A study by the University of California, Davis found that coral reef fish experience "landscapes of fear." The term describes how fish and other organisms perceive the safety of their environment based on where and how much shelter from predators is available.
In a study that involved setting up different sized "buffets" of algae off the island of Mo'orea in French Polynesia, the research team also found that the fish are willing to move past this fear, straying far from their sheltered coral refuge and risk being eaten by predators–especially if the payoff is higher.
Comparing it to hazardous duty pay, lead author Mike Gil, a National Science Foundation postdoctoral fellow in the university's Department of Environmental Science and Policy, said, "If you worked construction at a particularly dangerous site, you would want higher pay. Similarly, these fish also appear willing to take on greater risk to capitalise on greater food rewards."
While coral reefs provide shelter from predators, reef fish have a critical job as they eat algae that, in high abundance, kill corals. However, as coastal development and other human activities bring increasing amounts of nutrient pollution to the ocean, algae multiply. Understanding how fish feeding behaviour responds to algal blooms, overfishing and other disturbances is important for coral reef conservation and requires further study, Gil said.
"Our findings suggest that if we prevent overfishing in coral reefs, intact fish communities can at least partially counteract increases in algae by using this food incentive to overcome their fear of being eaten in dangerous parts of the reef," Gil said. "So fish boldness may play an important role in large-scale algal blooms that result from nutrient pollution and threaten coral reefs worldwide."