h2. Introduction to the Current Problem Facing Fisheries
h3. Bycatch
Fishing vessels throw back into the ocean a large percentage of their haul because they are not big enough or are not in demand. Federal regulations mandate that bycatch be returned to the ocean as "unharmed as possible" which are suppose to keep fish from being overexploited but bycatch restrictions often not implemented or enforced. When they are, most fish thrown back eventually die (Turning A Blind Eye ¶ 1-3).
Though federal law requires it, fisheries managers sometimes do not monitor bycatch levels. "In order to manage our fisheries effectively, fisheries managers must account for the additional fish and other ocean wildlife killed as bycatch, so that healthy fish populations are not overfished, sensitive or depressed populations are not driven to levels below which they cannot recover, and marine ecosystems are not degraded" (Turning A Blind Eye ¶ 4).
High mortality rates for non target fish species can change the ecology of an area such as changing the food web relationships, altering predator-prey relationships, 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 ¶ 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 anually in fisherman's catch (Verrengia ¶ 1). The study "suggests that accidental captures known as "bycatch" in the fishing industry, may be the biggest immediate threat to these animals' survival - even more than ship collisions and pollution" (Verrengia ¶ 4). The researchers do however caution that their methods were not very precise as mortality statistics in some regions were unavailable so they arrived at their numbers by multiplying numbers from the United States numbers (Verrengia ¶ 17).
"The IWC banned most whaling in the 1980s. Norway ignores the ban, while Japan takes nearly 700 whales a year under a controversial IWC research exemption. Some native cultures are allowed to conduct strictly limited hunts" (Verrengia ¶ 10). "Commercial fishing advocates point out that cetacean deaths decreased 40 percent in the United States in the last decade as new federal laws were enacted and equipment improved" (Verrengia ¶ 13). Some improvements such as underwater alarms were implemented with the aid of fishermen during the 1990s (Verrengia ¶ 14). Scientists say that nets wrapped around the bodies of these mammals are often quickly cut away by fishermen so that they will not be traced by their equipment (Verrengia ¶ 15).
h2. Introduction to Different Fishing Gear and Their Impacts
h4. Precatching Technology
Precatching technology is a technology that prepares an area for catching fish. The purpose of having this technology is to reduce the amount of bycatch. The ideal technology would separate the fish not only based on size but on type as well. This can be done in several ways.
The technology can use a fish's basic instinctual defense mechanisms to separate fish type. Because fish respond differently when faced with danger, some fish will exhibit a behavior that others may not. Some fish may dive while others may rise. Some may stop moving while some may move in the opposite direction.
The technology can also use electric fields generated in water to separate fish. This is based on the fact that fish respond to electric fields. Currently, this is being used in research and fishing in a form of fishing called electrofishing. Electrofishing means using electric fields generated by two electrodes placed in the water to attract fish. It can use both AC or DC waves which causes different behavior in the fish. When generating an electric field using DC, fish will swim to the positive electrode placed in the water. When using AC, based on the wavelength of the wave, different sized fish will be attracted. Fish smaller than the wavelength will not be attracted while fish larger than the wavelength will be attracted to the electric field zone between the two electrodes. Also, by changing the size and shape of the electrodes, the field changes allows for a larger area or a more specific area.
Another idea that our technology can use is underwater cameras or underwater three-dimensional imaging in real time using an AM laser. By doing this, fishermen can be more selective in where they fish and what they fish.
We hope to achieve precatching technology that can separate fish based on size and type using one or a combination of these ideas.
h3. Mobile Gear
h4. Midwater Trawling
h4. Bottom Trawling
{color:black}Trawling is usually done by one or two fishing boats vessels with a large net that is dragged for a few hours at a speed of three or four knots in order to catch a range of species that includes orange roughy, hoki, ling, hake, and squid. Trawling is not an option for recreational fishers (Starfish ¶ 8-9).{color}
{color:black}Dredging is usually used to collect scallops, oysters, and clams with a fishing vessel pulling a rigid metal framed dredge along the ocean floor. The bottom of the frame has a raking bar that, depending on the desired species, may or may not have teeth. The haul is pulled up by these teeth and into a holding container. Dredges are typically used on each side of a ship at the same time (Fishing Methods ¶ 7).{color}
{color:black}Beam trawls drag along the sea floor in front of nets that in mud and sand conditions use tickler chains or in rockier conditions, heavy chain mats. The chains cause fish along the bottom to rise up into the path of the trawl by disturbing them. Depending on the type of ship, the trawls can have beams measuring from 4 to 12 meters that can weigh up seven and a half tons in air (Fishing Methods ¶ 1).{color}
{color:black}Demersal Otter Trawls are also dragged along the sea floor to where boards on the net guide fish into the cone shaped net where they swim. Once exhausted, the fish move backward in the net through the funnel into the cod-end, the fish keeping receptacle (Fishing Methods ¶ 2).{color}
{color:black}"The use of new fish-trawling gear is doing incalculable damage to the seabed, destroying essential habitats for marine life...Nowadays, every kind of seabed - silt, sand, clay, gravel, cobble, boulder, rock reef, worm reef, mussel bed, seagrass flat, sponge bottom, or coral reef is vulnerable to trawling. For fishing rough terrain or areas with coral heads, trawlers have since the mid-1980s employed "rockhopper" nets equipped with heavy wheels that roll over obstructions...this fishing gear also displaces commercial hook and line and trap fishers who formerly worked such sites without degrading the habitat" (Safina ¶ 4).{color}
{color:black}Bottom trawls affect 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 crush, kill, and expose to enemies, and remove these sources of nourishment and hiding places, making life difficult for young fish and lowering the quality of the habitat and its ability to produce abundant fish populations" (Safina ¶ 5).{color}
{color:black}"Trawling commonly affects the top two inches of sediment, which are the habitat of most of the animals that provide shelter and food for the fish, shrimp, and other animals that humans eat. In a Gulf of Maine site surveyed before and after rockhopper gear was used, researchers noted profound changes. Trawling had eliminated much of the mud surface of the site, along with extensive colonies of sponges and other surface growing organisms.{color}{color:black} {color} {color:black}Rocks and boulders had been moved and overturned" (Safina ¶ 6).{color}
{color:black}"The simplification of habitat caused by trawling makes the young fish of commercially important species more vulnerable to natural predation. In lab studies of the effects of bottom type on fish predation, the presence of cobbles, as opposed to open sand or gravel-pebble bottoms, extended the time it took for a predatory fish to capture a young cod and allowed more juvenile cod to escape predation....New England's celebrated Georges Bank, the once-premier and now-exhausted fishing ground, is swept three to four times per year. Parts of the North Sea are hit seven times, and along Australia's Queensland coast, shrimp trawlers plow along the bottom up to eight times annually. A single pass kills 5 to 20 percent of the seafloor animals, so a year's shrimping can wholly deplete the bottom communities" (Safina ¶ 7-8).{color}
{color:black}"The effects on fish populations and the fishing industry, although probably significant, have been difficult to quantify because there are few unaltered reference sites. But the studies available suggest that the large increases in bottom fishing from the 1960s through the early 1990s are likely to have reduced the productivity of seafloor habitats substantially, exacerbating depletion from overfishing"{color} {color:black}(Safina ¶ 9).{color}
{color:black}"At three New England sites, which scientists have studied either within and adjacent to areas closed to bottom trawls or before and after initial impact, trawls significantly reduced cover for juvenile fishes and the bottom community. In northwestern Australia, the proportion of high-value snappers, emperors, and groupers-species that congregate around sponge and soft-coral communities-dropped from about 60 percent of the catch before trawling to 15 percent thereafter, whereas less valuable fish associated with sand bottoms became more abundant.{color} {color:black}(Safina ¶ 10)"{color}
{color:black}"Studies off Nova Scotia indicate that the survival of juvenile cod is higher in more complex habitats, which offer more protection from predators. In another study, the density of small shrimp was 13 per square meter outside trawl drag paths and zero in scallop dredge's path" (Safina ¶ 12).{color}
{color:black}"Trawling is not uniformly bad for all species or all bottom habitats. In fact, just as a few species do better in clear-cuts, some marine species do better in trawled than in undisturbed habitats. A flatfish called dab, for instance benefits because trawling eliminates its predators and competitors and the trawls' wakes provide them with food.{color} {color:black}But most species are not helped by trawling, and marine communities can be seriously damaged, sometimes for many decades"{color} {color:black}(Safina ¶ 16).{color}
{color:black}"Communities that live in shallow sandy habitats subject to storms or natural traumas such as ice scouring tend to be resilient and resist physical disturbances. But deeper communities that seldom experience natural disturbances are more vulnerable and less equipped to recover quickly from trawling. In Watling and Norse's global review of studies covering various habitats and depths, none showed general increases in species after bottom trawling, one showed that some species increased while others decreased, and four indicated little significant change. But 18 showed serious negative effects, and many of these were done in relatively shallow areas, which generally tend to be more resilient than deeper areas. Watling has said that if trawling stopped today, some areas could recover substantially within months, but certain bottom communities may need as much as a century"{color} {color:black}(Safina ¶ 17-18).{color}
{color:black}"The Grand Banks study showed trawls making furrows but also smoothing out the sandy bottom, and lowering the abundance of sea urchins, snow crabs, soft corals, and other "epibenthic" creatures atop the seabed. As in Minas Basis,{color} {color:black}effects were less than expected, and were overshadowed by natural variability. Recovery took place within a year, and no long-term impacts were observed.{color} {color:black}The researchers moved on to Western Bank off Nova Scotia, with a gravelly seabed typical of trawling areas. The 1997-1999 study in this area also monitored trawling's effects on the food supply of fish. It turned out that it made some food organisms, such as horse mussels and worms, more available as prey items. Physical disruptions were less than on sandy bottom, but lasted longer, because gravel bottom undergoes less disturbance from storms...On fishing banks, relatively shallow plateaus in the ocean, strong winds can swirl the{color} {color:black}water right down to the bottom. Gales and storms will often remould sandy bottom, but gravel is harder to move"{color} {color:black}(Does fish-trawling harm the seabed? ¶ 10-12).{color}
{color:black}"On all the banks, trawls did less damage than many had expected. But the harm increased with the size of bottom organisms, especially the epibenthic{color} {color:black}forms that grow up into the water column. Sponges, corals, and the like were particularly vulnerable"{color} {color:black}(Does fish-trawling harm the seabed? ¶ 15){color}
{color:black}"Research has shown that the degree of damage depends on the nature of the seabed and its organisms, fishing effort, and other factors. Sandy bottoms are the most resilient; hard bottoms with corals, sponges, and the like, the least resilient. Drags and trawls can be tolerable in some areas, unacceptable in others. Don Gordon hopes for a future, fine-scale seabed inventory for the seabed off Atlantic Canada. Detailed seabed maps are essential, he believes, to manage human activities in a scientifically sound manner and minimize environmental"{color} {color:black}(Does fish-trawling harm the seabed? ¶ 17-18).{color}
{color:black}{*}Sediment clouds{*}{color}
{color:black}The clouds of sediment caused by the dragging trawl doors of trawling nets help bring fish into the nets. The sediment load is also increased by the sediment disturbed by the trawls and can diminish light levels reaching the bottom as well as stifling the bottom inhabitants when the cloud returns to the bottom. "Galtsoff (1964) showed that as little as 1mm of silt over a settlement could prevent spat settlement in{color} {color:black}{_}Ostrea virginica{_}{color} {color:black}{_}and{_}{color} {color:black}Stevens (1987) claimed that high turbidity levels inhibited settlement of{color} {color:black}{_}Pecten novaezelandiae{_}{color} {color:black}veliger larvae, depresses growth rates of adults, and caused inefficient metabolism of glycogen stores through enforced anaerobic respiration" (J. B. Jones{color} {color:black}¶ 16{color}{color:black}).{color}{color:black}Trawl gear can also bring about vertical redistribution of sediment layers...Mayer et al. (1991) showed that heavy chain dredges could mix organic material into subsurface layers. This organic material removed from the surface metazoan-microbial aerobic chain to an anaerobic system. If the subsurface layers are already anoxic, further problems can occur. Churning up the soft bottom can create anaerobic turbid conditions which are, for example, capable of killing scallop larvae...Anderson & Meyer (1986) who found that sediment resuspended from clam dredges in a Maine estuary did not improve the food value of the suspended materials available to filter feeders... actually decreased the food value since filter feeders had to filter more material to obtain nutrients" (J. B. Jones{color} {color:black}¶ 18{color}{color:black}).{color}
{color:black}{*}Destruction of Non-target Benthos{*}{color}
{color:black}"{color}The large, heavy-shelled bivalve _Cyprina islandica_ formed a substantial part of the food of cod and flatfish in KielBay (Baltic) only after trawling began in the area. Arntz & Weber (1970) concluded that the fish were feeding on bivalves crushed by the otter boards. Medcof & Caddy (1971) and Caddy (1973) confirmed there was feeding on exposed and damaged benthic animals in trawl tracks. By contrast, observations made using submersibles, reported in Stevens (1990), found that trawling caused no observable injuries to crabs whereas Butcher et al. (1981) found little or no damage to the Jervis Bay (Australia) environment by scallop dredging...Bull (1986) found that survival _oiPecten novaezelandiae_ spat in Golden Bay (New Zealand) was better than 20% after 9 months in an area closed to trawling but was only 0.8% for an adjacent site which was open to trawling" {color:black}(J. B. Jones ¶ 19).{color}
{color:black}{*}Indirect Effects{*}{color}
{color:black}"{color}McLoughlin et al. (1991) review studies of natural mortality on scallop beds which showed that natural mortality and indirect fishing mortality rates were much higher on fished scallop beds than the natural mortality on unfished beds. They point out that postfishing mortality is not just confined to shells damaged by dredges. Their study showed that 4-5 times as many scallops were crushed or damaged as were caught and landed by the scallop gear used in the Bass Strait (*Australia) fishery. However, within 9 months of the start of the fishery "virtually the entire stock was lost", which McLoughlin et al. (1991) attributed to a suspected bacterial infection resulting from decomposing scallops on the seabed...Saxton (1980) noted a decline in juvenile fish with the removal of bryozoan beds in Tasman Bay, New Zealand. Sainsbury (1988) found a significant reduction in sponge frequency on the Australian north-west shelf between 1967-73 and 1979. Loss of sponges, together with alcyonarians and gorgonians, lead to a change in the catch composition of the pair-trawl fishery on the Australian north-west shelf between those years. The fishes\* _Lethrinus_ and _Lutjanus_ were associated with habitats containing large epibenthos and catches of these fish species had significantly declined. The fishes _Nemipterus_ and _Saurida_ occurred mostly over the open sand and had increased in biomass" {color:black}(J. B. Jones ¶ 23).{color}
{color:black}{*}Conclusion{*}{color}
"The removal of the macrobenthos also has variable effects. In shallow-water areas where the damage is intermittent, recolonisation soon occurs. However, where the macrobenthos is substantially removed and recovery is not permitted (such as the\* _Sabellaria_ beds of the Wadden Sea and the bryozoan beds of TasmanBay), the change is permanent"\* {color:black}(J. B. Jones ¶ 29).{color}
h2. Nonmobile Gear
h3. Purse Seining
The purse seine is a vertically hanging net with floats on its surface line and lead weights on its bottom edge. Attached to the weighted line are rings strung together by a drawstring wire. Ships encircle entire schools with the outstretched purse seine, then they pull the drawstring wire tight to trap the fish inside (Australian Fisheries Management Authority, 2005, diagram 1). The Marine Conservation Society summarizes purse seining as, "one of the most aggressive methods of fishing and aims to capture large, dense shoals of mobile fish . . ." (Marine Conservation Society, 2000, ¶1). This method is extremely effective for catching both surface dwelling and mid-water fish, especially tuna, sardines, mackerel, jack mackerel, and herring (Kuznetsov, 2006, ¶4). Historically, the purse seine was also used extensively for harvesting barracuda, yellowtail, and white sea bass (Skogsberg, 1925, article V.I). The Alaska Department of Fish and Game reports that, in the commercial fisheries of Southeast Alaska, purse seines are responsible for 70-90% of the tuna catch. This yield consists of mainly pink salmon, but it also includes sockeye, coho, chum, and chinook salmon. This Current regulations in Alaska allow purse seining only in specific districts (Alaska Department of Fish and Game, 2005, ¶1,4).
*New Technologies*
While fishing companies have practiced purse seining essentially unchanged for the past 100 years, slight innovations in technology have recently made the net even more efficient and, therefore, lucrative. One such example is the "autonomous distance-controlled hydroacoustic system" which, once attached to strategic points along the net and submersed, emanates a low-frequency pulse which frightens fish into the net. This invention consists of a management block onboard the ship as well as the underwater blocks, attached to the net, which emanate the frequencies (Kuznetsov, 2006, ¶4).
One invention analogous to the hydroacoustic system, but used for trawling, is the "towed remote controlled pneumoacoustic system." This machine, which is dragged between ship and trawl, creates a strategically located acoustic field, imitating the acoustics generated by predatory whales. Seeking to avoid the predator, fish congregate in the trawl's catching zone. This method greatly increases the catch without the necessity of altering boats or nets (Kuznetsov, 2006, ¶1).
*Pros*
From the fisherman's point of view, the most obvious advantage of purse seining is its capability to harvest massive quantities of a species at once. With respect to the geographical environment (i.e. ocean floor, plant life), the purse seine is nearly harmless because, when properly handled, it never touches the sea floor. It doesn't sit in one place for a length of time longer than the boat can set it out and pull it in, thereby hardly altering the long term habitat with its temporary presence. Yet another defense for purse seining is its longevity. Purse seining has been practiced to the same end, and with virtually the same means, for the past one hundred years. Its practice preserves a culture more than one hundred years old of seine net fishing, especially prominent in California and the Northeastern coast of the United States (Skogsberg, 1925, footnotes 7,12).
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*Cons*
Two general problems with purse seining are caused by its large-scale capabilities. The first is simply ecosystem disruption. The instantaneous removal of entire schools of a certain species of fish from an area leaves a vacant hole in the food web. This leads, initially, to predator death by starvation and prey overpopulation because their numbers are suddenly unchecked by a predator. In the long run, if the affected species survive, they may adapt their eating/breeding habits to flourish in a new and altered ecosystem.
The second flaw of purse seining is the large quantities of bycatch routinely caught and killed along with market fish. Marine mammals are commonly trapped within the encircling net, and they perish without means to escape. Before regulations forbade it, seining for yellowfin tuna often consisted of setting nets around dolphins (predators of tuna) on purpose to catch the most fish. Congress's Marine Mammals Protection Act of 1972, however, almost entirely eliminated the practice by 1997 (Marine Conservation Society, 2000, ¶2). Additional regulations were set up by the Earth Island Institute and the HJ Heinz corporation in their 1990 "Dolphin Safe" standards (presented in International Marine Mammal Project, 2003, ¶2). Since their introduction in 1990, these guidelines have been accepted by 90% of world canned tuna companies and have reduced dolphin mortality (as bycatch) by 98% (now about 2-3,00 dolphin deaths per year) (Marine Conservation Society, 2000, ¶2).
*Reducing Bycatch: The Dolphin Safe Standard*
* * The Earth Island Institute writes:
"In order for tuna to be considered "Dolphin Safe", it must meet the following standards:
# No intentional chasing, netting or encirclement of dolphins during an entire tuna fishing trip;
# No use of drift gill nets to catch tuna;
# No accidental killing or serious injury to any dolphins during net sets;
# No mixing of dolphin-safe and dolphin-deadly tuna in individual boat wells (for accidental kill of dolphins), or in processing or storage facilities; and
# Each trip in the Eastern Tropical Pacific Ocean (ETP) by vessels 400 gross tons and above must have an independent observer on board attesting to the compliance with points (1) through (4) above." (International Marine Mammal Project, 2003, ¶2)
As stated before, since the Earth Island Institute introduced them in 1990, these guidelines have been accepted by 90% of world canned tuna companies and have reduced dolphin mortality (as bycatch) by 98% (now about 2-3,00 dolphin deaths per year) (MCS). Fifty-one world nations, including the United States, Canada, Japan, and the United Kingdom, are currently monitored for Dolphin Safe in their tuna industry by the International Marine Mammal Project, a division of the Earth Island Institute (International Marine Mammal Project, 2003, table 1).
*Summary*
To conclude the past sections, the world's three most lucrative fishing methods (and likewise the ones that remove most of the ocean's fish) are:
1. Bottom trawling
2. Mid-water trawling
3. Purse Seining* \* (Gabriel, 2005, chap. 26)
h1.
*Bibliography*
Alaska Department of Fish and Game: Division of Commercial Fisheries. (2005, July 26). _Commercial Purse Seine Fishery_. Retrieved November 8, 2007, from [http://www.cf.adfg.state.ak.us/region1/finfish/salmon/netfisheries/ps_info.php]
Australian Fisheries Management Authority, Australian Government. (2005). "Seine." Retrieved November 8, 2007, from [http://www.afma.gov.au/information/students/methods/]
Gabriel, O., ed. (2005). _Fish catching methods of the world_. Oxford, UK; Ames, IA: Blackwell Publishing.
International Marine Mammal Project, Earth Island Institute. (2003) _International Dolphin Safe Monitoring Program_. Retrieved November 8, 2007, from [http://www.earthisland.org/dolphinSafeTuna/]
Kuznetsov, Dr. J.A. (2006, June 21). Innovational Projects. _Intensification of Multispecies Fishery_. Retrieved November 8, 2007, from imf.fish-net.ru/inpr.htm
Marine Conservation Society. (2000). Purse seining. _Fish Online: Fishing Methods_. Retrieved October 17, 2007, from [http://www.fishonline.org/caught_at_sea/methods/]
Skogsberg, Tage. (1925). Preliminary Investigation of the Purse Seine Industry of Southern California, Fish Bulletin No. 9. _State of California Fish and Game Commission, State Fisheries Laboratory_. Sacramento: California State Printing.
h3. Traps
Traps are one of the most environmentally friendly fishing methods. They are highly selective, since fishermen can release unwanted fish alive when the traps are hauled up. They also do little to no harm to the ocean floor or other oceanic surroundings, as they are nonmobile. However, there is a huge problem associated with traps - ghost fishing.
In 1995, the FAO deemed ghost fishing to be one of the most seriously negative impacts in the present capture fishery industry (Matsuoka). When traps are lost, from storms or human negligence or otherwise, the vast majority will continue to catch and trap fish or other ocean life for months, or even years. Ghost fishing in some commercial stocks is estimated to be equal to 5-30% of the annual catch levels (Laist). There are already some measures being taken to prevent ghost fishing: the FAO code of conduct states that States should try to minimize catch by lost or abandoned gear, and many countries including Sweden, Poland, New Zealand, and the United States all have gear retrieval programs (Brown).
Gear retrieval programs, however, are not the best way to prevent ghost fishing. A study by Brown and Macfayden indicates that while these programs save fishermen about $32,000 per fleet per year, the time and money spent in retrieving the gear exceeds $65,000. But if these programs are used along with measures that prevent gear loss in the first place, the cost will decrease significantly. Another possibility is to develop new technology that allows for easier and cheaper retrieval of lost nets and traps.
Another measure being taken is the requirement of escape mechanisms. <<INFO>>. If these requirements are made more strict and widespread, then ghost fishing should decrease dramatically.
Unfortunately, there is little data about the effectiveness of escape mechanisms, or even truly accurate data regarding the impacts of ghost fishing on fish populations; most of the numbers discussed above are mere approximations. This is another area in which we can improve
h3. Hook and Line
h2. Alternative Fishing Technologies
"Electrified ticklers, which are less damaging to the seabed, have been developed but used only experimentally. Work is also being carried out to investigate whether square mesh panels (see below) fitted in the 'belly' or lower panel of the net can reduce the impact of beam trawling on communities living on or in the seabed" {color:black}(Fishonline ¶ 1).{color}{color:windowtext}"The selectivity of trawl fisheries may be increased by the use of devices known as separator trawls. Separator trawls exploit behavioural differences between fish species and can be used, for example, to segregate cod and plaice into the lower compartment of the net, whilst haddock are taken in the upper part. The mesh size for the two compartments can be altered according to the size of the adult fish being targeted. Insertion of square mesh panels also improves selectivity of the net because square meshes, unlike the traditional diamond shape meshes, do not close when the net is towed. Discarding of immature fish may also be reduced by increasing the basic mesh size in fishing nets. Sorting grids are compulsorily fitted in nets in some prawn and shrimp fisheries to reduce bycatch of unwanted or non-target species, including small prawns and shrimp" (Fishonline ¶ 3).{color}{color:windowtext}"Most fishing methods target fish for direct human consumption. Fisheries targeting species for reduction purposes i.e. the manufacture of fish oil and meal, are referred to as industrial fisheries. Fish meal and oil is produced almost exclusively from small, pelagic species, for which there is little or no demand for direct human consumption. The methods of capture are purse-seining and trawling with small mesh nets in the range of 16-32 mm. Important industrial fisheries in{color} South America {color:windowtext}include the Chilean jack mackerel fishery and the Peruvian fishery for anchoveta. Industrial species in the North Sea and North-East Atlantic include: sandeel, sprat, capelin, blue whiting,{color} Norway {color:windowtext}pout and horse mackerel. Fish oil is used in a range of products including margarine and biscuits. Fish meal and oil has more widespread use, however, in the manufacture of pelleted feedstuffs for intensively farmed poultry, pigs and, not least, aquaculture. One of the main impacts associated with industrial fishing is the removal of large quantities of species from the base of the food chain" (Fishonline ¶ 28-29).{color}
h2. Policy and Regulation Relating to Fishing Technology
"Actions that would simultaneously safeguard the fishing industry as well as the seabed need to be taken now. These measures would include: 1) No-take replenishment zones where fishing is prohibited. This would help create healthy habitats supplying adjacent areas with catchable fish. Such designations are increasingly common around the world, particularly in certain areas of the tropics, and benefits often appear within a few years. In New England, fish populations are still very low, but they are increasing in areas that the regional fishery management councils and National Marine Fisheries Service have temporarily closed to fishing after the collapse of cod and other important fish populations. The agencies should make some of these closings permanent to permit the areas' replenishment and allow research on their recovery rates. 2) Fixed-gear-only zones where trawls and other mobile gear are banned in favor of stationary fishing gear, such as traps or hooks and lines, that doesn't destroy habitat. New Zealand and Australia have closed areas to bottom trawls. So have some U.S. states, although these closures are usually attempts to protect fish in especially vulnerable areas or to reduce conflicts between trawls and other fishers, not to protect habitat. Temporary closures in federal waters, such as those in New England, should in some cases be made permanent for trawls but opened to relatively benign stationary gear. What gear is permitted should depend on bottom type, with mobile gear allowed more on shallow sandy bottoms that are relatively resistant to disturbance but barred from harder, higher-relief, and deeper bottoms where trawler damage is much more serious. 3) Incentives for development of fishing gear that does not degrade the very habitat on which the fishing communities ultimately depend. Fish and fisheries have been hurt by perverse subsidies that have encouraged overfishing, overcapacity of fishing boats, and degradation of habitat and marine ecosystems. Intelligently designed financial incentives for encouraging new and more benign technology could tap the inherent inventiveness of fishers in constructive ways" {color:black}(Safina{color} ¶ 19-22{color:black}).{color}
h2. Citations
Verrengia, Joseph. "Nearly 1,000 whales drowning daily in fishing nets: study ." +European Cetacean Bycatch Campaign+. 15 June 2003. 13 Sep. 2007 <[http://www.eurocbc.org/bycatch_death_toll_may_exceed_1000_cetaceans_daily_15june2003page1156.html]>.
"Fishing Methods." +STARFISH Student and teacher Resource Science Fact Sheets+. New Zealand Ministry of Fisheries. 13 Sep. 2007 <[http://www.starfish.govt.nz/science/facts/fact-methods.htm]>.
"Fishing Methods." +FISHONLINE+. Marine Conservation Society. 13 Sep. 2007 <[http://www.fishonline.org/site/www/caught_at_sea/methods/]>.
Jones, J. B. . "Environmental impact of trawling on the seabed: a review." New Zealand +Journal of Marine and Freshwater Research+ 26 (1992): 59-67. 13 Sep. 2007 <[http://www.rsnz.org/publish/nzjmfr/1992/4.php]>.
Safina, Carl. "Scorched-Earth Fishing." +Issues Online in Science and Technology+ (1998): 22 pars. 27 Sep. 2007 <[http://issues.org/14.3/safina.htm]>.
"Turning A Blind Eye: A Marine Fish Conservation Network Report." 1 June 2006. U.S. Public Interest Research Groups . 27 Sep. 2007 <[http://www.uspirg.org/home/reports/report-archives/ocean-conservation/ocean-conservation/turning-a-blind-eye-a-marine-fish-conservation-network-report]>.
"Does fish-trawling harm the seabed? - finding out the facts." +Fisheries and Oceans+ Canada Science. Department of Fisheries and Oceans Canada. 27 Sep. 2007 <[http://www.dfo-mpo.gc.ca/science/Story/maritimes/trawling_e.htm]>.
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h2. World Fish Production
{center:class=myclass}
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| Figure-1 | Figure-2 |
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Figure-3
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|| Year || Fish Caught (million tons) || Aquaculture (million tons) || Total (million tons) || Fishing to Aquaculture Ratio ||
| 1950 | 18.7 | .6 | 19.3 | 31.17 |
| 1960 | 33.8 | 1.7 | 35.5 | 19.88 |
| 1970 | 62.7 | 2.6 | 65.2 | 24.12 |
| 1980 | 67.2 | 4.7 | 71.9 | 14.3 |
| 1990 | 84.8 | 13.1 | 97.9 | 6.47 |
| 2000 | 95.5 | 35.5 | 131.0 | 2.69 |
| 2001 | 92.8 | 37.8 | 130.6 | 2.46 |
| 2002 | 93.0 | 40.0 | 133.0 | 2.33 |
| 2003 | 90.2 | 42.3 | 132.5 | 2.13 |
Table-1
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h3. Current
As you can see from figures 1 and 2, the overall amount of fish being put out to market all over the world is increasing every year. This is due to the amount of fish being pulled from our oceans leveling off while the amount of fish provided by aquaculture is increasing. The problem is that our oceans can't currently support the amount of fish that we are pulling from them. This means that the amount of fish being pulled from the ocean currently (wild catch) cannot just level off but must decrease for the ecosystem to stabilize. Currently, there is about 132.5 millions tons of fish being produced worldwide. Of that, 90.2 million tons are fish that are pulled from the oceans and 42.3 million tons of fish are the result of aquaculture. It is at a point now where almost one-third of the world's fish production is provided by aquaculture.
| !http://www.earth-policy.org/Indicators/Fish/FishPerCap.gif! | !http://www.earth-policy.org/Indicators/Fish/FishPerCapSplit.gif! |
| Figure-4 | Figure-5 |
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. This will cause people to starve, economies to collapse, and our fish stocks to be depleted.
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| !http://cache.eb.com/eb/image?id=73561&rendTypeId=4! | !http://cache.eb.com/eb/image?id=77058&rendTypeId=4! |
| Figure-6 | Figure-7 |
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.{center}
h1. Sources (in progress)
General Knowledge / Article Search Engine
* Wikipedia - [http://en.wikipedia.org/wiki/Fishing#Fishing_techniques]
* Encyclopedia Britannica - [http://search.eb.com/]
* Web of Knowledge - [http://portal.isiknowledge.com/portal.cgi/wos?Init=Yes&SID=2AN2mMFka9JegBPfAKb]
Articles
* World Fish Production - [http://www.earth-policy.org/Indicators/Fish/Fish_data.htm#fig1]
* Marine Fishery Production - [http://search.eb.com/eb/article-230490]
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