All maritime crimes are local: Understanding the causal link between illegal fishing and maritime piracy

Two types of maritime crime, piracy and illegal fishing, are common and pose risks to marine security. Past studies show a correlational link between the two activities, but the causal direction is far from clear. A popular narrative of the event is that foreign fishing events deplete local resources, causing local fishers to turn to piracy. We propose another mechanism that links the two events by focusing on local perpetrators. We argue that maritime piracy is a high -risk, high-reward substitute for local actors who engage in illegal fishing. Empirically, this would mean that a constraint placed on illegal fishing at the local level should lead to a higher likelihood of pirate attacks if the area provides an abundant opportunity. For evidence, we explore these relationships in Indonesian waters. Our unit of analysis is the 0.5 x 0.5 grid cell year within Indonesian EEZ from 1990 to 2017. Results support our hypotheses. When there is a decline in Illegal, Unreported, and Unregulated (IUU) fishing in an area, we find a greater likelihood of ship attacks, especially if vessel traffic in the grid cell is high. Importantly, we fail to see a similar relationship with legal fishing, which tells us that local capacity and conditions, rather than environmental factors, are likely the driving force behind piracy attacks. We also find little evidence of a reverse relationship where piracy drives IUU fishing.