...
Illegal, unreported, and unregulated (IUU) fishing is defined as fishing within the waters of a state without permission of and against the laws of that state, along with non-reported and misreported catches, and fish stocks with no conservation measures (International Plan Of Action to Prevent, Deter and Eliminate Illegal, Unreported and Unregulated Fishing, 2001). IUU fishing is a major threat to the world's oceans. For example, the North East Atlantic Fisheries Commission (NEAFC) estimates that nearly 20% of the 2001 trade in redfish was illegal, unreported, or unregulated, and the International Council for the Exploration of the Seas (ICES) Baltic Fisheries Assessment Working Group estimates that the actual value of Baltic cod catches are 35% to 45% higher than the reported values (ICES, 2005). Most strikingly, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) estimates that between 1997 and 2000 about 90 kilotonnes of toothfish was taken from the oceans in an illegal manner, more than twice the reported catch for the same period (ICES, 2005).
...
All ICES advice starts with analysis of single and mixed stock statistics (most notably fishing mortality and spawning stock biomass). The analysis combines publicly available catch data with ICES internal estimates for unaccounted fishing mortality (UFM) to create estimates for the stock's fishing mortality rate. ICES uses historical records to develop critical limits on the spawning stock biomass; outside these limits the stock is considered to have "reduced reproductive capability" (ICES, 2006). The stock is then classified on its reproductive capacity and sustainability; ICES defines sustainability as the ability to withstand a population crash at status quo fishing intensity (ICES, 2006). These stock parameters are also used to set boundaries on fishing mortality rates and spawning stock biomass values for use in management plans.
...
Many countries subsidize their fishing industries because of the important roles they play in the economy and food supply. Annual subsidies for fishing amount to about $26 billion world wide, only $7 billion of which goes towards fisheries management and the support of conservation. On the other hand, $16 billion is going towards the sponsorship of fishing fleets, thus encouraging the global fishing effort and increasing fishing capacity . This has led to a 250% increase in the global fishing fleet (Sumaila & Pauly, 2006).
Fishing subsidies come in many forms. Direct government payments to the industry reduce operating costs of fishing vessels in order to encourage fishing. Such assistance includes grants made for the purchase of new fishing vessels, vessel decommissioning payments (buybacks), fishermen's unemployment insurance, compensation for closed seasons, equity infusions, and price support programs (Schrank, 2003). When implemented by developed countries for their distant water fleets (DWF), they provide an advantage over the fishing boats of developing countries. Indirect financial assistance comes in the form of subsidizing shipbuilders and fish processors, credit and loan assistance, and tax reductions. Governments can also help their fishermen by imposing trade restrictions such as import tariffs, which ensures that prices for foreign fish are not lower than prices for domestic fish, and import quotas, which restricts the number of fish that can be imported.
...
Fishing nets and traps today are made of durable polymer fibers, built to last. While this seems great at first, this durability 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), fish deaths caused by ghost fishing may account for up to be as big as 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 issue of ghost fishing, but more, and more universal, measures will be needed if we want to completely solve the problem (Brown and Macfadyen, 2007).
...
Trawl surveys are generally short in duration; NOAA uses a thirty-minute trawl (NOAA). ICES data indicates that trawl surveys are generally better with shorter durations than with longer durations, as the short duration gives a more precise point assessment and reduces the number of individual fish that are collected, reducing the work load on the scientists conducting the survey (ICES, 2005).
...
While there are many variations in trawl survey design, most trawl surveys consist of a short bottom trawl using commercial trawling gear. Following a predetermined course, the trawler makes repeated short trawls, analyzing the collected sample after each trawl. All of the fish in the trawl are counted, measured, and weighed, and then a small subsample is selected to be dissected to reveal age, diet, and health information (NOAA).
Research by ICES by ICES indicates that the distribution of fish species is dependent on depth and seafloor characteristics (ICES, 2005). Thus, an optimally designed optimal survey would stratify by take into account depth and seafloor sediment before surveyingtype.
Tagging Projects
While trawl surveys produce large produce large amounts of data on the distribution of fish, they cannot determine fish migratory patterns. Such information can be provided by a tagging project (Swain & Caradine, 1960). Tagging surveys allow scientists to record locations for capture and release, as well as vital data, such as length and weight, about each fish at both capture and release. The scientists can then use the data then use the data to document migration paths (Schwarz, Schweigert, & Arnason, 1993).
...