of reports. The transmission is usually via satellite, but some countries are using coastal VHF repeater systems. VMS components can also integrate with other shipboard electronics. For example, if the report generation component is on a general-purpose personal computer, that computer may also run a chartplotter and various catch planning applications. The chart plotter function may be a general-purpose graphic display, presenting radar or bottom sounder/fish finder data, perhaps merged with electronic charts. Surface components Catch inspectors, as well as electronic or hard copy filings of catch and other reports, are basic land components of MCS. Fisheries management authorities who make real-time decisions about opening or closing restricted fishing areas are usually on land, and will communicate their decisions on paper, using websites or electronic mail, and by voice radio. Within a vessel monitoring system (VMS), the Fisheries Management Center (FMC) components are on land. Minimally, this is a regional or national center of the nation in whose waters the fishing is happening. Under the Flag Principle, the VMS of a vessel registered in a nation other than the coastal or EEZ nation of the fishing area will transmit to its national FMC, which will then relay the information to the FMC where the vessel is operating. Patrol vessels may do visual or electronic surveillance of fishing vessels at sea, or may board them for spot inspections. Fisheries management vessels also may independently monitor fish densities in the areas of interest, water conditions, or other observations of interest for operations or research. Aerospace components Low-flying aircraft can visually identify fishing vessels, and, with reasonable navigational skills, determine whether a given craft is in an authorized area. This is aided if the fishing craft display distinctive identifiers. Higher-flying aircraft using radar and other sensors can determine which vessels are in a designated open or closed fishing area, and the ashore FMC can correlate these observations with VMS data. Communications satellites, in both low Earth orbit and geosynchronous orbit are the backbone of VMS communications with FMCs. Radar satellites can locate vessels in a far larger area than can aircraft, but have little or no ability to characterize the vessel. External links International Monitoring Control and Surveillance Network FAO: An introduction to monitoring, control and surveillance systems for capture fisheries Chatham House: MCS Document Database Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR): Monitoring, Control, and Surveillance References Fishing industry