From Marine Protected Areas South Africa website:

After the 2011 National Biodiversity Assessment noted that offshore ecosystems were poorly protected, the Offshore MPA project (2007- 2011) initiated plans to increase protection of offshore ecosystems, which were advanced towards implementation during Operation Phakisa Oceans Economy. A total of 22 new MPAs were gazetted for comment in 2016 as part of a lengthy consultation process. The South African Cabinet granted permission to declare a revised network of 20 new MPAs in October 2018. It took several months to prepare the declaration notices and final regulations. This culminated in the gazetting of 20 new MPAs on 23 May 2019. These take effect on 1 August 2019 and expand the protection of South Africa’s mainland ocean territory to 5%.

From the Operation Phakisa website:

20 new MPAs, and two expanded MPAs were identified through Operation Phakisa‚ a presidential project to fast-track the development of South Africa’s Ocean Economy. The new MPAs will secure protection of marine habitats like reefs‚ mangroves and coastal wetlands which are required to help protect coastal communities from the results of storm surges‚ rising sea-levels and extreme weather. Offshore‚ these MPAs will protect vulnerable habitats and secure spawning grounds for various marine species‚ therefore helping to sustain fisheries and ensure long-term benefits important to food and job security.

From Government Gazette Staatskoerant:

The Agulhas Bank Complex Marine Protected Area in the Western Cape is an offshore marine protected area in the 50m to 150m depth range lying approximately 39 nautical miles southeast of Cape Agulhas. 

The purpose for declaring this marine protected area is:

(a) To contribute to a national and global representative system of marine protected areas by providing protection to the offshore benthic and pelagic shelf ecosystems of the Agulhas Bank;

(b) to conserve and protect rocky, gravel, sandy and pelagic habitats of the Agulhas Bank, which includes the Alphard Banks, parts of the 45 Mile Bank and parts of the 72 Mile Bank;

(c) to conserve and protect threatened ecosystems and fish species;

(d) to conserve and protect the biodiversity and ecological processes associated with the ecosystems in this area, which includes the nursery function of the Agulhas Bank;

(e) to support the recovery of linefish by protecting important nursery, spawning, foraging, aggregation and refuge areas for overexploited linefish;

(f) to facilitate species management and sustainable use of linefish and south coast rock lobster to enhance species abundance in adjacent areas; and

(g) to protect and provide an appropriate environment for research and monitoring particularly research on ecosystem impacts and recovery, habitat requirements of south coast rock lobster and recovery of linefish.