OceTHE OFFICIALa MAGAZINEnog OF THE OCEANOGRAPHYra SOCIETYphy CITATION Froelich, F. 2014. In praise of marine chemists. Oceanography 27(1):88–91, http://dx.doi.org/10.5670/oceanog.2014.12. DOI http://dx.doi.org/10.5670/oceanog.2014.12 COPYRIGHT This article has been published inOceanography , Volume 27, Number 1, a quarterly journal of The Oceanography Society. Copyright 2014 by The Oceanography Society. All rights reserved. USAGE Permission is granted to copy this article for use in teaching and research. Republication, systematic reproduction, or collective redistribution of any portion of this article by photocopy machine, reposting, or other means is permitted only with the approval of The Oceanography Society. Send all correspondence to: [email protected] or The Oceanography Society, PO Box 1931, Rockville, MD 20849-1931, USA. DOWNLOADED FROM HTTP://WWW.TOS.ORG/OCEANOGRAPHY SPECIAL ISSUE ON CHANGING OCEAN CHEMISTRY » ANTHROPOCENE: THE FUTURE…SO FAR In Praise of Marine Chemists BY FLIP FROELICH 88 Oceanography | Vol. 27, No. 1 Shortly after the birth of the science biochemistry involved (i.e., Ge substitut- on lives of their own, lives often bor- of analytical chemistry, over 100 years ing for Si in opal, Zn and Cd cofactors in rowed from the study of the geochemis- ago, the art of measuring the chemi- carbonic anhydrase). These “smooth pro- try of Earth, the moon, and meteorites. cals in the sea began with the arduous files” thus became criteria against which It was as if the ocean had just been task of analyzing the six major salts in to judge the quality of later data sets. discovered and a flotilla of chemists had sea water—sodium, magnesium, potas- The oldest citations in the Nozaki been set loose to figure it out. The flotilla sium, calcium, sulfate, and chloride. It compilation date from about 1966 included Gerald Wasserburg, Harmon soon became apparent that these four (though one from 1961 is the classic Craig, Karl Turekian, Ed Goldberg, cations and two anions make up the bulk Noakes and Hood boron paper). Two Clair Patterson, John Edmond, John of sea salt, and a few more, like boron, 1966 papers (still cited today for the law Martin, Ken Bruland, Ray Weiss, Ed strontium, fluorine, and bromine, were of conservation) are Morris and Riley Boyle—and the list goes on to include all “conservative.” In other words, the (on the bromide/chlorinity and sulfate/ their students and grand-students. The salt composition of seawater was quite chlorinity ratios) and Culkin and Cox major programs that made significant boring—the salts in seawater from (on sodium, potassium, magnesium, ocean biogeochemistry advances were anywhere in the world ocean contain calcium, and strontium). A few rare gas GEOSECS (Geochemical Ocean Sections almost exactly the same proportional papers also first appeared in 1964 and Study), VERTEX (Vertical Transport composition as seawater from anywhere else—and in direct relationship to its “salinity”—a concept that originated with ocean chemists but was forfeited HE WHO DIES WITH THE to ocean physicists when the chemi- cal definition of salinity as a measure MOST TOYS WINS. of salt mass content got corrupted and – Anonymous was no longer useful to calculate in situ “ seawater density. In Nozaki’s 2001 compilation of the vertical profiles of the elements and gases 1967: Mazor, Wasserburg, and Craig, and and Exchange of Ocean Particulate” in the periodic chart (Figure 1), it is clear Craig, Weiss, and Clarke. Thus, I claim Program), BATS (Bermuda-Atlantic that only a small handful of the vertical that the field of trace element and tracer Time-series Study), HOT (Hawaii Ocean profiles we have today are conserva- marine chemistry essentially began after Time-series), and many others. These tive. Most of the trace elements in the the mid-1960s and in earnest by the programs also took on lives of their interior of the periodic chart—the first, early 1970s. Before that, as Karl Turekian own. To quote Turekian again (Edmond, second, and third row transition ele- is reported to have stated (Danielsson, 1980): “GEOSECS is like the Yankees: ments plus the lanthanides (rare earths) 1979): “Indeed, one has the feeling that Everyone hates it and it always wins.” I and actinides plus the metalloid ele- the whole field of trace metal marine always suspected Karl had come to the ments out near the right-hand edge (Ge, geochemistry would have been a com- late realization that oceanographers As, Se, Sn, Sb, Te)—are not conservative pletely dull one over the past [fifty] years are a collective lot—all for one and one but instead display distinct geochemi- if it weren’t for analytical errors.” And, for all. Just so long as the one gets the cal behaviors in their vertical profiles. he could have added, contamination right answer and that the answer makes These profile shapes helped to identify artifacts. After that, analytical chemists “oceanographic sense.” the likely vectors carrying each element camouflaged as seagoing oceanographers The success of the Nozaki compila- into the deep sea (e.g., nutrient-like and began to methodically pull apart the tion, and ocean tracer chemistry in gen- thus bioactive, downward decreasing trace element and radioisotope system- eral, derived from the paranoid realiza- and thus scavenged, particulate reactive atics of the ocean’s chemistry. Famous tion in the 1970s and 1980s that marine or surface ocean input, opal and carbon- names and programs are splattered chemists had to figure out how to collect ate vs. organic tissue) and hinted at the across these references, names that took pristine (uncompromised) samples from Oceanography | March 2014 89 Figure 1. Vertical profiles of elements in the North Pacific Ocean.Reprinted from Nozaki (2001) with permission from Elsevier an ocean that was unforgiving: they had tested to avoid trace metal contamina- 2014, in this issue). Things that go into to get them out of the ocean and out of tion from rusting steel hydro cables, the ocean often don’t come back and are the sampling device and delivered back from painted steel boats (both the hulls, thus best interpreted as expendable— home to the lab (that is, storing and the houses, and the interior labs), or as Bill Landing, Chris Measures, and transporting bottles) without transfor- from the conductivity-temperature- scientific crew discovered when their mation of the seawater contained inside depth (CTD) rosette itself (Fe, Co, Ni, Kevlar cable parted and their rosette (no sorption onto bottle walls, no bio- Cu, V, Cr, Mn, Zn …... Al, Ti) or in the ended up on the bottom in the Southern logical activity, and no contamination background atmosphere (dust Al and Fe, Ocean. The worst actor of the elemental from the accelerators and plasticizers in ship’s stack exhaust, tailpipe fine phase lot—mercury—proved recalcitrant until the bottles themselves), and then they Pb). Chemists went to sea sheathed in recently because of its obtuse speciation had to do the lab work (column concen- plastic and bathed in acid. Boyle devised (liquid, vapor, redox, and methylated) trations and separations of interfering his “weather vane” water suckers that and tendency to stick to anything and components and the final analyses, the clamp onto the wire individually and everything (see Lamborg et al., 2014, in analytical chemistry part). Sampling sample water “upwind” of the hydro this issue). MeHg is second only to plu- gear had to be designed, fabricated, and wire (see Boyle et al., 2014, in this issue). tonium in its toxicity. Despite decades of The Al and Fe groups devised their own work elucidating the Hg-biomethylation Flip Froelich ([email protected]) is metal-free rosette and its bottles, and process by sulfate reducing bacteria in Chief Scientist, Froelich Education Services, hung them on their own one-of-a-kind anaerobic sediments, the open ocean Tallahassee, FL, USA. 1,000 m Kevlar cable (see Grand et al., processes leading to biomethylation and 90 Oceanography | Vol. 27, No. 1 bioaccumulation of this toxin at the top and their isotopes, but also the trace the biogeochemistry of Fe and Al in the of the pelagic food chain remained enig- man-made synthetic organic compounds upper ocean: A decade of collaboration with the US CLIVAR-CO2 Repeat Hydrography matic. Just last year, the first reliable iso- and particles that are showing up in the Program. Oceanography 27(1):62–65, http:// topic values for MeHg in seawater were environment as harbingers of human dx.doi.org/10.5670/oceanog.2014.08. Lamborg, C., K. Bowman, C. Hammerschmidt, published (Blum et al., 2013). domination of the planet (see Farrington C. Gilmour, K. Munson, N. Selin, Today, this practice of trace ele- et al., 2014, in this issue). The tool kit of and C.-M. Tseng. 2014. Mercury in the Anthropocene ocean. ment paranoia is universally accepted. the next generation of analytical marine Oceanography 27(1):76–87, http://dx.doi.org/ Modern lab instrumentation involves chemists will need more and better toys 10.5670/oceanog.2014.11. mass spectrometers (MC-ICP-MS) with to marry the organic and inorganic trace Mazor, E., G.J. Wasserburg, and H. Craig. 1964. Rare gases in Pacific Ocean water. Deep hyphenated front-end chemistries (HG, components and isotopes in the sea. Sea Research 11:929–932, http://dx.doi.org/ GC, LC, HPLC, CE, ESI, MALDI—the 10.1016/0011-7471(64)90343-2. Morris, A.W., and J.P. Riley. 1966. The bromide/ list is almost endless) with incredible REFERENCES chlorinity and sulphate/chlorinity ratio in sea- selectivity and sensitivity, enabling iso- Anderson, R.F., E. Mawji, G.A. Cutter, water. Deep Sea Research 13:669–705, http:// C.I. Measures, and C.