| Autor: |
James, Rh, Statham, Pj, Morley, Nh, Burton, Jd |
| Jazyk: |
angličtina |
| Rok vydání: |
1993 |
| Předmět: |
|
| Zdroj: |
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1993, Vol. 16, N. 5-6, P. 553-564 |
| Popis: |
Water column samples have been collected at six stations across the Dover Strait within the framework of the FluxManche programme every month for fifteen months and analyzed for particulate and dissolved trace metals. Important seasonal variations in trace metal distributions have been identified. Dissolved Cu and Ni exhibit similar behaviour in the Strait; while seasonal variation in their distribution may be determined by changes in freshwater input, additional processes including biological uptake and regeneration and benthic input probably perturb water column inventories. Consistently with the suggestion of other authors, Co and Mn in both the dissolved and particulate phase exhibit some degree of covariance; substantial increases in the concentration of dissolved Mn in the summer (9.0-69.0 nM as opposed to 3.3-9.6 nM in the winter) across the entire Channel are to some extent supported by increases in dissolved Co concentrations. Summer maxima are accompanied by a reduction in the acetic acid leachable particulate Mn, possibly implying release from this phase in the summer or increased uptake during the winter. Data for particulate cadmium are consistent with the metal being largely associated with biogenic material; biological activity is inferred to generate a spring depletion in dissolved Cd concentrations. In contrast to deep ocean environments, there is no obvious correspondence between dissolved Cd and the classical nutrient elements in this environment. Dissolved Pb concentrations appear to be strongly influenced by seasonal variation in freshwater input and shorter time scale variation in atmospheric input. There is some evidence that biological activity perturbs the water column inventory. This is supported by observations from the particulate phase where atmospheric or fluvially derived particles appear largely to determine the total particulate Pb concentration in winter but other phases become important in its regulation in summer. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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