Assessment of stable nitrogen isotopes in fingerprinting surface water inorganic nitrogen sources

Lindau, C. W.; DeLaune, Ronald D.; Patrick, W. H.; Lambremont, Edward N.

doi:10.1007/bf00283346

Cited by 28 publications

(14 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Impacts of anthropogenic nutrient inputs were further confirmed by the enriched δ 15 N signatures found in the sediment and macroalgae in the nearshore sites (Lindau et al, 1989). Wastewater is generally enriched in 15 N, from 10 to 20‰, compared to other N sources (Heaton, 1986).…”

Section: Evidence Of a Cross-shelf Gradient Of Water Quality In Spermmentioning

confidence: 77%

Spatio-Temporal Patterns in Coral Reef Communities of the Spermonde Archipelago, 2012–2014, I: Comprehensive Reef Monitoring of Water and Benthic Indicators Reflect Changes in Reef Health

et al. 2018

View full text Add to dashboard Cite

Pollution, fishing, and outbreaks of predators can heavily impact coastal coral reef ecosystems, leading to decreased water quality and benthic community shifts. To determine the main environmental drivers of coral reef status in the Spermonde Archipelago, Indonesia, we monitored environmental variables and coral reef benthic community structure along an on-to-offshore gradient annually from 2012 to 2014. Findings revealed that concentrations of phosphate, chlorophyll a-like fluorescence, suspended particulate matter, and light attenuation significantly decreased from on-to-offshore, while concentrations of dissolved O 2 and values of water pH significantly increased on-to-offshore. Nitrogen stable isotope signatures of sediment and an exemplary common brown alga were significantly enriched nearshore, identifying wastewater input from the city of Makassar as primary N source. In contrast to the high temporal variability in water quality, coral reef benthic community cover did not show strong temporal, but rather, spatial patterns. Turf algae was the dominant group next to live coral, and was negatively correlated to live coral, crustose coralline algae (CCA), rubble and hard substrate. Variation in benthic cover along the gradient was explained by water quality variables linked to trophic status and physico-chemical variables. As an integrated measure of reef status and structural complexity, the benthic index, based on the ratio of relative cover of live coral and CCA to other coral reef organisms, and reef rugosity were determined. The benthic index was consistently low nearshore and increased offshore, with high variability in the midshelf sites across years. Reef rugosity was also lowest nearshore and increased further offshore. Both indices dropped in 2013, increasing again in 2014, indicating a period of acute disturbance and recovery within the study and suggesting that the mid-shelf reefs are more resilient to disturbance than nearshore reefs. We thus recommend using these two indices with a selected number of environmental variables as an integral part of future reef monitoring.

show abstract

Section: Evidence Of a Cross-shelf Gradient Of Water Quality In Spermmentioning

confidence: 77%

Spatio-Temporal Patterns in Coral Reef Communities of the Spermonde Archipelago, 2012–2014, I: Comprehensive Reef Monitoring of Water and Benthic Indicators Reflect Changes in Reef Health

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The major sources of N enrichment to surface waters and groundwaters in southeast Florida include atmospheric deposition, nitrogenous fertilizers, and human and animal wastes, all which have distinguishable 615N values. Groundwater influenced only by atmospheric deposition typically has 61sN values ranging from +2 to + 8%0 (McClelland et al in press); that derived from human or animal wastes is more enriched in '"N, bearing S15N values >+ 10%0 (Lindau et al 1989). N from fertilizers is depleted in lsN, having 6"N values between -3 and +3%0 (Fryer and Aly 1974).…”

Section: Discussionmentioning

confidence: 99%

Nutrient thresholds for bottom‐up control of macroalgal blooms on coral reefs in Jamaica and southeast Florida

Lapointe

1997

Limnology & Oceanography

578

487

View full text Add to dashboard Cite

During the past two decades coral reefs in the greater Caribbean area have been altered by phase shifts away from corals and toward macroalgae or algal turfs. This study tested the hypothesis that because the phase shift on reefs in Jamaica and southeast Florida involved frondose macroalgae, bottom-up control via nutrient enrichment must be a causal factor. The approach was multifaceted and included measurement of near-bottom nutrient concentrations, salinity, nutrient enrichment bioassays, alkaline phosphatase assays, tissue C : N : P ratios, and tissue 15N : 14N (6"N) ratios. In both locations, concentrations of dissolved inorganic nitrogen (DIN) and soluble reactive phosphorus (SRP) exceeded nutrient thresholds (-1 .O PM DIN, 0.1 PM SRP) noted to sustain macroalgal blooms on Caribbean coral reefs. High seawater DIN : SRP ratios, alkaline phosphatase activity, and tissue C : P and N : P ratios of macroalgae on the carbonate-rich Jamaican reef suggested SRP limitation of productivity compared to lower values of these variables on siliciclastic reefs in Florida that suggested DIN limitation. This pattern was corroborated experimentally when SRP enrichment increased P,,,, (photosynthetic capacity at light saturation) of the chlorophyte Chaetomorpha Zinum in Jamaica compared to DIN enrichment that increased (x (the photosynthetic efficiency under low irradiance) of the deeper growing chlorophyte Codium isthmocladum in southeast Florida. Increased DIN concentrations were associated with reduced salinity on both reefs, indicating submarine groundwatcr discharge was a significant source of DIN. Elevated S15N values of C. isthmocladum tissue further pointed to wastewater DIN as a source of nitrogen contributing to the blooms in southeast Florida.

show abstract

“…Enrichment of 15 N in aquatic systems can result from N transformations occurring prior to, during, or after the treatment and discharge of sewage. Volatilization of ammonia and isotopic fractionation by microbes during nitrification and denitrification produce residual DIN with elevated d 15 N values of +6 to +22% (Heaton, 1986;Lindau et al, 1989). This range includes secondarily treated discharges from sewage outfalls (Hoch et al, 1995; Table 1), as well as shallow (<10 m) groundwaters contaminated by septic tanks in southern Florida (Lapointe and Krupa, 1995a,b; Table 1).…”

Section: Introductionmentioning

confidence: 95%

Drift rhodophyte blooms emerge in Lee County, Florida, USA: Evidence of escalating coastal eutrophication

Lapointe

Bedford

2007

Harmful Algae

View full text Add to dashboard Cite

Assessment of stable nitrogen isotopes in fingerprinting surface water inorganic nitrogen sources

Cited by 28 publications

References 12 publications

Spatio-Temporal Patterns in Coral Reef Communities of the Spermonde Archipelago, 2012–2014, I: Comprehensive Reef Monitoring of Water and Benthic Indicators Reflect Changes in Reef Health

Spatio-Temporal Patterns in Coral Reef Communities of the Spermonde Archipelago, 2012–2014, I: Comprehensive Reef Monitoring of Water and Benthic Indicators Reflect Changes in Reef Health

Nutrient thresholds for bottom‐up control of macroalgal blooms on coral reefs in Jamaica and southeast Florida

Drift rhodophyte blooms emerge in Lee County, Florida, USA: Evidence of escalating coastal eutrophication

Contact Info

Product

Resources

About