Seasonal abundance of zooplankton in Pala Lagoon
Kluge KD. 1992. Seasonal abundance of zooplankton in Pala Lagoon. Dept. of Marine & Wildlife Resources biological report no. 36. Department of Marine and Wildlife Resources. Pago Pago, AS
Samples of zooplankton were collected using 20u and 500u mesh plankton nets at two stations in Pala Lagoon over a one year period (march 1991 to February 1992). Surface tows were conducted monthly during the new moon period at dusk at the lagoon outlet and an inner mangrove area. Of the few larval fish collected, lagoon-resident gobies were the most abundant family of the six families (Gobiidae, Atherinidae, Blennidae, Pempherididae, Engraulididae, Synathidae) collected in the lagoon. The absence of non-resident fish indicates that Pala Lagoon is not a nursery area for the non-resident fish that migrate into the lagoon to feed. Invertebrates, primarily decapods (particularly a caridean shrimp) and copepods, were far more abundant (75-98% of specimens collected) than larval fishes (0.1-0.5%) or eggs (1.5-17%) at both stations in the lagoon. The abundance of zooplankton was 3-4 times greater in the mangrove area than at the lagoon outlet. Average densities ranged from 411-435 no.m3 at Station 1 and 1454-1829 no.m3 at Station 2.