discouraged the early infiltration of the area by groups of people moving through the numerous protected and interlinked creeks and lagoons inland that stretch from the Volta Delta to the Bonny Estuary.
The two ecozones of the district have different human settlement patterns and the people of Nembe and Okoroba are only distantly related.
The Okoroba people speak one of what are called the Central Delta group of languages, closely related to most of the languages of Southern Nigeria (in the BenueCongo family), while the Nembe people speak the Ijo language of the Atlantic-Congo family (from which the Benue-Congo is, nonetheless, descended). The likely settlement patterns are that the Central Group people (who may have moved from the East via the Cross River) were in the area before the Ijo group moved in from a dispersal point to the Northeast of Nembe, near Obiama, on their way to Akassa and Eastwards towards the Port Harcourt area.
The inter-relationship between the two communities is long standing. Whilst Nembe may have been established as a farming community exploiting the dry land on the two islands (perhaps as a refuge) its position ensured that it soon became a trading centre, for fish and agricultural produce, between coastal fishing communities and the agricultural communities inland (like Okoroba). Later it was involved in the slave trade and finally in palm oil trade. Nembe became so important that the Nembe Kingdom extended to Brass and in 1850 a hundred European traders were said to be living in the kingdom. But although it had its own small farming settlements Nembe would have depended on Okoroba for most of its food just as Okoroba depended on Nembe as a market for its palm oil and agricultural production.
The fresh-water ecozone is the most influenced by mankind's exploitation because it contains more of the things that mankind wants: agricultural land, timber, bush-meat and other forest products. Thus as the local population grew and the demands of the market at Nembe grew, so the human influence on the Okoroba ecosystem became more pervasive. Today Okoroba is largely a cultured ecosystem: a mosaic of small farms, oil-palms, exotic fruit trees, forest trees that have been retained for their economic value (such as the bush mango, Irvingia gabonensis, and timber species like the Ironwood, Lophora procera), interspersed with bits of forest which are too wet to farm and from which most of the useful timber trees have been removed. The flood forests close to the village are depleted, with few big trees, patches where palms have been favoured, and small farms in drier areas. It is the back-swamps that appear to be the least disturbed, partly because they are so inaccessible.
However the inaccessible flood and swamp lowland tropical rainforest to the North of Okoroba, where there is no settlement for 12 kms, is closer to its natural state than the area immediately around Okoroba. Here are to be found, for instance, patches of relatively natural forest and five types of higher primate including the endangered chimpanzee and Sclater's guenon (endemic to the area between the Niger and Cross Rivers and found in only five other locations). Interestingly, the farm-forest ecosystem of Okoroba and its neighbours may actively encourage the Chimpanzee population with extra food, in the same way as it encourages a much wider variety of birds than would have been found in the natural ecosystem of the area. Okoroba is a viable ecosystem of high biological productivity.
In the mangrove ecozone South and East of Nembe the traditional activities remain: fishing; collecting crabs, oysters (cutting the stilt roots of R. racemosa to get them) and periwinkles; cutting aerial roots to make fish drying racks; and cutting dead wood for firewood. It is a low-level activity which does not damage the mangrove ecosystem, whose relatively low bio-productivity does not, in any event, allow for much
