International Journal of Marine Science 2016, Vol.6, No.27, 1-22
10
FAMILY
Relative
abundance
of families
(%)
Species observed
Abundance
in lean
season
(numbers)
Relative
abundance in
lean season
(%)
Abundance in
peak sea son
(number)
Relative
abundance in
peak season
(%)
CLUPEIDAE
5.000
Ethmalosa fimbriata
5.000
0.180
4.000
0.090
Illisha africana
0.000
0.000
344.0
7.600
Sardinella maderensis
10.00
0.350
8.000
0.180
DREPANIDAE
1.000
Chaetodipterus lippei
0.000
0.000
4.000
0.090
Drepane africana
0.000
0.000
52.00
1.150
SCOMBRIDAE
1.000
Orcynopsis unicolor
0.000
0.000
28.00
0.620
Scomber japonicus
20.00
0.700
0.000
0.000
Scomberomorus tritor
0.000
0.000
2.000
0.040
TETRAODONTIDAE
1.000
Ephippion guttiffer
5.000
0.180
4.000
0.090
Lagocephalus laevigatus
31.00
1.090
14.00
0.310
CYNOGLOSSIDAE
38.00
Cynoglossus senegalensis
3.000
0.110
4.000
0.090
DASYATIDAE
Dasyatis margarita
15.00
0.530
8.000
0.180
SEPIIDAE
Sepia officinalis
10.00
0.350
24.00
0.530
SOLEIDAE
Bathysolea albida
0.000
0.000
2.000
0.040
SPHYRAENIDAE
Sphyraena sphyraena
336.0
11.80
114.0
2.520
STROMATEIDAE
Stromateus fiatola
15.00
0.530
2.000
0.040
MUGLIDAE
Mugil cephalus
4.000
0.140
0.000
0.000
PENAEIDAE
Penaeus notialis
0.000
0.000
128.0
2.830
POLYNEMIDAE
Galeoides decadactylus
138.0
4.850
116.0
2.560
POMADASYDAE
Brachydeuterus auritus
522.0
18.33
1202
26.56
PORTUNIDAE
Callinectes sapidus
1.000
0.040
160.0
3.540
RHINOBATIDAE
Rhinobatos rhinobatos
0.000
0.000
2.000
0.040
Total
100.0
2848
100.0
4526
100.0
As shown on Table 4,
Decapterus
punctatus
was the most abundant species for the semi-industrial fishery with a
relative abundance of 45.35%. In the lean season, it accounted for 30.79% of fish catch, with
Sardinella aurita
following with 19.81% as the next dominant species. In the peak season,
Decapterus
punctatus
constituted
46.41% of fish catches and 40.94% for
Sardinella aurita
. Together, these two species dominated the entire catches
in the peak season with a relative abundance of 87.35%.
Brachydeuterus auritus
, which hitherto in the lean season
constituted 19.25% relative abundance and the third dominating species, was not observed at all in the peak
season. This was the same for species such as
Sardinella maderensis
,
Scyacium micrurum
,
Ethmalosa fimbriata
and
Sphyraena sphyraena
, which were observed in the lean season but not observed in the peak season.
Species that were not available in the lean season but observed in the peak season include Sepia officinalis,
Ephippion guttifer
,
Priacanthus arenatus
and
Dactylopterus volitans
, with relative abundances of 0.29%, 0.33%,
0.18% and 0.03% respectively (Table 6). The differences between the relative abundances of species in the two
seasons in the semi-industrial fishery were however found to be not significant (Kruskal-Wallis H test, df =1, P >
0.05).
The dominant taxonomic family observed in the artisanal fishery was
Carangidae
, with a relative abundance of
44.39% (Table 3).
