Significance of euphotic sediments to oxygen and nutrient cycling in a temperate estuary

Rizzo, WM; Lackey, GL; Christian, R. R.

doi:10.3354/meps087051

Cited by 39 publications

(51 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Given the high nutrient inputs to Elkhorn Slough, further studies examining the role of benthic Benthic flux and pore water NH 4 + measurements from this study were similar to previous measurements in Elkhorn Slough (Caffrey 1996). SOC and NH 4 + flux from sites in Elkhorn Slough receiving agricultural and other non-point source runoff are among the highest recorded values from the literature (Nixon 1981, Hammond et al 1985, Mackin & Swider 1989, Enoksson et al 1990, Dollar et al 1991, Kamp-Nielsen 1992, Rizzo et al 1992, Upton et al 1993, Banta et al 1995, Lohse et al 1995, Reay et al 1995, Hopkinson et al 1999, Twilley et al 1999, Mortazavi et al 2000. In contrast, benthic fluxes from Vierra mudflat at the well-flushed mouth of Elkhorn Slough were similar to other estuarine and shallow coastal systems.…”

Section: Discussionmentioning

confidence: 88%

“…These factors lead to large differences in nutrient and oxygen status of local environments, which can differ significantly from nearby sites and from the overall average conditions of the estuary. (Caffrey 1996), 7 San Francisco Bay (Hammond et al 1985, 8 Chesapeake Bay , Reay et al 1995, 9 Narragansett Bay (McCaffrey et al 1980, Seitzinger et al 1984, 10 Neuse River (Rizzo et al 1992), 11 North Sea (Upton et al 1993), 12 Bering Sea (Henriksen et al 1993), 13 Parker River (Hopkinson et al 1999), 14 Baltic Sea (Enoksson et al 1990, Jørgensen 1996b, 15 Ochlockonee Bay (Twilley et al 1999), 16 Mobile Bay (Twilley et al 1999), 17 Fourleague Bay (Twilley et al 1999), 18 Trinity-San Jacinto estuary (Twilley et al 1999), 19 Guadeloupe estuary (Twilley et al 1999), 20 Nueces estuary (Twilley et al 1999), 21 Laguna Madre (Twilley et al 1999), 22 Flax Pond (Mackin & Swider 1989) …”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Biogeochemical processes in a small California estuary. 1. Benthic fluxes and pore water constituents reflect high nutrient freshwater inputs

Caffrey¹,

Harrington²,

Ward³

2002

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Elkhorn Slough, a small estuary in central California, receives nutrient inputs from agricultural and other non-point source runoff. To evaluate the effect of nutrient loading on ecosystem processes, rates of sediment oxygen consumption, benthic nutrient fluxes, pore water ammonium (NH 4 + ), dissolved inorganic phosphate (DIP) and sulfide (S 2 -) concentrations were measured at 5 sites several times each year between 1998 and 1999. Two sites near the head of the slough receive direct runoff from agricultural fields, while the sites in the middle reaches and mouth receive direct runoff from grasslands and woodlands. Sites receiving agricultural runoff usually had high water column concentrations of dissolved inorganic nitrogen and chlorophyll a (50 µM and 30 µg l -1 , respectively). High precipitation in the winter of 1998 caused low salinities in the slough at that time. In general, salinity and nutrient concentrations were inversely correlated. Sites receiving agricultural runoff had high pore water NH 4 + , DIP and dissolved S 2 -concentrations, particularly in the summer. Oxygen penetration into sediments was the greatest at the sites adjacent to grasslands and woodlands, and least at the sites receiving high nutrient runoff. Sediment oxygen consumption was 4 times greater at sites near agricultural fields than the site near the mouth, while NH 4 + flux out of sediments was between 4 and 20 times greater at agricultural sites than at non-agricultural sites. This study suggests that high nutrient runoff has primarily a local rather than estuary-wide effect on sediment biogeochemical processes in Elkhorn Slough, perhaps due to longer water residence time at the head of the slough compared to the mouth. KEY WORDS: Estuary · Eutrophication · Nutrients · Oxygen · Elkhorn SloughResale or republication not permitted without written consent of the publisher

show abstract

Section: Discussionmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Biogeochemical processes in a small California estuary. 1. Benthic fluxes and pore water constituents reflect high nutrient freshwater inputs

Caffrey¹,

Harrington²,

Ward³

2002

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…By this method, it is possible to estimate the degree to which the microphytobenthos controls the release of mineralized nitrogen from the sediment to the water column. This filter effect has mainly been recognized when DIN fluxes in light and dark were different (e.g., Nowicki and Nixon 1985;Sundbäck 1986;Sundbäck and Granéli 1988;Rizzo 1990;Sundbäck et al 1991;Rizzo et al 1992;Rysgaard et al 1995), but with this technique, the retention of nitrogen in the sediment can be estimated in both light and dark. From the data presented here, it is evident that estimating denitrification from deviations of the ratio of O 2 flux : NAP or O 2 flux : DIN from the Redfield ratio can be problematic in sediments with an active microphytobenthic community.…”

Section: Discussionmentioning

confidence: 99%

“…The effect of the microphytobenthic community on the nutrient exchange between sediment and water varies between sites as well as diurnally and seasonally (e.g., Nowicki and Nixon 1985;Sundbäck and Granéli 1988;Rizzo 1990;Sundbäck et al 1991;Rysgaard et al 1995;Cowan et al 1996;Sundbäck et al 2000). The microphytobenthic community also affects denitrification in the sediment, and both positive and negative interactions have been found.…”

mentioning

confidence: 99%

Benthic primary production and nutrient cycling in sediments with benthic microalgae and transient accumulation of macroalgae

Dalsgaard¹

2003

Limnology & Oceanography

View full text Add to dashboard Cite

Annual rates of sediment denitrification and sediment-water fluxes of oxygen and nutrients were quantified at two shallow locations, Virksund and Ulbjerg, in the Limfjorden, Denmark. The sediment was sandy and colonized mainly by bivalves with a wet weight of 2,508 g m Ϫ2 at Virksund and 572 g m Ϫ2 at Ulbjerg. A benthic microalgal community was present throughout the year, and for 1-2 months in the summer, floating macroalgae partly covered the sediment. Annual budgets for the sediment both including and excluding the activity of macroalgae were calculated. In the absence of macroalgae, the benthic primary production was highest at Ulbjerg, which was autotrophic on an annual basis, whereas Virksund was heterotrophic. When macroalgae were included, both sites were strongly autotrophic on an annual basis. From 13% to 58% of the NH produced by mineralization was retained ϩ 4 in the sediment in the absence of macroalgae, primarily because of the assimilation of NH by the microphytobenthic ϩ 4 community. Only 25% and 38% of the total NO uptake at Ulbjerg and Virksund, respectively, was denitrified inthe absence of macroalgae, whereas in the presence of macroalgae, 12% and 39% of the NO uptake was denitrified Ϫ 3 at those sites. Nitrate uptake associated with benthic primary production limited denitrification through competition for NO . The release of NH from the sediment at Virksund was reduced more than 50%, and at Ulbjerg, releaseof NH changed to uptake when the macroalgae were included in the annual budget. Nutrient uptake by macroalgaecompeted with all other nutrient-consuming processes, and the transient occurrence of macroalgae totally changed both the primary productivity and the nutrient budgets for the two sites.In the marine environment, primary production is remineralized both in the water column and in the sediment, and the relative importance of these two compartments depends very much on the water depth. In Chesapeake Bay, for instance, it was found that at water depths of Ͻ5 m, the benthic respiration exceeded the planktonic respiration (Rowe et al. 1975;Kemp et al. 1992). The nutrients that are produced by degradation of organic matter in the sediment can be transported back to the photic zone where it can fuel new primary production (Rowe et al. 1975). The relative importance of this supply of nutrients, the so-called internal loading, compared to the external loading has been found to vary substantially. In a study in the Chesapeake Bay, release of remineralized ammonia from the sediment could account for between 13% and 40% of the photosynthetic nitrogen demand in the water column (Boynton and Kemp 1985), and in the Neuse River estuary, the internal loading of dissolved inorganic nitrogen (DIN) contributed 13% to 21% of the total DIN input to the water column. A compilation of data from 10 different estuaries demonstrated an even more var-1 Corresponding author (tda@dmu.dk). AcknowledgmentsKitte Gerlich Lauridsen, Marlene Venø Skjaerbaek, Egon Frandsen, and Tanja Quottrup are acknowledged ...

show abstract

“…The microphytobenthos is presumed to be important in stabilising sediments (de Brouwer et al 2003) and in controlling nutrient fluxes directly at the sediment/water interface through nutrient uptake , Rizzo et al 1992, Wiltshire 1992. Moreover, oxygenation of the sediment surface layers by photosynthetic activity leads to indirect geochemical fixation of nutrients and heavy metals (Koop et al 1990, Nielsen et al 1990).…”

Section: Introductionmentioning

confidence: 99%

Microphytobenthic primary production in the Bodden estuaries, southern Baltic Sea, at two study sites differing in trophic status

Gerbersdorf¹,

Meyercordt²,

Meyer‐Reil³

2005

Aquat. Microb. Ecol.

View full text Add to dashboard Cite

Eutrophication in coastal areas has stimulated phytoplankton growth, sustaining a high biomass and leading to a shift in the underwater light field. With the significance of the microphytobenthos for oxygen supply and carbon budget of both benthic and pelagic habitats in mind, the possible effects of reduced light availability were investigated in the estuarine Bodden area (southern Baltic Sea) at 2 sites differing in trophic status -the eutrophic Kirr Bucht (KB) and the mesotrophic Rassower Strom (RS). Using for the first time microsensors in Bodden sediments, it was possible to visualize small-scale heterogeneity in the light regime, photosynthetic activity and oxygen penetration with high spatial and temporal resolution. Hence, differences at the 2 sites related to sediment characteristics (KB sandy, RS muddy), and photoautotrophic biomass (benthic chlorophyll a in the upper 1 cm, µg cm -3 = 11 to 48 at KB and 13 to 17 at RS) could be ruled out. Calculations of benthic primary production based solely on microelectrode measurements revealed substantial oxygen fluxes and carbon fixation rates at in situ light intensities at both study sites (e.g. gross primary production, GPP, mg C m -2 h -1 = 28 to 80 at KB and 3 to 36 at RS). The different combinations of water transparency (pelagic chlorophyll a, µg l -1 = 12 to 33 at KB and 1.3 to 4.5 at RS), light attenuation k (3.17 m -1 at KB, 0.61 m -1 at RS) and water depth (0.6 m at KB, 3.4 m at RA) have led to a similar light availability for benthic algae on the sediment surface at both study sites. Consequently, the benthic algae had comparable productivity at both sites, with maximum primary production, P B max (mg C mg -1 chlorophyll a h -1 ) of 0.29 to 1.46 at KB and 0.17 to 1.63 at RS; and were adapted to rather low light conditions, with light saturation, E k (µE m -2 s -1 ) of 22 to 152 at KB and 10 to 116 at RS). Varying with season, microphytobenthic photosynthetic activity accounted for 26 to 59 and 2 to 53% to the total primary production at the KB and RS, respectively, with the highest contribution in spring coincident with the most favourable light conditions at the sediment surface. With an annual average of about 37 and 30% (KB and RS, respectively), the contribution of the microphytobenthos to total production was significant and comparable at both study sites. Nevertheless, the higher trophic status at KB resulted in a change in the benthic microalgal community towards sedimentated phytoplankton species and had a negative impact on microphytobenthic primary production rates. This was estimated by calculating the gross primary production for varying water depths on the basis of the different water transparency at the 2 sites.

show abstract

Significance of euphotic sediments to oxygen and nutrient cycling in a temperate estuary

Cited by 39 publications

References 0 publications

Biogeochemical processes in a small California estuary. 1. Benthic fluxes and pore water constituents reflect high nutrient freshwater inputs

Biogeochemical processes in a small California estuary. 1. Benthic fluxes and pore water constituents reflect high nutrient freshwater inputs

Benthic primary production and nutrient cycling in sediments with benthic microalgae and transient accumulation of macroalgae

Microphytobenthic primary production in the Bodden estuaries, southern Baltic Sea, at two study sites differing in trophic status

Contact Info

Product

Resources

About