The changes in the environmental conditions influence the abundance, distribution, availability and recruitment of marine resource in ocean. The measurement of ocean characteristics like concentration of suspended and dissolved matters, sea surface temperature, upwelling regions, frontal boundaries, water circulation pattern etc gives the information on the environmental conditions deciding the distribution of fishery resources. These features can be sensed remotely in detection and assessment of the fishery resources by using remote sensing techniques. The book details about the application of Remote Sensing and GIS in fisheries.