Periphyton of Freshwater Ecosystems

Wetzel, Robert G.

doi:10.1007/978-94-009-7293-3

Cited by 99 publications

(3 citation statements)

References 182 publications

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“…In all equations, y = arcsine square root of the proportional contribution of N 2 fixers PAR. However, light attenuates quickly in benthic algal mats (Dodds, Biggs, & Lowe, 1999;Losee & Wetzel, 1983). As a higher light supply penetrates deeper into the mat, more algal biomass can accrue with increasing light supply even if the top layer of the mat is light saturated (Revsbech, Jørgensen, & Blackburn, 1983;Revsbech, Nielsen, & Hansen, 1988).…”

Section: Correlation Versus Causation In Relationships With Tpmentioning

confidence: 99%

Inverse relationship of epilithic algae and pelagic phosphorus in unproductive lakes: Roles of N₂ fixers and light

et al. 2018

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Phosphorus (P) often limits the biomass of primary producers in freshwater lakes. However, in unproductive northern lakes, where anthropogenic nitrogen (N) deposition is low, N instead of P can limit primary producers. In addition, light can be limiting to primary producers at high concentrations of coloured dissolved organic matter (cDOM), as cDOM is the major determinant of light penetration in these lakes. To address resource limitation of epilithic algal biomass, we repeatedly sampled epilithon (periphyton on stony substrata) in 20 lakes covering a large, correlated cDOM and N‐deposition gradient across boreal and subarctic Sweden. Across these lakes, pelagic total N (TN) and total P (TP) were positively correlated, and benthic light supply was negatively correlated, with cDOM. Microscopically determined algal biovolume and epilithic carbon (C), N and P were subsequently regressed against benthic light supply and pelagic TN and TP. Patterns in epilithic biovolume were driven by N2‐fixing cyanobacteria, which accounted for 2%–90% of total epilithic biovolume. Averaged over the growing season, epilithic algal biovolume, C and N were negatively related to TP and positively to TN, and were highest in the clearest, most phosphorus‐poor lakes, where epilithon was heavily dominated by potentially N2‐fixing cyanobacteria. A structural equation model supports the hypothesis that cDOM had two counteracting effects on total epilithic algal biovolume: a positive one by providing N to algae that depend on dissolved N for growth, and a negative one by shading N2‐fixing cyanobacteria, with the negative effect being somewhat stronger. Together, these findings suggest that (1) light and N are the main resources limiting epilithic algal biomass in boreal to subarctic Swedish lakes, (2) epilithic cyanobacteria are more competitive in high‐light and low‐nitrogen environments, where their N2‐fixing ability allows them to reach high biomass, and (3) epilithic N increases with N2 fixer biomass and is—seemingly paradoxically—highest in the most oligotrophic lakes.

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Section: Correlation Versus Causation In Relationships With Tpmentioning

confidence: 99%

Inverse relationship of epilithic algae and pelagic phosphorus in unproductive lakes: Roles of N₂ fixers and light

et al. 2018

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“…In numerous aquatic ecosystems, a large proportion of primary production is ensured by phototrophic biofilms. These biofilms are composed of attached communities generally dominated by microalgae, and containing different amounts of bacteria, fungi, and micro-eukaryotic species embedded in an organic polysaccharidic matrix (Wetzel, 1983). As a central basal resource, these biofilms play a fundamental role in aquatic food webs (Wetzel, 1983).…”

Section: Introductionmentioning

confidence: 99%

“…These biofilms are composed of attached communities generally dominated by microalgae, and containing different amounts of bacteria, fungi, and micro-eukaryotic species embedded in an organic polysaccharidic matrix (Wetzel, 1983). As a central basal resource, these biofilms play a fundamental role in aquatic food webs (Wetzel, 1983). These biofilms also have large impacts on aquatic biogeochemical cycles, ensuring the production, the decomposition, and the transfer of numerous organic molecules (Battin et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Interactive Impacts of Silver and Phosphorus on Autotrophic Biofilm Elemental and Biochemical Quality for a Macroinvertebrate Consumer

et al. 2019

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Autotrophic biofilms are complex and fundamental biological compartments of many aquatic ecosystems. In particular, these biofilms represent a major resource for many invertebrate consumers and the first ecological barrier against toxic metals. To date, very few studies have investigated the indirect effects of stressors on upper trophic levels through alterations of the quality of biofilms for their consumers. In a laboratory study, we investigated the single and combined effects of phosphorus (P) availability and silver, a re-emerging contaminant, on the elemental [carbon (C):nitrogen (N):P ratios] and biochemical (fatty acid profiles) compositions of a diatom-dominated biofilm initially collected in a shallow lake. We hypothesized that (1) P and silver, through the replacement of diatoms by more tolerant primary producer species, reduce the biochemical quality of biofilms for their consumers while (2) P enhances biofilm elemental quality and (3) silver contamination of biofilm has negative effects on consumers life history traits. The quality of biofilms for consumers was assessed for a common crustacean species, Gammarus fossarum , by measuring organisms’ survival and growth rates during a 42-days feeding experiment. Results mainly showed that species replacement induced by both stressors affected biofilm fatty acid compositions, and that P immobilization permitted to achieve low C:P biofilms, whatever the level of silver contamination. Gammarids growth and survival rates were not significantly impacted by the ingestion of silver-contaminated resource. On the contrary, we found a significant positive relationship between the biofilm P-content and gammarids growth. This study underlines the large indirect consequences stressors could play on the quality of microbial biomass for consumers, and, in turn, on the whole food web.

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Influence of a chlor‐alkali superfund site on mercury bioaccumulation in periphyton and low‐trophic level fauna

Buckman

Marvin-DiPasquale

Taylor

et al. 2015

Enviro Toxic and Chemistry

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In Berlin, NH, the Androscoggin River flows adjacent to a former chlor-alkali facility that is a US EPA Superfund site and source of mercury (Hg) to the river. A study was conducted to determine the fate and bioaccumulation of methylmercury (MeHg) to lower trophic-level taxa in the river. Surface sediment directly adjacent to the source showed significantly elevated MeHg (10–40x increase, mean±sd: 20.1±24.8 ng g−1 DW) and total mercury (THg, 10–30x increase, mean±sd: 2045±2669 ng g−1 DW) compared to all other reaches, with sediment THg and MeHg from downstream reaches elevated (3–7x on average) relative to the reference (THg mean±sd: 33.5±9.33 ng g−1 DW; MeHg mean±sd: 0.52±0.21 ng g−1 DW). Water column THg concentrations adjacent to the point source for both particulate (0.23 ng L−1) and dissolved (0.76 ng L−1) fractions were 5-fold higher than at the reference sites, and 2–5-fold higher than downstream. Methylmercury production potential (MPP) of periphyton material was highest (2–9 ng g−1 d−1 DW) adjacent to the Superfund site; other reaches were close to or below reporting limits (0. 1 ng g−1 d−1 DW). Total Hg and MeHg bioaccumulation in fauna was variable across sites and taxa, with no clear spatial patterns downstream of the contamination source. Crayfish, mayflies and shiners showed a weak positive relationship with porewater MeHg concentration.

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Periphyton of Freshwater Ecosystems

Cited by 99 publications

References 182 publications

Inverse relationship of epilithic algae and pelagic phosphorus in unproductive lakes: Roles of N₂ fixers and light

Inverse relationship of epilithic algae and pelagic phosphorus in unproductive lakes: Roles of N₂ fixers and light

Interactive Impacts of Silver and Phosphorus on Autotrophic Biofilm Elemental and Biochemical Quality for a Macroinvertebrate Consumer

Influence of a chlor‐alkali superfund site on mercury bioaccumulation in periphyton and low‐trophic level fauna

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Periphyton of Freshwater Ecosystems

Cited by 99 publications

References 182 publications

Inverse relationship of epilithic algae and pelagic phosphorus in unproductive lakes: Roles of N2 fixers and light

Inverse relationship of epilithic algae and pelagic phosphorus in unproductive lakes: Roles of N2 fixers and light

Interactive Impacts of Silver and Phosphorus on Autotrophic Biofilm Elemental and Biochemical Quality for a Macroinvertebrate Consumer

Influence of a chlor‐alkali superfund site on mercury bioaccumulation in periphyton and low‐trophic level fauna

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Inverse relationship of epilithic algae and pelagic phosphorus in unproductive lakes: Roles of N₂ fixers and light

Inverse relationship of epilithic algae and pelagic phosphorus in unproductive lakes: Roles of N₂ fixers and light