The issue of outwelling in the Guadiana River estuary (Portugal): some findings and research suggestions in the context of recent evidence

Bettencourt, Alexandre; Quaresma, L.; Lança, Maria João

doi:10.1007/s10750-007-0674-x

Cited by 3 publications

(2 citation statements)

References 22 publications

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“…Upper and Lower Beaver Ponds exported 31–60% of the total suspended solids, chloride and bromide and 5–70% of the major nutrients nitrate, ammonium, soluble phosphorus, total phosphorus and silica. Nitrogen, phosphorus, chloride and silica are often released from sediments in wetlands through plant uptake or leaching and decomposition of organic matter (Noe and Childers 2007 ; de Bettencourt et al 2007 ). Main Pond also exported suspended sediment, soluble and total phosphorus in most seasons between 2004 and 2005 (Lehman et al 2010 ).…”

Section: Discussionmentioning

confidence: 99%

Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland

Lehman¹,

Mayr²,

Liu³

et al. 2015

SpringerPlus

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The loss of inorganic and organic material export and habitat produced by freshwater tidal wetlands is hypothesized to be an important contributing factor to the long-term decline in fishery production in San Francisco Estuary. However, due to the absence of freshwater tidal wetlands in the estuary, there is little information on the export of inorganic and organic carbon, nutrient or phytoplankton community biomass and the associated mechanisms. A single-day study was conducted to assess the potential contribution of two small vegetated ponds and one large open-water pond to the inorganic and organic material flux within the freshwater tidal wetland Liberty Island in San Francisco Estuary. The study consisted of an intensive tidal day (25.5 h) sampling program that measured the flux of inorganic and organic material at three ponds using continuous monitoring of flow, chlorophyll a, turbidity and salt combined with discrete measurements of phytoplankton community carbon, total and dissolved organic carbon and nutrient concentration at 1.5 h intervals. Vegetated ponds had greater material concentrations than the open water pond and, despite their small area, contributed up to 81% of the organic and 61% of the inorganic material flux of the wetland. Exchange between ponds was important to wetland flux. The small vegetated pond in the interior of the wetland contributed as much as 72–87% of the total organic carbon and chlorophyll a and 10% of the diatom flux of the wetland. Export of inorganic and organic material from the small vegetated ponds was facilitated by small-scale topography and tidal asymmetry that produced a 40% greater material export on ebb tide. The small vegetated ponds contrasted with the large open water pond, which imported 29–96% of the inorganic and 4–81% of the organic material into the wetland from the adjacent river. This study identified small vegetated ponds as an important source of inorganic and organic material to the wetland and the importance of small scale physical processes within ponds to material flux of the wetland.

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Section: Discussionmentioning

confidence: 99%

Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland

Lehman¹,

Mayr²,

Liu³

et al. 2015

SpringerPlus

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“…Fundamental scientific topics are being progressively studied in the Guadiana estuary within several disciplines, such as ecology (Esteves et al ., 2000; Chícharo et al . 2001a; Rocha et al ., 2002; Vaz Pinto, 2004; Chícharo et al ., 2006b; Faria et al ., 2006; de Bettencourt et al ., 2007; Barbosa et al ., 2009; Chícharo et al ., 2009a,b; Freitas et al ., 2009; Morais et al ., 2009a; Vasconcelos et al ., 2009, 2010), ecotoxicology (Caetano et al ., 2008; Company et al ., 2008; Gomes et al ., 2009), geology (Polvillo et al ., 2009), pollution (Vasconcelos et al ., 2007; Delgado et al ., 2009) and hydrology (Garel et al ., 2009a,b). However, an effort to continue producing integrative science, as Ecohydrology, is needed (Chícharo et al ., 2006a; Wolanski et al ., 2006), and must be developed in simultaneous with new research on fundamental disciplines.…”

Section: Introductionmentioning

confidence: 99%

Merging anchovy eggs abundance into a hydrodynamic model as an assessment tool for estuarine ecohydrological management

Morais

Martins

Chı́charo

et al. 2010

River Research & Apps

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The impoundment of rivers by large dams is the biggest direct anthropogenic impact on the hydrological cycle. However, dams can help solving eutrophication in estuaries by controlling flow pulses, which in turn might enhance the advection of fish larval stages from their spawning and nursery areas. Thus, this work aimed to merge data on the abundance of anchovy eggs with MOHID hydrodynamic model for the Guadiana estuary, allowing dam/basin managers to set river discharge scenarios that might mitigate/prevent eutrophication, without compromising the presence of fish larval stages inside the estuary. Data on anchovy larval stages were assessed in the Guadiana estuary and adjacent coast and three simulation setups were developed. In Simulation A, anchovy eggs abundance was merged in the hydrodynamic model to compare the outputs with data on the abundance, distribution and development stage of anchovy eggs and larvae. In Simulation B, lagrangian particles were incorporated in the model to determine the percentage of particles released from the upper, middle and lower estuary that remain in the estuary along 10 days, in two tidal situations and in seven river discharge scenarios. In Simulation C, the abundance of anchovy eggs was merged in the model to select the discharge scenario(s) that do not compromise the presence of anchovy larval stages in the estuary. Results confirmed the spawning and nursery areas of anchovy and showed that scenarios B (Qmax = 20 m3 s−1) and C (Qmax = 50 m3 s−1) should be applied during neap tides. The choice between scenarios depends on the degree of eutrophication, the effectiveness of an inexistent monitoring program and on plankton response experiments to flushing and increased nutrient loading. This work produced an easy‐to‐use management tool for Guadiana managers, serving as an example to other estuarine sites around the world. Ultimately, this work suggests that river flow management must be guided by robust ecological studies, under an adequate sociological framework and adopting sustainable economic principles to maintain and improve the ecosystem services. Copyright © 2010 John Wiley & Sons, Ltd.

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Temporal Changes in Seawater Carbonate Chemistry and Carbon Export from a Southern California Estuary

Paulsen

Andersson

Aluwihare

et al. 2017

Estuaries and Coasts

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The issue of outwelling in the Guadiana River estuary (Portugal): some findings and research suggestions in the context of recent evidence

Cited by 3 publications

References 22 publications

Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland

Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland

Merging anchovy eggs abundance into a hydrodynamic model as an assessment tool for estuarine ecohydrological management

Temporal Changes in Seawater Carbonate Chemistry and Carbon Export from a Southern California Estuary

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