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CITATION Froelich, F. 2014. In praise of marine . 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.

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DOWNLOADED FROM HTTP://WWW.TOS.ORG/OCEANOGRAPHY SPECIAL ISSUE ON CHANGING » 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 involved (i.e., Ge substitut- on lives of their own, lives often bor- of , 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 , the , and meteorites. cals in the 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 sea­water—sodium, , potas- The oldest citations in the Nozaki been set loose to figure it out. The flotilla sium, , 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 was quite chlorinity ratios) and Culkin and Cox major programs that made significant boring—the salts in seawater from (on sodium, potassium, magnesium, ocean 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 “”—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 ) 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, 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 (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 . 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 , 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 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. Jeandel. 2014. dx.doi.org/10.1016/0011-7471(66)90601-2. topic values for speciation arrays that GEOTRACES: Changing the way we explore Noakes, J.E., and D.W. Hood. 1961. Boron- are down in the picomolar (10-12 M) ocean chemistry. Oceanography 27(1):50–61, boric acid complexes in sea water. Deep http://dx.doi.org/10.5670/oceanog.2014.07. concentration range. Sea Research 8:121–129, http://dx.doi.org/​ Blum, J., B.N. Popp, J.C. Drazen, C.A. Choy, and 10.1016/0146-6313(61)90004-1. Who is going to update Nozaki’s M.W. Johnson. 2013. Methylmercury produc- Nozaki, Y. 2001. Elemental distribution: Overview. tion below the mixed layer in the North Pacific chart? The new challenges are to pro- Pp. 840–845 in Encyclopedia of Ocean Ocean. Geoscience 6:879–884, http:// Sciences, vol. 2. J.H. Steele, S.A. Thorpe, and duce a three-dimensional version of the dx.doi.org/10.1038/ngeo1918. K.K. Turekian, eds, Academic Press, London, Nozaki chart that includes not only the Boyle, E.A., J.-M. Lee, Y. Echegoyen, A. Noble, http://dx.doi.org/10.1006/rwos.2001.0402. S. Moos, G. Carrasco, N. Zhao, R. Kayser, redox behavior (although by 2001 many J. Zhang, T. Gamo, H. Obata, and K. Norisuye. of the major redox elements had been 2014. Anthropogenic lead emissions in the ocean: The evolving global experiment. sorted out) but also isotopic signatures Oceanography 27(1):69–75, http://dx.doi.org/​ by speciation for the “nontraditional sta- 10.5670/oceanog.2014.10. Craig, H., R.F. Weiss, and W.B. Clarke. 1967. ble isotopes”—those other than carbon, Dissolved gases in Equatorial and South , hydrogen, nitrogen, and . Pacific Ocean. Journal of Geophysical Thus, the international GEOTRACES Research 72:6,165–6,181, http://dx.doi.org/​ 10.1029/JZ072i024p06165. program is building on its predecessors, Culkin, F., and R.A. Cox. 1966. Sodium, potas- especially GEOSECS, to obtain time sium, magnesium, calcium and strontium in seawater. Deep Sea Research 13:789–804, http:// and space “TEI” maps—trace element dx.doi.org/10.1016/0011-7471(76)90905-0. and isotope profiles and sections (see Danielsson, L.-G. 1979. Trace metals in marine waters: Analytical investigations on cadmium, Anderson et al., 2014, in this issue). cobalt, copper, , lead, nickel and zinc. This “TEI” mapping holds out the hope PhD Thesis, University of Gothenburg. of unraveling the processes involved in Edmond, J. 1980. GEOSECS is like the Yankees: everybody hates it and it elemental and compositional sources, always wins… K.K. Turekian (1978). sinks, transformation mechanisms, Oceanus 23(1):33–39. Available online at: http://www.biodiversitylibrary.org/ia/ and transport, a sort of biogeochemical oceanusv2301wood#page/37/mode/1up blood screen for the planet as refer- (accessed December 23, 2013). Farrington, J.W., and H. Takada. 2014. Persistent ence for future ailments. These sorts of organic pollutants (POPs), polycyclic aromatic time and space snapshots will become hydrocarbons (PAHs), and plastics: Examples of more and more important as time goes the status, trend, and cycling of organic chemi- cals of environmental concern in the ocean. by and the burgeoning human popula- Oceanography 27(1):196–213, http://dx.doi.org/​ tion living on the edges of the ocean has 10.5670/oceanog.2014.23. Grand, M.M., C.S. Buck, W.M. Landing, greater and greater impact on the . C.I. Measures, M. Hatta, W.T. Hiscock, The game is afoot—the quarry is not M. Brown, and J.A. Resing. 2014. Quantifying the impact of atmospheric deposition on only the inorganic ultra trace elements

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