IMIS

The plankton samples were collected in oblique trawls up to a maximum depth of 200 m using the FAO net. The Smith and Richardson (1977) expressions were used to calculate the volume. A network of 33 oceanographic stations, spread around 10 radials, in the territorial waters of Guinea-Bissau was used for the collection of biological parameters from 29 May to 16 June 1995. The trawls were carried out at a steady speed of 3 knots and the samples stored in 4 percent formalin, previously neutralised with sodium bicarbonate.