Change always brings risks, whatever the change is. Change risks may result from a chain of causes, and may have multiple impacts. Understanding them may help you adapt and exploit them, but if you do not understand what is happening, your livelihood might be threatened.
Now if you ran a shark tourism business in Cape Town South Africa, you might have a whole range of customers such as thrill seekers who want to cage dive, wildlife enthusiasts, and documentary film-makers. The presence of great white sharks is the big draw, and they are there for the abundance of food (seals).
You might think that the biggest risk to a business like this is a safety one, particularly with cage-diving, but then there is also the significant dependency on the sharks actually being there. Between 2005 and 2015, sightings of great whites averaged over 200 a year in the sea around Cape Town. However, in 2020, not a single great white was seen in the area.
A few years ago, fishermen starting noticing dead sevengill sharks that had had their livers removed. It was not clear if this was through human activity or not. Then great whites were found dead with the same injury, a gash to the abdomen and the livers removed.
Investigations and observations finally revealed what was happening. Killer whales had moved into the territory. They work together and pull on a shark’s fins on either side which splits its abdomen open; then they grab the liver.
And it appears the killer whales have moved in on the sharks’ territory because of over-fishing in their usual habitats – it is a chain of causes. And the impacts include reductions in the population of endangered penguins as there are now more seals which eat the penguins. And no doubt there are further impacts we may yet find out about, including the end of shark tourism.
Data Source: The Economist magazine