enforced. The actual enforcement mechanisms are not part of control. Management criteria include: Establishing designated fishing areas in which no fishing, fishing by vessels with permits, or open fishing is allowed. Restrictions on fishing gear, including the banning of certain types on vessels in give areas, or controls on such parameters as the mesh size of fishing nets. These restrictions can be enforced only by physical inspection at sea or at dockside. Catch and quota controls, by species or total take Days at sea Daily time at sea Seasonal catch limits Per-trip catch limits Limits on catch within certain areas Individual (vessel) transferable quotas Minimum or maximum fish sizes Bycatch Vessel movement controls Into areas Exiting areas Sightings in areas Onboard observers Licensing Vessel inspections Surveillance Surveillance, according to the 1981 Conference of Experts, are "the degree and types of observations required to maintain compliance with the regulatory controls imposed on fishing activities." The Ghana workshop termed it the "regulation and supervision of fishing activity..." This definition does not clearly include enforcement. Through surveillance, overfishing by authorized fishers and poaching by unauthorized fishers can be detected. Many systems are involved in the technical process of surveillance. Radar, including coastal, airborne, and spaceborne systems, may be intended for national security or law enforcement, but can simultaneously provide information to fisheries management and environmental protection authorities. Vessel monitoring system principally intended for fisheries surveillance can provide critical information to search and rescue (SAR) under the International Convention for the Safety of Life at Sea (SOLAS) and its associated Global Maritime Distress Safety System (GMDSS). Enforcement Enforcement ranges from self-regulation to onboard observers to patrol platforms (vessels and aircraft) to law enforcement activity. Spatial Components MCS implementation has sea, land, and aerospace aspects. Monitoring systems, such as Vessel monitoring system, may operate in all three of these regimes. These aspects also affect other maritime systems that can cooperate with VMS, such as Automatic Identification Systems (AIS) with their specialized Vessel Traffic Services (VTS), radar surveillance of the seas, and pollution tracking mechanisms. Sea components Perhaps the most basic component, aboard fishing vessels, are the logs and catch reporting completed by the fishers themselves. Closely associated are reports prepared by onboard observers. Also on the fishing vessel can be the shipboard components of vessel monitoring system (VMS). These can be independent systems involving navigational and time input, embedded and dedicated computer, and radio transmission