Aquatic chemistry is becoming both a rewarding and substantial area of inquiry and is drawing many prominent scientists to its fold. Its literature has changed from a compilation of compositional tables to studies of the chemical reactions occurring within the aquatic environments. But more than this is the recognition that human society in part is determining the nature of aquatic systems. Since rivers deliver to the world ocean most of its dissolved and particulate components, the interactions of these two sets of waters determine the vitality of our coastal waters. This significant vol ume provides not only an introduction to the dynamics of aquatic chem istries but also identifies those materials that jeopardize the resources of both the marine and fluvial domains. Its very title provides its emphasis but clearly not its breadth in considering natural processes. The book will be of great value to those environmental scientists who are dedicated to keeping the resources of the hydrosphere renewable. As the size of the world population becomes larger in the near future and as the uses of materials and energy show parallel increases, the rivers and oceans must be considered as a resource to accept some of the wastes of society. The ability of these waters and the sediments below them to accommodate wastes must be assessed continually. The key questions relate to the capacities of aqueous systems to carry one or more pollutants."

Metal pollution in the aquatic environment

Elemental mass-balance of material carried by major world rivers

The South Atlantic Ocean receives waters from the North Atlantic, the Weddell Sea, and from the Circumpolar Current through the Drake Passage. The circumpolar and North Atlantic waters are of widely different characteristics (temperature, salinity, oxygen and nutrients) but of overlapping density ranges, and as they enter the South Atlantic are caught up in the circulation imposed by the winds and thermohaline processes. Interleaving of these different characteristics takes place in various ranges of depth and density, and more than a dozen vertical extrema are created in the tracer fields. These are spread by lateral flow in recognizable layers. These patterns as seen on vertical sections and on isopycnals can be taken to indicate the sense of flow in various areas and depths, and I have used them, with the density field, to add the barotropic component to the baroclinic flow defined by the density field. This gives the total geostrophic flow at all depths in a manner that appears to be consonant with the tracer patterns, and that satisfies continuity of mass. The resulting flow field has the traditional western boundary current from the Weddell Sea to the equator, beneath a poleward flow north of 50°S. In the upper waters the flow pattern shows a cyclonic gyre in the Weddell Sea, a northward flow from the Antarctic along the western boundary from 55°S to 40°S, an anticyclonic gyre between 15°S and 40°S, and an eastward flow near 10°S. Below the upper layer the axis of the anticyclonic gyre shifts southward, to 35°S at 1500 m, and at greater depths the gyre is confined to the Brazil Basin, west of the Mid-Atlantic Ridge and north of the Rio Grande Rise. Below the crest of the Mid-Atlantic Ridge in the Brazil Basin waters from the south flow northward along the Ridge, and part of them crosses the Ridge at or near the equator and returns southward in the eastern basin, joined by waters from the North Atlantic. The northward abyssal flow in the Brazil Basin is not confined to the western boundary but extends some distance across the basin, diverted only slightly at 3500 m by the small deep remnant of the overlying anticyclonic gyre. From 3000 to 4000 decibars the flow within the Weddell Sea and the Argentine Basin form a single cyclonic gyre and the flow within the Cape Basin is cyclonic below 3000 m.

On the Total Geostrophic Circulation of the South Pacific Ocean: Flow Patterns, Tracers and Transports

Elevated levels of mercury in aquatic environments remote from industrial sources have been broadly attributed to long-range atmospheric transport and deposition of anthropogenic Hg. Evidence in support of this prevailing scientific viewglobal biogeochemical Hg models, sedimentary archives of historic Hg fluxes, and geographic trends in soil Hghave been challenged as being insuf ficiently rigorous to rule out the alternative explanation that natural geologic sources are the principal contributors of Hg in remote locations. In this review, we examine the weaknesses in interpretation and the choice of information that has been used to argue against atmospheric Hg contamination. Analytical advances in measuring trace levels of environmental Hg have greatly narrowed estimates of natural Hg fluxes, providing a clear measure of the relative magnitude of anthropogenic Hg emissions and deposition. Recent experimental results indicate that diagenetic processes cannot explain the mounting number of lake sediment an...

The Case for Atmospheric Mercury Contamination in Remote Areas

Marine biogeochemical cycling of mercury.

The origin of aluminum-poor ferromanganoan sediments in areas of high heat flow on the East Pacific Rise

The results of 399 new analyses and 144 analyses from the literature indicate that the carbonate-free fraction of sediments from active oceanic ridges is characterized by very low aluminum and titanium content and high iron and manganese content compared with sediments from other volcanic regions and from inactive ridges. These active ridge sediments appear to originate by volcanic processes associated with ocean-floor spreading and high heat flow. The total mass of these sediments is probably only a few per cent of all deep-sea sediments.

Kurt Boström

Papers

The origin of aluminum-poor ferromanganoan sediments in areas of high heat flow on the East Pacific Rise

Aluminum‐poor ferromanganoan sediments on active oceanic ridges

Provenance and accumulation rates of opaline silica, Al, Ti, Fe, Mn, Cu, Ni and Co in Pacific pelagic sediments

Metaborate digestion procedure for inductively coupled plasma-optical emission spectrometry

Submarine volcanism as a source for iron