James H. Mathewson

Bio: James H. Mathewson is an academic researcher. The author has contributed to research in topics: Pacific Rim & Pacific hurricane. The author has an hindex of 1, co-authored 1 publications receiving 21 citations.

Organic Mercury Compounds in Coastal Waters

Abstract: ORGANIC mercury compounds have been demonstrated in biological material1–3 and the pioneering work of Jensen and Jernelov4–6 and Wood, Rosen and Kennedy7 has demonstrated that these organic mercury compounds can be synthesized by microorganisms in fresh water sediments. Their studies strongly suggest that organic compounds of mercury may be present in natural waters, although there is little experimental evidence for the existence of organic forms of Hg in either fresh or marine water. The role of mercury and its ultimate fate in fresh or marine environments will depend on its chemical and physical form. Thus, a meaningful assessment of the effects of toxic or latently toxic metals, such as mercury, on the biosphere requires identification and differentiation of the various chemical species of the metal in the environment. Here we present experimental data indicating the presence of organic forms of mercury in river water and in coastal sea-water, and we hope to encourage further study of the role of mercury in natural waters.

Mercury in tunas: a review

Abstract: Mercury in the aquatic environment comes from both natural processes and industrial activities. The latter probably have not significantly altered the mercury content of the high seas where most tunas are captured. Mercury compounds enter aquatic organisms through the food web and/or by direct extraction from solution. The relative importance of these pathways in tunas is unknown. Mercury occurs in tuna principally in the form of methylmercury. Generally. tunas appear to have higher mercury levels than those fish species which occupy a lower level in the food chain. Mercury content of tunas varies according to fish size. However, other factors such as area of capture, differential growth rates, varying analytical techniques, and different sampling methods may account for some of the observed variation. The U.S. Food and Drug Administration has established an "in-house" standard of 0.5 ppm of mercury for fishery products sold in the United States. Other countries have established limits as high as 1.0 ppm. Seawater contains a wide array of dissolved elements and salts including mercury. Some of these occur in quantities that can be re­ covered on a commercial scale whereas the minute concentrations of others can be de­ tected only by highly sophisticated techniques. Mercury does not playa prominent role among the metals dissolved in seawater because it occurs there only in very small quantities. Mercury in its various forms is also present in the earth's crust fro'm which it can be dissolved by water. In the absence of water, especially under conditions of increased heat, mercury will enter the atmosphere in the form of vapor, from which it can dissolve in water at the water-air interfaces, Le., rain or the sea surface. It is difficult to conceive that life could have evolved on this planet in an environment devoid of this ubiquitous element so it is of no great surprise that mercury is present in the bodies of living organisms. Furthermore, as is the case with many elements and their compounds, living organisms are even capable of concentrating mercury within or outside of their bodies. ! ~nt~r.American Tropical Tuna Commission, Scripps InstttutlOn of Oceanography, La Jolla, CA 92037.

Mercury in the Kuroshio and Oyashio regions and the Japan Sea

Abstract: ALTHOUGH measurements of the mercury concentration in sea water have been made by several investigators1–13, the reported values are widely scattered and it may be significant that almost all the samples were kept in polyethylene bottles after acidification. Weiss et al.14 have reported that the main source of mercury in the oceans was the degassing of the Earth's crust by way of the atmosphere. It should then be supposed that the large experimental variations for open oceans does not reflect the true situation.