85 research outputs found
Festuca baffinensis (Baffin Island Fescue) : Baffin Island Fescue
No full textClass: Monocotyledoneae
Family: Poaceae
Genus: Festuca
Species: baffinensi
Report on Botanical Explorations in Arctic America, 1946-48
No full textBrief account, in general terms, of the author\u27s field-trips in the northern Quebec, Southampton Island, and Baker Lake (Keewatin) regions, summer 1946; in the northwestern part of Mackenzie District, summer 1947; and in Fairbanks, Alaska, 1948, whence he made high altitude, aerological, bacteriological, collecting flights to the North Pole. Includes remarks on the vegetation in regions visited in 1946 and 1947
Offshore pelagic subsidies dominate carbon inputs to coral reef predators
No full text© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Skinner, C., Mill, A. C., Fox, M. D., Newman, S. P., Zhu, Y., Kuhl, A., & Polunin, N. V. C. Offshore pelagic subsidies dominate carbon inputs to coral reef predators. Science Advances, 7(8), (2021): eabf3792, https://doi.org/10.1126/sciadv.abf3792.Coral reefs were traditionally perceived as productive hot spots in oligotrophic waters. While modern evidence indicates that many coral reef food webs are heavily subsidized by planktonic production, the pathways through which this occurs remain unresolved. We used the analytical power of carbon isotope analysis of essential amino acids to distinguish between alternative carbon pathways supporting four key reef predators across an oceanic atoll. This technique separates benthic versus planktonic inputs, further identifying two distinct planktonic pathways (nearshore reef-associated plankton and offshore pelagic plankton), and revealing that these reef predators are overwhelmingly sustained by offshore pelagic sources rather than by reef sources (including reef-associated plankton). Notably, pelagic reliance did not vary between species or reef habitats, emphasizing that allochthonous energetic subsidies may have system-wide importance. These results help explain how coral reefs maintain exceptional productivity in apparently nutrient-poor tropical settings, but also emphasize their susceptibility to future ocean productivity fluctuations.Sample analysis funding was provided by NERC LSMSF grant BRIS/102/0717 and BRIS/125/1418. C.S. was supported by a Newcastle University SAgE DTA studentship and a cooperative agreement with Banyan Tree
Our Global Environment and the World Campaign for the Biosphere
No full textAfter a requested account of how, starting from his student days, he had come gradually to ‘care about our Only One Biosphere' and think globally (even if commonly acting only locally), the Author presents his ‘thoughts on what might best be done to [foster a World Campaign for the Biosphere] and make it operationally effective'. This Campaign should be world-wide and have the objective of educating everybody everywhere to full realization of the following facts and their often imperatively grave implications: (1) The Biosphere constitutes a single integrated whole of which all parts are often intricately interdependent, (2) we humans form an integral part of the Biosphere but are becoming far too numerous and heavily dominant for its or our own good, (3) we are absolutely dependent on the health of the Biosphere for our own subsistence and more as it constitutes our sole life-support, (4) The Biosphere in part or even in toto is in several ways fragile, but (5) it is gravely threatened by various human activities and out-sized capabilities such as those of nuclear weaponry which are said to be sufficient to destroy our civilization several times over, and conceivably even the entire Biosphere. The second, longer part of the article is devoted to consideration of the following chosen ‘round dozen' recommended activities through which it is thought the Campaign might best be advanced, at least in its early stages: (1) Publishing and broadcasting pertinent information and support by all appropriate means; (2) Using other vehicles of desirable publicity, including posters and stickers; (3) Instructive advertising and audienceattracting showmanship; (4) Books on the Biosphere and illustrated study manuals; (5) Specialist research and its vigorous application; (6) Need to control human numbers and behaviour; (7) National Parks, Biosphere Reserves, and Biological Gardens, etc.; (8) Pertinent conferences, meetings, and other ‘free' deliberations; (9) Need to change human attitudes and priorities; (10) Need to establish due ethics and laws; (11) Institutional and organizational involvement towards survival; and (12) ‘Guardians of the Biosphere' recognition and awards. The above 12 points largely follow those presaged in the Editorial in our preceding issue, since completion of which it has emerged that this Campaign should be socalled (without reference to any time-scale), and that it might best be furthered by two United Nations agencies, an intergovernmental one, and at least one nongovernmental one—all hopefully working in concer
Author Correction: Multi-trophic markers illuminate the understanding of the functioning of a remote, low coral cover Marquesan coral reef food web (Scientific Reports, (2021), 11, 1, (20950), 10.1038/s41598-021-00348-w)
No full text\ua9 The Author(s) 2021The Supplementary Information 1 and 2 files published with this Article contained errors, where the title was incorrectly given as “Multi-trophic marker analysis of a Marquesan food web highlights how reef ecosystems might respond to a warmer and nutrient-rich ocean future.” This error has now been corrected in the Supplementary Information 1 and 2 files that accompany the original Article
Century-Scale Changes in the Feeding Patterns of Demersal Fish Species in the Western North Sea
No full text\ua9 2025 The Author(s). Fish and Fisheries published by John Wiley & Sons Ltd.Understanding the extent and magnitude of change in marine food webs requires historical data that predates modern monitoring efforts. Such information can provide invaluable insights into the longer-term impacts of altered trophic interactions, yet it is rarely incorporated into marine policy frameworks. Using multiple stomach records spanning over a century, we investigated long-term changes in the diet composition of six demersal fish species in the western North Sea. Plaice, dab and haddock exhibited marked dietary shifts from larger, more sessile bivalves in the early 20th century to an increase in the prevalence of shorter-lived, more opportunistic prey (polychaetes and echinoderms) in the latter part of the century. Cod, whiting, and grey gurnard exhibited variable diets, but some prey groups (amphipods and echinoderms) were consistently more important in particular decades. Compared to the 1900s, sandeels became an increasingly dominant dietary component for nearly all predators in later decades. These findings likely reflect ‘bottom-up’ effects of altered benthic prey communities caused by the intensification of trawling, eutrophication and climatic changes, especially in the latter part of the 20th century. Our study highlights the value of using alternative historical data in detecting broad-scale change over extended timescales, and provides additional evidence that can guide relevant policies aimed at restoring the functional integrity of marine food webs
The importance of oceanic atoll lagoons for coral reef predators
No full text\ua9 2020, The Author(s). Predators on coral reefs play an important ecological role structuring reef fish communities and are important fishery targets. It is thought that reef predator assemblages increase in density and diversity from inner lagoonal to outer edge reefs. Oceanic atolls may differ though, as nutrients are available throughout. Reef predator populations are declining, but there is little known about how their distributions may vary across oceanic atolls. Using a combination of underwater visual census and baited remote underwater video, this study aimed to compare reef predator populations between inner and outer reefs of North Mal\ue9 Atoll (Maldives) and determine which reef metrics may drive any differences in assemblage structure. We found that predator assemblages were significantly different between inner and outer atoll. Body sizes of several predator families were consistently larger in the outer atoll, however, abundance, biomass and species richness were similar between outer edge reefs and inner lagoonal reefs suggesting atoll lagoons may be undervalued habitats. Depth and complexity were consistently important predictors of the predator assemblage. Inner atoll lagoonal habitat is equally as important for reef predator assemblages as outer reef slopes, although the dominant species differ. This study provides important information on reef predator populations in the Maldives, where detailed assessments of the reef predator assemblage are lacking but the reef fishery is thriving and annual catch will continue to increase
Using δ13c Stable Isotopes To Quantify Individual-level Diet Variation
No full textIndividual-level diet variation can be easily quantified by gut-content analysis. However, because gut contents are a 'snapshot' of individuals' feeding habits, such cross-sectional data can be subject to sampling error and lead one to overestimate levels of diet variation. In contrast, stable isotopes reflect an individual's long-term diet, so isotope variation among individuals can be interpreted as diet variation. Nevertheless, population isotope variances alone cannot be directly compared among populations, because they depend on both the level of diet variation and the variance of prey isotope ratios. We developed a method to convert population isotope variances into a standardized index of individual specialization (WIC/TNW) that can be compared among populations, or to gut-content variation. We applied this method to diet and carbon isotope data of four species of frogs of the Brazilian savannah. Isotopes showed that gut contents provided a reliable measure of diet variation in three populations, but greatly overestimated diet variation in another population. Our method is sensitive to incomplete sampling of the prey and to among-individual variance in fractionation. Therefore, thorough sampling of prey and estimates of fractionation variance are desirable. Otherwise, the method is straightforward and provides a new tool for quantifying individual-level diet variation in natural populations that combines both gut-content and isotope data. © 2007 Springer-Verlag.1524643654Angerbjörn, A., Hersteinsson, P., Lidén, K., Nelson, E., Dietary variation in arctic foxes (Alopex lagopus)-an analysis of stable carbon isotopes (1994) Oecologia, 99, pp. 226-232Bolnick, D.I., Can intraspecific competition drive disruptive selection? 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Towards Deep-Sea Toxicology: Experimental Approaches With Echinoderms
No full textAs anthropogenic activities expand into the deep sea, it is only recently that the importance ofdeep-sea ecosystems and processes to global biogeochemical systems has become clear. If thepotential impact of human activity upon deep-sea organisms and ecosystems is to be understoodand predicted, experimental studies are required to improve our knowledge of their sensitivity tocontamination and disturbance. Echinoderms are integral components of deep-sea benthiccommunities and, by virtue of their abundance, they contribute significantly to deep-seabiogeochemical processes. As such, echinoderms can be considered relevant target organisms fordeep-sea experimental studies.Three approaches to the investigation of deep-sea anthropogenic impact upon echinodermswere undertaken in this study. The first was based on contaminant exposure experiments with twospecies of shallow-water echinoid, the eurytopic Psammechinus miliaris and the stenotopicBrissopsis lyrifera. A range of biomarkers was used to assess the responses of the echinoids tocontaminant exposure. Compared with the significant cytological and molecular (assess via qPCR)responses in P. miliaris, a reduced capacity to respond to contaminant exposure was found in B.lyrifera at these levels of biological organisation. Stenotopic species are hence recommended forfuture experimental studies as proxies for deep-sea echinoderms which, due to their adaptation tothe stable environment of the deep sea, are also considered to have a reduced capacity forhomeostasis in the face of environmental perturbation.The second experimental approach involved sediment burial experiments, simulatinganthropogenic drilling disturbance, with the deep-water echinoderm species Echinus acutus. ROVtechnology was used to perform the burial experiments in situ at 114 m depth. The application ofquantitative PCR molecular biomarker methodology revealed a significant increase in theexpression of a stress-70 protein in response to sediment burial. These results demonstrate thesensitivity of the qPCR technique to assess an organism’s stress-response, and its relevance todeep-sea experimental studies.Finally, the development and successful deployment of an in situ respirometer, the benthicincubation chamber system (BICS) 2, made possible the acquisition of physiologicalmeasurements from deep-sea echinoderms at the abyssal sea floor at 3500 m. The results revealedsimilarities between the oxygen consumption rates of shallow-water and deep-sea echinoderms.The future performance of in situ deep-sea experimentation is dependent on the development ofexperimental equipment that confers the ability to perform experiments in situ with ROVtechnology and to obtain results without interference from recovery-related side effects
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Regional variation in successional trajectories and rates of vegetation change on glacier forelands in south-central Norway
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