This is just showing the areas on the map where the dark alleys might be, because that's also where all the streets and boulevards are. Red spots are where two

This is just showing the areas on the map where the dark alleys might be, because that's also where all the streets and boulevards are. Red spots are where two AIS transponders got close enough for a transfer between their vessels. Black spots are where one AIS transponder slowed or stopped long enough for a transfer with a non-transponder vessel. A lot of the spots can be explained by completely legitimate floating factory ships, or cargo-ferrying vessels that bring the fish back to port while the fishing boats stay where the fish are. You would need a second data set, containing known-legitimate transfers, to filter out results from the first. As it is now, it's just a map of where fishing activity typically happens. Of course there will be shady transactions somewhere in there, using the massive amount of above-board activity as cover. It's about as useful as saying that one of the fast-food employees at a gigantic food court might also be selling marijuana.