Derelict fishing gear (DFG) is a highly persistent form of marine pollution known to cause environmental
and economic damage. At-sea detection of DFG would support pelagic removal of this gear to prevent and
minimize impacts on marine environments and species. In 2008, experts in marine debris, oceanography,
remote sensing, and marine policy outlined a strategy to develop the capability to detect and ultimately
remove DFG from the open ocean. The strategy includes three interrelated components: understanding
the characteristics of the targeted DFG, indirectly detecting DFG by modeling likely locations, and directly
detecting pelagic DFG using remote sensing. Together, these components aim to refine the search area,
increase the likelihood of detection, and decrease mitigation response time, thereby providing guidance
for removal operations. Here, we present this at-sea detection strategy, relate it to relevant extant research
and technology, and identify gaps that currently prevent successful at-sea detection and removal of DFG.