Submitted to Marine Ecology Progress Series Spatial Patterns in Abundance and Biomass of Tropical Zooplankton: The Role of Scale and Environmental Factors

A study was conducted to assess the leading physical and biological processes influencing the spatial patterns of tropical mesozooplankton in a coral reef lagoon in Guadeloupe (French West Indies, Caribbean Sea), considering two size classes (190–600 μm and > 600 μm). The spatial variability of mesozooplankton biomass and abundance was examined along a transect, and related to environmental heterogeneity. Using a high capacity pump, sampling was carried out during the dry season (March 1999) at 51 stations arranged along a cross-shelf transect from the coast to the open sea. The method of principal coordinates of neighbour matrices—a new form of multiscale analysis—was used to determine the spatial patterns of zooplankton from fine to broad scales. Spatial patterns for the two mesozooplankton fractions changed along the continuum of scales. (1) Although the small and large zooplankton displayed different scales of spatial dependency, they showed common patterns at some scales. (2) The small zooplankton (190–600 μm) exhibited more multiscale variability in biomass and abundance than large zooplankton (> 600 μm). (3) The spatial scales of variability in biomass and abundance of the small zooplankton were similar, whereas (4) large zooplankton presented different multiscale patterns for biomass and abundance. Our results suggest that local hydrodynamics, coastal and oceanic influences, phytoplankton patchiness, zooplankton behaviour, and habitat patterning generated the observed spatial patterns. The types and effects of these processes depended upon spatial scale.