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Figure-4 shows that rate at which the demand for fish has been met has slowed over the last 30 years due to the increase in the worlds population. The amount of fish per person has gone up, but the amount of that provide for by wild catch has remained constant over the years. The amount of fish per person has been allowed to increase due to the increased supply of fish provided by aquaculture. Because the population is still increasing, the world's demand for fish is increasing. If the amount of fish pulled from the ocean remains constant, as it has over the last 20 or so years, the amount of fish per person will begin to drop if which will cause people to starve, economies to collapse, and our fish stocks to be depleted.
Figure-6
(Left) and Figure-7 (Right)
China is a major fish producer but is also a major consumer. Over the last few years, China has been putting more stock into aquaculture which has caused the amount of fish they produce to increase overall and the amount of wild catch to level off.
All facts and figures from this section come from the supplied tables.
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The main culprit here is a fishing method called bottom trawling. Bottom trawling is usually done by one or two fishing boats vessels with a large net that is dragged along the bottom for a few hours at a speed of three or four knots. Target species vary widely, and can include orange roughy, hoki, ling, hake, and squid (Starfish, 2003). There are several types of bottom trawls: dredging, beam trawls, and demersal otter trawls. Each of these methods involve scraping the bottom of the ocean floor with a rigid metal frame, causing massive damage (FishOnline, 2007). Some of the newest equipment is even worse; "rockhopper" equipment, which is used in areas that have rough terrain, involve rolling weighty wheels over the sea floor, crushing anything in their way (Safina). Unfortunately, bottom trawling is the world's most lucrative fishing method, and so is quickly replacing much more ocean-floor-friendly methods like hook-and-line and trapping (Gabriel, 2005; Safina, Safina ¶ 4).
Bottom trawls can dig up to several inches into the seabed, disrupting the bottom habitat and the animals that live there, including unique structures made by living creatures. Trawls kill marine life, destroying food sources and shelters, endangering young fish and thus future generations of oceanic fauna (Safina ¶ , 5). Lab studies of the relationship between sea floor composition and predation showed that more complex habitats like rocks, rather than simple habitats like sand or mud, gave prey fish like young cod more time to escape their predators (Safina). For a sense of scale, George's Bank is trawled 3 or 4 times a year, regions of the North Sea as many as 7 times, and Queensland of Australia as many as 8 times a year. Each trawl pass kills between 5 and 20 percent of the marine life on the sea floor, so that even a single year's trawling can wholly take out the bottom life (Safina ¶ , p. 7-8). Deeper areas are affected even more; a study by Watling reveals that "certain bottom communities may need as much as a century" to recover (Safina p18, p. 18).
Dragging metal frames along the ocean floor also kicks up a cloud of sediment. While this does make the nets more efficient, as the dirt helps bring the fish into the net, it also causes numerous problems. The increased amount of particles suspended in the water can diminish light levels and stifle bottom-dwelling inhabitants (Jones, 1992). As little as one millimeter of silt could prevent spat settlement in Ostrea virginica (Jones, 1992). The high turbidity caused by the movement of the trawl frame also inhibit settlement of Pecten novaezelandiae veliger larvae, depress the growth rate of adults, and reduce the metabolism of glycocen stores (Jones, 1992). Trawl gear can also redistribute vertical layers of sediment, mixing organic material into the water, creating anaerobic conditions that can kill scallop larvae (Jones, 1992).
The dragging metal frame of bottom trawlers indirectly kills a great deal of ocean life, including commercial fish such as cod. Is it not, then, in the interest of everyone to find a way to fish without destroying the ocean floor?
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Fishing nets and traps today are made of durable polymer fibers, built to last forever. While this seems great at first, this ability to "last forever" can kill millions of fish and other organisms. When fishing nets or traps are lost due to storms or negligence, they actually continue to catch fish (Gabriel, 2005). And thanks to those polymer fibers, they can keep catching fish or crabs or other life for months, or years. To make matters worse, many traps and nets become self-baiting: fish become trapped in the gear and die, other fish come to feed on the dead fish, become trapped themselves, and continue the cycle until the net becomes completely full (Matsuoka, 2005). This is called "ghost fishing," and it is probably the most frustrating problem plaguing the fishing industry today. Hundreds or thousands of fish or crustaceans can be caught in a single net, and the fish aren't even used in any way; they are completely wasted. According to Laist (1996), ghost fishing may account for up to 30% of the annual landings in some areas. Some countries, such as Sweden, Poland, New Zealand, and the United States, have already instated gear retrieval programs to try to address the issues of ghost fishing, but more, and more universal, measures will be needed if we want to make these issues truly negligible (Brown and Macfadyen, 2007).
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Every fishing methods has a risk of catching and killing non-target fauna, called bycatch. It is by far the most widespread problem; every fishing method is at risk for catching unwanted fish or other fauna (Gabriel, 2005).
Most commercial fishing methods today involve dragging an enormous net through vast amounts of water. Inevitably, these nets will catch fish other than those species the fishermen want. In 2005 alone, 7.3 million tons of commercially viable fish were discarded into the ocean (ICES 2005). This would be fine, if the fish were able to stay alive to breed or be caught later. However, despite federal regulations that bycatch be returned to the ocean as "unharmed as possible," most fish thrown back are either already dead or die shortly afterwards (Turning a Blind Eye p1, p. 1-3). Ironically, such discards are often the result of regulations that are trying to limit overfishing by placing quotas on the amount of fish a boat can bring in, or the minimum size (ICES, 2005).
High mortality rates for non-target fish species can change the ecology of an area by changing the food web relationships, altering predator-prey interactions, and destroying the environment. In the long term, bycatch can lead to overfishing, decreased productivity, and reduction in the amount of catch (Turning A Blind Eye ¶ , p. 5). Almost 1,000 marine mammals, many species of which are critically endangered, die every day due to being tangled in fishing equipment, mainly nets. It is estimated that there are 308,000 accidental marine mammal deaths annually in fishermen's catch (Verrengia ¶ , p. 1). The study indicates that the largest threat facing marine animals is bycatch, more so than pollution and collisions with ships (Verrengia ¶ , p. 4).
Clearly, bycatch is a problem that must be addressed if we are to live in a world of sustainable fisheries.
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Mission 2011 is about saving the oceans and the fisheries, and an integral part of solving the current problem is taking action against all forces of nature which are destroying marine life and the marine environment. One such force which the public is not aware of are the 'Floating Cities' known to the general public as cruise ships. California Represenative Sam Farr, whose district includes the Monterey Bay National Marine Sanctuary, writes, "The pristine ocean cruisers we see in TV commercials are also massive ocean polluters, often generating and dumping wastes equivalent to those of a small city into our coastal waters" (CITATION). Even more devastating are the effects of cruise ships near delicate environments such Caribbean coral reefs, where the effects of pollution are magnified: cruise ships are allowed to dump raw, untreated sewage into the ocean after the ship has moved beyond the three-mile limit, and many ships routinely perform this action. Indeed, this waste is filled with bacteria killing and sickening marine life and harming human health (CITATION).
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