Project: Dispersal and Life History Dynamics in Benthic Foraminifera

This Collaborative Research award was funded by NSF under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

Project description from the NSF award abstract ...
Dispersal and connectivity are fundamental processes known to underpin the health and stability of marine populations and communities. Effective dispersal and recruitment facilitate recovery from a variety of environmental perturbations and allow populations and communities to respond to environmental change operating over a range of temporal scales. This project will study to examine key aspects of dispersal, connectivity, and life history dynamics in benthic foraminifera, a well-defined group of protists that are abundant and diverse in nearly all marine settings. Foraminifera are largely heterotrophic, important in carbon cycling, sensitive to environmental conditions, and their rich fossil record provides insight into processes functioning over the span of historical to deep time. Dispersal and connectivity patterns are not well understood, particularly in benthic representatives of this group. Recent studies, however, suggest very broad connectivity patterns in deep-sea settings yet different dispersal capabilities among closely related species of at least one coastal foraminiferal genus. The overarching goal of this project is to characterize the dispersal patterns and capabilities of coastal to bathyal benthic foraminifera and to relate these patterns to their life history dynamics, ability to respond to different environmental conditions, and the extent of population connectivity as reflected by the presence or absence of cryptic phylotypes in otherwise broadly distributed morphospecies. The PIs utilize coastal to bathyal study sites off the Northeastern US and coastal sites in Georgia (SE US) and will use interdisciplinary methodology for experimental manipulation of the foraminiferal propagule bank (juveniles present in sediments derived from both local and distant sources); morphological, epifluorescence and fine structural techniques; and molecular genetics.

This project will: (1) Determine the extent of dispersal perpendicular to the coastal zone, both from onshore-to offshore sites, and in the opposite offshore-to-onshore direction; (2) Determine whether dispersal within the coastal zone (i.e., parallel to the coast) occurs over long distances (i.e., between adjacent coastal provinces), as implied by numerous reports of "cosmopolitan" intertidal species, or whether dispersal is generally limited by region. (3) Determine the relationship between dispersal in selected benthic foraminifera and their life history dynamics; and (4) Assess the diversity of adult foraminiferal assemblages that can be grown from a single propagule bank under different environmental conditions, thus providing insight into the environmental adaptability of the propagule bank at each of the sites and hence the ability to respond to environmental change.

Broader Impacts: This project will contribute to a more comprehensive understanding of the processes of dispersal, life history dynamics, and connectivity in marine systems. Results would further resolve the debate between the ubiquity and moderate endemicity models of microbial dispersal, provide additional comparisons of dispersal patterns between eukaryotic microbes and macro-organisms, and contribute to our understanding of community-level modifications that result from environmental perturbations and change.