Silicon Retention in River Basins: Far-reaching Effects on Biogeochemistry and Aquatic Food Webs in Coastal Marine Environments

Humborg, Christoph; Conley, Daniel J.; Rahm, Lars; Wulff, Fredrik; Cociasu, Adriana; Ittekkot, V.

doi:10.1579/0044-7447-29.1.45

Cited by 312 publications

(67 citation statements)

References 37 publications

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“…It has been reported that reservoir construction along the CR first caused a dramatic reduction of dissolved silicate concentrations, from 3.15 to 1.86 mg L −1 , mainly due to enhanced growths of diatoms and their subsequent sedimentation in the reservoirs (Mayer and Gloss, 1980). Similar observations were also reported for the Danube (Humborg et al, 2000). Our value from the CR at the international border is however equal to concentrations reported for pre-dam construction (3.15 mg L −1 ) by Mayer and Gloss (1980).…”

Section: Discussionsupporting

confidence: 77%

Turnover and release of P-, N-, Si-nutrients in the Mexicali Valley (Mexico): Interactions between the lower Colorado River and adjacent ground- and surface water systems

Orozco-Durán

Daesslé

Camacho-Ibar

et al. 2015

Science of The Total Environment

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Section: Discussionsupporting

confidence: 77%

Turnover and release of P-, N-, Si-nutrients in the Mexicali Valley (Mexico): Interactions between the lower Colorado River and adjacent ground- and surface water systems

Orozco-Durán

Daesslé

Camacho-Ibar

et al. 2015

Science of The Total Environment

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“…Strong upwelling can reduce recruitment of benthic organisms due to the offshore export of larvae away from favourable settling grounds [25]. Likewise, coastal phytoplankton composition fluctuates seasonally in response to the nutrient input associated with the seasonality of upwelling [26], usually going through a succession of communities dominated first by diatoms and then dinoflagellates [27–29]. These changes at the base of the food web may cause structural changes at different scales of observation, from individuals to the whole food web, by influencing the richness and abundance of intermediate and higher trophic levels [30].…”

Section: Introductionmentioning

confidence: 99%

Spatio-Temporal Variation in Effects of Upwelling on the Fatty Acid Composition of Benthic Filter Feeders in the Southern Benguela Ecosystem: Not All Upwelling Is Equal

2016

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Variability in mesoscale nearshore oceanographic conditions plays an important role in the distribution of primary production and food availability for intertidal consumers. Advection of nutrient rich waters by upwelling usually allows the proliferation of diatoms, later replaced by dinoflagellates. We examined upwelling effects on the fatty acid (FA) signature of a benthic intertidal filter feeder to identify its response to pulsed variability in food availability. The study took place in two contrasting seasons and at two upwelling and two non-upwelling sites interspersed within the southern Benguela upwelling system of South Africa. We investigated the FA composition of the adductor muscles and gonads of the mussel Mytilus galloprovincialis to assess how FA are apportioned to the different tissues and whether this changes between upwelling and non-upwelling conditions. In situ temperature loggers used to identify upwelling conditions at the four sites indicated that such events occurred only at the upwelling centres and only in summer. Tissues differed strongly, with gonads presenting a higher proportion of essential FAs. This could reflect the faster turnover rate of gonad tissue or preferential retention of specific FA for reproductive purposes. FA composition did not vary as a direct function of upwelling, but there were strong dissimilarities among sites. Upwelling influenced mussel diets at one upwelling site while at the other, the expected signature of upwelling was displaced downstream of the core of upwelling. Condition Index (CI) and Gonad Index (GI) differed among sites and were not influenced by upwelling, with GI being comparable among sites. In addition, FA proportions were consistent among sites, indicating similar food quality and quantity over time and under upwelling and non-upwelling conditions. This suggests that the influence of upwelling on the west coast of South Africa is pervasive and diffuse, rather than discrete; while nearshore retention or advection of upwelled water is critical and site-specific so that the effects of upwelling differ even among sites categorised as upwelling centres.

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“…Globally, anthropogenic perturbations (e.g., wastewater and fertilizer inputs) have caused significant increases in fluvial nutrient fluxes [7], and have substantially modified coastal ecosystems [8,9,10]. In addition, the construction of riverine impoundments such as dams and reservoirs can modify the hydrology and consequently the fluvial transport of nutrients and sediments [11,12,13]. …”

Section: Introductionmentioning

confidence: 99%

Seasonal Variation and Sources of Dissolved Nutrients in the Yellow River, China

Gong

Yao

et al. 2015

IJERPH

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The rapid growth of the economy in China has caused dramatic growth in the industrial and agricultural development in the Yellow River (YR) watershed. The hydrology of the YR has changed dramatically due to the climate changes and water management practices, which have resulted in a great variation in the fluxes of riverine nutrients carried by the YR. To study these changes dissolved nutrients in the YR were measured monthly at Lijin station in the downstream region of the YR from 2002 to 2004. This study provides detailed information on the nutrient status for the relevant studies in the lower YR and the Bohai Sea. The YR was enriched in nitrate (average 314 μmol·L−1) with a lower concentration of dissolved silicate (average 131 μmol·L−1) and relatively low dissolved phosphate (average 0.35 μmol·L−1). Nutrient concentrations exhibited substantial seasonal and yearly variations. The annual fluxes of dissolved inorganic nitrogen, phosphate, and silicate in 2004 were 5.3, 2.5, and 4.2 times those in 2002, respectively, primarily due to the increase in river discharge. The relative contributions of nutrient inputs to nitrogen in the YR were: wastewater > fertilizer > atmospheric deposition > soil; while to phosphorus were: wastewater > fertilizer > soil > atmospheric deposition. The ratios of N, P and Si suggest that the YR at Lijin is strongly P-limited with respect to potential phytoplankton growth.

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Silicon Retention in River Basins: Far-reaching Effects on Biogeochemistry and Aquatic Food Webs in Coastal Marine Environments

Cited by 312 publications

References 37 publications

Turnover and release of P-, N-, Si-nutrients in the Mexicali Valley (Mexico): Interactions between the lower Colorado River and adjacent ground- and surface water systems

Turnover and release of P-, N-, Si-nutrients in the Mexicali Valley (Mexico): Interactions between the lower Colorado River and adjacent ground- and surface water systems

Spatio-Temporal Variation in Effects of Upwelling on the Fatty Acid Composition of Benthic Filter Feeders in the Southern Benguela Ecosystem: Not All Upwelling Is Equal

Seasonal Variation and Sources of Dissolved Nutrients in the Yellow River, China

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