because of a huge demand on seafood. Fish such as Tuna and cod are two major species of fish that are being overfished. In the last decade, in the north Atlantic region, commercial fish populations of cod, hake, haddock and flounder have fallen by as much as 95%, prompting calls for urgent measures. Fishing fleets are three to four times as big as needed. There are enough fleets to cover FOUR Earths! Why do we need so much fish? Fish provide a major food source for coastal communities. 1 in 5 people rely on fish as a major source of protein. More and more people are living near coastal areas which means that the demand for seafood is bigger than before. It's not just that there are massive fishing fleets in the world that catch huge amounts of fish, but overfishing also has to do with methods of fishing. Some methods of fishing are very sustainable, like the classic line and hook that you do when fishing with your father in a lake, but new types of fishing styles like bottom trawling result not only in overfishing, but also bycatch, unintentional catching of fish. Fishing styles that are able to catch huge amounts of fish help contribute to the declining populations of marine animals.

3. What are the effects of overfishing?

      Overfishing doesn't just have an effect on the species of fish, it has an effect on all marine life. Overfishing affects biological diversity which includes genetic and species diversity. Altering any one of these aspects of life has severe consequences on a population. Let's take a look at each of these groups.
1. Genetic Diversity
         Fish live in a vast ecosystem and therefore have tons of space to reproduce and grow into a very large population. Since they live in such a big area, they have a lot of genetic diversity among a species. Selection pressures, whether natural or human-related, can remold the heritable adaptations of a species, therefore altering its characteristics over time. More simply stated, fishing can cause evolution. Gene frequency can be altered by overfishing in two ways: if fishing activity applies a selective pressure; and if the fishing activity applies a random pressure so great that the population is driven low enough to reduce genetic variability. 
2. Species Diversity
   Overfishing can affect species diversity by causing extinctions. Overfishing can affect biological diversity by reducing species richness. When an animal's population is decreased to such a low level, it no longer can fulfill its role as prey, predator or competitor and results in the decline of competition or predation, which will allow other species to become more dominant in its ecosystem. 

4. Methods of fishing and how they contribute to overfishing

     Fishing methods help contribute to overfishing with bycatch. As mention earlier, bycatch is the unintentional catching of marine organisms such as turtles, sharks, manta rays and so forth. Most of the time, fisherman do not return these animals back into the sea and when they do, they are nearly dying. Some fishing methods are very unsustainable and others are sustainable. Let's look at some of the fishing methods used to day. 

Bottom Trawling

http://mission-blue.org

     Bottom trawling is when a large net is dragged across the ocean floor. Fisherman usually use this method to catch ship and bottom dwelling fish such as halibut and sole. This method of fishing results in a lot of bycatch. Most of the bycatch is thrown back either dead or dying and this causes problems within marine species. 

Dredging

http://www.montereyfish.com/

     Dredges are large, metal-framed baskets that are dragged across the seafloor to collect shellfish like oysters, clams and scallops. The basket contains metal teeth that help lift it. These teeth dig into the sea floor and significantly impact the seafloor habitat and bottom dwelling species. Dredging also results in a high amount of bycatch. 

http://www.seafoodwatch.org

Harpooning

     Harpooning is a traditional method for catching large fish—and it's still used today by skilled fishermen. Harpooning is environmentally safe because a fisherman only kills what he wants to kill and usually he only catches one fish at a time. 

http://www.wakeproject.net/

Long lining

     Long lining employs a central fishing line that can range from one to 50 miles long; this line is strung with smaller lines of baited hooks, dangling at evenly spaced intervals. Longlines can be set at different depths depending what a fisherman is trying to catch. This is good because fisherman only catch one fish on each line and the amount of bycatch is very little although a turtle or unwanted fish may be caught every once in a while. 

http://www.seafoodwatch.org

Pole/troll

     Pole-and-line fishermen use the classic method of fishing. They cast a fishing wire into the ocean and catch one fish at a time. This type of fishing is environmentally stable because fisherman can throw unwanted catches back into the ocean and they are only catching one fish at a time. 

Purse Seining

http://www.montereyfish.com/

     Purse seining is used to catch schools of fish such as sardines or squids. Purse seining involves creating a large wall of netting to encircle the school of fish. Fishermen then pull the bottom of the netting closed to move the fish to the center.  This results in bycatch  which is not good. 

5. What can be done to stop overfishing?

     There are 2 major ways we can stop overfishing:

          1. Spread awareness

              To be completely honest, I had no idea that overfishing was a problem until my geography professor introduced the topic one day during lecture; that was a couple months ago. In order to solve this problem, the issue needs to be spread. Environmental issues are a big problem in our society. Unlike global warming, the effects of overfishing will have an immediate consequence on marine ecosystem and more importantly on the human race. We rely so heavily of the oceans that we don't even know it. Spreading awareness is the most important way to help stop overfishing. The more people know about the issue, the more effort there will be to try and stop it.

http://www.seafoodwatch.org/cr/cr_seafoodwatch/download.aspx

           2. Stop eating fish (or at least from certain regions)
               It's simple, don't eat it! Fish are friends Not food!! The Monterey Bay Aquarium has these things that I like to call fish cards. The card is divided up into 3 regions, the good, the ok and the ugly. Each section gives a type of fish, and where it comes from. If it's in the good section, it is safe to eat, if it's in the okay section, you can eat it, but highly recommended that you don't. If it is in the ugly section, order something else my friend because you will be a contributor to overfishing. How would you like to be the reason why a certain type of fish went extinct? You wouldn't, so don't eat it!!! Next time you feel like eating some sushi, as where the tuna came from. If it is on your fish card, don't eat it and order something else.

Bibliography

1. "Fishing and Farming Methods." Monterey Bay Aquarium Seafood Watch. N.p.. Web. 25 Feb 2014. <http://www.seafoodwatch.org/cr/cr_seafoodwatch/sfw_gear.asp&xgt;.
2. Koster, Pepijn . "Overfishing-A global disaster."Overfishing. N.p.. Web. 25 Feb 2014. <http://overfishing.org/pages/why_is_overfishing_a_problem.php>.
3. Lee, Mercedes, and Carl Safina. "Effects of Overfishing on Marine BioDiversity." . N.p.. Web. 25 Feb 2014. <http://www.rain.org/~cdem/aoc/impacts/content/biodiversity.html>.
4. "Overfishing: A threat to marine biodiversity." . N.p.. Web. 25 Feb 2014. <http://www.un.org/events/tenstories/06/story.asp?storyID=800>.
5. "Overfishing." . N.p.. Web. 25 Feb 2014. <http://worldwildlife.org/threats/overfishing>.