| 1. |
- Helske, Jouni, et al.
(författare)
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Estimating aggregated nutrient fluxes in four Finnish rivers via Gaussian state space models
- 2013
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Ingår i: Environmetrics. - : Wiley. - 1180-4009 .- 1099-095X. ; 24:4, s. 237-247
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Tidskriftsartikel (refereegranskat)abstract
- Reliable estimates of the nutrient fluxes carried by rivers from land-based sources to the sea are needed for efficient abatement of marine eutrophication. Although nutrient concentrations in rivers generally display large temporal variation, sampling and analysis for nutrients, unlike flow measurements, are rarely performed on a daily basis. The infrequent data calls for ways to reliably estimate the nutrient concentrations of the missing days. Here, we use the Gaussian state space models with daily water flow as a predictor variable to predict missing nutrient concentrations for four agriculturally impacted Finnish rivers. Via simulation of Gaussian state space models, we are able to estimate aggregated yearly phosphorus and nitrogen fluxes, and their confidence intervals.The effect of model uncertainty is evaluated through a Monte Carlo experiment, where randomly selected sets of nutrient measurements are removed and then predicted by the remaining values together with re-estimated parameters. Results show that our model performs well for rivers with long-term records of flow. Finally, despite the drastic decreases in nutrient loads on the agricultural catchments of the rivers over the last 25years, we observe no corresponding trends in riverine nutrient fluxes.
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| 2. |
- Kahlert, Maria, et al.
(författare)
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Gaps in current Baltic Sea environmental monitoring – Science versus management perspectives
- 2020
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Ingår i: Marine Pollution Bulletin. - London : Elsevier. - 0025-326X .- 1879-3363. ; 160
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Tidskriftsartikel (refereegranskat)abstract
- Legislations and commitments regulate Baltic Sea status assessments and monitoring. These assessments suffer from monitoring gaps that need prioritization. We used three sources of information; scientific articles, projectreports and a stakeholder survey to identify gaps in relation to requirements set by the HELCOM's Baltic SeaAction Plan, the Marine Strategy Framework Directive and the Water Framework Directive. The most frequentlymentioned gap was that key requirements are not sufficiently monitored in space and time. Biodiversity monitoringwas the category containing most gaps. However, whereas more than half of the gaps in reports related tobiodiversity, scientific articles pointed out many gaps in the monitoring of pollution and water quality. Animportant finding was that the three sources differed notably with respect to which gaps were mentioned mostoften. Thus, conclusions about gap prioritization for management should be drawn after carefully consideringthe different viewpoints of scientists and stakeholders. © 2020 The Authors. Published by Elsevier Ltd.
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| 3. |
- Mack, Leoni, et al.
(författare)
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A Synthesis of Marine Monitoring Methods With the Potential to Enhance the Status Assessment of the Baltic Sea
- 2020
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Ingår i: Frontiers in Marine Science. - Lausanne : Frontiers Media S.A.. - 2296-7745. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- A multitude of anthropogenic pressures deteriorate the Baltic Sea, resulting in theneed to protect and restore its marine ecosystem. For an efficient conservation,comprehensive monitoring and assessment of all ecosystem elements is of fundamentalimportance. The Baltic Marine Environment Protection Commission HELCOMcoordinates conservation measures regulated by several European directives. However,this holistic assessment is hindered by gaps within the current monitoring schemes.Here, twenty-two novel methods with the potential to fill some of these gaps andimprove the monitoring of the Baltic marine environment are examined. We asked keystakeholders to point out methods likely to improve current Baltic Sea monitoring. Wethen described these methods in a comparable way and evaluated them based ontheir costs and applicability potential (i.e., possibility to make them operational). Twelvemethods require low to very low costs, while five require moderate and two high costs.Seventeen methods were rated with a high to very high applicability, whereas fourmethods had moderate and one low applicability for Baltic Sea monitoring. Methodswith both low costs and a high applicability include the Manta Trawl, Rocket, SedimentCorer, Argo Float, Artificial Substrates, Citizen Observation, Earth Observation, theHydroFIARpH system, DNA Metabarcoding and Stable Isotope Analysis. © 2020 Mack, Attila, Aylagas, Beermann, Borja, Hering, Kahlert, Leese, Lenz, Lehtiniemi, Liess, Lips, Mattila, Meissner, Pyhälahti, Setälä, Strehse, Uusitalo, Willstrand Wranne and Birk.
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| 4. |
- Meissner, Kristian, et al.
(författare)
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Predator-prey interactions in a variable environment : responses of a caddis larva and its blackfly prey to variations in stream flow
- 2009
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Ingår i: Annales Zoologici Fennici. - : Finnish Zoological and Botanical Publishing Board. - 0003-455X .- 1797-2450. ; 46:3, s. 193-204
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Predator-prey studies in streams have traditionally focused on mayfly-stonefly interactions in relatively constant flow conditions. In reality, however, lotic prey encounter multiple types of predators, most of which are restricted to low-velocity microhabitats. By contrast, some invertebrate prey may occur in very high current velocities. For example, many blackfly species are able to feed at velocities of 100 cm s(-1), whereas even moderate currents reduce the hunting efficiency of their invertebrate predators. The caddisfly larvae of the genus Rhyacophila, however, may be an exception to the pattern of reducing predator efficiency with increasing velocity. Using a combination of laboratory and field experiments and behavioral field observations, we examined the interaction between predatory Rhyacophila caddis larvae and larval blackflies along a velocity gradient of 20-120 cm s(-1). In laboratory experiments, Rhyacophila preferred currents slower than 50 cm s(-1) while blackflies exhibited a wide tolerance of currents and frequently occurred in currents exceeding 100 cm s(-1). In direct field observations, total activity and distance moved by Rhyacophila were similar at all current velocity regimes tested, but frequency of predation attempts on blackflies was lowest at the highest velocities (> 100 cm s(-1)). In a field colonization study, blackflies avoided substrates with the slowest velocities (< 40 cm s(-1)), as also did the caddis larvae. Only velocities approaching 100 cm s(-1) provide blackflies with refuge from predation by Rhyacophila. Being able to maneuver across a wide range of velocities, Rhyacophila may have more pervasive effects on their prey than other lotic invertebrate predators.
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| 5. |
- Tiegs, Scott D., et al.
(författare)
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Global patterns and drivers of ecosystem functioning in rivers and riparian zones
- 2019
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Ingår i: Science Advances. - Washington : American Association of Advancement in Science. - 2375-2548. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.
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