Evaluation of ammonium and phosphate release from intertidal and subtidal sediments of a shallow coastal lagoon (Ria Formosa – Portugal): a modelling approach

Serpa, Dalila; Falcão, Manuela; Duarte, Pedro; Fonseca, Luı́s Cancela da; Vale, Carlos

doi:10.1007/s10533-007-9076-4

Cited by 40 publications

(38 citation statements)

References 42 publications

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“…As nitrification, ammonium regeneration in sediments appears to be correlated with oxygen with steadily decreasing rates at decreasing oxygen concentrations (Chapelle, 1995;Serpa et al, 2007). Thus, we conclude (from the sparse data at hand) that the negative correlation of deep layer ammonium concentrations with seawater CO 2 was more likely caused by reduced ammonium regeneration rates rather than higher nitrification rates in the 3× compared to the 2× and 1× CO 2 mesocosms.…”

Section: Inorganic Nutrient Uptake and Organic Materials Build-upmentioning

confidence: 73%

Build-up and decline of organic matter during PeECE III

et al. 2008

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Abstract. Increasing atmospheric carbon dioxide (CO 2 ) concentrations due to anthropogenic fossil fuel combustion are currently changing the ocean's chemistry. Increasing oceanic [CO 2 ] and consequently decreasing seawater pH have the potential to significantly impact marine life. Here we describe and analyze the build-up and decline of a natural phytoplankton bloom initiated during the 2005 mesocosm Pelagic Ecosystem CO 2 Enrichment study (PeECE III). The draw-down of inorganic nutrients in the upper surface layer of the mesocosms was reflected by a concomitant increase of organic matter until day t 11 , the peak of the bloom. From then on, biomass standing stocks steadily decreased as more and more particulate organic matter was lost into the deeper layer of the mesocosms. We show that organic carbon export to the deeper layer was significantly enhanced at elevated CO 2 . This phenomenon might have impacted organic matter remineralization leading to decreased oxygen concentrations in the deeper layer of the high CO 2 mesocosms as indicated by deep water ammonium concentrations. This would have important implications for our understanding of pelagic ecosystem functioning and future carbon cycling.

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Section: Inorganic Nutrient Uptake and Organic Materials Build-upmentioning

confidence: 73%

Build-up and decline of organic matter during PeECE III

et al. 2008

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“…16,18,45 Falcão 16 and Serpa et al 35 observed larger values of ammonium during the summer in Ria Formosa. Our results agree with this pattern but these high values were sustained after summer.…”

Section: Nutrient and Chlorophyll Conditions In The Sedimentsmentioning

confidence: 93%

“…Total benthic concentrations were also calculated, considering that sediment surface is approximately constituted by 50% of sandy sediments and 50% of muddy sediments. 35 Concentrations of pelagic chlorophyll were converted to mg m À2 units so that they could be easily comparable with MPB concentrations. Pelagic chlorophyll amounts of about 132 kg (or 2.49 mg m…”

Section: Chlorophyllmentioning

confidence: 99%

Sediment and waternutrients and microalgae in a coastal shallow lagoon, Ria Formosa (Portugal): Implications for the Water Framework Directive

et al. 2010

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Coastal shallow lagoons are considered to be highly important systems, which have specific biogeochemical cycles and characteristics. The assessment of sediment-water interfaces is essential to understand nutrient dynamics and to evaluate the vulnerability to eutrophication, especially in regions of restricted water exchange (RRE), such as the Ria Formosa, which have natural conditions for the accumulation of nutrients. Water samples were collected during the years of 2006 and 2007-08 for nutrients, chlorophyll a and dissolved oxygen. Sediment samples were also collected for pore water nutrients and microphytobenthic chlorophyll a. Measurements of temperature, salinity and photosynthetic active radiation were also taken. The lagoon salinity is affected by occasional strong rainfall events. From comparison with previous work, a decrease in the nitrogen concentration in the water column can be observed, which may indicate an improvement of the water quality. Pore water nutrient concentrations were significantly larger than in the water column. Sediment-water exchanges are considered to be the most important processes in nutrient dynamics of the lagoon. Benthic microalgal biomass was also large compared with that of the phytoplankton. It represents about 99% of the total microalgal chlorophyll biomass of the system. The lagoon also contains (discontinuous) meadows of intertidal seagrass, but we did not study these. Due to the importance of sediments, the standard monitoring plans required by the Water Framework Directive may fail to track changes in the nutrient conditions and the microalgal responses to them.

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“…Mussels and barnacles ----: y = 0.25 -0.02 t; r 2 = 0.72. Manila clams, mussels and barnacles ---: y = 0.32 -0.035 t; r 2 = 0.78 noted during summer as compared to cooler seasons (Serpa et al 2007). Ammonium was not supplied to intertidal sediments via ground water as indicated by the pore water profiles; however, there was greater sorption of ammonium by surficial sediments of farmed as compared to reference sites.…”

Section: Ammoniummentioning

confidence: 96%

“…Enoksson 1993, Twichell et al 2002, Hou et al 2003, Burgin & Hamilton 2007, Fulweiler et al 2007, Serpa et al 2007). Perhaps receiving less attention although no less important are iron and phosphorus (reviewed in Newell 2004).…”

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

Changes in geochemical foreshore attributes as a consequence of intertidal shellfish aquaculture: a case study

Bendell¹,

Duckham²,

L'Espérance³

et al. 2010

Mar. Ecol. Prog. Ser.

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On the west coast of British Columbia (BC), Canada, the intertidal is under pressure by commercial farming of the non-native Manila clam Venerupis philippinarum. We applied a 3-tiered approach to determine how farming practices were affecting the geochemical attributes of the intertidal. We compared farmed and reference sites with respect to % silt, organic matter, ammonium, phosphorus, iron and manganese in surface (0 to 3 cm) and bulk (0 to 10 cm) sediments. Ammonium porewater profiles and sediment sorption coefficients were determined for 1 of the 3 regions where the greatest intensity of shellfish farming occurred (Tier I). Mesocosm studies were conducted in which intertidal species were manipulated to match the community composition on the farmed as compared to reference sites (Tier II). Microcosm studies were applied to determine how shifts in community structure as observed on farmed versus reference sites and as manipulated in the mesocosm studies, altered the rate of ammonium diffusion to overlying surface waters (Tier III). All geochemical attributes and ammonium sorption coefficients were greater in either surficial and/or bulk sediments of farmed as compared to reference beaches. Tier III studies indicated that the rate of ammonium diffusion from sediments to surface waters was less in microcosms with only bivalves compared to those with mussels, barnacles and bivalves. Tier I and II studies suggest that greater recovery of ammonium and phosphorus is related to increased bivalve density and % plant coverage on farmed versus reference sites. In contrast, greater amounts of organic matter and silt are due to the presence of antipredator nets. Farming practices that ensure well aerated sediments and support a diverse intertidal community would be advised so that important nutrient geochemical cycles are not altered such to be a detriment to the quality of habitat or to interfere with primary productivity.KEY WORDS: Intertidal · Community composition · Shellfish aquaculture · Nutrients · Organic matter · Nitrogen · Phosphorous · Iron Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 404: [91][92][93][94][95][96][97][98][99][100][101][102][103][104][105][106][107][108] 2010 Given the importance of the intertidal as the interface between terrestrial and oceanic processes, much attention has been given to the behaviour of nutrients within this region with possibly nitrogen being the most well studied of the nutrients required for primary productivity (e.g. Enoksson 1993, Twichell et al. 2002, Hou et al. 2003, Burgin & Hamilton 2007, Fulweiler et al. 2007, Serpa et al. 2007). Perhaps receiving less attention although no less important are iron and phosphorus (reviewed in Newell 2004). A review of the literature suggests that while the geochemical cycling of these elements on the intertidal is complex, amounts of organic matter and hence oxygen availability are key drivers in their geochemical transformations (e.g. Jensen et al. 1995, Gunnars & Blomqv...

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Evaluation of ammonium and phosphate release from intertidal and subtidal sediments of a shallow coastal lagoon (Ria Formosa – Portugal): a modelling approach

Cited by 40 publications

References 42 publications

Build-up and decline of organic matter during PeECE III

Build-up and decline of organic matter during PeECE III

Sediment and waternutrients and microalgae in a coastal shallow lagoon, Ria Formosa (Portugal): Implications for the Water Framework Directive

Changes in geochemical foreshore attributes as a consequence of intertidal shellfish aquaculture: a case study

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