Peacock Emily E.

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Last Name
Peacock
First Name
Emily E.
ORCID
0000-0003-0194-7282

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  • Preprint
    Mesoscale variability in intact and ghost colonies of Phaeocystis antarctica in the Ross Sea : distribution and abundance
    ( 2016-05) Smith, Walker O. ; McGillicuddy, Dennis J. ; Olson, Elise M. B. ; Kosnyrev, Valery ; Peacock, Emily E. ; Sosik, Heidi M.
    Phaeocystis, a genus with a cosmopolitan distribution and a polymorphic life cycle, was observed during summer in the Ross Sea, Antarctica, where large blooms of this haptophyte regularly occur. The mesoscale vertical and horizontal distributions of colonies of P. antarctica were assessed using a towed Video Plankton Recorder (VPR). The mean size of colonies was 1.20 mm, and mean abundances within the three VPR surveys were 4.86, 1.96, and 11.5 mL-1. In addition to the typical spherical, transparent colonies, the VPR quantified an optically dissimilar form of colony that had a distinctive translucent appearance. It also measured the abundance of collapsed colonies, similar to those observed previously from cultures and mesocosms, which we called “ghost colonies”. The translucent colonial form had a different distribution than the more common colonial form, and at times was more abundant. Relative to intact colonies, the ghost colonies occurred less frequently, with mean abundances in the three surveys being 0.01, 0.08, and 0.0004 mL-1. Ghost colonies generally were found below the euphotic zone, where they often were in greater abundance than intact colonies. However, the relationship of ghost colonies to intact P. antarctica colonies was not direct or consistent, suggesting that the formation of ghost colonies from living colonies and their appearance within the water column were not tightly coupled. Given their relative scarcity and low carbon content, it is unlikely that ghost colonies contribute substantially to vertical flux; however, it is possible that we did not sample periods of major flux events, and as a result minimized the importance of ghost colonies to vertical flux. They do, however, represent a poorly documented feature of polar haptophyte life cycles.
  • Preprint
    Long-term biological effects of petroleum residues on fiddler crabs in salt marshes
    ( 2007) Culbertson, Jennifer B. ; Valiela, Ivan ; Peacock, Emily E. ; Reddy, Christopher M. ; Carter, Anna ; VanderKruik, Rachel
    In September 1969,the Florida barge spilled 700,000 L of No. 2 fuel oil into the salt marsh sediments of Wild Harbor (Buzzards Bay, MA). Today the aboveground environment appears unaffected, but a substantial amount of moderately degraded petroleum still remains 8 to 20 cm below the surface. The salt marsh fiddler crabs, Uca pugnax, which burrow into the sediments at depths of 5 to 25 cm, are chronically exposed to the spilled oil. Behavioral studies conducted with U. pugnax from Wild Harbor and a control site, Great Sippewissett marsh, found that crabs exposed to the oil avoided burrowing into oiled layers, suffered delayed escape responses, lowered feeding rates, and lower densities. The oil residues are therefore biologically active and affect U. pugnax populations. Our results add new knowledge about long-term consequences of spilled oil, a dimension that should be included when assessing oil-impacted areas and developing management plans designed to restore, rehabilitate, or replace impacted areas.