...
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 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 based on its reproductive capacity and ability to withstand a population crash at status quo fishing intensity ability remain stable under current fishing pressure (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.
...
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 be as big as 30% of the up to 30% as large as 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).
...