They landed on a small island, now called Santa Cruz, where they devoutly set up the cross, and swore they would cut the captain's throat if he attempted to sail farther.

Beyond this they thought was the edge of the world, which they too believed was flat; and fearing that their ship would sail over the brink of it, they compelled Captain Dias, their commander, to retrace his course, all being only too glad to get home.

that "projectiles and badly corroded mustard gas containers have been found in the area between Cape St Francis and Bird Island out to depths of 400 m (1,300 ft).

[6] During that conflict, Port Elizabeth was used as a research, manufacturing and storage site for mustard gas ordered by the British Air Ministry.

All six islands and their adjacent waters are declared nature reserves and form part of the Addo Elephant National Park.

Worthy of mention as an obstacle to navigation is Despatch Rock, 2.4 km (1+1⁄2 mi) due east of the Port Elizabeth suburb of Summerstrand.

Further south, about 1 km (5⁄8 mi) southwest of Cape Recife, the western starting point of the bay is Thunderbolt Reef.

"Much of the island group is covered by sparse growth of mixed vegetation dominated by the fleshy herb Mesembryanthemum (fig marigold/icicle plants).

Tetragonia (duneweed) and Chenopodium (goosefoot) form localised thickets that provide cover for some seabirds," the fact sheet says.

“Larus dominicanus (the Kelp Gull) and Haematopus moquini (the African Oystercatcher) are found throughout the Algoa Bay complex.

Competition with commercial fisheries, especially purse-seining for surface-shoaling fish such as anchovy (Engraulis capensis) and pilchard (Sardinops sagax), has been implicated as one of the most significant factors causing seabird population declines."

The organisation has recommended that marine reserves with a radius of 25 km be created around important breeding islands, and that commercial fishing be banned or restricted in these zones.

The African Penguin (Spheniscus demersus) is particularly susceptible to these events, and a single oil disaster has the ability to severely affect populations.

It is believed that the breeding sites in Algoa Bay, at the eastern extremity of the species' range, are at highest risk as they are closest to the major oil-shipping routes.