Coral Reef Habitats
Coral reefs are complex three-dimensional landscapes and coral reef fish experience this ‘landscape of fear’ based on how much shelter is available compared to the number of predators roaming the reef.
A new study from the University of California, Davis looked at the distribution of reef fish, reef habitats, algae growth, and predator abundance to determine the risk fish are willing to take for a tasty meal. The study, which was published January 12th, finds that fish which are willing to overcome their fear of predators, such as sharks or groupers could reap the benefits.
Risk and Reward
Researchers collected four types of algae and set up grazing station at 30 different locations off the remote islands of Mo’orea French Polynesia. They found that certain species of fish would venture further from shelter when fresh algae were present.
“It’s the idea of hazardous duty pay,” said lead author Mike Gil, a National Science Foundation postdoctoral fellow in UC Davis’ Department of Environmental Science and Policy. “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 capitalize on greater food rewards.”
How Feeding Behavior Protects Coral Reefs
While coral reefs provide shelter from predators, reef fish have a critical job to do in return: They eat algae that, in high abundance, kill corals.
However, algae multiply as coastal development and other human activities bring increasing amounts of nutrient pollution to the ocean. Understanding how fish feeding behavior 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.” [Science Daily]