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Manyeruke, M. H., C.Hoppe, H., Isaacs, M., Seldon, R., Warner, D. F., Krause, R. W. M., et al. (2024). Synthesis and exploratory biological evaluation of 3-[(N-4-benzyloxyphenyl)iminoethyl]- and 3-(1-hydrazonoethyl)-4-hydroxycoumarins. Arkivoc, 2022(5).
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Chapelle, G., & Peck, L. S. (1999). Polar gigantism dictated by oxygen availability. Nature, 399, 114–115.
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Aberle, N., & Witte, U. (2003). Deep-sea macrofauna exposed to a simulated sedimentation event in the abyssal NE Atlantic: in situ pulse-chase experiments using 13C-labelled phytodetritus. Mar Ecol Prog Ser, 251, 37–47.
Abstract: Tracer experiments with 13C-labelled diatoms Thalassiosira rotula (Bacillariophycea, 98% 13C-labelled) were conducted at the Porcupine Abyssal Plain (PAP) in the NE Atlantic (BENGAL Station; 48°50'N, 16°30'W, 4850 m depth) during May/June 2000. In situ enrichment experiments were carried out using de
ep-sea benthic chamber landers: within the chambers a spring bloom was simulated and the fate of this food-pulse within the abyssal macrobenthic community was followed. In focus was the role of different macrofauna taxa and their vertical distribution within the sediment column in consuming and reworking the freshly deposited material. T. rotula is one of the most abundant pelagic diatoms in the NE Atlantic and therefore 0.2 g of freeze dried T. rotula, equivalent to 1 g algal C m-2 yr-1, was injected into each incubation chamber. Three different incubation times of 2.5, 8 and 23 d were chosen in order to follow the uptake of 13C-labelled phytodetritus by macrofauna. After only 2.5 d, 77% of all macrofauna organisms showed tracer uptake. After 23 d the highest degree of enrichment was measured and 95% of the individuals had taken up 13C from the introduced algal material. In addition to that a downward transport of organic matter was observed, even though the mixing was not
very intense. The initial processing of carbon was dominated by polychaetes that made up a percentage of 52% of total macrofauna. In general macrofauna organisms that lived close to the sediment surface had higher access to the simulated food-pulse, confirming the hypothesis that individuals close to the sediment surface have the strongest impact on the decomposition of phytodetritus. In our study we observed only modest vertical entrainment of 13C tracers into the sediment. With regard to contradictory results from former 13C-enrichment experiments in bathyal regions, compared to results from our study site in the abyssal plain, we thus propose pronounced differences in feeding strategies between macrofauna communities from continental margins and abyssal plains.
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Hobson, K. A., Ambrose Jr, W. G., & Renaud, P. E. (1995). Sources of primary production, benthic-pelagic coupling, and trophic relationships within the Northeast Water Polynya: Insights from δ13C and δ15N analysis. Mar Ecol Prog Ser, 128(1-3), 1–10.
Abstract: We used stable carbon (13C/12C) and nitrogen (15N/14N) isotope analysis to investigate linkages between sources of primary production and the pelagic and benthic components of the Northeast Water (NEW) Polynya off northeastern Greenland. Ice algae was enriched in 13C (mean δ13C = -18.6 vs -27.9 ppt) and 15N (mean δ15N = 8.3 vs 4.9 ppt) over particulate organic matter
(POM) suggesting that the relative importance of these sources might be traced isotopically. Most grazing crustaceans and filter-feeding bivalves had δ13C and δ15N values in the range of -21 to -23 ppt and 7 to 9 ppt, respectively, indicating a direct pathway from POM. Close benthic-pelagic coupling was also confirmed for other benthic organisms examined with the exception of the predatory or deposit feeding echinoderms Ophiocten, Ophiacantha and Pontaster. Compared with other Arctic and temperate marine food webs, stable-carbon isotope values for the NEW Polynya were depleted in 13C. A δ15N trophic model that incorporated taxon-specific isotopic fractionation factors indicated that the NEW Polynya consisted of 4.5 to 5 trophic levels. Stable-isotope analysis may be well suited to establishing the importance of polynyas as sites of high primary productivity and tight benthic-pelagic coupling relative to regions of more permanent ice cover.
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Hobson, K. A., Ambrose Jr, W. G., & Renaud, P. E. (1995). Sources of primary production, benthic-pelagic coupling, and trophic relationships within the Northeast Water Polynya: insights from δ13C and δ15N analysis. Mar Ecol Prog Ser, 128, 1–10.
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