Mesozooplankton composition and abundance in San Ildefonso Cape, Casiguran, Aurora, Northern Philippines.

TLDR: In this paper, mesozooplankton composition, diversity, abundance and their relation with the physicochemical parameters of the waters during high and low tides in San Ildefonso Cape, Aurora Province, Philippines were compared.

Abstract: Mesozooplankton composition, diversity, abundance and their relation with the physicochemical parameters of the waters during high and low tides in San Ildefonso Cape, Aurora Province, Philippines were compared. A total of 60 species belonging to 9 major groups were identified. Copepoda constituted the major bulk of the mesozooplankton community with Paracalanus parvus, Corycaeus andrewsii, Oithona similis and Oncaea venusta being the most abundant and widely distributed copepods in the said area. Using several diversity indices, high diversity in the mesozooplankton taxa was observed, but no differences were seen between the sampling stations and between the two tidal cycles. Likewise, the results of NPMANOVA revealed no significant differences (p>0.05) in mesozooplankton relative abundance between and within sampling stations between and during high and low tides. The results may imply that the level of mesozooplankton diversity and abundance did not fluctuate with changes in the tide levels and that mesozooplankton taxa were thus uniformly distributed in the waters of San Ildefonso Cape. Results of Canonical Correspondence Analysis revealed dissolved oxygen in influencing the mesozooplankton composition and abundance; however other factors (i.e. Kuroshio current) may also be important in shaping the community structure of mesozooplankton. Considering the importance of copepods as major component of the marine zooplankton and its function in marine food webs, the present records are therefore crucial in understanding the dynamics of marine ecosystems and are necessary for purposes of management and conservation of marine resources.