The findings are presented of a study conducted to assess the post harvest losses in Shiroro Lake, Nigeria. The major objectives were to identify and quantify the types of losses, to provide recommendations that would enhance formulation of policy guidelines for utilization and exploitation of the declining fishery resources of the lak

Oyero, J.O.

English

Aquatic Commons

A PRELEVIINARY INVESTIGATION INTO THE POST HARVEST LOSSES OF FISH
IN SHTRORO LAKE AREA
BY
OVERO
Department of Fisheries, Federal University of 'Technology
Minna, Niger
INTRODUCTION
Post harvest losses occur at various points from capture to marketing. In some fishery the
level of losses could be considerable. In Nigeria few workers (Azeza 1977; Dada and
Gnanados 1983; Tobor 1984; Eyo 1989 and Shimang 1990) have at different times estimated
post harvest losses from our water bodies to be between 30 and 50 percent Eyo and Mdaihili
(1997) estimated a loss of 80 million Naira worth of fish through poor handling in Kainji Lake
Basin. Prior to this study, no work had been conducted on the post-harvest losses in the
Kainji Lake fishery.
The freshwater bodies in Niger State in the Northern Nigeria include the three major
hydroelectric power dams at Kainji, Shiroro a.nd Jebba. Others include man made lakes such
as Tagwai, Kagara. and Rivers Niger and Kaduna and their numerous tributaries and flood
plains. The combined surface area of all the freshwater bodies; located in the state is
approximately 436,196 hectares and the potential annual fish yield from these water bodies has
been estimated at about 41;485 nietric tones (Sikoki e al 1992).
Despite its high potential, fish production in the state is estimated at only about 20 tonnes of
fish in 1990 representing about 17.48% of the Gross National Domestic Fish Production (FDF
1991). Many factors could be responsible for the low production including overfishing,
improper fishing methods, habitat disruption, pollution and post harvest losses, due to bad
handling, processing, preservation and storage.
This study attempts to assess post harvest losses in Shiroro lake.
The objectives were to have a rapid survey to identify and quantify types of losses, to provide
recommendations that would enhance formulation of policy guidelines for utilization and
exploitation of the declining fishery resources of Shiroro Lake.
BACKGROUND INFORMATION
The Shiroro dam water shed covers an area of about 20,300km2 in Niger state alone. It drains
about 27% of the total land mass of the state. The reservoir created by the dam has a surface
area of about 306kin2 and elevation of 382m with a tremendous storage capacity of 605
billion cubic metres. This lake is a reservoir of valuable renewable resources in the semi-arid
zone ecosystem of our nation.
The rich soil deposits and abundant water supply of Shiroro Lake basin ha.ve brought about
increased agricultural and fisheries activities in the basin. In a rapid inventory survey by
213
214
FUTMIN CONSULT in (1992), it was found that the Gill net was the commonest fishing
gear. The net mesh size ranged between 6.35cm (2.5") and 17.78cm (7.0"). Other fishing
gear included hooks and line, cast nets and traps. On the average, each fisherman owns a boat
and three bundles of net measuring 92.30m (100yds) each. They also reported that most of
the catch from the basin were marketed fresh as only the unsold catch were usually smoke
dried while it was observed that huge losses occurred through spoilage of the product during
the distribution process owing to a variety of factors including poor handling practices
resulting from delayed processing; unhygienic marketing facilities; inadequate packaging
especially of smoke dried fish; lack of electricity at the landing sites, and th.e reluctance of
fishermen to adopt modem methods of fish preservation.
Sikoki and Van Der Veen (1992) reported that the total standing fish crop of Shiroro reservoir
using the Morpho Edaphic Index (MEI) was approximately 293 metric tones while the total
catch per year based on average fish caught per fishermen per year gave a value of 298 metric
tones. Thus, theoretically it could be adduced that the lake was being over-fished. It could
further be concluded that all the fish produced in the Lake each year are taken out by the
fishermen and this looked unrealistic.
MATE LS AND METHOD
Study Area
One of the major landing sites (Zuba Water Side) was chosen as a case study. Major landings
in Zuba water side always occur on Saturdays which are also the market days. During the
other days of the week only few fishermen come ashore to sell their catch. Other major
landing sites Sarkin Pawa and Shedkona have different market days.
The investigation was conducted on two consecutive market days. (Saturday). On each
occasion the following evaluations were rnade:
1. Enumeration of the boats that came ashore
2 Conduction of an interview with the "Sarkin Ruwa" (chief of the fishermen).
Random interview with fishermen, middlemen and fishmongers.
Visual estimate of catch landed
5 Organoleptic Assessment of the catch lan.ded.
The folio ing infortnation were obtained from those terviewed:-
Number of major landing sites
Number of fishing villages
Types of fishing gear in use
The predominant species landed
Proportion of spoilage after hauling the net
Preprocessing methods in use
Preservation methods in use
Form of distribution of the catches.
RESULTS AND DISCUSSION
The first set of boats started coming ashore at about 7.00am. The traffic became heavy between
8.30am and 12 noon. The last of the boats trickled ashore between 12 noon and 1. oo.pm.
Almost all the canoes which were dug out were motorized with minimum 25 horse power outboard
engines The canoes were passenger boats conveying the fishermen. Villagers and goods including
yams and cows. Average count of 35 motorized boats were counted on the two days of
investigation, 7 were counted for dugout canoes with no outboard engines.
The major fish species encountered according to their .predominance were (7iris/chi/7),s
ffOrrodigitatus, Bagrus ipp.; illainagras g41.,S'ynodoniss p p, fleteratis
nitotira,c,Alestes spp, Clarias spit, Tales niloticas and Gyisnarchus
The proportion of smoked fish to fi-esh fish at the landing site was about 80% to 20% respectively.
The average number of cartons/basin/basket landed was 200, each having a net weight of a.bout
6.5kg. Thus, average total weight of smoked fish landed was about 1.3 tons while the average total
weight of fresh fish landed was 0.35 tons.
From the interview only two landing sites at Sarjub Pawa and Shedkona were confirmed as the
major landing sites around the basin. The number of fishing villages around th.e basin were
estimated to be 45. The type of gear predominantly in use was gill net. No infortnation could be
obtained about the proportion of spoilage after hauling the net.
For fresh fish there were no preprocessing methods of gutting, scaling etc., before being landed and
during sale. Unsold fish were either smoked or if they were large enough (at least 2kg) were kept
in deep freezers in the nearby Zuba village.
The organonoleptic assessment revealed that most of the fi-esh fish were of good quality but close
to half of the smoked fish were not freshly smoked at least not within a week before landing while
some were really charred. This could be due to the effect of unregulated smoking or re-smoking
with evident insect or mite infestation.
Any programme of fishery development in the artisanal sector should take into consideration an
improved or efficient post harvest technology. The results of the investigation showed that most of
the artisanal fishermen fishing on Shiroro Lake usually come to the landing site with their catch
with passengers boats as most of them have no motorized boats. They sell their catch to the
middlement at variable prices. A delay in getting tbe fish to the consumer fresh or processed could
lead to loss of the fish through spoilage. This delay in getting to the landing site is also one of the
reasons adduced to the high rate of smoked fish in the area. The fishermen in order not to lose their
catch have resulted to preservation by smoke drying. However, choice species like Lates niloticus
of relatively large sizes were always left fresh and preserved in deep freezers in Zuba if unsold.
Some of these fi-eezers were provided to some fish mongers through the United Nations
Development Programe(UNDP) project, through the Fisheries department of the Ministry of
Agriculture and Natural resources of Niger State, while some smoking kilns were donated to some
fish processors in Sarkin Pawa and Shadkona.
One basic problem that is still hindering accurate and effective control of post harvest losses is the
unavailability of reliable baseline data for researchers to work on. There is the need to do detailed
researches into the post harvest losses of all the major Lakes in Nigeria as it was done for Kainji
Lake by Eyo and Mdailili (1997).
215
EYO, A.A. (1989):
EVO, A.A. AND M. MDA iii LI (1997): Studies on Post-harvest losses in Kainji Lake Fishery,
Nigeria Abetellung 424 Walk Viehwirtschaff Fischerei,
Naturschutz. Vieh & Fisch. Eschborn 1997
FUTMIN CONSU (1992): A Federal University of Technology Minna Consultancy
Report on Rapid Inventory Survey of Shiroro Lake
watershed and Fisheries. Edited by F.D.Sikoki.
SHIMANG G.N. (1990): Post-harvest Losses in Inland Fisheries in Nigeria with
emphasis on Lake Chad and Lake Kainji. An FAO
Symposium on Post-harvest Fish Technology. Cairo
Egypt. 21 25 October 1990.
STKOKI F.D.; OVERO J.O. AND TSADU (1992): Options, Limitations and Approaches to
Fisheries Development and Policy Formulation in Niger
State. An Invited paper presented to the National Fisheries
Development Committee (NFDC), July 1992.
S1KOIKI F.D. AN J. VAN DER VEEN (1992):Aspect of water quality parameters and the
potential for fish production of Shiroro dam reservour,
Niger State. A paper presented at the National Conference
of Aquatic Resources May 11 14 1992, Calabar.
TOBOR T.G (1984): The Fisheries Industry in Nigeria Status of Fish
preservation methods and future growth pre-requisites to
cope with anticipated production in: Proceedings of the
symposium on Fisheries Development Sponsored by
Almarine 31st August, 1984 pp. 85 105.
REFERENCES
AZEZA N.I. (1997): Fish handling, processing and marketing in the Lake Chad
Basin (North West Shores). In the Proceedings of
Conference on Handling, Processing and Marketing of
Tropical Fish (Land.) Pages 349 351.
ADA B.F AND GNANADOS D.A.S (1983) :
Nigerian Fisheries Development: Challenges and
Opportunities of the 1980's. In the proceedings of the 3rd
annual Conference of the Fisheries Society of Nigeria
(FISON) Maiduguri 22n' 251 February 1983 pp. 14 24.
Artisanal fish handling, preservation and processing in
Nigeria problems and prospects. In proceedings of the
Conference of Tvvo Decades of Research on Lake Kainji,
Nigeria. Eds. Ayeni J.S.0 and Olatunde A.A. pp. 167
178.
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A preliminary investigation into the post harvest losses of fish in Shiroro Lake area

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A preliminary investigation into the post harvest losses of fish in Shiroro Lake area

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