Stable isotope analysis of some representative fish and invertebrates of the Newfoundland and Labrador continental shelf food web

Sherwood, Graham D.; Rose, George A.

doi:10.1016/j.ecss.2004.12.010

Cited by 138 publications

(139 citation statements)

References 37 publications

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“…2). Based on an approximate 3‰ increase in bulk δ 15 N with each step in trophic level (29,30), P. resedaeformis (tissue δ 15 N ¼ 10.31 AE 0.19) likely feeds opportunistically on a mixture of sinking POM and small zooplankton, as previously noted (13). By this mechanism, δ 15 N NO 3 signatures in the euphotic zone are trans- mitted to and incorporated into the skeletal protein of deep-sea gorgonians.…”

Section: Resultsmentioning

confidence: 90%

Nutrient regime shift in the western North Atlantic indicated by compound-specific δ ¹⁵ N of deep-sea gorgonian corals

Sherwood

Lehmann

Schubert

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

155

172

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Despite the importance of the nitrogen (N) cycle on marine productivity, little is known about variability in N sources and cycling in the ocean in relation to natural and anthropogenic climate change. Beyond the last few decades of scientific observation, knowledge depends largely on proxy records derived from nitrogen stable isotopes ( δ 15 N) preserved in sediments and other bioarchives. Traditional bulk δ 15 N measurements, however, represent the combined influence of N source and subsequent trophic transfers, often confounding environmental interpretation. Recently, compound-specific analysis of individual amino acids ( δ 15 N-AA) has been shown as a means to deconvolve trophic level versus N source effects on the δ 15 N variability of bulk organic matter. Here, we demonstrate the first use of δ 15 N-AA in a paleoceanographic study, through analysis of annually secreted growth rings preserved in the organic endoskeletons of deep-sea gorgonian corals. In the Northwest Atlantic off Nova Scotia, coral δ 15 N is correlated with increasing presence of subtropical versus subpolar slope waters over the twentieth century. By using the new δ 15 N-AA approach to control for variable trophic processing, we are able to interpret coral bulk δ 15 N values as a proxy for nitrate source and, hence, slope water source partitioning. We conclude that the persistence of the warm, nutrient-rich regime since the early 1970s is largely unique in the context of the last approximately 1,800 yr. This evidence suggests that nutrient variability in this region is coordinated with recent changes in global climate and underscores the broad potential of δ 15 N-AA for paleoceanographic studies of the marine N cycle.

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Section: Resultsmentioning

confidence: 90%

Nutrient regime shift in the western North Atlantic indicated by compound-specific δ ¹⁵ N of deep-sea gorgonian corals

Sherwood

Lehmann

Schubert

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

155

172

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“…Mixing-model overestimation of MPB dietary contribution-The comparatively high d 13 C observed in benthic compared to pelagic consumers can result from causes other than the consumption of MPB. For example, Sherwood and Rose (2005) collected pelagic and benthic invertebrates over shelf sediments with little possibility for benthic production (. 200 m) and found a d 13 Cenrichment of 2-3% in benthic consumers.…”

Section: Discussionmentioning

confidence: 99%

“…Working on the Louisiana shelf, Wells et al (2008) actually measured MPB isotopically and concluded that the indirect dependence of red snapper (Lutjanus campechanus) on MPB increased with age, reaching 50% in year 3+ fish. However, such studies are few, and, despite the potential utility of stable isotopes, most isotope studies of shelf food webs have only distinguished between benthic or pelagic consumers without specifically addressing the trophic roles of MPB and settled phytoplankton (Fry et al 1984;Davenport and Bax 2002;Sherwood and Rose 2005). Complicating isotope investigations is evidence that the high d 13 C observed in benthic compared to pelagic consumers is, at least in part, a natural phenomenon and not a result of the consumption of 13 C-enriched food sources such as MPB (Nadon and Himmelman 2006).…”

mentioning

confidence: 99%

Spatial variation in basal resources supporting benthic food webs revealed for the inner continental shelf

Grippo

Fleeger

Dubois

et al. 2011

Limnology & Oceanography

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We used stable isotopes to examine the relative importance of phytodetritus and microphytobenthos (MPB) in supporting benthic food webs on the Louisiana continental shelf. Primary producers and macroinfauna were collected from Ship Shoal (SS), a submerged, sandy, barrier island where sediment-associated algae are primarily MPB and from silty, off-shoal areas where sediment-associated algae are primarily phytodetritus or a mixture of the two resources. Macroinfauna, as individual taxa and trophic guilds, were significantly more enriched in 13 C on SS indicating greater dependence on MPB, which is enriched in 13 C compared to phytoplankton. Using d 13 C in a two-source mixing model, the estimated MPB dietary contribution for SS macroinfauna averaged across trophic guilds, ranged from 53.4% to 83.0%, depending on the mixing-model end-members used, and 5 of 14 taxa had lower 95% confidence intervals (CI) . 20%, indicating that MPB was a primary resource for most SS macroinfauna. Off-shoal, the dietary contribution of MPB ranged from14.5% to 47.7% and most taxa had a lower CI near 0%. Settled phytoplankton are the primary microalgal food source in muddy sediments, but the importance of MPB increases in more sandy sediments where MPB are the predominant microalgal resource. Sandy shoals play a unique food-web role in deltaic shelf systems and support benthic food webs on the continental shelf.

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“…It has been shown that coastal ecosystems often exhibit lower Δδ 15 N than the globally accepted value of 3.4 ‰ (Wu et al 1997, Sherwood & Rose 2005. To validate our TL estimates, we also looked at 4 taxa that were sampled in both the NE Pacific and NW Atlantic: euphausiids, bivalves, pollock and sole.…”

Section: Trophic Levelmentioning

confidence: 99%

Stable isotopic composition of deep-sea gorgonian corals Primnoa spp.: a new archive of surface processes

Sherwood¹,

Heikoop²,

Scott³

et al. 2005

Mar. Ecol. Prog. Ser.

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Stable isotope analysis of some representative fish and invertebrates of the Newfoundland and Labrador continental shelf food web

Cited by 138 publications

References 37 publications

Nutrient regime shift in the western North Atlantic indicated by compound-specific δ ¹⁵ N of deep-sea gorgonian corals

Nutrient regime shift in the western North Atlantic indicated by compound-specific δ ¹⁵ N of deep-sea gorgonian corals

Spatial variation in basal resources supporting benthic food webs revealed for the inner continental shelf

Stable isotopic composition of deep-sea gorgonian corals Primnoa spp.: a new archive of surface processes

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Stable isotope analysis of some representative fish and invertebrates of the Newfoundland and Labrador continental shelf food web

Cited by 138 publications

References 37 publications

Nutrient regime shift in the western North Atlantic indicated by compound-specific δ 15 N of deep-sea gorgonian corals

Nutrient regime shift in the western North Atlantic indicated by compound-specific δ 15 N of deep-sea gorgonian corals

Spatial variation in basal resources supporting benthic food webs revealed for the inner continental shelf

Stable isotopic composition of deep-sea gorgonian corals Primnoa spp.: a new archive of surface processes

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Nutrient regime shift in the western North Atlantic indicated by compound-specific δ ¹⁵ N of deep-sea gorgonian corals

Nutrient regime shift in the western North Atlantic indicated by compound-specific δ ¹⁵ N of deep-sea gorgonian corals