Climate change: mitigation and adaptation strategies in fisheries and aquaculture in Nigeria

This paper examined possible mitigation and adaptation measures in small-scale fisheries, aquaculture and the fishing communities in Nigeria to cope with the impact of climate change. It is recognized that mitigation measures in fisheries are limited but must consider options on the inputs, equipments and methods employed in fishing and fish processing activities. Several opportunities for options in the country's artisanal fisheries and aquaculture, and by the fishing communities to reduce their vulnerability change impacts, and protect the livelihoods and food security have been identified. The areas of research on climate change to enhance knowledge on the socioeconomic , biolog1cal and ecological impacts, and to guide decision on mitigation and adaptation in fisheries and aquaculture and the fishing communities, are also outlined. Proper integration of fisheries and aquaculture into the national policy on climate change and the political will for implementation are key to effective climate change mitigation and to ensure sustainable fisheries, and protect the livelihoods and food security in the country

Assessment of consumer acceptance of kilishi of African carp (Labeo coubie Rueppell) and Elephant snout (Hyperopisus bebe occidentalis, Guenther)

This study was carried out to assess consumers' acceptance of kilishi prepared from Labeo coubie and Hyperopisus bebe occidentalis in Sokoto. The organoleptic properties (texture, odour, taste and flavour) of kilishi in its fresh form and under storage for 16 weeks were determined. The mean scores for the organoleptic assessment (6.90 and 7.19 for kilishi of Labeo and Hyperopisus respectively) showed that fish kilishi was highly acceptable. Hyperopisus kilishi recorded slightly higher mean scores for the tested organoleptic properties. The declining pattern of the sensory assessment scores with length of storage indicated that the optimum storage period under the room temperature for kilishi made from the experimental fish species in the study area was 6-8 weeks. Further research on appropriate storage methods is desirable. However, preparation of fish kilishi could be explored as alternative preservation technique to reduce fish spoilage especially during the glut in supply and to diversify fish product

Evaluation of slurry formulations for processing of kilishi of bony tongue (Heterotis niloticus, Cuvier)

The kilishi of Heterotis niloticus was produced for determination of appropriate slurry formulations for fish kilishi preparation. Thirty six freshly caught samples of H. niloticus with average weight of 306.20 ~c 18.33g, kilishi of this species was prepared with three different slurry formulations of high (F1), medium (F2) and low (F3) proportions of groundnut dough to spice mixture in the ratio of 1.3: 1.0, 1.0: 1.2 and 1.0: 1.8, respectively. Results of proximate composition indicated that kilishi of the H. niloticus prepared with formulation 3 (F3) recorded significantly higher (p<0.05) protein content (54.22 ~c 0.01 %) and lower lipid content (8.00 ~c 0.00%), despite recording significantly higher (p<0.05) moisture content (9.93 ~c 0.07%). Sensory score of kilishi of H. niloticus processed with F3 formulation rated significantly higher (p<0.05) for taste, flavour and general acceptability with mean scores of 5.94 ~c 0.21,5.77 ~c 0.20 and 5.50 ~c 0.22, respectively. It could be concluded that kilishi of H. niloticus prepared with F3 formulation was the most acceptable hence, recommended for use in kilishi production

Potential impact of climate change on fisheries and aquaculture in Nigeria

Climate change will have significant impacts on Nigeria's freshwater and marine aquatic systems. and hence on the countries fisheries and aquaculture. Fisheries and aquaculture are highly vulnerable to changes in weather pattern. and the impacts, which could be negative or positive, will vary from the coastal areas to the drier northern parts of the country. Elevated water temperalures will affect fish physiological processes, thereby affecting spawning. survival of the juveniles, recruit into the exploitable phase of population, population size, production and yield. The impacts of increased flooding of the freswater bodies will be negative through erosion of watershed, destruction of fish feeding and breeding habitats, decrease in primary productivity and alteration of the normal resilience of the aquatic systems, or positive in expansion of aquatic habitats for primary and fish productions especially during the dry season. Drought will exacerbate draw down of the lakes and reservoirs, and insufficient flow in the river hasins for spawning and primary pro duction thereby affecting fish production. Rise in the water level of the Atlantic ocean will lead to intrusion of more salty wafer into The river delta areas, and inundation of the coastal low-lying areas, thus affecting distribution of both the freshwater and marine fishes as a result of changes in the physical and chemical properties of the waters. The impacts will ultimately affect fish population, production and supply, thereby affecting the livelihood of over 26 million people engaged in the primary and secondary sectors of the fisheries industry, as well as food security of the country. The adaptation and mitigation strategies will be based on the peculiar characteristics and interactions of fisheries and aquaculture within the framework of feasible policy instruments. Strategies and policy measures need to be evolved to combat the observable and projected impacts of climate change on fisheries and aquaculture, in order to protect the livelihoods of the fishing communities and food security

Exploratory survey of Malian and Ndururu traps in River Rima, north western Nigeria

The fabrication and operational techniques of Malian and Ndurutu traps mostly used by the fishermen in River Rima in north western Nigeria were evaluated through structured questionnaire and measurement of samples of the Data collected were analyzed using descriptive statistics. There was no standard in the dimensions of either of the traps. The traps were made of locally sourced materials, except the synthetic net of the Malian trap. About 81 and 80% of the respondents fabricated their Malian and Ndurutu traps, respectively. The major problems encountered in the structure and operation of the Malian trap included projection above water, stealing of catches and trap, and trapping of small sized fishes as indicated by 61.9, 47.6 and 28.6% of the respondents, respectively. In the case of the Ndurutu trap, 72.0, 48.0, 12.0 and 8.0% of the respondents respectively indicated poor durability, single entrance valve, destruction by cattle and instability in water, as the major problems encountered. As improvement measures for the Malian trap, the respondents suggested increase in number and size of valve (81.0%), horizontal positioning (57.1%) and square shape (47.6%) while 52.0% each suggested increase in number of entrance valve and netting of Ndurutu trap. The fishermen demonstrated ingenuity in the fabrication and operation of the traps, but they failed to initiate the required improvement. It is important to critically examine the designs, materials, costs and limitations of the traps and the suggestions of the fishermen, as basis for improvement on the technology of the trap

Effect of Drying Methods on the Nutritive Value of Some Aquatic Macrophytes in River Rima, North Western Nigeria

A comparative study on the effectiveness of different drying methods on the nutrient contents of water hyacinth (Eichorniacrassipes) , Water lilly(Nymphae lotus) and water primrose (Ludwigiahysopifollia ) leavewas carried out in order to ascertain their potential as nutrient supplements in fish feed formulation. Whole components of each plant were weighted and 600g each of the leave were separately weighted in triplicates and was subjected to oven dying, sun drying and air drying. Results of analysis indicated that oven dried leave of Ludwigiahysopifolliahad significant (p&lt; 0.05) high crude protein (15.13± 0.01) than sun dried and air dried (11.64±0.01 and 4.84±0.60), this follows the same trend with Eichorniacrassipes and Nymphaea lotus 12.52± 0.12 and with 11.76 ± 0.02 respectively. The ash, crude fiber and crude lipid contents exhibit no significant (p&gt; 0.05) difference in the oven drying method of the three plants. Moisture content differ significantly (p&lt; 0.05) in Eichorniacrassipes in all the drying methods, higher values Nitrogen Free Extract was recorded in each drying method. The percentage composition of leaves shows that Ludwigiahysopifollia has 64.74% Eichorniacrassipes has 16.01% and Nymphea lotus 55.95%. The study concluded that oven drying recorded the best effect on the nutrients contents of the plant leaves this grossly followed by air and sun drying method, and also the leaves of these macrophytes can be used to substitute conventional carbohydrate not protein supplements in fish feeds. Further studies should be carried to assess the potential of these macrophytes subjected to the various drying methods in feeding cultured fish species

Hematological Indices of Clarias griepinus (Burchell, 1882) Fingerlings Fed Diet Containing Graded Levels of Calabash (Lagenaria vulgaries) Seed Meal

The effect of graded levels of calabash (Lagneria vulgaries) seed meal (CSM) on hematological response of Clarias gariepinus juveniles was investigated. Five isonitrogeneous  (45% crude protein level) diets at 0, 15, 30, 45 and 60%  inclusion levels of CSM designed as diets I, II, III, IV and V  were fed to 15 groups of Clarias gariepinus juveniles for 56 days. There was no clear trend in the Packed Cell Volume, Hemoglobin, Red Blood Cell and Mean Cell Volume of the fish fed the experimental diets. However, there was decreased in Parked Cell Volume (24.00±1.00%), Hemoglobin (8.27±0.06g/dl), Red Blood Cell (2.09±0.091012/ml) and Mean Cell Volume (114.52±6.08)  with significant (p&lt;0.05) difference between the treatments on the fish fed the highest inclusion  level (60%) than the control. White Blood Cell (2.09±0.10109ml) and Mean Corpuscular Hemoglobin Concentration (34.48±1.23%) exhibit a significant (p&lt;0.05) difference at higher inclusion level (60%) than the control and other dietary treatments. The study recommends that Clarias gariepinus fingerlings can be fed up to 29.69(60%) inclusion level of calabash seed meal with out negative effect on the health status of the fish. Keywords: Calabash seed meal, Clarias gariepinus fingerlings, Heamatological parameter

Relative efficiency of monofilament and multifilament trammel nets in southern portion of Lake Kainji, Nigeria

The relative efficiency and selectivity of monofilament and multifilament trammel nets in southern basin of Lake Kainji were studied. The netswere set and inspected daily for 30 consecutive fishing days. Monofilaments trammel nets had the highest relative species diversity index of 0.52 while multifilament had 0.48. A total of 204 fish were caught, 64.7% was caught by monofilament nets and multifilament net 35.3%. This suggests, that there was significant (P < 0.05) variation in catching efficiency of the trammel netswith regardto Citharinus citharus with the monofilament net having the highest 79 fishes, but was not significant (P > 0.05) in overall number of difference species caught. However, trammel nets showed better efficiency for catching C. citharus, S. membranaceous, C. laticeps, O. nitoticus, Sarotherodon, than other species caught. There is no significant difference (P > 0.05) in the minimum and maximum sizes of fish caught, and this indicates the efficiency of the trammel nets in avoiding juveniles of commercial species, due to the meshsizes used (3" and 5"). This implies that rational exploitation could lead to proper management of fish stocks in the lake, which is now lacking. It is concluded that monofilament net is more efficient than multifilament trammel net Keywords:Trammel nets, Catch efficiency, Mode of capture, Lake Kainj

Food and feeding habit of freshwater Mormyrid (Hyperopisus bebe occidentalis, Gunther) in River Rima and Goronyo Dam, Nigeria

The food and feeding habits of Hyperopisus bebe occidentalis caught in River Rima and Goronyo Dam in North western Nigeria were investigated A total of four hundred and fifty four (454) fish samples were collected on monthly basis from October, 2001 to September, 2002 are examined for feeding adaptations and gizzard content. The mouth is terminal in studied species. Two types of teeth were identified viz; cardiform and molariform. The gill rakers were 0.09~c 0.04cm in length with 0.010~ccm interspacing. The compartment of gut included gizzard-like stomach. The gut length and fish length (GL-TL) indicated rectilinear positive relationship. The regression coefficient (b) and correlation coefficient (r) of the gut length fish length relationships were significant (p< 0.05). The main taxa of food items identified included substances of plant and animal origins, with overall percentage occurrence of 69.8 and 20.7% for samples from River Rima and 59.1 and 20. 0% for those from Goronyo Dam in the same order. During the dry season, the frequency occurrence of plant substances were higher in the juveniles (<30cm, TL) 70.9% and adults (=30cm, TL) 64.7% in River Rima than the values obtained in samples from Goronyo Dam. Their occurrences in Goronyo Dam were fairly higher in the adults (62.9%) than in the juveniles (53.6%) during the same season. The results of this study showed higher occurrence of plant materials in juveniles than in the adults from the two water bodies during the rainy season. Contrary to this, low frequency occurrence of substances of animal in the juvenile samples from River Rima (15.2%) and Goronyo Dam (17.1%) were obtained in adult samples, the occurrence of animal substances were more than those of plants from the two seasons and water body. The feeding adaptive features revealed the ecological roles of the fish species that could be useful in satisfying their food requirements in culture systems and for teaching and further research

Yields of Protopterus annectens (Owen) from River Rima and Goronyo Dam, Sokoto State

Ninety five (95) specimena of P. Annectens (Owen) were caught from Goronyo Dam (26) and River Rima (69). The result revealed flesh yield of 44.29~c2.52 in August to 49.46~c to 5.68 in October which was not significant in samples from River Rima. The flesh yield from samples in Goronyo Dam ranged from 46-95~c2.43 in June to 54.28~c3.36 in September indicating significant difference between the months. The waste yield also varied significantly in samples from Goronyo Dam 45.72~c3.36 in September to 53.05~c 2.43 in June. However the results indicated non-significance (P>0.05) difference in samples from River Rima with a range of 50.54~c6.68 in October to 55.71~c2.55 in August. Similarly the flesh yields were found to be higher during the dry season than in the rainy season. The sample specimens were found to contain enough flesh thereby creating potentialities to caning industries