There is a lot of misunderstanding and myths surrounding the method of chumming. This post is to help educate you about how important chumming is to collecting the information that we do, and how it is not increasing the likelihood of injuries to humans.
For those who may not know, chumming is when oily chopped fish are spread in the water to attract animals to the boat, most commonly sharks. Oceans Campus uses mainly sardines because they are such an oily fish to start.
One of the first misconceptions is that chumming attracts sharks to the area where surfers and other water recreationists are. This is false when the people chumming are responsible. The chum can only reach around 160 meters from where it is dumped, and Oceans Campus is always about 800 or more meters from where common surf and recreation spots are. This means that the chumming would only attract the sharks within the 160m and bring them even further from the shore in most cases.
Another common misconception is that chumming conditions the sharks to associate humans with being fed. Although this can be true in some extreme cases where shark feedings are a common occurrence, chumming rarely, if ever, conditions the sharks. In order for animals to be conditioned, they must be rewarded for doing something, thus reenforcing the behavior. This is not the case with chumming. The sharks (white sharks) are not interested in eating the chum; it only attracts them. They are interested in the bait line that is tossed out and used to maneuver the shark into a position where photo identification can be used to identify the shark and assess the white shark population. Even with the bait line, sharks rarely consume the bait, so they are not being rewarded for showing up to the boat. We actually work very hard to try and keep the sharks from eating the bait.
There is actually a resident shark here in Mossel Bay nicknamed BlackGill, and she breaches (comes out of the water) almost every time she goes for the bait. Although she does consume the bait almost every time because she takes the bait handler by surprise, the fact that she still pursues the bait with just rigor and speed shows that she does not expect to receive the food in return for showing up. She still sees the bait as a food source that she still has a chance of losing, and therefore, needs to work for.
Another misconception is that chumming is done with pigs or human blood. This is false for Oceans Campus and many other responsible organizations who use only fish products. This also reenforces that sharks are not craving or conditioned to want humans for food. Chumming most commonly uses fish that would normally be part of their diet in the wild.
Overall, know that chumming is an important tool used by researchers to better understand and study sharks and their populations, and that, when done responsibly, it poses no threat to humans.