24,571 research outputs found
Importance of species interactions in moderating altered levels of reactive nitrogen
No full textThe amount of anthropogenic reactive nitrogen that is generated and emitted at a global scale has greatly increased since the pre-industrial period, disrupting the natural balance of the nitrogen cycle and causing adverse impacts on human health, biodiversity, ecosystem services, and climate change. Consequently, how altered nitrogen availability and/or supply affects natural systems has received a significant amount of attention, but investigators have tended to focus on detailing microbial processes and biogeochemical pathways or on summarizing effects observed at the very broadest ecosystem scale. The way in which the effects of changing nitrogen concentrations are expressed in the environment, however, is also dependent on natural communities, yet how species–environment interactions may alter, or be altered by, the effects of nitrogen forcing has received much less attention. In this chapter, consideration is given to how changes to the stocks and flows of nitrogen may affect individuals, species, and species–environment interactions that, in turn, may either exacerbate or buffer the wider ecosystem effects of nitrogen forcing
The changing Arctic ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning
No full textThe Arctic region is undergoing some of the most rapid rates of climate change in the world [1], with dramatic transformations underway in terrestrial, coastal and offshore environments that have immediate and long-term consequences for socio-ecological systems (e.g. [2–5]). Significant changes in the type, extent and thickness of ice cover [6], meltwater input [7] and water mass dynamics [8], coupled with warming and ocean acidification [9], have already begun to impact ecosystem processes and the flora and fauna that inhabit a range of Arctic habitats [10]. The pace of change is such that our understanding of the way in which Arctic systems are structured and function is outdated, and insufficient to inform management, mitigation and adaptation efforts across the region [11,12]. Projections indicate that, even if global stabilization of temperature below 1.5°C is realized, changes will continue to manifest over an extended period, perhaps even millennial timescales [13] and may include unprecedented shifts in structure [14]. Changes to key components of Arctic ecosystems are already occurring, yet the collated evidence of how changes to baseline conditions are proceeding across the Arctic Ocean is still poorly constrained [15], focused on a limited number of exemplar areas [16], and seldom adopts a holistic view that begins to provide a nuanced understanding of the modus operandi of the Arctic [17]. This is concerning because informed decision- and policy-making benefits from a broad understanding of system dynamics, including feedbacks and the likelihood of ecological surprises [18], yet the focus of study is already shifting from the natural sciences to social sciences and humanities to meet legislative and policy demands [19]. Now more than ever, foundational concepts and evidence are needed to support sustainable management and policy, preferably with a focus on continually acquiring, interpreting and applying new interdisciplinary knowledge to enhance understanding [20]
A global database of measured values of benthic invertebrate bioturbation intensity, ventilation rate, and the mixed depth of marine soft sediments
No full textThe activities of a diverse array of sediment-dwelling fauna are known to mediate carbon remineralisation, biogeochemical cycling and other important properties of marine ecosystems, but the contributions that different seabed communities make to the global inventory have not been established. Here we provide a comprehensive georeferenced database of measured values of bioturbation intensity (Db), burrow ventilation rate (42 species) and the mixed depth (L) of marine soft sediments compiled from the scientific literature (1970-2017). These data provide reference information that can be used to inform and parameterise global, habitat specific and/or species level biogeochemical models that will be of value within the fields of geochemistry, ecology, climate, and palaeobiology. We include metadata relating to the source, timing and location of each study, the methodology used, and environmental and experimental information. The dataset presents opportunity to interrogate current ecological theory, refine functional typologies, quantify uncertainty and/or test the relevance and robustness of models used to project ecosystem responses to change
Sediment reworking activity of high-latitude marine invertebrates exposed to dilute concentrations of maritime fuel
No full textWe provide the data from an experiment investigating the effect low concentrations of the water-accommodated fraction of marine fuel oil, representative of a dilute fuel oil spill, on aspects of the behaviour of marine sediment-dwelling invertebrates from Greenland. The data include fluorescent sediment profile images (fSPI) for the full experiment, and the derived data extracted from these images that characterise the reworking activity of each invertebrate
A global database of measured values of benthic invertebrate bioturbation intensity, ventilation rate, and the mixed depth of marine soft sediments
No full textThe activities of a diverse array of sediment-dwelling fauna are known to mediate carbon remineralisation, biogeochemical cycling and other important properties of marine ecosystems, but the contributions that different seabed communities make to the global inventory have not been established. Here we provide a comprehensive georeferenced database of measured values of bioturbation intensity (Db), burrow ventilation rate (42 species) and the mixed depth (L) of marine soft sediments compiled from the scientific literature (1970-2017). These data provide reference information that can be used to inform and parameterise global, habitat specific and/or species level biogeochemical models that will be of value within the fields of geochemistry, ecology, climate, and palaeobiology. We include metadata relating to the source, timing and location of each study, the methodology used, and environmental and experimental information. The dataset presents opportunity to interrogate current ecological theory, refine functional typologies, quantify uncertainty and/or test the relevance and robustness of models used to project ecosystem responses to change
A global database of measured values of benthic invertebrate bioturbation intensity, ventilation rate, and the mixed depth of marine soft sediments
No full textThe activities of a diverse array of sediment-dwelling fauna are known to mediate carbon remineralisation, biogeochemical cycling and other important properties of marine ecosystems, but the contributions that different seabed communities make to the global inventory have not been established. Here we provide a comprehensive georeferenced database of measured values of bioturbation intensity (Db), burrow ventilation rate (42 species) and the mixed depth (L) of marine soft sediments compiled from the scientific literature (1970-2017). These data provide reference information that can be used to inform and parameterise global, habitat specific and/or species level biogeochemical models that will be of value within the fields of geochemistry, ecology, climate, and palaeobiology. We include metadata relating to the source, timing and location of each study, the methodology used, and environmental and experimental information. The dataset presents opportunity to interrogate current ecological theory, refine functional typologies, quantify uncertainty and/or test the relevance and robustness of models used to project ecosystem responses to change.</span
Introduction: Marine biodiversity: current understanding and future research
No full textHuman activity extensively, and often irreversibly, alters marine biodiversity andecosystems on a global scale. Notwithstanding a substantial research effort on the ecosystem consequences of altered biodiversity, it is vital that the marine community summarise and communicate itsknowledge to policy makers. This Theme Section celebrates the establishment of the World Conference on Marine Biodiversity as a vehicle for integrating marine biodiversity science and co-ordinating future research efforts
Complex interactions mediate the effects of fish farming on benthic chemistry within a region of Scotland
No full textFish farms typically generate a localised gradient of both organic and inorganic pollutants in the underlying sediments. The factors governing the extent of such impacts remain poorly understood, particularly when multiple sites are considered. We used regression-type techniques to examine the drivers of sediment chemistry patterns around five Scottish fish farms that ranged in size (120–2106 tonnes) and fish species, but were located within <40 km of each other. Correlations between observations made at the same farm illustrate that between-site variability can be high, even at this regional-scale. These effects must be accounted for when comparing the effects of fish farming at different locations. All measured chemical parameters declined rapidly as a function of distance from the cage edge, with the rate of decline depending on local current speeds. Only phosphorus concentrations increased directly with farm size. Increasing current speeds at farms <900 tonnes reduced the accumulation of organic carbon in the underlying sediments, whereas the opposite occurred at larger farms. The counterintuitive effect of current speed at farms above the threshold size suggests that the physical properties of the seabed at these locations favour the accumulation of organic wastes and/or that the underlying communities have a lower assimilative capacity. These imply that the environmental efficiency of fish farming activities may be further optimised by taking into account the interaction between current speed, substrate complexity and the functional characteristics of the benthos. Collectively, our analyses demonstrate that the fate of fish farm-derived wastes is complex and highlight the need for site-specific management techniques
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