In the Pacific, the idea of closing fishing grounds has been around for generations, due to traditional values and beliefs. Local chiefs close areas of reefs to fishing, sometimes for years, when fish populations become too shy or sparse.
Do fish that have more contact with humans act differently in our presence? Studies suggest fish exposed to speargun fishing stay further away from divers than their counterparts less exposed to this form of human interaction. To assess the difference in behavior researchers decided to measure what they call, “flight distance,” the distance a fish stays from a diver, in different coral reef fish that are popular catch for local fishermen.
To study fish flight distances, a scuba diver will approach a fish subject, and drop a marker on the sea floor at the point where the diver was when the fish took flight. A second marker is placed at the point on the sea floor where the fish was when it fled. This is repeated by researchers to measure the distance from where the fish fled the diver, both inside and outside MPAs in order to compare data.
Interestingly when an area that was heavily hunted is closed, fish appear to recover their confidence and over time allow divers to come much closer, within speargun range, allowing for the area to be reopened for responsible fishing.
After gaining this knowledge, countries should be responsible when reopening previously protected areas for fishing, as well as using caution when closing and reopening areas. Closing an area from hunting should regenerate the “bank account,” of resources that make up a coral reef. Countries must be careful when reopening a protected area, since the change in environment and behavior can make some fish species’ more susceptible to spearfishing.
The encouragement, or restriction of certain types of spearfishing can help to tackle any negative outcome that could unfold from closing and reopening protected areas; such as, gear-restrictions, like the illegality of spearing with a tank on. Encouraging larger fish to become accustomed to relative safety while living on a coral reef will encourage a steady equilibrium in biomass.