Interactive effects of porewater nutrient enrichment, bioturbation and sediment characteristics on benthic assemblages in sandy sediments

O’Brien, Allyson L.; Volkenborn, Nils; Beusekom, Justus van; Morris, Liz; Keough, Michael J.

doi:10.1016/j.jembe.2009.01.004

Cited by 14 publications

(13 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3. Contrary to previous studies that have manipulated nutrient concentrations in intertidal marine sediments (Granéli & Sundbäck 1985;Nilsson et al 1991;Hillebrand et al 2002;Morris & Keough 2003;O'Brien et al 2009), fertilizer additions in this study did not result in significantly higher nutrient levels in the sediments. and possibly higher-order consumers (Posey et al 1999(Posey et al , 2006Rossi et al 2001;Rossi & Lardicci 2002).…”

Section: Experimental Nutrient Manipulationscontrasting

confidence: 99%

“…and possibly higher-order consumers (Posey et al 1999(Posey et al , 2006Rossi et al 2001;Rossi & Lardicci 2002). Contrary to previous studies that have manipulated nutrient concentrations in intertidal marine sediments (Granéli & Sundbäck 1985;Nilsson et al 1991;Hillebrand et al 2002;Morris & Keough 2003;O'Brien et al 2009), fertilizer additions in this study did not result in significantly higher nutrient levels in the sediments. However, most of the published experimental work on benthic nutrient responses comes from sheltered, fine-grained mud-or sandflats.…”

Section: Experimental Nutrient Manipulationscontrasting

confidence: 99%

“…= 34.5 mm) to a depth of 30 mm. This depth is consistent with sampling methods for sediment nutrients reported in the literature O'Brien et al 2009). Field samples were stored and transported on ice and frozen (-20°C) within 12 h of collection.…”

Section: Sediment Nutrient Analysissupporting

confidence: 91%

“…Concentrations of inorganic nutrients in intertidal sand flats following fertilizer additions have been related to tidal amplitude, sediment characteristics and bioturbation (O'Brien et al 2009). We observed a marked shift towards coarser sands during the experiment (electronic Appendix S2).…”

Section: Experimental Nutrient Manipulationsmentioning

confidence: 99%

See 3 more Smart Citations

Bottom‐up control in the benthos of ocean‐exposed sandy beaches?

Schlacher

Hartwig

2012

Austral Ecology

View full text Add to dashboard Cite

Bottom-up control is a fundamental structuring force in food webs. Food webs of ocean-exposed sandy beaches are predicted to be bottom-up controlled systems, underpinned by imported organic matter rather than in situ primary production.This ecological model of resource-based regulation of biological assemblages is juxtaposed against a prevailing paradigm built around a dominance of physical drivers in sandy beach ecosystems. Surprisingly, given the apparently ubiquitous energetic subsidies of beach food webs, the central premise of bottom-up control has not been tested. Here we experimentally manipulated in situ nutrient levels on a sandy beach to test food web responses at the levels of primary producers (benthic microalgae) and their grazers (meiofauna). The meiofauna community as a whole appeared most strongly influenced by the local physical environment, particularly changes in sediment grain size -this supports the traditional 'environmental control paradigm'. We also detected a significant, positive response of two consumer groups of the meiofauna (nematodes, ostracods) to nutrient enrichment that supports a model of biological, bottom-up control. Although the predicted response of elevated producer biomass following nutrient enrichment was not detected, intense grazing pressure on new, stimulated production may have masked positive responses by the primary producers. Multichannel regulation of food webs is likely for many exposed sandy beaches, albeit an often lower importance of in situ bottom-up forces compared with stronger environmental control.

show abstract

Section: Experimental Nutrient Manipulationscontrasting

confidence: 99%

Section: Experimental Nutrient Manipulationscontrasting

confidence: 99%

Section: Sediment Nutrient Analysissupporting

confidence: 91%

Section: Experimental Nutrient Manipulationsmentioning

confidence: 99%

See 2 more Smart Citations

Bottom‐up control in the benthos of ocean‐exposed sandy beaches?

Schlacher

Hartwig

2012

Austral Ecology

View full text Add to dashboard Cite

show abstract

“…The lack of any relationships between TN ratio and sediment organic matter content regardless of grain size, is in agreement with the oligotrophic nature of Australian estuaries. Studies experimentally fertilizing sediments have found minimal impacts of enrichment on macrofaunal assemblages of south-east Australian estuaries [57], [58].…”

Section: Discussionmentioning

confidence: 99%

Weak and Habitat-Dependent Effects of Nutrient Pollution on Macrofaunal Communities of Southeast Australian Estuaries

Nicastro

Bishop

2013

PLoS ONE

View full text Add to dashboard Cite

Among the impacts of coastal settlements to estuaries, nutrient pollution is often singled out as a leading cause of modification to the ecological communities of soft sediments. Through sampling of 48 sites, distributed among 16 estuaries of New South Wales, Australia, we tested the hypotheses that (1) anthropogenic nutrient loads would be a better predictor of macrofaunal communities than estuarine geomorphology or local sediment characteristics; and (2) local environmental context, as determined largely by sediment characteristics, would modify the relationship between nutrient loading and community composition. Contrary to the hypothesis, multivariate multiple regression analyses revealed that sediment grain size was the best predictor of macrofaunal assemblage composition. When samples were stratified according to median grain size, relationships between faunal communities and nitrogen loading and latitude emerged, but only among estuaries with sandier sediments. In these estuaries, capitellid and nereid polychaetes and chironomid larvae were the taxa that showed the strongest correlations with nutrient loading. Overall, this study failed to provide evidence of a differential relationship between diffuse nutrient enrichment and benthic macrofauna across a gradient of 7° of latitude and 4°C temperature. Nevertheless, as human population growth continues to place increasing pressure on southeast Australian estuaries, manipulative field studies examining when and where nutrient loading will lead to significant changes in estuarine community structure are needed.

show abstract

Spatially variable synergistic effects of disturbance and additional nutrients on kelp recruitment and recovery

Carnell

Keough

2014

Oecologia

Self Cite

View full text Add to dashboard Cite

Understanding the impact of multiple stressors on ecosystems is of pronounced importance, particularly when one or more of those stressors is anthropogenic. Here we investigated the role of physical disturbance and increased nutrients on reefs dominated by the canopy-forming kelp Ecklonia radiata. We combined experimental kelp canopy removals and additional nutrient at three different locations in a large embayment in temperate southeastern Australia. Over the following winter recruitment season, Ecklonia recruitment was unaffected by increased nutrients alone, but tripled at all sites where the canopy had been removed. At one site, the combination of disturbance and increased nutrients resulted in more than four times the recruitment of the introduced kelp Undaria pinnatifida. Six months after disturbance, the proliferation of the Undaria canopy in the canopy-removal and nutrient-addition treatment negatively influenced the recovery of the native kelp Ecklonia. Given the otherwise competitive dominance of adult Ecklonia, this provides a mechanism whereby Undaria could maintain open space for the following recruitment season. This interplay between disturbance, nutrients and the response of native and invasive species makes a compelling case for how a combination of factors can influence species dynamics.

show abstract

Interactive effects of porewater nutrient enrichment, bioturbation and sediment characteristics on benthic assemblages in sandy sediments

Cited by 14 publications

References 48 publications

Bottom‐up control in the benthos of ocean‐exposed sandy beaches?

Bottom‐up control in the benthos of ocean‐exposed sandy beaches?

Weak and Habitat-Dependent Effects of Nutrient Pollution on Macrofaunal Communities of Southeast Australian Estuaries

Spatially variable synergistic effects of disturbance and additional nutrients on kelp recruitment and recovery

Contact Info

Product

Resources

About