Pressure-Induced Shifts in Trophic Linkages in a Simplified Aquatic Food Web

Title
Pressure-Induced Shifts in Trophic Linkages in a Simplified Aquatic Food Web

Publication Type
Journal Article

Year of Publication
2017

Authors

Schrama M, Barmentlo SH, Hunting ER, van Logtestijn RSP, Vijver MG, van Bodegom PM

Journal
Frontiers in Environmental Science

Volume
5

Pagination
1-10

ISBN Number

Keywords

stable isotopes, imidacloprid, terbuthylazine, multiple stressors, anthropogenic pressures, interaction
web, green web, brown web

Abstract

It is essential to understand effects of existing and emerging anthropogenic stressors on the structure of aquatic food webs in more natural settings, to obtain realistic predictions on how they can affect major ecosystem properties and functioning. We therefore examined whether (1) realistic concentrations of key agricultural pesticides and nutrients induce shifts in trophic linkages (2) observed changes in trophic linkages are qualitatively different between the green (algal-based) and brown (detritus-based) part of the food web. To this end, we exposed a simplified, yet realistic freshwater invertebrate community to environmentally relevant concentrations of three anthropogenic pressures (eutrophication; the herbicide terbuthylazine; and the insecticide imidacloprid) in a full factorial mesocosm design. Trophic linkages and the changes therein were assessed measuring stable isotopes of natural carbon and nitrogen. Results show that the green and brown part of the food web react qualitatively different to interacting pressures. Whereas, herbivorous species react mainly to the nutrients and herbicides and the synergistic interaction between these, species in the detritivore part of the food web were affected by insecticide applications and interactions with nutrients. These results suggest that agricultural pressures can induce shifts in trophic linkages, but that they can have contrasting effects on the different parts of the food web. Such antagonistic and synergistic interactions can provide powerful explanations for observed responses of ecosystems to interacting stressors. These findings may have important implications for our understanding on interactions of agricultural stressors and their propagation in aquatic food webs.

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Assessing combined impacts of agrochemicals: Aquatic macroinvertebrate population responses in outdoor mesocosms

Title
Assessing combined impacts of agrochemicals: Aquatic macroinvertebrate population responses in outdoor mesocosms

Publication Type
Journal Article

Year of Publication
2018

Authors

Barmentlo SH, Schrama M, Hunting ER, Heutink R, van Bodegom PM, de Snoo GR, Vijver MG

Journal
Science of The Total Environment

Volume
631-632

Pagination
341-347

ISBN Number

Keywords

Agrochemicals
Mixtures
Outdoor testing
Aquatic invertebrates
Mesocosm

Abstract

Agricultural ditches host a diverse community of species. These species often are unwarrantedly exposed to fertilizers and a wide-array of pesticides (hereafter: agrochemicals). Standardized ecotoxicological research provides valuable information to predict whether these pesticides possibly pose a threat to the organisms living within these ditches, in particular macro-invertebrates. However, knowledge on how mixtures of these agrochemicals affect macro-invertebrates under realistic abiotic conditions and with population and community complexity is mostly lacking. Therefore we examined here, using a full factorial design, the population responses of macroinvertebrate species assemblages exposed to environmentally relevant concentrations of three commonly used agrochemicals (for 35 days) in an outdoor experiment. The agrochemicals selected were an insecticide (imidacloprid), herbicide (terbuthylazine) and nutrients (NPK), all having a widespread usage and often detected together in watersheds. Effects on species abundance and body length caused by binary mixture combinations could be described from single substance exposure. However, when agrochemicals were applied as tertiary mixtures, as they are commonly found in agricultural waters, species’ abundance often deviated from expectations made based on the three single treatments. This indicates that pesticide-mixture induced toxicity to population relevant endpoints are difficult to extrapolate to field conditions. As in agricultural ditches often a multitude (approx. up to 7) of agrochemicals residues are detected, we call other scientist to verify the ecological complexity of non-additive induced shifts in natural aquatic invertebrate populations and aquatic species assemblages.

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Thiacloprid‐induced toxicity influenced by nutrients: Evidence from in situ bioassays in experimental ditches

Title
Thiacloprid‐induced toxicity influenced by nutrients: Evidence from in situ bioassays in experimental ditches

Publication Type
Journal Article

Year of Publication
2018

Authors

Barmento SH, Parmentier EM, de Snoo GR, Vijver MG

Journal
Environmental Toxicology

Volume
37

Pagination
1907-1915

ISBN Number

Keywords

Agrochemical; Crustacean; Fertilizer; Insect; Multiple stressors; Neonicotinoid

Abstract

Many studies show that neonicotinoid insecticides cause toxicity to aquatic invertebrates. Some studies report that insecticide toxicity may differ in combination with other agrochemicals under realistic field conditions. To explore such altered toxicity further, we aimed to determine the single and combined effects of environmentally relevant levels of the neonicotinoid thiacloprid and nutrients on different endpoints of 4 aquatic invertebrate species. Animals were exposed to these agrochemicals using a caged experiment within experimental ditches. We observed thiacloprid‐induced toxicity for 2 crustaceans, Daphnia magna and Asellus aquaticus, and for 1 out of 2 tested insect species, Cloeon dipterum. We observed no toxic effects for Chironomus riparius at the time‐weighted average test concentration of 0.51 μg thiacloprid/L. For D. magna, the observed toxicity, expressed as the lowest‐observed‐effect concentration (LOEC), on growth and reproduction was present at thiacloprid concentrations that were 2456‐fold lower than laboratory‐derived LOEC values. This shows that these species, when exposed under natural conditions, may exhibit neonicotinoid‐induced toxic stress. Contrary to the low nutrient treatment, such toxicity was often not observed under nutrient‐enriched conditions. This was likely attributable to the increased primary production that allowed for compensatory feeding. These findings warrant the inclusion of different feeding regimes in laboratory experiments to retrieve the best estimates of neonicotinoid‐induced toxicity in the natural environment. Environ Toxicol Chem 2018;37:1907–1915. © 2018 SETAC

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Multiple-stressor effects of sediment, phosphorus and nitrogen on stream macroinvertebrate communities

Title
Multiple-stressor effects of sediment, phosphorus and nitrogen on stream macroinvertebrate communities

Publication Type
Journal Article

Year of Publication
2018

Authors

Davis SJ, Ó hUallacháina D, Mellander PE, Kelly AM, Matthaei CD, Piggott JJ, Kelly-Quinn M

Journal
Science of The Total Environment

Volume
637-638

Pagination
577-587

ISBN Number

Keywords

Agricultural stressors, Mesocosm experiment, Invertebrate drift, Nutrients, Europe

Abstract

Multiple stressors affect stream ecosystems worldwide and their interactions are of particular concern, with gaps existing in understanding stressor impacts on stream communities. Addressing these knowledge gaps will aid in targeting and designing of appropriate mitigation measures. In this study, the agricultural stressors fine sediment (ambient, low, medium, high), phosphorus (ambient, enriched) and nitrogen (ambient, enriched) were manipulated simultaneously in 64 streamside mesocosms to determine their individual and combined effects on the macroinvertebrate community (benthos and drift). Stressor levels were chosen to reflect those typically observed in European agricultural streams. A 21-day colonisation period was followed by a 14-day manipulative period. Results indicate that added sediment had the most pervasive effects, significantly reducing total macroinvertebrate abundance, total EPT abundance and abundances of three common EPT taxa. The greatest effect was at high sediment cover (90%), with decreasing negative impacts at medium (50%) and low (30%) covers. Added sediment also led to higher drift propensities for nine of the twelve drift variables. The effects of nitrogen and phosphorus were relatively weak compared to sediment. Several complex and unpredictable 2-way or 3-way interactions among stressors were observed. While sediment addition generally reduced total abundance at high levels, this decrease was amplified by P enrichment at low sediment, whereas the opposite effect occurred at medium sediment and little effect at high sediment. These results have direct implications for water management as they highlight the importance of managing sediment inputs while also considering the complex interactions which can occur between sediment and nutrient stressors.

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A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum

Title
A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum

Publication Type
Journal Article

Year of Publication
2016

Authors

Sordo L​, Santos R, Reis J, Shulika A, Silva J

Journal
PeerJ

Volume

Pagination

ISBN Number

Keywords

Control system, Ocean acidification (OA), CO2 bubbling, Coralline algae

Abstract
 

Most ocean acidification (OA) experimental systems rely on pH as an indirect way to control CO2. However, accurate pH measurements are difficult to obtain and shifts in temperature and/or salinity alter the relationship between pH and pCO2. Here we describe a system in which the target pCO2 is controlled via direct analysis of pCO2 in seawater. This direct type of control accommodates potential temperature and salinity shifts, as the target variable is directly measured instead of being estimated. Water in a header tank is permanently re-circulated through an air-water equilibrator. The equilibrated air is then routed to an infrared gas analyzer (IRGA) that measures pCO2 and conveys this value to a Proportional-Integral-Derivative (PID) controller. The controller commands a solenoid valve that opens and closes the CO2 flush that is bubbled into the header tank. This low-cost control system allows the maintenance of stabilized levels of pCO2 for extended periods of time ensuring accurate experimental conditions. This system was used to study the long term effect of OA on the coralline red algae Phymatolithon lusitanicum. We found that after 11 months of high CO2 exposure, photosynthesis increased with CO2 as opposed to respiration, which was positively affected by temperature. Results showed that this system is adequate to run long-term OA experiments and can be easily adapted to test other relevant variables simultaneously with CO2, such as temperature, irradiance and nutrients.

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Genomewide transcriptional reprogramming in the seagrass Cymodocea nodosa under experimental ocean acidification

Title
Genomewide transcriptional reprogramming in the seagrass Cymodocea nodosa under experimental ocean acidification

Publication Type
Journal Article

Year of Publication
2017

Authors

Ruocco M, Musacchia F, Olivé I, Costa MM, Barrote I, Santos R, Sanges R, Procaccini G, Silva J

Journal
Molecular Ecology

Volume
26

Pagination
4241-4259

ISBN Number

Keywords

carbohydrate metabolism, Cymodocea nodosa, ocean acidification, protein folding, seagrasses, transcriptome

Abstract

Here, we report the first use of massive‐scale RNA‐sequencing to explore seagrass response to CO2‐driven ocean acidification (OA). Large‐scale gene expression changes in the seagrass Cymodocea nodosa occurred at CO2 levels projected by the end of the century. C. nodosa transcriptome was obtained using Illumina RNA‐Seq technology and de novo assembly, and differential gene expression was explored in plants exposed to short‐term high CO2/low pH conditions. At high pCO2, there was a significant increased expression of transcripts associated with photosynthesis, including light reaction functions and CO2 fixation, and also to respiratory pathways, specifically for enzymes involved in glycolysis, in the tricarboxylic acid cycle and in the energy metabolism of the mitochondrial electron transport. The upregulation of respiratory metabolism is probably supported by the increased availability of photosynthates and increased energy demand for biosynthesis and stress‐related processes under elevated CO2 and low pH. The upregulation of several chaperones resembling heat stress‐induced changes in gene expression highlighted the positive role these proteins play in tolerance to intracellular acid stress in seagrasses. OA further modifies C. nodosa secondary metabolism inducing the transcription of enzymes related to biosynthesis of carbon‐based secondary compounds, in particular the synthesis of polyphenols and isoprenoid compounds that have a variety of biological functions including plant defence. By demonstrating which physiological processes are most sensitive to OA, this research provides a major advance in the understanding of seagrass metabolism in the context of altered seawater chemistry from global climate change.

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High CO2 decreases the long-term resilience of the free-living coralline algae Phymatolithon lusitanicum

Title
High CO2 decreases the long-term resilience of the free-living coralline algae Phymatolithon lusitanicum

Publication Type
Journal Article

Year of Publication
2018

Authors

Sordo L, Santos R, Barrote I, Silva J

Journal
Ecology and Evolution

Volume

Pagination

ISBN Number

Keywords

calcification, coralline algae, long-term, ocean acidification, photosynthesis, photosynthetic pigments, Phymatolithon lusitanicum, respiration, southern Portugal

Abstract
Mäerl/rhodolith beds are protected habitats that may be affected by ocean acidification (OA), but it is still unclear how the availability of CO2 will affect the metabolism of these organisms. Some of the inconsistencies found among OA experimental studies may be related to experimental exposure time and synergetic effects with other stressors. Here, we investigated the long-term (up to 20 months) effects of OA on the production and calcification of the most common mäerl species of southern Portugal, Phymatolithon lusitanicum. Both the photosynthetic and calcification rates increased with CO2 after the first 11 months of the experiment, whereas respiration slightly decreased with CO2 . After 20 months, the pattern was reversed. Acidified algae showed lower photosynthetic and calcification rates, as well as lower accumulated growth than control algae, suggesting that a metabolic threshold was exceeded. Our results indicate that long-term exposure to high CO2 will decrease the resilience of Phymatolithon lusitanicum . Our results also show that shallow communities of these rhodoliths may be particularly at risk, while deeper rhodolith beds may become ocean acidification refuges for this biological community.
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A mesocosm concept for the simulation of near-natural shallow underwater climates: The Kiel Outdoor Benthocosms (KOB)

Title
A mesocosm concept for the simulation of near-natural shallow underwater climates: The Kiel Outdoor Benthocosms (KOB)

Publication Type
Journal Article

Year of Publication
2015

Authors

Wahl M, Buchholz B, Winde V, Golomb D, Guy-Haim T, Müller J,
Rilov G, Scotti M, Böttcher ME

Journal
LIMNOLOGY and OCEANOGRAPHY: Methods

Volume

Pagination

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Keywords

Abstract

Biogenic, seasonal, and stochastic fluctuations at various scales characterize coastal marine habitats and modulate environmental stress. The relevance of most past studies into climate change impacts is weakened by the usually intentional  exclusion of fluctuations from the experimental design. We describe a new outdoor mesocosm system for benthic research (“benthocosms”) which permit the control and manipulation of several environmental variables while admitting all natural in situ fluctuations. This is achieved by continuously measuring the relevant variables (e.g., temperature, pH, O2, CO2) in situ, defining these in real time as reference values in the control software and simulating target climates by delta treatments. The latter constitute the manipulative addition of predefined changes (e.g., “warming”, “acidification”) to the reference values. We illustrate the performance of the system by presenting the environmental data of four seasonal experiments which together represent an entire year. The “Kiel Outdoor Benthocosms” allow realizing nearnatural climate change experiments on complex benthic communities under controlled scenarios.

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Molecular and physiological responses of two classes of marine chromophytic phytoplankton (Diatoms and Prymnesiophytes) during the development of nutrient stimulated blooms

Title
Molecular and physiological responses of two classes of marine chromophytic phytoplankton (Diatoms and Prymnesiophytes) during the development of nutrient stimulated blooms
Publication Type
Journal Article
Year of Publication
2000
Authors

Wyman M, Davies JT, Crawford DW, Purdie DA

Journal
Applied and Environmental Microbiology
Volume
66
Pagination
2349-2357
ISBN Number
Keywords

mesocosm, Bergen, Espergend, 11 m3, nutrient addition, phytoplankton, DNA probes, RubisCO, Primary production, Norway

Abstract
URL
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Improving marine ecosystem models: Use of data assimilation and mesocosm experiments

Title
Improving marine ecosystem models: Use of data assimilation and mesocosm experiments
Publication Type
Journal Article
Year of Publication
2000
Authors

Vallino JJ

Journal
Journal of Marine Research
Volume
58
Pagination
117-164
ISBN Number
Keywords

mesocosm, model, parameter estimation, DOM, 7 m3, Woods Hole Great Harbor, USA

Abstract
URL
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