Effects of grazer and substrate amendments on nutrient and plankton dynamics in estuarine enclosures

Miller, Christopher A.; Glibert, Patricia M.; Gm, Berg; Mr, Mulholland

doi:10.3354/ame012251

Cited by 13 publications

(18 citation statements)

References 20 publications

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“…Aureococcus anophagefferens can grow efficiently on urea in culture (Dzurica et al 1989), and it has been reported that most of the N assimilated by blooms is from urea (Berg et al 1997). However, the failure of urea additions to increase the relative abundance of A. anophagefferens among phytoplankton in 9 of 10 experiments (Figs.…”

Section: Nitrogenmentioning

confidence: 81%

“…It has been proposed that inorganic N inputs can repress the formation of brown tides (Keller & Rice 1989, LaRoche et al 1997, while organic N inputs stimulate them (LaRoche et al 1997), and that urea is the organic N compound most important for sustaining Aureococcus anophagefferens blooms (Berg et al 1997). The decrease in relative abundance of A. anophagefferens among phytoplankton in our N-addition treatments when ambient nitrate levels were relatively high (average > 7 µM; 31 May, 4, 8, 12, 22 June) supports the hypothesis that eutrophic conditions (>10 µM labile N) do not favor the initiation of monospecific brown tides (Keller & Rice 1989, Nixon et al 1994, LaRoche et al 1997).…”

Section: Nitrogenmentioning

confidence: 99%

“…Annual recurrence of brown tides on Long Island have led to the collapse of the scallop fishery (Argopecten irradians irradians; Bricelj & Kuenstner 1989), and have decimated eelgrass beds . While multiple factors have been implicated as potential bloom initiators (reviewed by Bricelj & Lonsdale 1997), nutrients have been most frequently cited (Cosper et al 1987, 1989, 1993, Dzurica et al 1989, Keller & Rice 1989, Smayda & Villareal 1989, Milligan 1992, Nixon et al 1994, Gobler & Cosper 1996, Berg et al 1997, LaRoche et al 1997, Breuer et al 1999. To date, a consensus as to which nutrient(s) control A. anophagefferens growth in the field does not exist, as inorganic nitrogen (Nixon et al 1994, LaRoche et al 1997, dissolved organic carbon (DOC) (Dzurica et al 1989, Milligan & Cosper 1997, Breuer et al 1999, dissolved organic nitrogen (DON) (Dzurica et al 1989, Berg et al 1997, LaRoche et al 1997, urea (Dzurica et al 1989, Berg et al 1997) and iron (Milligan 1992, Cosper et al 1993, Gobler & Cosper 1996 have all been hypothesized to influence initiation of brown tides.…”

Section: Introductionmentioning

confidence: 99%

“…Aureococcus anophagefferens is capable of efficiently taking up several organic nitrogen compounds in laboratory cultures (Dzurica et al 1989) and during bloom events (Berg et al 1997). In the Peconic Estuary of Long Island, brown tides commonly occur in drought years when inputs of nitrate-rich groundwater are greatly reduced (LaRoche et al 1997).…”

Section: Introductionmentioning

confidence: 99%

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Effects of organic carbon, organic nitrogen, inorganic nutrients, and iron additions on the growth of phytoplankton and bacteria during a brown tide bloom

Gobler

Sañudo‐Wilhelmy²

2001

Mar. Ecol. Prog. Ser.

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Although nutrient inputs are the most commonly cited cause of brown tide blooms of Aureococcus anophagefferens on Long Island, New York, there is no consensus as to which nutrient(s) stimulates A. anophagefferens growth in the field. To evaluate the ability of dissolved organic carbon (DOC as glucose), dissolved organic nitrogen (DON as urea), nitrate, phosphate and iron to enhance A. anophagefferens growth during blooms, 10 nutrient enrichment experiments were conducted over the course of a brown-tide bloom during May, June and July of 1998 in West Neck Bay (WNB), Long Island, USA, using whole bay water. During the experiments, A. anophagefferens densities ranged from 1 × 10 4 to 5 × 10 5 cells ml -1, representing between 2 and 90% of algal biomass. Brown tide growth changed as a function of ambient nutrient levels during experiments, as the bloom shifted from organic carbon to N-limitation when nitrate levels in WNB decreased from elevated (2 to 20 µM) to low (< 0.5 µM) levels. Contrary to current hypotheses that organic nitrogen fuels A. anophagefferens bloom formation and inorganic nitrogen can repress it, brown tide growth in response to equimolar nitrate and urea additions was nearly identical during experiments. Additions of nitrate or urea either had no effect or significantly decreased the relative abundance of the brown tide among the algal community during experiments. In contrast, augmentation of A. anophagefferens growth and decreases in non-brown-tide phytoplankton (NBTP) growth during organic carbon (glucose) additions resulted in significant increases in the relative abundance of brown tide among phytoplankton. Simultaneous enhancement of bacterial growth by glucose additions indicated a possible A. anophagefferens-NBTPbacterial interaction by which monospecific brown tides may be initiated. Therefore, it is hypothesized that processes introducing copious amounts of labile DOC during A. anophagefferens blooms, such as leakage or remineralization of NBTP blooms, could promote monospecific brown tides.

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Section: Nitrogenmentioning

confidence: 81%

Section: Nitrogenmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of organic carbon, organic nitrogen, inorganic nutrients, and iron additions on the growth of phytoplankton and bacteria during a brown tide bloom

Gobler

Sañudo‐Wilhelmy²

2001

Mar. Ecol. Prog. Ser.

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“…As the cells degraded, the release of organic matter presumably stimulated microbial activity, as has been observed following the addition of glucose or arginine during phytoplankton growth and decay experiments with Chesapeake Bay waters (Miller et al 1997 (Stumm and Morgan 1996). In studies in which fulvic acid was added to inorganic particles, creation of an organic coating enhanced Hg(II) sorption (Xu and Allard 1991;Gagnon and Fisher 1997).…”

Section: Discussionmentioning

confidence: 99%

Role of phytoplankton in mercury cycling in the San Francisco Bay estuary

Luengen

Flegal

2009

Limnol. Oceanogr.

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To study the role of phytoplankton in mercury cycling, we measured methylmercury (MeHg) and total mercury (Hg T ) in surface waters during the spring 2003 phytoplankton bloom in San Francisco Bay. Conditions that described the peak of the bloom, the amount of sorbent, and decay of the bloom were summarized by principal component analysis (PCA). Multivariate analyses conducted with the PCA factors demonstrated that the bloom accounted for a significant (p 5 0.03) decrease in dissolved (,0.45 mm) MeHg. Dissolved MeHg was depleted to 0.026 pmol L 21 and was unaffected when chlorophyll a concentrations nearly tripled, indicating that bloom dilution could occur as a result of a limited amount of MeHg. The calculated algal MeHg concentration was 3-10 pmol g 21 (dry weight). As the bloom decayed, dissolved MeHg concentrations significantly (p 5 0.04) increased, likely due to MeHg remineralization from decaying phytoplankton and/or production in sediments. By creating suboxic conditions in surface sediments and stimulating microbial activity, decomposing phytoplankton could bolster MeHg production, a potential side effect of large blooms. Unlike dissolved MeHg, dissolved Hg T concentrations were not measurably altered by the bloom or decay factors. That difference corroborated previous culture studies in which phytoplankton actively accumulated MeHg, but not Hg T . As the bloom decayed, Hg T K d values significantly (p 5 0.012) increased, possibly because particles (i.e., phytoplankton) with low Hg T concentrations were lost from the water column. Based on the relationship between Hg T particulate concentrations and percent phytoplankton, the calculated algal Hg T concentration was ,0.5 nmol g 21 (dry weight).

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Nitrogen excretion by copepods and its effect on ammonia‐oxidizing communities from a coastal upwelling zone

Valdés

Fernández

Molina

et al. 2017

Limnology & Oceanography

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The role of zooplankton in microbial nitrogen turnover in marine environments is poorly understood. Here, we present results from two experiments designed to determine the excretion rate of ammonium and dissolved organic nitrogen (DON) by dominant copepods, Acartia tonsa and Paracalanus cf indicus, fed with two natural sized-fractioned diets (20-150 lm and < 20 lm), and its possible effects on the transcriptional activity of ammonia monooxygenase subunit A (amoA), a functional marker for ammonia-oxidizing archaea (AOA) and bacteria (AOB), as a response to the input of ammonium and DON by copepod excretion, during autumn and winter in central/southern Chile. Our results reveal that DON was the main excretion product, with rates up to 3.7 lmol L 21 h 21 . DON production increased in copepods fed with the small-sized food.Ammonium was also excreted, with rates up to 0.08 lmol L 21 h 21 in autumn and 0.4 lmol L 21 h 21 in winter, and rapidly consumed by the microbial community, decreasing down to 0.07 lmol L 21 between the initial time to 4 h. Ammonium consumption coincided with increased AOB and AOA amoA transcript copies in copepods fed with the larger-sized food, while a different microbial community, probably heterotrophic, reacted to nitrogen input via excretion by copepods fed with the smaller-sized food in autumn. AOA-A was transcriptionally active in winter with nearly zero ammonium concentration, suggesting that AOA outcompete AOB when ammonium becomes limited. We conclude that nitrogen excreted by copepods can be used directly by microbial communities, including nitrifying ones. Zooplankton excretion may thus provide significant remineralized nitrogen for new and regenerated production in the upper ocean.

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Effects of grazer and substrate amendments on nutrient and plankton dynamics in estuarine enclosures

Cited by 13 publications

References 20 publications

Effects of organic carbon, organic nitrogen, inorganic nutrients, and iron additions on the growth of phytoplankton and bacteria during a brown tide bloom

Effects of organic carbon, organic nitrogen, inorganic nutrients, and iron additions on the growth of phytoplankton and bacteria during a brown tide bloom

Role of phytoplankton in mercury cycling in the San Francisco Bay estuary

Nitrogen excretion by copepods and its effect on ammonia‐oxidizing communities from a coastal upwelling zone

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