Catch-and-release angling can be valuable, with low consequences for the long-term survival of a population, when done responsibly according to best practices. Catch-and-release can equally still be detrimental when these considerations aren’t applied, or when particularly vulnerable animals are caught and don’t survive handling and release. The impacts of catch and release angling can vary from species to species, with very different considerations and consequences for all different sharks, rays and bony fishes (we call these teleosts) – both for their individual stress and responses, and for the survival of their population. For that reason, it’s most useful to assess each species on a case-by-case basis. It’s difficult to give a blanket statement that applies in all cases.
Just so that we know we’re all talking about the same thing: in catch-and-release fishing, fish are unhooked after capture and released back into the water. This is often after a quick measurement and weighing of the fish, followed by photography. We get two different kinds of catch-and-release fishing: for recreation (sport, competition or fun), by anglers in the public and for science.
Scientific catch-and-release is usually to tag, weigh, measure and identify different species, and from this we get valuable information necessary for management and protection. For example, it’s thanks to a scientific catch-and-release programme that we got some of the first evidence that MPAs (Marine Protected Areas) work in SA. Scientists showed that the galjoen, as well as zebra seabreams, white steenbras, Cape stumpnose, white musselcracker and blacktail seabream recovered after the proclamation of the De Hoop MPA. That kind of information is vital to help motivate for other protected areas, or to keep track of the health of populations.
Recreational catch-and-release fishers need a permit, and often adopt voluntary actions (such as barbless hooks) to minimise negative impacts on fish. When done using the best fishing practices and handling procedures, catch-and-release has little negative impact on some fish, but many others (such as silver kob) can suffer barotrauma (stress caused by decreased pressure, often from ascending too rapidly to the surface). Effects include organ rupture and skin haemorrhage, and some animals die post-release – or their behaviour is so altered, their ability to hunt and move is impaired. Some people also wrongly assume that all sharks and rays are stronger and more resilient to catch-and-release, but they too can die a slow death when, for example, they are left on the jetty or shore for too long, or become stressed and exhausted when they fight on a fishing line for too long.
If catch-and-release is happening, how can we be more responsible, informed and minimise harm? There is a lot of work happening along the South African coast to help educate anglers so that they can apply best-practice: check out WWF and Fish For Life’s Responsible Angler guide (http://fishforlife.co.za/static//uploads/images/WWF%20WEB%20VERSION%20proof.pdf), the Fish for Life programme, ORI’s TAG programme (http://www.oritag.org.za/GettingStarted) and this article that uncovers a little of why scientific catch-and-release for tagging can be helpful: https://mg.co.za/article/2019-05-31-00-fish-species-overexploited-or-collapsed/. Arm yourself with the right knowledge for whichever species you’re handling, and avoid those which scientists point out as too vulnerable.