Fisheries for highly migratory species are important in all oceans and semi-enclosed seas, except for polar regions. Fisheries for straddling fish stocks are much more localised, primarily occurring in a few regions where continental shelves extend beyond the 200 miles Exclusive Economic Zone (EEZ), while most fisheries for other high seas fishery resources are deep-water fisheries. This publication examines issues relating to the stocks of these resources, including information on their state of exploitation. Findings include that about 30 percent of the stocks of highly migratory tuna and tuna-like species, more than half of highly migratory oceanic sharks and nearly two-thirds of the straddling stocks and the stocks of other high seas fishery resources are overexploited or depleted. Although the stocks concerned represent only a small fraction of the world fishery resources, they are key indicators of the state of an overwhelming part of the ocean ecosystem which appears to be more overexploited than EEZs.