3 research studies that show the positive impact of MPAs

Protected marine areas should serve nature and people: A review of South Africa's efforts

Judy Mann-Lang, Bruce Quintin Mann and George Branch  20 Jan 2022

“MPAs provide many benefits for both ocean health and human activities,” he explained. “One benefit is that they enable fish stocks to increase in abundance and biomass and, over time, these spill over into adjacent fished areas, improving catches and ensuring fisheries sustainability.”

He adds that the quality of these conservation areas also gives a clearer idea of what nature looks like when it is not impacted by humans: “This forms a useful ‘control’ which provides a solid foundation for our research into the natural world and the conservation techniques needed.”

Here are three examples of the beneficial impacts of MPAs on the East Coast of SA

Release of a tagged Scotsman in the Pondoland MPA (Photo credit: Paul Cowley)

The Scotsman

For 16 years, Dr Mann and his team have studied the Pondoland MPA in the Eastern Cape with impressive results. They tagged and released 1,042 Scotsman seabream, recapturing 255 (24%) -- some multiple times. Most (85%) stayed within small home ranges on MPA reefs, proving the no-take zone’s effectiveness in protecting resident fish. The rest (15%) travelled northeast along the KZN coast, likely to spawn, and were later caught by recreational and commercial ski-boat fishers, highlighting how MPAs can support both conservation and local fisheries.

Spawning aggregation of giant kingfish in the Maputo National Park in Mozambique (Photo credit: Ryan Daly)

Giant Kingfish

To track giant kingfish (GTs), Dr Mann was part of a team that tagged 36 adult fish with acoustic tags along the coast from southern Mozambique to the Eastern Cape over five years. The findings were remarkable: every kingfish visited a spawning site in the Maputo National Park (an MPA) during full moons between November and January each year -- some travelling distances of 632km at speeds of up to 130km a day. After spawning, they returned to individual home ranges, many within MPAs along the KZN and Eastern Cape coast. GTs thus rely on MPAs for their survival, and if we want to continue catching this iconic species in future, we need to look after our MPAs.

Release of a tagged speckled snapper in the iSimangaliso MPA (Photo credit: Bruce Mann).

iSimangaliso MPA

Can catch-and-release (C&R) help conserve shore angling species? A 20-year study in the iSimangaliso MPA tested this by tagging fish caught by volunteer anglers in zoned areas within the MPA. The findings showed that when best-practice handling was used, C&R angling had minimal impact on most species, but more sensitive species still showed higher post-release mortality, especially with increased angling pressure. The study concluded that while C&R isn’t suitable in strict no-take zones, it offers real conservation value as a buffer around MPAs or in specially zoned areas.