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(1 - 25 of 41)
Pages
- Title
- Primary production, new production and vertical flux in the eastern Pacific Ocean,
- Description
- The sinking of participate organic matter in the ocean links food webs beneath the euphotic zone to surface primary production and is an important pathway for the downward transport of many elements 1-3. The flux of particulate organic carbon (POC) is also an important parameter in the global carbon cycle and may be related to long-term changes in atmospheric CO 24,5. In 1980, Suess 6synthesized existing measurements from sediment trap studies into a model to predict the vertical flux of POC from depth (z) and primary production (PP)6. The Suess model has become the standard for evaluating vertical flux data 7, for estimating the annual flux of POC in the ocean 8and for parameterizing ocean carbon cycle models 4,5. We present here a new model of the vertical flux of POC and particulate organic nitrogen (PON) from a set of contemporaneous measurements of PP and fluxes made during the VERTEX (Vertical Transport and Exchange) programme in the north-east Pacific. The VERTEX model indicates that PP and vertical fluxes of POC and PON, in the oligotrophic ocean are greater than previously suggested. In addition, the vertical flux of PON from the photic zone represents a measure of the PP that is supported by new nitrogen (new production) 9,10. In the north-east Pacific, new production ranged from 13 to 25% of primary production and was positively related to total PP. © 2002 Nature Publishing Group., Cited By (since 1996):144, ,
- Author
- Pace, Knauer, Karl, Martin
- Date
- 1987-01-01T00:00:00Z
- Title
- The effects of Cu on the adenylate energy charge of open ocean phytoplankton,
- Description
- The effects of short-term, acute Cu exposure (6 h) on the adenylate energy charge (EC A) of open-ocean phytoplankton populations (northeastern equatorial Pacific) were investigated. Energy charge remained at ̃0.77 over the range of Cu additions (0.025 - 5.μg l -1), even though 14C uptake and total adenylate levels (ATP + ADP + AMP) were reduced by as much as 60%. These findings suggest that EC A alone is not a sensitive indicator of acute sublethal metal effects on phytoplankton. © 1983 IRL Press Ltd., Cited By (since 1996):1, Oceanography, CODEN: JPLRD, ,
- Author
- Fitzwater, Knauer, Martin
- Date
- 1983-01-01T00:00:00Z
- Title
- Techniques for enhancing vertebral bands in age estimation of California elasmobranchs
- Description
- Vertebrae from 1,152 elasmobranchs representing 22 species were collected between 1979 and 1981 to assess methods of enhancing incremental growth bands for age estimation. Thus far, we have tested methods previouslyreported in the literature, and have developed new procedures to enhance growth increments on 684 individuals of 14 species of elasmobranchs. Silver nitrate impregnation, X-radiograpby, and cedarwood oil clearing were the most successful techniques. Less effeetive were alizarin red staining, paraffin impregnation, alcohol immersiorn, and formic acid etching. Methods for preparing vertebrae and enhancing and counting growth increments are presented, and the problems associated with interpreting tile annual nature of such counts are discussed.
- Author
- Cailliet, Martin, Kusher, Wolf, Welden, Prince, Pulos
- Date
- 1983-01-01T00:00:00Z
- Title
- Age and growth determination of the bat ray, Myliobatis californica Gill, in central California,
- Description
- , , ,
- Author
- Martin, Cailliet
- Date
- 1988-01-01T00:00:00Z
- Title
- Downward flux of particulate organic matter in the Ocean,
- Description
- Oceanographers now recognize two distinct classes of particles in seawater, broadly categorized as suspended and sinking. The former class dominates the standing stock of particulate matter in the ocean and the latter class dominates the exchange between the surface waters and greater ocean depths 1. The downward vertical flux of particulate organic matter (POM) in the open ocean exhibits a non-linear decrease with increasing water depth 2-6, and greater than 75% of the net POM loss occurs in the upper 500 m of the water column 6. Because sinking particles contain viable, metabolically active microorganisms 7-12, the process of microbial decomposition is considered to be an important mechanism controlling POM flux. This model is consistent with the observed correspondence between POM flux and dissolved inorganic carbon concentrations 13, and with the reported selective loss of biochemically labile compounds from sinking particles 14-17. From our experiments, however, we conclude that the large sinking particles are, in general, poor habitats for bacterial growth and therefore unlikely sites for the active remineralization of organic matter. Our results require a shift in the emphasis of current ideas of particle decomposition from microbes attached to rapidly sinking particles to the microbial populations which are either free-living in the water column or attached to suspended (non-sinking) particulate matter. © 1988 Nature Publishing Group., Cited By (since 1996):108, Oceanography, ,
- Author
- Karl, Knauer, Martin
- Date
- 1988-01-01T00:00:00Z
- Title
- Iron, primary production and carbon-nitrogen flux studies during the JGOFS North Atlantic bloom experiment,
- Description
- Primary production was measured every other day towards the end (18-31 May) of the 1989 North Atlantic spring bloom. Rates varied with light and averaged 90.4 mmol C m -2 day -1 at the 47°N, 20°W station. Productivities measured south of Iceland (59°30′N, 20°45′W) were somewhat lower, averaging 83.6 mmol C m -2 day -1. Carbon and nitrogen fluxes were estimated using free-floating, VERTEX type particle trap arrays. To obtain mean rates representative of the North Atlantic spring bloom, flux data from three trap deployments were combined and fitted to normalized power functions:. mmol C m -2 day -1 = 14.35 (z/100) -0.946, mmol N m -2 day -1 = 2.34(z/100) -1.02, with depth z in meters. Regeneration rates were:. mmol C m -2 day -1 = 0.136(z/100) -1.946, mmol N m -2 day -1 = 0.0239(z/100) -2.02. The carbon export rate from the upper 35 m for the entire NABE study period (24 April to 1 June) was 39 mmol m -2 day -1. This value divided by the averaged productivity for the entire study (86 mmol N m -2 day -1) gave an F-ratio of 0.45. Concentrations of Cu, Fe, Ni, Pb and Zn were determined in water samples provided by JGOFS NABE scientists involved with primary productivity measurements. Although little contamination was observed for Cu, Ni and Pb, relatively large amounts of Zn (10 nmol kg -1) were found in some cases. In subsequent studies it was learned that this quantity of Zn can depress productivity rates by 25%. North Atlantic dissolved Fe concentrations were similar to those occurring in the Pacific (surface = 0.07; deep = 0.5-0.6 nmol kg -1). Although no evidence of Fe deficiency was found in enrichment experiments, the addition of nmol amounts of Fe did increase CO 2 uptake and POC formation by factors of 1.3-1.7. In this region, most of the phytoplankton's Fe requirement is probably met via the lateral transport of Fe from distant continental margins., Cited By (since 1996):170, CODEN: DSROE, ,
- Author
- Martin, Fitzwater, Michael Gordon, Hunter, Tanner
- Date
- 1993-01-01T00:00:00Z
- Title
- Elevated concentrations of mercury in mussels (Mytilus californianus) associated with pinniped colonies,
- Description
- The geographic distribution of mercury concentrations in the California mussel Mytilus californianus, collected from 1977-1978 at 43 sites along the western coastline of the continental United States is marked by consistently elevated levels at two locations. These two sites, which are relatively isolated from anthropogenic inputs and mercury-rich minerals, both contain large pinniped and marine bird populations. The relatively elevated mercury levels measured in the excrement of a pinniped from one of those locales indicate that the concentrated discharge of mercury-rich waste products from the marine ecosystem's top carnivores is contaminating lower trophic levels., Cited By (since 1996):1, Ecology, CODEN: MBIOA, ,
- Author
- Flegal, Stephenson, Martin, Martin
- Date
- 1981-01-01T00:00:00Z
- Title
- Notes on the JGOFS North Atlantic Bloom Experiment-dissolved organic carbon intercomparison,
- Description
- Using high temperature catalytic oxidation (HTCO), personnel from four laboratories analyzed water samples collected during the JGOFS North Atlantic Bloom study for their dissolved organic carbon (DOC) content. In general, good agreement was obtained. Values obtained on samples filtered and frozen compared well with those analyzed immediately after collection. DON analyses of the same frozen samples did not co-vary with DOC; thus far, DON results have only been reported by Moss Landing Marine Laboratories. © 1993., Cited By (since 1996):7, CODEN: MRCHB, ,
- Author
- Fitzwater, Martin
- Date
- 1993-01-01T00:00:00Z
- Title
- Mercury-selenium-bromine imbalance in premature parturient California sea lions,
- Description
- High premature birth rates have been observed in the rookeries of the California sea lion Zalophus californianus since 1968. The reasons for the premature pupping are complex and, hence, not well understood, although leptospirosis infection and elevated PCB and DDT residues have been implicated. We were interested in determining what role trace and major elements played in these events. Livers and kidneys from 10 normal parturient and 10 premature parturient mothers and their pups were analyzed for Hg, Se, Br, Cd, Ag, Cu, Fe, Zn, Mn, K, Na, Ca, and Mg in order to detect differences that might exist between the two groups. A further objective was to establish how these elements varied in relation to each other in the normal and abnormal sea lions. Our results revealed that Hg, Se, Cd, and Br levels were significantly higher in the livers of the normal mothers and that these elements were all in balance (highly correlated) with each other. This was especially true for Hg, Se, and Br. In mothers with high concentrations of these elements (e.g. Hg greater than 800 μg/g dry weight), atomic ratios of approximately 1Hg:1Se:1Br were observed. Atomic Se:Hg ratios were also near unity in the abnormal mothers; however, Br concentrations were always severely depressed in these individuals. Normal full-term pups had higher hepatic levels of Hg and Se, and near-perfect 1:1 Se:Hg atomic ratios were almost always observed. In contrast, the livers of the premature pups appeared to be deficient in Hg, and, consequently, elevated Se:Hg ratios were always found. In almost all cases, the premature pups had increased concentrations of Na, Ca, and Br. Levels of these elements were correlated with their Se:Hg ratios. Amounts of Mn and Cu were reduced in the premature pups and negatively correlated with Se:Hg ratios. The results suggest that balance between elements is of more importance than absolute concentration when the possible effects of toxic elements are considered. It also appears that bromine may be important in the detoxification process involving Se and Hg and perhaps Cd as well; i.e., every mother that had Br in balance with Hg, Cd, and Se had a normal pup, while every mother that lacked sufficient Br had a premature pup. The question of whether Hg detoxifies Se is also raised. All the normal pups had Se:Hg atomic ratios of less than 2.2, while all the premature pups had reduced Hg amounts and Se:Hg ratios above 3.4. © 1976 Springer-Verlag., Cited By (since 1996):11, CODEN: MBIOA, ,
- Author
- Martin, Elliott, Anderlini, Girvin, Jacobs, Risebrough, Delong, Gilmartin
- Date
- 1976-01-01T00:00:00Z
- Title
- Validation of ultrasound as a noninvasive tool to measure subcutaneous fat depth in leatherback sea turtles (Dermochelys coriacea)
- Description
- Leatherback turtles (Dermochelys coriacea) undergo substantial cyclical changes in body condition between foraging and nesting. Ultrasonography has been used to measure subcutaneous fat as an indicator of body condition in many species but has not been applied in sea turtles. To validate this technique in leatherback turtles, ultrasound images were obtained from 36 live-captured and dead-stranded immature and adult turtles from foraging and nesting areas in the Pacific and Atlantic oceans. Ultrasound measurements were compared with direct measurements from surgical biopsy or necropsy. Tissue architecture was confirmed histologically in a subset of turtles. The dorsal shoulder region provided the best site for differentiation of tissues. Maximum fat depth values with the front flipper in a neutral (45–90°) position demonstrated good correlation with direct measurements. Ultrasound-derived fat measurements may be used in the future for quantitative assessment of body condition as an index of health in this critically endangered species.
- Author
- Harris, Benson, James, Martin, Stacy, Daoust, Rist, Work, Balazs, Seminoff
- Date
- 2016-01-01T00:00:00Z
- Title
- VERTEX manganese transport: Manganese transport through oxygen minima,
- Description
- Manganese transport through a well-developed oxygen minimum was studied off central Mexico (18°N, 108°W) in October-November 1981 as part of the VERTEX (Vertical Transport and Exchange) research program. Refractory, leachable and dissolved Mn fractions associated with particulates caught in traps set at eight depths (120-1950 m) were analyzed. Particles entering the oxygen minimum had relatively large Mn loads; however, as the particulates sank further into the minimum, total Mn fluxes steadily decreased from 190 nmol m -2 day -1 at 120 m to 36 nmol m -2 day -1 at 400 m. Manganese fluxes then steadily increased in the remaining 800-1950 m, reaching rates of up to 230 nmol m -2 day -1 at 1950 m. Manganese concentrations were also measured in the water column. Dissolved Mn levels < 3.0 nmol kg -1 were consistently observed within the 150-600 m depth interval. In contrast, suspended particulate leachable Mn amounts were especially low at those depths, and never exceeded 0.04 nmol kg -1. The combined water column and particle trap data clearly indicate that Mn is released from particles as they sink through the oxygen minimum. Rate-of-change estimates based on trap flux data yield regeneration rates of up to 0.44 nmol kg -1 yr -1 in the upper oxygen minimum (120-200 m). However, only 30% of the dissolved Mn in the oxygen minimum appears to be from sinking particulate regeneration; the other 70% probably results from continental-slope-release-horizontal-transport processes. Dissolved Mn scavenges back onto particles as oxygen levels begin to increase with depth. Scavenging rates ranging from -0.03 to -0.09 nmol kg -1 yr -1 were observed at depths from 700 to 1950 m. These scavenging rates result in Mn residence times of 16-19 years, and scavenging rate constants on the order of 0.057 yr -1. Manganese removal via scavenging on sinking particles below the oxygen minimum is balanced by Mn released along continental boundaries and transported horizontally via advective-diffusive processes. Manganese appears to be very weakly associated with particulates. Nevertheless, the amounts of Mn involved with sinking biogenic particles are large, and the resulting fluxes are on the same order of magnitude as those necessary to explain the excess Mn accumulating on the sea floor. The overall behavior of Mn observed in this, and other, studies strongly suggests some type of equilibrium occurring between dissolved and particulate phases. This equilibrium appears to shift in direct or indirect response to dissolved oxygen levels. © 1984., Cited By (since 1996):29, Oceanography, ,
- Author
- Martin, Knauer
- Date
- 1984-01-01T00:00:00Z
- Title
- Iron deficiency limits phytoplankton growth in the north-east Pacific subarctic,
- Description
- An interesting oceanographic problem concerns the excess major plant nutrients (PO 4, NO 3, SiO 3) occurring in offshore surface waters of the Antarctic 1-3 and north-east Pacific subarctic Oceans 4. In a previous study 5, we presented indirect evidence suggesting that inadequate Fe input was responsible for this limitation of growth; recently we had the opportunity to seek direct evidence for this hypothesis in the north-east Pacific subarctic. We report here that the addition of nmol amounts of dissolved iron resulted in the nearly complete utilization of excess NO 3, whereas in the controls-without added Fe-only 25% of the available NO 3 was used. We also observed that the amounts of chlorophyll in the phytoplankton increased in proportion to the Fe added. We conclude that Fe deficiency is limiting phytoplankton growth in these major-nutrient-rich waters., Cited By (since 1996):854, ,
- Author
- Martin, Fitzwater
- Date
- 1988-01-01T00:00:00Z
- Title
- Glacial-interglacial CO2 change: The iron hypothesis,
- Description
- Several explanations for the 200 to 280 ppm glacial/interglacial change in atmospheric CO2 concentrations deal with variations in southern ocean phytoplankton productivity and the related use or nonuse of major plant nutrients. An hypothesis is presented herein in which arguments are made that new productivity in today's southern ocean (7.4 × 1013 g yr-1) is limited by iron deficiency, and hence the phytoplankton are unable to take advantage of the excess surface nitrate/phosphate that, if used, could result in total southern ocean new production of 2.3 × 1015 g C yr-1. As a consequence of Fe-limited new productivity, Holocene interglacial CO2 levels (preindustrial) are as high as they were during the last interglacial (~ 280 ppm). -from Author, Cited By (since 1996):759, ,
- Author
- Martin
- Date
- 1990-01-01T00:00:00Z
- Title
- ,
- Description
- This paper presents current information concerning the formation, make-up, distribution and transport of biogenic particles in the belief that this knowledge will provide greater understanding of the role of these particles in the cycling of trace elements., Oceanography, CODEN: NCSFD, ,
- Author
- Knauer, Martin
- Date
- 1983-01-01T00:00:00Z
- Title
- Long-term trends in DDT, polychlorinated biphenyls, and chlordane in California mussels,
- Description
- The California State Mussel Watch program is a long-term monitoring program conducted by the State Water Resources Control Board and the Department of Fish and Game. In a fifteen year time span, from 1977-1992, mussels were collected at 378 stations. From these stations, 47 were chosen to conduct statistical analysis based on the criteria that they had been sampled at least 6 times for total DDTs, total polychlorinated biphenyls (PCBs), and total chlordanes. Declines of total DDTs and chlordanes were noted at approximately half of the stations. Declines of total PCBs were noted at approximately one-quarter of the stations. Declines of PCBs but not DDTs in mussels near Los Angeles County's sewer discharge corresponded to declines of these contaminants in treated effluent., Cited By (since 1996):29, Invertebrates, Ecology, CODEN: AECTC, ,
- Author
- Stephenson, Martin, Tjeerdema
- Date
- 1995-01-01T00:00:00Z
- Title
- Trace elements and primary production: Problems, effects and solutions,
- Description
- The measurement of primary production in the ocean is basic to biological oceanographic processes. Factors which control primary production are varied, but include micronutrients (i. e. , N and P) in sufficient supply, as well as many nanonutrients such as Cu, Mn and Zn. High levels of many of these trace constituents are toxic. Recent studies have shown that ambient concentrations of a number of nanonutrients in sea water are lower by an order of magnitude than previously believed., Cited By (since 1996):1, Oceanography, CODEN: NCSFD, ,
- Author
- Knauer, Martin
- Date
- 1983-01-01T00:00:00Z
- Title
- Iron still comes from above,
- Description
- Cited By (since 1996):19, , ,
- Author
- Martin
- Date
- 1991-01-01T00:00:00Z
- Title
- Bacterial chemolithotrophy in the ocean is associated with sinking particles,
- Description
- The oceanic carbon cycle has traditionally been viewed as a reversible, one step reduction-oxidation reaction (CO 2CH 2O). Principle pathways were thought to involve eukaryotic photoautotrophy and oxygen-dependent bacterial respiration, respectively. However, prokaryotic (cyanobacterial) photoautotrophy is now well documented and has even been proposed as a major carbon pathway 1-6. In a previous study of the mesopelagic zone in the North Pacific Ocean 7, the observed downward fluxes of organic carbon, nitrogen, ATP and RNA suggested production in situ of new particulate organic carbon at 700-900 m. Here we present evidence that this is indeed the case and that it is mediated by bacterial chemolithotrophy. Energy for this process may be in part provided by detrital NH + 4 derived from the downward flux of large particles. © 1984 Nature Publishing Group., Cited By (since 1996):33, Oceanography, ,
- Author
- Karl, Knauer, Martin, Ward
- Date
- 1984-01-01T00:00:00Z
- Title
- Chronic oiling of marine birds in California by natural petroleum seeps, shipwrecks, and other sources
- Description
- We assessed temporal and spatial patterns of chronic oiling of seabirds in California during 2005-2010, using data on: (1) live oiled birds reported to the Oiled Wildlife Care Network (OWCN) from throughout the state, and (2) dead oiled birds found during systematic monthly beached-bird surveys in central California. A mean of 245 (±141 SD) live miscellaneous oiled birds (not associated with known oil spills) were reported to the OWCN per year, and 0.1 oiled dead birds km-1 per month were found on beach surveys in central California. Chemical fingerprinting of oiled feathers from a subset of these birds (n = 101) indicated that 89% of samples tested were likely from natural petroleum seeps off southern and central California. There was a pronounced peak during late winter in the number of oiled birds reported in southern California, which we theorize may be related to large storm waves disturbing underwater seeps. © 2013., Marine Mammals, Birds & Turtles, Article in Press
- Author
- Henkel, Nevins, Martin, Sugarman, Harvey, Ziccardi
- Date
- 2014-01-01T00:00:00Z
- Title
- Trace metals in large agglomerates (marine snow),
- Description
- Marine agglomerates were collected by SCUBA from surface waters of Monterey Bay, California and one coastal site 100 km off Point Sur, California using trace metal clean techniques. Concentrations of Al, Fe, Mn, Cu, Ni, Zn, Cd and Pb were measured for both weak acid soluble and refractory metals and compared to suspend material collected in water bottles at the same locations. Gravimetric analysis of agglomerate and surrounding suspended particulate matter indicated that although agglomerates represented <0.1% of total water sample volume (determined photographically), they contained up to 50% of the total particulate dry weight; trace metal concentrations in the agglomerate fraction were also disproportionately high. Agglomerates collected within Monterey Bay contained large quantitites of inorganic material (>40% dry weight), with most of the associated metals contained primarily within the refractory fraction. In contrast, the offshore station agglomerates contained <0.3% inorganic material with metals primarily associated with the weak acid soluble fraction. Both the metal concentrations and leach characteristics of the offshore station suggest that these agglomerates were comprised of an active phytoplankton assemblage highly enriched in Cd. Metal concentrations in the offshore samples in conjunction with agglomerate abundance indicate that agglomerates may be a major transporter of trace metals out of the euphotic zone. © 1986 IRL Press Limited., Cited By (since 1996):14, CODEN: JPLRD, ,
- Author
- Hebel, Knauer, Martin
- Date
- 1986-01-01T00:00:00Z
- Title
- In situ effects of selected preservatives on total carbon, nitrogen and metals collected in sediment traps.,
- Description
- Presents results on in situ effects of formalin, azide and mercuric ion on material collected in MULTITRAPS set at 100 and 300 m for 6 days in a coastal environment, and at 150 m for a period of 20.6 days in an oligotrophic environment., Cited By (since 1996):59, ,
- Author
- Knauer, Karl, Martin, Hunter
- Date
- 1984-01-01T00:00:00Z
- Title
- High copper concentrations in squid livers in association with elevated levels of silver, cadmium, and zinc,
- Description
- Cited By (since 1996):71, CODEN: MBIOA, Livers from 43 Loligo opalescens, 14 Ommastrephes bartrami, and 7 Symplectoteuthis oualaniensis were analyzed for their silver, cadmium, copper, zinc and iron contents. Copper concentrations of up to 15,000 μg/g dry weight were found in L. opalescens in conjunction with significant correlations between this element and Ag, Cd and Zn. The latter elements are known to affect Cu metabolism in terrestrial organisms; however, whether the correlations occurring in marine organisms represent casual, or cause and effect, relationships is as yet unknown., ,
- Author
- Martin, Flegal
- Date
- 1975-01-01T00:00:00Z
- Title
- Aspects of reproduction in the bat ray, Myliobatis californica, in central California,
- Description
- , , ,
- Author
- Martin, Cailliet
- Date
- 1988-01-01T00:00:00Z
- Title
- Widespread fluid expulsion on a translational continental margin: Mud volcanoes, fault zones, headless canyons, and organic-rich substrate in Monterey Bay, California,
- Description
- Remotely operated vehicle (ROV)-based mapping of tectonic features, zones of anomalous reflectivity, and geomorphic targets in Monterey Bay, California, demonstrates the regional abundance of fluid expulsion along the active transform margin between the Pacific and North American plates. Cold seeps - extant communities characterized by chemosynthetic bivalves, bacterial mats, and rare tubeworms - are the surface manifestations of present-day fluid expulsion of sulfide- and methane-rich fluids, whereas slabs, veins, and chimneys of authigenic carbonate represent regions of either dormant methane-rich fluid expulsion, or areas where the present rate of flow is too low to support chemosynthetic fauna. We have found both active and dormant fluid seepage along fault zones, at the surface expression of mud volcanoes, on organic-rich or permeable substrate, and within headless canyons across a wide range of depths within Monterey Bay. The fluid egress at these sites may be driven by a combination of (1) pore-space reduction caused by rapid sedimentation and/or tectonic compaction related to residual Pacific-North America compression, and (2) increased buoyancy due to a decrease in pore-fluid density related to diagenesis and/or catagenesis at depth. Although provocative, the relationship between topographically driven aquifer discharge and sea-floor fluid expulsion remains speculative for Monterey Bay. The widespread distribution of fluid expulsion features controlled by a variety of conduits in Monterey Bay implies that cold seeps may be common features on translational margins., Cited By (since 1996):60, CODEN: BUGMA, ,
- Author
- Orange, Greene, Reed, Martin, McHugh, Ryan, Maher, Stakes, Barry
- Date
- 1999-01-01T00:00:00Z
- Title
- Manganese cycling in northeast Pacific equatorial waters,
- Description
- Sea water samples collected above, within and below a pronounced oxygen minimum were analyzed for their Mn content. Amounts of dissolved Mn slowly decreased with depth and little, if any, relationship with oxygen was found. In contrast, suspended particulate Mn values increased markedly at the top of the oxygen minimum. Concentrations of weakly leachable Mn probably resulted from microbial oxidation. Labile Mn fluxes, measured with particle interceptor traps at depths of 125, 275, 525 and 900m slowly increased with depth. These rates are the same order of magnitude as those estimated for excess Mn accumulating in open-ocean sediments, which implies that biogenic transport is a major factor in the oceanic cycling of Mn., Cited By (since 1996):5, Oceanography, ,
- Author
- Martin, Knauer
- Date
- 1982-01-01T00:00:00Z