The purpose of the Department of Industries was to promote the development of secondary industries.

The Sea Fisheries Branch of the Department of Industries promoted rational utilisation of the botanical and zoological resources of the sea.

The guano island on the west coast of South Africa and South-West Africa (Namibia) were in the beginning exploited and managed by private contractors, but as the contracts expired the islands were gradually placed under direct government control. A Superintendent of Government Guano Islands was appointed in 1898 to take care of the administration of the islands and to arrange for the exploitation of the islands on behalf of the government. Access to the proclaimed islands were forbidden except under permit issued by the Superintendent. The islands stretched from Algoa Bay on the south-east coast to about 200km north of Lüderitz on the west coast.

Central control of the islands was vested in the Superintendent of Government Guano Islands, whose offices were in Cape Town. Every year the Superintendent would recruit several hundred labourers in Cape Town to undertake collection of the guano on the islands under the supervision of the island headmen. These labourers were housed and fed on the islands. Fresh water, provisions, fuel and all stores and equipment were shipped to the island from Cape Town. The guano season commenced in the early autumn when the birds' nesting season has ended and the chicks have reached the stage where they could leave the nests and fend for themselves. The season usually lasted from March until July/August