Over-exploitation consists of exploiting a species beyond biologically sustainable levels – i.e. fish populations are exploited at a rate much faster than the rate needed for them to recover.

Traffickers commonly over-exploit species, far exceeding export quotas or circumventing them entirely. European eel stocks have dropped 90 percent in three decades. It is estimated that more than 90 percent of ornamental fish are dead within a year of being caught.

Sea cucumber traffickers wipe out entire populations very quickly before moving on to new and more fertile grounds. The totaoba trade has directly led to the near extinction of vaquita populations in Mexico. All marine turtles are endangered, and populations of most shark species are declining.