abstract:For collecting fisheries data for scientific purposes, Taiwan started to deploy observers on distant water fishing vessels since 2002. Observers were trained to collect fisheries data and biological samplings. The data recorded include the fishing activities, catch number and weight, species identification, bycatch species, status and biological samples for some species.This report provides a general overview of the Taiwan observer program and summary of data collected. From 2002 to 2006, 35 trips on large scale tuna longline fishing vessels were observed in the Atlantic Ocean. The observations days were 4,755, with an average coverage rate of 5.33% by trips. More than 21 species were recorded, and 282,621 fishes were sampled. The catch composition varied by areas. In tropical area, over 36% of catch were bigeye. In temperate waters, the albacore accounted over 80% in the northern area, and 87% in the southern area. In addition, length frequency of major species and the sighting and incidental catch of ecological related species were recorded, and biological samplings were collected for biological research.