Nutrient Loading Fosters Seagrass Productivity Under Ocean Acidification

Ravaglioli, Chiara; Lauritano, Chiara; Buia, María Cristina; Balestri, Elena; Capocchi, Antonella; Fontanini, Debora; Pardi, G.; Tamburello, Laura; Procaccini, Gabriele; Bulleri, Fabio

doi:10.1038/s41598-017-14075-8

Cited by 35 publications

(27 citation statements)

References 80 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our results indicate that OA predicted by the end of this century could trigger OM degradation in seagrass sediments, reducing their carbon storage capacity and enhancing CO 2 release. Although seagrass productivity is generally expected to increase in response to low pH, under nutrient concentration unlikely to cause N‐limitation (Stitt and Krapp ; Alexandre et al ; Russell et al ; Sunday et al ; Ravaglioli et al ), our study highlights the need of assessing belowground processes to understand the mechanisms underpinning the net carbon budget in seagrass meadows.…”

Section: Discussionmentioning

confidence: 88%

“…Coastal eutrophication is one of the major drivers of seagrass loss, either resulting in nitrogen toxicity for plants or reduced light availability on leaves due to epiphyte overgrowth (Ralph et al ; Burkholder et al ; Marbà et al ). More recently, global‐scale stressors, such us seawater warming, ocean acidification (OA), and extreme events, have been shown to impair plant production and contribute to the decline and degradation of seagrasses (Marba and Duarte ; Jordà et al ; Ravaglioli et al ; Arias‐Ortiz et al ; Chefaoui et al ). As seagrass meadows are key for organic carbon sequestration, their decline is raising concerns over the potential release in the atmosphere, as CO 2 , of large amounts of the carbon immobilized by the belowground compartment, potentially exacerbating climate changes (Fourqurean et al ; Pendleton et al ).…”

mentioning

confidence: 99%

“…Anthropogenic OA, resulting from the global enhancement of CO 2 emission, is one of the greatest threats to coastal habitats (IPCC ). Although the responses of seagrasses and the associated epiphytic communities to low pH have been thoroughly assessed (Hall‐Spencer et al ; Martin et al ; Campbell and Fourqurean ; Cox et al ; Guilini et al ; Ravaglioli et al ), there is a dearth of studies dealing with the impacts of OA on meiofauna that inhabit seagrass sediments. This abundant and high diverse group of small invertebrates (< 1 mm) plays key ecological roles in marine sediments, contributing to energy transfer to higher trophic levels (Schratzberger and Ingels ) and increasing OM remineralization, through the stimulation of microbial activities (Nascimento et al ; Bonaglia et al ; Lacoste et al ).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Ocean acidification alters meiobenthic assemblage composition and organic matter degradation rates in seagrass sediments

Ravaglioli

Lardicci

Pusceddu

et al. 2019

Limnology & Oceanography

Self Cite

View full text Add to dashboard Cite

Seagrass meadows are an important organic matter (OM) reservoir but, are currently being lost due to global and regional stressors. Yet, there is limited research investigating the cumulative impacts of anthropogenic stressors on the structure and functioning of seagrass benthic assemblages, key drivers of OM mineralization and burial. Here, using a 16‐month field experiment, we assessed how meiobenthic assemblages and extracellular enzymatic activities (as a proxy of OM degradation) in Posidonia oceanica sediments responded to ocean acidification (OA) and nutrient loadings, at CO2 vents. P. oceanica meadows were exposed to three nutrient levels (control, moderate, and high) at both ambient and low pH sites. OA altered meiobenthic assemblage structure, resulting in increased abundance of annelids and crustaceans, along with a decline in foraminifera. In addition, low pH enhanced OM degradation rates in seagrass sediments by enhancing extracellular enzymatic activities, potentially decreasing the sediment carbon storage capacity of seagrasses. Nutrient enrichment had no effect on the response variables analyzed, suggesting that, under nutrient concentration unlikely to cause N or P imitation, a moderate increase of dissolved nutrients in the water column had limited influence on meiobenthic assemblages. These findings show that OA can significantly alter meiobenthic assemblage structure and enhance OM degradation rates in seagrass sediments. As meiofauna are ubiquitous key actors in the functioning of benthic ecosystems, we postulated that OA, altering the structure of meiobenthic assemblages and OM degradation, could affect organic carbon sequestration over large spatial scales.

show abstract

Section: Discussionmentioning

confidence: 88%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Ocean acidification alters meiobenthic assemblage composition and organic matter degradation rates in seagrass sediments

Ravaglioli

Lardicci

Pusceddu

et al. 2019

Limnology & Oceanography

Self Cite

View full text Add to dashboard Cite

show abstract

“…Interestingly, long-term nutrient enrichment seems to modulate the effects of ocean acidification on P. oceanica . Molecular analysis indicates that after 18 months at low pH (7.78) conditions the expression of nitrate transporter genes in P. oceanica leaves is altered; while NRT1_6.3 and NRT1_2.13 (involved in

sensing and low-affinity transport, respectively) are overexpressed the high-affinity

transporter gene NRT2 shows a down-regulated expression ( Ravaglioli et al., 2017 ). Thus, long-term overexpression of nitrogen transporter genes following nutrient additions at low pH suggests enhanced nutrient uptake and proposes that the effects of ocean acidification on P. oceanica depend upon local nutrient concentration ( Ravaglioli et al., 2017 ).…”

Section: Discussionmentioning

confidence: 99%

Short-Term Response of Cytosolic NO3− to Inorganic Carbon Increase in Posidonia oceanica Leaf Cells

et al. 2020

View full text Add to dashboard Cite

The concentration of CO 2 in the atmosphere has increased over the past 200 years and is expected to continue rising in the next 50 years at a rate of 3 ppm•year −1. This increase has led to a decrease in seawater pH that has changed inorganic carbon chemical speciation, increasing the dissolved HCO − 3. Posidonia oceanica is a marine angiosperm that uses HCO − 3 as an inorganic carbon source for photosynthesis. An important side effect of the direct uptake of HCO − 3 is the diminution of cytosolic Cl − (Cl − c) in mesophyll leaf cells due to the efflux through anion channels and, probably, to intracellular compartmentalization. Since anion channels are also permeable to NO − 3 we hypothesize that high HCO − 3 , or even CO 2 , would also promote a decrease of cytosolic NO − 3 (NO − 3 c). In this work we have used NO − 3-and Cl −-selective microelectrodes for the continuous monitoring of the cytosolic concentration of both anions in P. oceanica leaf cells. Under light conditions, mesophyll leaf cells showed a NO − 3 c of 5.7 ± 0.2 mM, which rose up to 7.2 ± 0.6 mM after 30 min in the dark. The enrichment of natural seawater (NSW) with 3 mM NaHCO 3 caused both a NO − 3 c decrease of 1 ± 0.04 mM and a Cl − c decrease of 3.5 ± 0.1 mM. The saturation of NSW with 1000 ppm CO 2 also produced a diminution of the NO − 3 c, but lower (0.4 ± 0.07 mM). These results indicate that the rise of dissolved inorganic carbon (HCO − 3 or CO 2) in NSW would have an effect on the cytosolic anion homeostasis mechanisms in P. oceanica leaf cells. In the presence of 0.1 mM ethoxyzolamide, the plasma membrane-permeable carbonic anhydrase inhibitor, the CO 2-induced cytosolic NO − 3 diminution was much lower (0.1 ± 0.08 mM), pointing to HCO − 3 as the inorganic carbon species that causes the cytosolic NO − 3 leak. The incubation of P. oceanica leaf pieces in 3 mM HCO − 3-enriched NSW triggered a shortterm external NO − 3 net concentration increase consistent with the NO − 3 c leak. As a consequence, the cytosolic NO − 3 diminution induced in high inorganic carbon could result in both the decrease of metabolic N flux and the concomitant biomass N impoverishment in P. oceanica and, probably, in other aquatic plants.

show abstract

“…Nor do seagrass productivity, in general, respond well to excessive eutrophication or turbidity (van der Heide et al ., 2011). Nevertheless, moderate supplies of nutrients are capable of stimulating seagrass productivity particularly in acidic waters may stimulate seagrass productivity (Ravaglioli et al ., 2017). In actual fact, these are the conditions seen within the eastern sectors of this archipelago where the Indonesian flowthrough nutrient upwelling dominates (Ayers et al ., 2014).…”

Section: Discussionmentioning

confidence: 99%

Valuing Carbon Stocks across a Tropical Lagoon after Accounting for Black and Inorganic Carbon: Bulk Density Proxies for monitoring

Gallagher

Chew

Madin

et al. 2019

Preprint

View full text Add to dashboard Cite

3Managing seagrass and mangrove can be enhanced through carbon valued payment 1 4 incentives schemes. Success will depend on the accuracy and extent of the carbon stock 1 5 mitigation and accessible methods of monitoring and marking changes. In a relatively 1 6 closed socioecological Southeast Asian lagoon we estimated the value of total organic 1 7 carbon stocks (TOC) of both seagrass and mangroves. Mitigation corrections were also 1 8 made for black carbon (BC) and calcareous inorganic carbon equivalents (PIC equiv ), and 1 9 their sediment dry bulk density (DBD) tested as a cost effective means of both estimating 2 0 those stock concepts and possible impacts outside their parameter confidence intervals. 2 1 Overall, seagrass and mangroves TOC densities across the lower lagoon ranged from 2 2 15.3±4.3 and 124.3±21.1 Mg C ha -1 respectively, 175.2±46.9 and 103.2±19.0 Mg C ha -1 2 3 for seagrass and 355.0±24.8 and 350.3±35.2 Mg C ha -1 ) for mangroves across the two 2 4 upper lagoon branches. Only mangrove biomass made significant additional 2 5 contributions ranging from 178.5±62.3 to 120.7±94.8 Mg C ha -1 for lower and upper 2 6 regions respectively. The difference between the lagoons total seagrass and mangroves 2 7 TOC stocks (5.98±0.69 and 390±33.22 GgC respectively) was further amplified by the 2 8 lagoons' larger mangrove area. When corrected for BC and PIC equiv , the carbon stock 2 9 mitigation was only reduced by a moderate 14.2%. Across the lagoon the sedimentary 3 0 DBD showed strong (R 2 = 0.85, P < 0.001) to moderate (R 2 = 0.67, P < 0.001) linear 3 1 correlations with seagrass and mangrove [TOC] respectively, moderate correlations with 3 2

show abstract

Nutrient Loading Fosters Seagrass Productivity Under Ocean Acidification

Cited by 35 publications

References 80 publications

Ocean acidification alters meiobenthic assemblage composition and organic matter degradation rates in seagrass sediments

Ocean acidification alters meiobenthic assemblage composition and organic matter degradation rates in seagrass sediments

Short-Term Response of Cytosolic NO3− to Inorganic Carbon Increase in Posidonia oceanica Leaf Cells

Valuing Carbon Stocks across a Tropical Lagoon after Accounting for Black and Inorganic Carbon: Bulk Density Proxies for monitoring

Contact Info

Product

Resources

About