This paper report findings of an investigation into the effect of aeration devices on some selected freshwater quality parameters. Three aeration columns, Upturned shower rose (USR), Downturned shower rose (DSR) and Perforated pipe (PEP) were experimented. Freshwater fish culture water was passed through the devices and analysed for Temperature, pH, Alkalinity and Dissolved oxygen (DO) in the morning, afternoon and evening. The percentage modification was used to measure the effect of aeration on the selected water quality parameters. Temperature modification ranged from-2.4% to 0% with equal value in all the aeration devices at all the period, Alkalinity ranged between-10.7% and 3.7% with least modification in DSR in the morning but highest in USR in the evening, The percentage modification in pH fell between-8.3% and-1.8% with the least modification in USR in the morning while the highest was recorded also in USR but in the evening. The DO ranged between 37.1% to 161.9% with the highest modification in DSR in the afternoon and the lowest in USR in the evening. The investigated aerating devices have little effect on all the selected water quality parameters, except for dissolved oxygen where the effect is very prominent.

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The study was carried out to investigate the biological condition of fish species in lower Ogun River wetlands. A total of 175 individual fish belonging to 10 species were collected from artisanal fishermen using different types of fishing gears. Two biological indices; condition factor "K" and growth exponent "b" obtained from length-weight relationship were used to determine the biological condition of the fishes. The condition factor (K) recorded during the study ranged between 0.55 in Liza grandisquamis and 5.61 in Oreochromis niloticus. The growth exponent (b) ranged from 1.48 in Penaus notialis to 5.67 in Gymnarchus niloticus. The regression coefficient of determination was significant for some of the fish with highest value of R 2 =0.98 for Sardinella madarensis. The study showed that most of the fish species in the study area are in poor biological condition and exhibit allometric growth.

Methods of improving the quality of fish seed supply to fish farmers in Benue State were studied. Data were obtained from one hundred and thirty three fish farmers' using multistage random sampling technique. Structured questionnaire was used to obtain information from the respondents; data obtained were analyzed using descriptive statistics and Chi square to test relationship between the variables. The result showed that 53.83% of the fish farmers source their fish seeds from the wild. Methods of improving the quality of fish seed supply through brood-stock management were culture method (97.10%), feeding (94.10%) and genetic composition (97.0%). The major constraints to the methods of improving the quality of fish seed supply were respondents' technical knowhow (99.2%), inconsistent government policy (99.20%), lack of government assistance (97.0%) and inadequate extension services (97.0%). The Chi square analysis showed significant relationship between brood stock management and methods of improving the quality of fish seed supply (p<0.05). Also, significant relationship existed between methods of improving the quality of fish seed supply and constraints, inadequate water supply, scarcity of feed, poor brood stock management and lack of government assistance. Government should encourage the fish seed production industry by providing infrastructures, formulation and effective enforcement of consistent policies and provision of credit facilities to fish farmers.