Aquaculture offers many advantages for people. We don't have to go out and hunt for seafood, and we can produce big animals in large quantities. However, farmed fish and shellfish are also very attractive to wild animals, who see the captive animals as a bountiful supply of food. Predation is a challenge that aquaculturalists who do not operate in closed containment facilities regularly face. Here are just a few of the methods troubled farmers can use to try keep predators at bay.
Noise and visual deterrents
Noise deterrents such as loud bangs, pings, and even distress calls, and visual deterrents ranging from simple streamers to models of top predators have been used to deter avian and marine mammal predators. In both cases the long-term benefits are debatable. At first noises can cause animals to flee, but they can become quickly habituated to the noise, particularly if that noise is frequent, occurs at regular times, and is always the same sound. Fibreglass models of killer whales have been shown to be effective at reducing predation from marine mammals for a few months at best. Similar short-term results have been found for scarecrows, buoys, flags, streamers, and even balloons. Animals learn quickly that there is no threat – or are at least willing to hedge their bets for a tasty meal.
This article was written for (and can be read in full at) The Fish Site.