Evidence for the importance of trophically transmitted parasites and predation at the lower latitudes of species ranges.

The lack of information concerning how parasitism maps onto host geographical distributions represents a striking gap in ecological knowledge. This knowledge gap limits our understanding of a wide range of phenomena, including the consequences of climate change-induced range shifts of both hosts and parasites. To help solve this problem, we created a predictive theoretical framework and quantified latitudinal variation in parasitism by animal and protozoan parasites throughout the entire contiguous geographical ranges of four estuarine fish species.

The Seasonal Flux and Fate of Dissolved Organic Carbon Through Bacterioplankton in the Western North Atlantic.

The oceans teem with heterotrophic bacterioplankton that play an appreciable role in the uptake of dissolved organic carbon (DOC) derived from phytoplankton net primary production (NPP). As such, bacterioplankton carbon demand (BCD), or gross heterotrophic production, represents a major carbon pathway that influences the seasonal accumulation of DOC in the surface ocean and, subsequently, the potential vertical or horizontal export of seasonally accumulated DOC. Here, we examine the contributions of bacterioplankton and DOM to ecological and biogeochemical carbon flow pathways, including those of the microbial loop and the biological carbon pump, in the Western North Atlantic Ocean (∼39-54°N along ∼40°W) over a composite annual phytoplankton bloom cycle.

Spatial and Temporal Examination of Bivalve Communities in Several Estuaries of Southern California and Northern Baja California, MX.

A combination of historical bivalve surveys spanning 30-50 years and contemporary sampling were used to document the changes in bivalve community structure over time at four southern California and one northern Baja California estuaries. While there are limitations to the interpretation of historic data, we observed generally similar trends of reduced total bivalve species richness, losses of relatively large and/or deeper-dwelling natives, and gains of relatively small, surface dwelling introduced species across the southern California estuaries, despite fairly distinct bivalve communities. A nearly 50-year absence of bivalves from two wetlands surveyed in a Baja California estuary continued.