Aspects Of Shrimp Fisheries On Sudanese Red Sea Coast
Aspects Of Shrimp Fisheries On Sudanese Red Sea Coast
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Date
2015-05-24
Authors
Abdalla Gadain, Elnaiem
Journal Title
Journal ISSN
Volume Title
Publisher
University of Khartoum
Abstract
The thesis has two main general objectives
:
to highlight the overall
marine shrimp fishery characteristics in
the coastal lagoons and coastal deep
water trawling grounds, and to focus
on the fishery of the Green Tiger
Prawn,
Penaeous semisulcatuus
in the Red Sea of Sudan. Two main shrimp
fishing methods were employed in this
research program. These comprised
the use of cast nets and the Otter traw
ling nets. The fishery statistical data
and shrimp biological data were collected during the period 1999 - 2002.
Penaeous monodon
and
P. indicus
constitute the coastal lagoon shrimp
fishery. Their catch composition
is 67% and 33% respectively.
Penaeous
monodon
predominated in Entabib while
P. indicus
was highly distributed
in Ashat. In the coastal deep wa
ter trawling grounds, four species are
reported. These are
Penaeous semisulcatus
,
Metapenaeous monoceros
,
Penaeous
latisulcatus
and
Penaeous japonicus
. The catch composition of
the
P.
semisulcatus
was 67.8%, that of
M. monoceros
was 26.9% while the
composition of the other two species collectively was only 5.3% in the
summer months. Shrimps were more catchable during the night (80%) while
the catch was very low during the
daytime (20%). The overall shrimp
distribution whether in the summer or
in the winter months had similar
trends along the coast-deep water axis
. But the catch rate was always
decreasing towards the deep waters with
a comparatively higher level in the
winter months. In the North-South
axis, the overall shrimps distribution
showed increasing trend from the north
towards the south in both seasons.
But the catch rate in the
winter was about four folds of that reported in the
summer season. The richest fishing grounds
are located at Fishing areas 3E
and 4E along the Sudanese Red sea coast,
where the catch rate averaged 13.1
kg/ hour.
The Green Tiger Prawn was only
found in the coastal deep waters
and not in the shallow coastal
lagoons. Its catch composition in the
commercial production was about 71%
by weight and 64% by numbers. A
very strong negative relationship between
the catch rate of this animal and
the length of the trawling fishing dur
ation was found. The best trawling
fishing duration for this animal was tw
o hours. The best time of fishing the
Green Tiger Prawn was from 8.00 pm to 4.00 am. This might have
suggested that this animal was nocturnal
in its distribution. The distribution
of
P. semisulcatus
had the same trends of distribution as the overall shrimps
did in the two axes.
The morphometric relationships are
established of the Green Tiger
Prawn were established. This animal
is detritus and most probably feeds on
silt, mud, organic matter. Female
s had a high sex ra
tio in May and
December. Smaller female
s had a low ratio (20%)
and the bigger ones had a
higher ratio (80%). Fec
undity data occur in October show a maximum
number of 9660 and an average of 4778 eggs.
Description
83 Pages
Keywords
Aspects,Shrimp,Fisheries,Sudanese,Red Sea,Coast;Distribution ; catch composition shrimp;water shrimp fishery;Green Tiger Prawn;Food ;feeding habits