Topic
Seston
About: Seston is a research topic. Over the lifetime, 1343 publications have been published within this topic receiving 47385 citations.
Papers published on a yearly basis
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Papers
TL;DR: The relative uniformity of marine C : N : P composition (compared to lakes) at the Redfield ratio suggests that marine plankton cannot be as severely, or as frequently, limited by N and P as lake plankton, and the paradigm of N limitation in the oceans requires qualification.
Abstract: The mean carbon, nitrogen, and phosphorus contents of particulate material for 5 1 lakes or lake basins, extending from arctic to tropical climatic regions, including small lakes as well as the largest lakes in the world, indicate that Redfield ratios are the exception rather than the rule in freshwater. The C: P and N : P ratios are more variable for lake particles but generally higher than marine particles, and the mean molar C: N, C: P, and N : P ratios are substantially higher than the Redfield ratio of 106 : 16: 1. On average, lower C : N, C : P, and N : P ratios occur in subarctic lakes while higher ratios occur in the tropics and in temperate, oligotrophic lakes on the Canadian Shield. In shield lakes with long residence times (>6 months) the high ratios of C : N, C : P, and N : P do not originate from streamborne or atmospherically deposited particles but arise from in-lake processes. Regression analysis demonstrates that small lakes are generally more N and P deficient than large lakes. In freshwaters, particulate composition ratios imply that a wide variety of conditions exists in lakes, including N and P deficiency, as well as N and P sufficiency. In the Experimental Lakes Area of Canada, independent physiological nutrient status indicators generally agree with the status indicated by seston ratios. The relative uniformity of marine C : N : P composition (compared to lakes) at the Redfield ratio suggests that marine plankton cannot be as severely, or as frequently, limited by N and P as lake plankton. Consequently, the paradigm of N limitation in the oceans requires qualification. Based on particulate comDosition, it is more correct to say that ocean plankton is noi as N grid P deficient as lake-plankton. The composition of marine particulate matter is relatively uniform. Redfield (1934, 1958) noted the near constancy of the ratio of C : N : P in marine plankton and the similarity of the N : P ratio of plankton to the oceanic deepwater ratio of nitrate to phosphate. As early as 1940, the C : N : P molar composition ratio of marine plankton was accepted to be 106 : 16 : 1 (Redfield et al. 1963); this ratio is now referred to as the Redfield ratio. The ratio has withstood the test of time, and the ever-growing number of analyses of marine particles and nutrient regeneration profiles, with relatively
651 citations
TL;DR: The feeding and metabolic rates of Mytilus edulis L.Edulis of different body sizes were measured in response to changes in particle concentrations ranging from 2 to 350 mg l-1, and the particulate carbohydrate, protein and lipid content provided an estimate of the food content of the seston.
Abstract: The feeding and metabolic rates of Mytilus edulis L. of different body sizes were measured in response to changes in particle concentrations ranging from 2 to 350 mg l-1. Rates of oxygen consumption were not significantly affected by changes in seston concentration, whereas clearance rates gradually declined with increasing particle concentration. Pseudofaeces production was initiated at relatively low seston concentrations (<5 mg l-1). Marked seasonal changes were recorded in the composition of suspended particulates (seston) in an estuary in south-west England. Total seston was sampled at frequent intervals throughout an annual cycle and analysed in terms of: particle size-frequency distributions, total dry weight (mg l-1), inorganic content, chlorophyll a, carbohydrate, protein and lipid. The particulate carbohydrate, protein and lipid content provided an estimate of the food content of the seston. The results are discussed in terms of the “food available” to a nonselective suspension feeder, such as M. edulis, during a seasonal cycle. The effect of inorganic silt in suspension was mainly to limit by “dilution” the amount of food material ingested rather than to reduce the amount of material filtered by the mussel. In winter, the food content of the material ingested was 5%, and this increased to 25% during the spring and summer.
606 citations
TL;DR: In this article, the authors used ancillary chemical and hydrologic data to refine and extend the interpretations of POM sources beyond the source characterizations that could be done solely with isotopic and elemental ratios.
Abstract: Riverine particulate organic matter (POM) samples were collected bi-weekly to monthly from 40 sites in the Mississippi, Colorado, Rio Grande, and Columbia River Basins (USA) in 1996–97 and analysed for carbon and nitrogen stable isotopic compositions. These isotopic compositions and C : N ratios were used to identify four endmember sources of POM: plankton, fresh terrestrial plant material, aquatic plants, and soil organic material. This large-scale study also incorporated ancillary chemical and hydrologic data to refine and extend the interpretations of POM sources beyond the source characterizations that could be done solely with isotopic and elemental ratios. The ancillary data were especially useful for differentiating between seasonal changes in POM source materials and the effects of local nutrient sources and in-stream biogeochemical processes.
Average values of δ13C and C : N for all four river systems suggested that plankton is the dominant source of POM in these rivers, with higher percentages of plankton downstream of reservoirs. Although the temporal patterns in some rivers are complex, the low δ13C and C : N values in spring and summer probably indicate plankton blooms, whereas relatively elevated values in fall and winter are consistent with greater proportions of decaying aquatic vegetation and/or terrestrial material. Seasonal shifts in the δ13C of POM when the C : N remains relatively constant probably indicate changes in the relative rates of photosynthesis and respiration. Periodic inputs of plant detritus are suggested by C : N ratios >15, principally on the Columbia and Ohio Rivers. The δ15N and δ13C also reflect the importance of internal and external sources of dissolved carbon and nitrogen, and the degree of in-stream processing. Elevated δ15N values at some sites probably reflect inputs from sewage and/or animal waste. This information on the spatial and temporal variation in sources of POM in four major river systems should prove useful in future food web and nutrient transport studies. Published in 2001 by John Wiley & Sons, Ltd.
582 citations
TL;DR: In this paper, seasonal variability in stable carbon (S’XZ) and nitrogen (b15N) isotope ratios was observed in suspended particulate matter of the Delaware estuary.
Abstract: ,Qbstract Seasonal variability in stable carbon (S’XZ) and nitrogen (b15N) isotope ratios was observed in suspended particulate matter of the Delaware estuary. Two major pools of organic matter were found in the estuary-phytoplankton growing in situ and a mixture of planktonic and terrestrial detritus. In general, the 6°C and 615N of suspended particulate matter reflected planktonic dominance. With the background chemical and physical information available for the estuary, it is evident that biogeochemical processes influence isotopic distributions in the estuary to a greater extent than does physical mixing. During spring, we postulate that isotopic fractionation of ammonium assimilated at concentrations >20 PM resulted in more negative 615N values for organic matter fixed by phytoplankton. As algal growth proceeded, the 615N of seston reached a maximum (+ 1 SY&) because phytoplankton were using a pool of NH,+ enriched in 15N as a result of previous fractionation during assimilation. Similarly, maximal 813C values were related to high rates of primary productivity associated with algal growth. Decreased isotopic fractionation occurred at high rates of production, implying that diffusion of CO, across the cell membrane became increasingly rate limiting. The 613C values in bottom sediments were equivalent to those in suspended particulate matter, but a 2Y60 difference in 615N was found between suspended and bottom sediments. With nitrogen isotopic differences between water-column seston and surficial sediments, we estimate that 1530% of planktonic production is deposited in the sediments during spring. If this organic matter is remineralized in late summer and fall, it could support up to 20% of primary production at that time.
535 citations
TL;DR: It is concluded that additional non-linear interactions between biomass of the benthos and water currents must exist to explain the observed patterns of spatial distribution, and a simple model framework to investigate the relation between community structure and quantity of organic flux is proposed.
Abstract: Macrobenthos is an important component of estuarine ecosystems. Based on a cross-system comparison, we show that estuarine macrobenthos may directly process a significant portion of the system-wide primary production, and that estuarine macrobenthic biomass may be predicted from primary production data. At large scales, food may be the prime limiting factor for benthic biomass. Depending on the characteristics of the system, grazing by benthic suspension feeders may be the most important factor determining system dynamics. The detailed spatial patterns and dynamics resulting from feeding interactions are discussed separately for suspension feeders and deposit feeders. The theory on local seston depletion and its consequences for spatial distribution of suspension feeders is compared critically with observed patterns of spatial distribution. It is concluded that additional non-linear interactions between biomass of the benthos and water currents must exist to explain the observed patterns. The relation between organic matter deposition fluxes and benthic community structure is discussed in the framework of the classical Pearson-Rosenberg paradigm. The importance of organic matter quality, in addition to quantity, is stressed. A simple model framework to investigate the relation between community structure and quantity of organic flux is proposed. Internal dynamics of benthic food webs are characterized by a high degree of omnivory (feeding on different trophic levels). This feature is contrasted with published data on food webs in other systems. It is hypothesized that the high quality of marine detritus (compared with terrestrial detritus) is the prime factor explaining the differences. Since theoretical studies suggest that omnivory destabilizes food webs, a number of stabilizing mechanisms in benthic food webs are discussed. Problems and mechanisms that could be explored fruitfully in theoretical studies and field comparisons are identified.
433 citations
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| Year | Papers |
|---|---|
| 2025 | 9 |
| 2024 | 11 |
| 2023 | 20 |
| 2022 | 34 |
| 2021 | 21 |
| 2020 | 20 |