Carbon Isotope Variations in Surface Waters of the Gulf of Mexico on Time Scales of 10,000, 30,000, 150,000 and 2 Million Years

Van Meter et al. (Reports, 27 April 2018, p. 427) warn that achieving nitrogen reduction goals in the Gulf of Mexico will take decades as a result of legacy nitrogen effects. We discuss limitations of the modeling approach and demonstrate that legacy effects ranging from a few years to decades are equally consistent with observations. The presented time scales for system recovery are therefore highly uncertain.

Download Full-text

Carbonate Chemistry Dynamics of Surface Waters in the Northern Gulf of Mexico

Aquatic Geochemistry ◽

10.1007/s10498-010-9091-2 ◽

2010 ◽

Vol 16 (3) ◽

pp. 337-351 ◽

Cited By ~ 11

Author(s):

Nina Keul ◽

John W. Morse ◽

Rik Wanninkhof ◽

Dwight K. Gledhill ◽

Thomas S. Bianchi

Keyword(s):

Gulf Of Mexico ◽

Surface Waters ◽

Carbonate Chemistry ◽

Northern Gulf Of Mexico ◽

Chemistry Dynamics

Download Full-text

Carbon isotope records from pacific surface waters and atmospheric carbon dioxide

Quaternary Science Reviews ◽

10.1016/0277-3791(92)90021-y ◽

1992 ◽

Vol 11 (4) ◽

pp. 387-400 ◽

Cited By ~ 55

Author(s):

N.J. Shackleton ◽

J. Le ◽

A. Mix ◽

M.A. Hall

Keyword(s):

Carbon Dioxide ◽

Carbon Isotope ◽

Surface Waters ◽

Atmospheric Carbon Dioxide ◽

Atmospheric Carbon

Download Full-text

Viral and bacterial assemblage covariance in oligotrophic waters of the West Florida Shelf (Gulf of Mexico)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315406013506 ◽

2006 ◽

Vol 86 (3) ◽

pp. 591-603 ◽

Cited By ~ 23

Author(s):

Ian Hewson ◽

Danielle M. Winget ◽

Kurt E. Williamson ◽

Jed A. Fuhrman ◽

K. Eric Wommack

Keyword(s):

Gulf Of Mexico ◽

Surface Waters ◽

Intergenic Spacer ◽

Rate Of Change ◽

Bacterial Assemblage ◽

Assemblage Composition ◽

Phylogenetic Resolution ◽

Oligotrophic Water ◽

Independent Observations ◽

Bacterial Assemblages

Viruses are hypothesized to cause enhanced diversity in bacterial communities by regulating the outcome of intertaxon competition. However, concomitant documentation of viral and bacterial assemblage composition in oligotrophic waters are rare, particularly in situ over time, and there is almost no information on the temporal variability in virioplankton assemblage composition in oligotrophic water masses. Assemblage composition of viruses (via pulsed-field gel electrophoresis, PFGE) and bacteria (via automated rRNA intergenic spacer analysis, ARISA) was compared during surface lagrangian drifter deployments in the oligotrophic Gulf of Mexico during summer 2001, 2002, and 2003. In vertical profile, viruses and bacteria both had maximum abundances in surface waters, which decreased with depth; however, the richness of their assemblages was not significantly different between depths, suggesting independence of biomass and diversity. Viral assemblages changed rapidly (0.17–0.32 Jaccard index d−1), which was similar to the rate of change in bacterial assemblages reported in surface waters. Patterns of viral and bacterial assemblage composition were significantly related (P<0.001, r=0.58 between node ranks), and both assemblages clustered primarily by year and then by depth. These cultivation-independent observations demonstrate relationships between viral and bacterial assemblages, which are dynamic in patches of open ocean water. Even at the relatively low phylogenetic resolution of the ARISA and PFGE methods, the results support the idea that viruses may influence the species composition of host assemblages.

Download Full-text