A total of 23 zooplankton taxa were identified from a zooplankton surv
ey carried out in Chetumal Bay during August, October and December, 19
90 and February and May, 1991. The most abundant group was decapod lar
vae, which represented 55.15% of the total catch, followed by fish egg
s and larvae (20.0%), copepods (13.74%), and appendicularians (9.9%).
Biomass values fluctuated from 0.43 to 20.98 mg/m3 during this period.
Highest density (>9 500 org/l 000 m3) and biomass (13.3-20.9 mg/m3) v
alues were registered in the southeast portion of the bay, which shows
a marine influence. Highest densities (11 587 org/l 000 m3) occurred
during October, while maximum mean biomass (10.59 mg/m3) values were d
etermined in February. Chetumal Bay is an hyposaline system, with a li
mited influence of marine zooplankton, and with high temperatures (25-
32-degrees-C). The area shows low production (<20.98 mg/m3) when compa
red with similar adjacent systems.