Stephen Amisah

Traditional Representations of the Natural Environment and Biodiversity Conservation: Sacred Groves in Ghana

Local cosmologies and traditional perceptions of the natural environment, especially forests, have been a major influence in the management of the natural resources and biodiversity amongst rural communities in the transitional zone of Ghana. Sacred groves, which are typical outputs of traditional conservation practices, derive from indigenous religious beliefs and perceptions of forest. Sacred groves are believed to be the abode of local gods, ancestral spirits and other super natural beings. These beliefs and perceptions have in the past strongly supported the conservation of biodiversity. However, changes in local cosmologies threaten the protection of rare species, habitats and ecological processes. Data from the study confirm evidence from several studies in Ghana and elsewhere in West Africa that the tremendous ecological, social, institutional, religious and economic changes in communities that have protected sacred groves threaten the survival of these cultural artefacts. The paper demonstrates that in contemporary natural resources management, the sacred grove model may still be used as a means of restoring and protecting landscapes in indigenous communities. Even in communities where population explosion and economic pressures have reached thresholds that undermine the natural landscape, the model may still be useful to keep pockets of forests within the landscape.

Characterisation of potential aquaculture pond effluents, and physico-chemical and microbial assessment of effluent-receiving waters in central Ghana

An understanding of specific aquaculture systems and the impacts of their management practices leads to sound and cost-effective policies to protect the aquatic environment. Water samples were collected in 2009 from fish ponds, streams that receive effluents directly from ponds and reference streams in Ghana to assess potential environmental impacts of pond aquaculture. Although relatively dilute, fish ponds had higher levels of all physico-chemical variables measured compared to those of locations upstream and downstream of farms, and to reference locations. Total nitrogen and BOD5 were most clearly statistically significant. Of 292 earthen fish ponds surveyed in central Ghana, approximately 92% were used for either Oreochromis monoculture or Oreochromis–Clarias polyculture. These had similar pond water (i.e. potential effluent) quality but different management practices. The study ponds had the potential to pollute effluent-receiving streams, but their actual impacts will depend on how pond effluents are managed. Conventional treatment of effluents from these small-scale, low-volume operations, which discharge relatively dilute effluents infrequently, might not be cost-effective.

Analysis of the use of credit facilities by small-scale fish farmers in Kenya

The government of Kenya encourages aquaculture development by offering credit facilities through the government agricultural finance institution, Agriculture Finance Corporation. Nevertheless, the level of credit use in fish farming is very low. Access to credit is among several factors that affect farmers’ decision of whether to use particular technology or services. The study examined factors that affected the decision of fish farmers in Kenya to utilize credit facilities in fish production using a probit model. The analysis suggests that farmers in the Western province will have a 19% more probability of using credit facilities for their fish farming operations than farmers from the other provinces such as the Rift Valley, Central, and the Eastern province. The effect of tilapia sales on the probability of credit use by fish farmers is more than three times that of catfish sales. Total pond acreage owned by fish farmers had a positive effect on credit use but the effect was very small and negligible. The level of fish farmers’ use of credit facilities is very low, and there is probably the need to educate farmers on credit use and for the government agricultural lending agency and other commercial agricultural lenders to invest in this enterprise. Kenyan lending institutions have financed traditional agricultural enterprises, and with the growing production of farmed fish, more research is needed to document the aquaculture business model to assist in assessing the profitability potential in aquaculture.

Effect of some common West African farm-made feeds on the oxygen consumption and ammonia excretion rates of Nile tilapia, Oreochromis niloticus

Abstract The effects of two common West African farm-made feeds on postprandial metabolism were assessed in adult Nile tilapia (Oreochromis niloticus) by quantifying the oxygen consumption rates (MO2) and total ammonia-nitrogen (TAN) excretion over a 24-h period. Measurements followed the ingestion of a single meal of a fishmeal-based control diet and two diets containing 30% copra (CM) or palm kernel meal (PKM) inclusions by groups of 15 adult O. niloticus per tank. The mean net MO2 (postprandial oxygen consumption corrected for routine metabolic rate) during digestion for the different tilapia groups varied narrowly between 112.2 ± 9.9 and 129.9 ± 20.4 mg O2 kg−1 h−1 with the fish fed the CM diet recording a significantly lower (p = 0.04) net MO2 response relative to the other two diets. Net TAN excretion rates of the different dietary groups varied between 3.4 ± 1.4 and 4.4 ± 1.6 mg TAN kg−1 h−1. Under the standardized experimental conditions, copra and PKMs appeared to be promising candidates as partial replacements to fishmeal in tilapia diets as far as rates of oxygen consumption and ammonia-nitrogen excretion are concerned.

Tono Reservoir fishery contribution to poverty reduction among fishers in northern Ghana

Fishery characteristics and livelihood status of fishers at Tono Reservoir, Ghana, were investigated between January 2015 and June 2016. Data on fisher demography, fishing gears, fishing methods, perceptions of the state of fish stocks, management practices, income and consumption of fishers were obtained through structured interviews. Censuses of fishers and fishing gears were conducted through direct observation and counts. The population of fishers was 950 and the majority (74%) of the sampled respondents fell within the ages of 24–41 years. Gillnet, cast net, trap and hook and line were the four main gears utilised. Illegal methods of fishing observed included the use of mosquito nets (nets with mesh <1.0 cm) and the use of brewer’s waste (pito mash) as bait. Brycinus nurse, Synodontis spp., Parailia spiniserrata and Chrysichthys spp. were perceived to have disappeared from the reservoir. The fishers were unaware of the existence of any fisheries regulations, hence there was no adherence to management practices. Their daily income was derived mainly from fishing. The incidence of poverty among fishers was low (8%). The Tono Reservoir has a great potential for supporting livelihood if it is properly managed.

Evaluation of Locally-available AgroindustrialByproducts as Partial Replacementsto Fishmeal in Diets for Nile Tilapia(Oreochromis niloticus) Production in Ghana

Objective: This study assessed the potential of three widely-available local oilseed byproducts, soybean (SBM), copra (CM) and palm kernel meals (PKM) as partial replacements of fishmeal in Nile tilapia (O. niloticus) diets in terms of their digestibility and effects on growth and nutrient utilization. Methods: Apparent digestibility coefficients (ADCs) were determined using chromic oxide as an inert marker in test diets formulated to contain 30% of each of the test ingredients by weight and 70% of a fishmeal-based reference diet. The 8-week growth trial evaluated the effects of partial replacements of fishmeal by the oilseed byproducts at different dietary inclusions. The soybean meal diets were formulated with the soybean meal contributing 25% (SBM25) and 50% (SBM50) of total dietary protein. Copra and palm kernel meals each contributed 10 (CM10 and PKM10) and 20% (CM20 and PKM20) of total dietary protein in their respective diets. The test diets were compared to a control diet with fishmeal as the sole protein source. Results: Nutrient digestibilities of the test ingredients were generally significantly higher for the soybean meal than the copra and palm kernel meals. The ADCs of the soybean, copra and palm kernel meals were; protein, 90.57%, 69.36% and 61.12; lipid, 96.14%, 95.64% and 95.85%; fibre, 96.74%, 77.61% and 55.07% and energy, 91.99%, 73.61% and 75.14% respectively. All the dietary treatment groups recorded significant growth at the end of the trials with the fish in the control and SBM25 groups more than tripling their respective mean initial weights. All the other treatment groups more than doubled their mean initial body weights. Daily growth rates ranged from 1.40% day-1 for the PKM20 group to 2.26% day-1 for the control group. Conclusion: The study has shown that the test ingredients can partially replace fishmeal in Nile tilapia diets without considerably compromising diet digestibility and carcass traits although higher dietary levels of the oilseed byproducts negatively affects growth.

Growth Performance, Feed Utilization and Sensory Characteristics of Nile Tilapia, Oreochromis niloticus Fed Diets with High Inclusion Levels of Copra Meal

Background: The low cost and wide-availability of copra meal in many tropical countries where aquaculture is practiced have generated much interest in its potential inclusion in fish diet formulations. The present study was designed to investigate the effect of very high inclusions of autoclaved copra meal on the growth and feed utilization parameters as well as the sensory qualities of the Nile tilapia, Oreochromis niloticus. Methods: Fish were fed three experimental diets, a control (CTRL) diet which had fishmeal as the main protein source at an inclusion of 365 gkg-1 and two test diets which contained copra meal at 680 g kg-1 inclusions for a 6-week period. One of the copra meal diets contained sesame meal supplementation (CM+S) as a natural high source of methionine which is the first limiting essential amino acid in copra meal. Results: The dietary treatments had no differential effects on growth, feed intake, or feed utilization parameters in O. niloticus. With the exception of the significantly higher lipid content of the CM+S group, the whole body compositions of the different fish groups were not significantly affected by the different dietary treatments. Remarkably, the high dietary inclusions of copra meal did not have any significant effects on fillet sensory attributes. Conclusions: The results of this study demonstrate that it is possible to include autoclaved copra meal up to 680 g kg-1 in Nile tilapia diets without any deleterious effects on fish growth or on flesh sensory characteristics.