1. Fall 2007 – Mak Saito Chief Scientist
Carl Lamborg, Phoebe Lam, Gabrielle Rocap, Eric Webb
Jack DiTullio, Mike Sieracki, Zehr lab
Samples collected for Karen Casciotti, Bob Anderson, Laura Robinson,
Oliver Rouxel, Chris Measures, Ben Thomas, Matt Charrette
South Atlantic Gyre and Benguela – Phytoplankton and Trace metal interactions
2.5 degree spacing, alternating 800m and full depth,14 hours steam between stations
5000m of non-metallic line, 11 bottle rosette, CTD package
Our first attempt at being Geotraces-Compliant

2. Fall 2007 – Mak Saito Chief Scientist
Cobalt analyses by Abigail Noble (WHOI Student)

4. Hybrid-type trace metals (iron and cobalt: subjected to both micronutrient and scavenging processes)
From Noble and Saito et al DSR II

5. In oligotrophic regions: Metal-Nitrogen colimitation - two types in a single water column
N-Fe

7. Montoya/Zehr 2006 Seward Johnson

8. Top: Cobalt time series at BATS (BTM) in 1999
from ~40m depth collected by MITESS
Bottom: Temperature data from 15m and 35m
on the same Bermuda Testbed Mooring
Saito and Moffett, Geochim. Cosmochim. Acta 2002

9. Cobalt and Iron are “Hybrid-Type” Metals
Nutrient-like: micronutrient role results in surface depletion
Scavenged-like: processes result in removal from intermediate depth
Oceanic inventories of Fe and Co are very small
No accumulation with oceanic circulation
Results in Co:P correlations only in surface waters, falls apart with depth. Unlike Zn, Cd, and the major nutrients.
(Noble, Saito et al., 2008 DSRII)