A Checklist of Planktonic Algae off Lagos Coast - Jsrd.org

A Checklist ofPlanktonic Algae off Lagos Coast
MATERIALS AND METHODS
Phytoplankton sample collection
Phytoplankton samples for the two years of study were collected with the aid of a 55/j.m standard
plankton net and the training vessel, 'Federal Argonaut'. The vessel is about 200m long and has an
engine capacity of 425 hp and collections were made between latitudes 3°27'E and 3° 29'S and longitudes
6° 17' Nand 16° 24^N for the study. On each occasion the net was tied to the vessel and towed at low
speed (< 4knots) for Smins. All samples were collected in 250ml plastic containers with screw caps and
preserved in 4% unbuffered formalin prior to biological analysis.
Figure 1: Hydrological map of Lagos showing study area
Phytoplankton analysis
In the laboratory one drop, five different times for each sample after concentration to lOmls were
investigated at different magnification (X15, X100 and X400) using a Zeiss binocular microscope with a
calibrated eye piece. The microtransect drop count method described by Lackey (1938) and employed by
Nwankwo (1984) was used. Since each drop is O.lml, results on abundance were multiplied by 10 to
give the values as numbers of organisms per ml. Appropriate texts were used to aid identification
(Subramanyan, 1946; Smith, 1950; Hendey, 1958,1964; Desikachary, 1959; Foged, 1966; Wimpenny,
1966; Patrick and Reimer, 1966, 1975; Nwankwo, 1990, 2004a). To
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