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Marine Fish Feeding: Why the FWC Thinks It’s Bad for Everyone

Marine Fish Feeding: Why the FWC Thinks It's Bad for Everyone
By Dan Roberts, Research Scientist
Florida Fish and Wildlife Conservation Commission
Published in Florida Fishing Weekly, Nov. 26, 2006


In 2001, the Florida Fish and Wildlife Conservation Commission (FWC) unanimously voted to prohibit divers from feeding marine life in Florida. You might be wondering why the FWC believes these "interactive marine experiences" are harmful. After all, the fish get an easy meal, and divers get entertained, so what's the problem?

Overall, feeding marine fish is a bad idea for everyone, including divers, fish and the ecosystem. Contrary to popular belief, fish have memories and can learn. Through behavioral conditioning, fed animals learn to associate people with a meal. When this happens, fish anticipate the hand-feeding experience and depend on handouts from divers.

Hand-feeding marine fish results in a variety of negative impacts. Most marine fish have around 10 essential amino acids required for growth and health maintenance. Fish cannot make these acids on their own, and they receive these building blocks from food. Fish generally consume a wide variety of prey in order to meet dietary requirements. To obtain the necessary nutrients, fish have complex feeding cycles.  Seasonal, daily and other temporal feeding strategies make up a fish's foraging behavior. Fish conditioned to take an easy meal from divers begin anticipating meals, which interrupts natural feeding cycles. A fish conditioned to feed on diver deliveries may actually stop normal foraging patterns and become malnourished, stressed and can even die.

In addition to nutritional consequences, hand-fed fish are especially vulnerable to predators. In carnivorous fish, sensations associated with feeding can override other associations, including predator avoidance and protection. Competition for the handout interferes with natural instincts and behaviors, which are essential for survival and cohabitation with other species.

Hand-feeding creates other ecological disturbances. These disturbances change community structure. Introducing a ration of food to a fish, even a ration of semi-natural food, is significant. By affecting the natural feeding behaviors, fish feeding can destabilize a number of ecological relationships including species abundance. The effects are unique to each marine community, but there is a measurable impact with recurring and prolonged disruption.

Marine life maintains balanced ecological relationships by competing for habitat and food. In many cases, different species share space and alternate the use of that space by feeding at different times of day. Some species do not interact at all. This intricate balance of behavior can be interrupted by the introduction of a free meal from a diver. Unnatural feeding overrides normal competitive relationships among species. It fosters combative behavior among species that, under usual circumstances, may never come in contact with each other. Combative behavior can seriously injure animals. For example, pelicans and harbor seals rarely come in contact with each other in a typical habitat. When people feed pelicans, harbor seals may actually bite the birds as they compete for food.

Hand-feeding-induced attacks on humans do occur. Feeding wildlife can place people in harm's way. In a letter to Governor Bush, a diver described a bad experience as a result of feeding fish.

"On a dive vacation to Florida in 1999, I was attacked and bitten by a large green moray eel while on an interactive feeding dive...My attack was completely unprovoked, coming from behind."

Moray eels, sharks, barracuda, groupers and a host of other species are can pose an increased danger to divers as a result of hand-feeding.

In addition to behavior changes in wild fish, fish in captivity also exhibit altered feeding behavior. Species such as red drum and snook, maintained by the FWC's Fish and Wildlife Research Institute, become almost tame and partially domesticated to the point where they learn feeding routines, including locations of feed, times of feeding and possibly even the person feeding them.  Research has demonstrated this in shallow tanks with clear water, as well as in 1-acre ponds with cloudy water. In other studies, researchers have described groupers' readiness to approach humans when in captivity.  Gag, a common grouper in the Gulf of Mexico and South Atlantic Ocean, would hold their heads out of the water to take food from humans, accepting direct hand-feeding in air much as you would feed a snack to a dog. This behavior demonstrates a feeding response overriding predator avoidance. Fish in nature learn the ways of the wild, while fish in captivity do not. Wild fish moved to captivity forget the ways of the wild and readily adapt to confinement and its routines.  Scientists have repeatedly observed this in science-based programs. Fish reared in captivity for stock enhancement sometimes undergo a process called habitation prior to release into the wild. This process conditions the fish to a more natural feeding behavior so they have a better chance of surviving in the wild.

Next time you're enjoying Florida's marine environment, don't be tempted to feed fish. FWC researchers are certain that feeding wild marine fish and invertebrates is bad for everyone.