The construction of the experimental brackish-water fish farm at Buguma was completed. The problems that arose in the eradication of unwanted tilapia from the experimental ponds were solved by devising suitable screens for the sluices and by the use of Aldrex 40. Methods of correcting oxygen deficiency created by sulphide accumulation in ponds were successfully tried.
Experiments for the selection of suitable species for culture in brackish-water ponds in the Niger Delta were started. Although these experiments had to be terminated due to internal strife in the country, preliminary results indicate the suitability of a number of local species besides mullet and pink prawn for culture.
The catfish Chrysichthys nigrodigitatus grew well on artificial feeds in ponds. The catfish Clarias lazera acclimatized itself easily to salinities up to 23.2 ‰ and the common carp Cyprinus carpio to salinities occurring in the creeks surrounding Buguma. The sardine Sardinella aurita showed a remarkably high growth rate in ponds.
The common tilapias in the area (Tilapia heudeloti and T. zillii) were incompatible with mullet and pink prawn for culture in ponds. These tilapias seem to be unsuitable for use as forage fish in the culture of the red snapper (Lutjanus sp.) as they were found to attack even larger specimens of the predator.
Preliminary studies of the mangrove oyster, Ostrea tulipa, showed that asbestos sheets form better collectors for its spat than old oyster shells. In creeks near Lagos, this species of oyster attained an average size of 70 mm in about seven months.
