Sequential rather than interactive effects of multiple stressors as drivers of phytoplankton community change in a large lake

2017 ◽  
Vol 62 (7) ◽  
pp. 1288-1302 ◽  
Author(s):  
Noreen E. Kelly ◽  
Joelle D. Young ◽  
Jennifer G. Winter ◽  
Michelle E. Palmer ◽  
Eleanor A. Stainsby ◽  
...  
Keyword(s):  
Phytoplankton Community ◽  
Multiple Stressors ◽  
Community Change ◽  
Interactive Effects ◽  
Large Lake

Can Indirect Herbicide Exposure Modify the Response of the Colorado Potato Beetle to an Organophosphate Insecticide?

2019 ◽  
Vol 112 (5) ◽  
pp. 2316-2323 ◽  
Author(s):  
Aigi Margus ◽  
Miia Rainio ◽  
Leena Lindström
Keyword(s):  
Colorado Potato Beetle ◽  
Target Genes ◽  
Multiple Stressors ◽  
Synergistic Effects ◽  
Oxidative Status ◽  
Interactive Effects ◽  
Invasive Pest ◽  
Lipid Hydroperoxides ◽  
Organophosphate Insecticide ◽  
Potato Beetle

AbstractOrganisms live in complex multivariate environments. In agroecosystems, this complexity is often human-induced as pest individuals can be exposed to many xenobiotics simultaneously. Predicting the effects of multiple stressors can be problematic, as two or more stressors can have interactive effects. Our objective was to investigate whether indirect glyphosate-based herbicide (GBH) exposure of the host plant has interactive effects in combination with an insecticide (azinphos-methyl) on an invasive pest Colorado potato beetle (Leptinotarsa decemlineata Say). We tested the effects of GBH and insecticide on the survival, insecticide target genes expression (acetylcholinesterase genes) and oxidative status biomarkers (glutathione S-transferase [GST], glucose-6-phosphate dehydrogenase [G6PDH], glutathione reductase homolog [GR], glutathione peroxidase homolog [GPx], total glutathione [totGSH], glutathione reduced-oxidized [GSH: GSSG], catalase [CAT], superoxide dismutase [SOD], lipid hydroperoxides). We found that exposure to indirect GBH has no single or interactive effects in combination with the insecticide on larval survival. However, prior exposure to GBH inhibits Ldace1 gene expression by 0.55-fold, which is the target site for the organophosphate and carbamate insecticides. This difference disappears when individuals are exposed to both GBH and insecticide, suggesting an antagonistic effect. On the other hand, oxidative status biomarker scores (PCAs of GPx, GR, and CAT) were decreased when exposed to both stressors, indicating a synergistic effect. Overall, we found that indirect GBH exposure can have both antagonistic and synergistic effects in combination with an insecticide, which should be considered when aiming for an ecologically relevant risk assessment of multiple human-induced stressors.

scholarly journals Invasion-mediated effects on marine trophic interactions in a changing climate: positive feedbacks favour kelp persistence

2019 ◽  
Vol 286 (1899) ◽  
pp. 20182866 ◽  
Author(s):  
Ricardo J. Miranda ◽  
Melinda A. Coleman ◽  
Alejandro Tagliafico ◽  
Maria S. Rangel ◽  
Lea T. Mamo ◽  
...  
Keyword(s):  
Climate Change ◽  
Trophic Interactions ◽  
Multiple Stressors ◽  
Grazing Intensity ◽  
Ocean Warming ◽  
Interactive Effects ◽  
Ecological Change ◽  
Climate Change Scenarios ◽  
Ecological Consequences ◽  
Management Actions

The interactive effects of ocean warming and invasive species are complex and remain a source of uncertainty for projecting future ecological change. Climate-mediated change to trophic interactions can have pervasive ecological consequences, but the role of invasion in mediating trophic effects is largely unstudied. Using manipulative experiments in replicated outdoor mesocosms, we reveal how near-future ocean warming and macrophyte invasion scenarios interactively impact gastropod grazing intensity and preference for consumption of foundation macroalgae ( Ecklonia radiata and Sargassum vestitum ). Elevated water temperature increased the consumption of both macroalgae through greater grazing intensity. Given the documented decline of kelp ( E. radiata ) growth at higher water temperatures, enhanced grazing could contribute to the shift from kelp-dominated to Sargassum -dominated reefs that is occurring at the low-latitude margins of kelp distribution. However, the presence of a native invader ( Caulerpa filiformis ) was related to low consumption by the herbivores on dominant kelp at warmer temperatures. Thus, antagonistic effects between climate change and a range expanding species can favour kelp persistence in a warmer future. Introduction of species should, therefore, not automatically be considered unfavourable under climate change scenarios. Climatic changes are increasing the need for effective management actions to address the interactive effects of multiple stressors and their ecological consequences, rather than single threats in isolation.

Multiple Stable Configurations in Ordination of Phytoplankton Community Change Rates

Ecology ◽  
1977 ◽  
Vol 58 (5) ◽  
pp. 1076-1084 ◽  
Author(s):  
T. F. H. Allen ◽  
Steven M. Bartell ◽  
Joseph F. Koonce
Keyword(s):  
Phytoplankton Community ◽  
Community Change

A biomarker record of temperature and phytoplankton community structure in the Okinawa Trough since the last glacial maximum

2017 ◽  
Vol 88 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Jiaping Ruan ◽  
Yunping Xu ◽  
Su Ding ◽  
Yinghui Wang ◽  
Xinyu Zhang
Keyword(s):  
Phytoplankton Community ◽  
Okinawa Trough ◽  
Kuroshio Current ◽  
Community Change ◽  
Community Structures ◽  
Ocean Drilling Program ◽  
The Holocene ◽  
The Okinawa Trough ◽  
The Kuroshio ◽  
The Last Glacial

AbstractA variety of biomarkers were examined from Ocean Drilling Program Core 1202B to reconstruct temperature and phytoplankton community structures in the southern Okinawa Trough since 20 ka. Two molecular temperature proxies ( $${\rm U}_{{37}}^{{{\rm K}\prime}} $$ and TEX86) show 5°C to ~6°C warming during the glacial-interglacial transition. Prior to the Holocene, the $${\rm U}_{{37}}^{{{\rm K}\prime}} $$ -derived temperature was generally 1°C to 4°C higher than TEX86-derived temperature. This difference, however, was reduced to <1°C in the Holocene. Correspondingly, the phytoplankton biomarkers (e.g., C37:2 alkenone, brassicasterol, C30 1,15 diol, and dinosterol) indicate a shift of planktonic community structures, with coccolithophorids becoming more abundant in the Holocene at the expense of diatoms/dinoflagellates. This shift is related to the variability of nutrients, temperature, and salinity in the Okinawa Trough, likely controlled by the sea level and the intensity of the Kuroshio Current. The phytoplankton community change may have had profound implications for atmospheric CO2 fluctuations during glacial-interglacial cycles since diatoms and dinoflagellates have a higher efficiency of the biological pump than coccolithophorids.

scholarly journals Variable responses of temperate calcified and fleshy macroalgae to elevated pCO2 and warming

2015 ◽  
Vol 73 (3) ◽  
pp. 693-703 ◽  
Author(s):  
S. L. Kram ◽  
N. N. Price ◽  
E. M. Donham ◽  
M. D. Johnson ◽  
E. L. A. Kelly ◽  
...  
Keyword(s):  
Growth Rates ◽  
Photosynthetic Efficiency ◽  
Multiple Stressors ◽  
Negative Impact ◽  
Co2 Enrichment ◽  
Elevated Pco2 ◽  
Interactive Effects ◽  
Calcareous Algae ◽  
High Pco2 ◽  
Physiological Tolerance

Abstract Anthropogenic carbon dioxide (CO2) emissions simultaneously increase ocean temperatures and reduce ocean surface pH, a process termed ocean acidification (OA). OA is expected to negatively affect the growth and physiology of many calcified organisms, but the response of non-calcified (fleshy) organisms is less well understood. Rising temperatures and pCO2 can enhance photosynthetic rates (within tolerance limits). Therefore, warming may interact with OA to alter biological responses of macroalgae in complicated ways. Beyond thresholds of physiological tolerance, however, rising temperatures could further exacerbate negative responses to OA. Many studies have investigated the effects of OA or warming independently of each other, but few studies have quantified the interactive effects of OA and warming on marine organisms. We conducted four short-term independent factorial CO2 enrichment and warming experiments on six common species of calcified and fleshy macroalgae from southern California to investigate the independent and interactive effects of CO2 and warming on growth, carbonic anhydrase (CA) enzyme activity, pigment concentrations, and photosynthetic efficiency. There was no effect of elevated pCO2 on CA activity, pigment concentration, and photosynthetic efficiency in the macroalgal species studies. However, we found that calcareous algae suffered reduced growth rates under high pCO2 conditions alone, although the magnitude of the effect varied by species. Fleshy algae had mixed responses of growth rates to high pCO2, indicating that the effects of pCO2 enrichment are inconsistent across species. The combined effects of elevated pCO2 and warming had a significantly negative impact on growth for both fleshy and calcareous algae; calcareous algae experienced five times more weight loss than specimens in ambient control conditions and fleshy growth was reduced by 76%. Our results demonstrate the need to study the interactive effects of multiple stressors associated with global change on marine communities.

scholarly journals A review of the effects of Bythotrephes longimanus and calcium decline on zooplankton communities — can interactive effects be predicted?

2015 ◽  
Vol 23 (4) ◽  
pp. 395-413 ◽  
Author(s):  
Shakira S.E. Azan ◽  
Shelley E. Arnott ◽  
Norman D. Yan
Keyword(s):  
Multiple Stressors ◽  
Current Knowledge ◽  
Canadian Shield ◽  
Interactive Effects ◽  
Bythotrephes Longimanus ◽  
Negative Impacts ◽  
The Individual ◽  
Zooplankton Communities ◽  
Shield Lakes ◽  
Review Current

Anthropogenic stressors including acid deposition, invasive species, and calcium (Ca) decline have produced widespread damage to Canadian Shield lakes, especially to their zooplankton communities. Here, we review current knowledge on the individual effects on zooplankton by the non-indigenous predator Bythotrephes longimanus and Ca decline; we identify knowledge gaps in this literature and examine the likely interactive impacts of Bythotrephes invasions and Ca decline on zooplankton. The negative impacts of Bythotrephes longimanus on zooplankton communities are well known, whereas current understanding of the effects of declining Ca on zooplankton is restricted to Daphnia spp.; hence, there is a large knowledge gap on how declining Ca may affect zooplankton communities in general. The co-occurring impacts of Bythotrephes and declining Ca have rarely been studied at the species level, and we expect daphniids, particularly Daphnia retrocurva and Daphnia pulicaria, to be the most sensitive to both stressors. We also expect a synergistic negative interaction on cladocerans in lakes with both stressors, leaving a community dominated by Holopedium glacialis and (or) copepods. Our predictions form testable hypotheses but since species and ecosystem response to multiple stressors are difficult to predict, we may actually see ecological surprises in Canadian Shield lakes as Bythotrephes continues to spread and Ca levels continue to fall.

scholarly journals Multiple stressors and recruitment failure of long-lived endangered freshwater mussels with a complex life cycle

2021 ◽  
Author(s):  
Kazuki Miura ◽  
Nobuo Ishiyama ◽  
Junjiro N Negishi ◽  
Daisetsu Ito ◽  
Keita Kawajiri ◽  
...  
Keyword(s):  
Survival Rate ◽  
Multiple Stressors ◽  
Life Cycles ◽  
Fine Sediment ◽  
Interactive Effects ◽  
Complex Life Cycle ◽  
Juvenile Survival ◽  
Study Region ◽  
Positive Effects ◽  
Juvenile Stages

Multiple stressors can interactively affect the population of organisms; however, the process by which they affect recruitment efficiency remains unclear for empirical populations. Recruitment efficiency can be regulated at multiple stages of life, particularly in organisms with complex life cycles. Understanding the interactive effects of multiple stressors on recruitment efficiency and determining the bottleneck life stages is imperative for species conservation. The proportion of <20-year-old juveniles of the endangered freshwater pearl mussel Margaritifera togakushiensis, which has an obligate parasitic larval stage, was investigated in 24 rivers from eastern Hokkaido, northern Japan to reveal the influence of nutrients, fine sediment, and their combined effects on juvenile recruitment efficiency. The following indices for recruitment at adult, parasitic, and post-parasitic juvenile stages were obtained from 11 of these rivers: gravid female density, glochidia density (the number of glochidia infections per stream area), and juvenile survival rate. This study explored the bottleneck stages of recruitment efficiency and the interactive effects of the two stressors on these stages. Twenty-four population status assessments determined that the proportion of juveniles ranged from 0.00 to 0.53, and juveniles were absent from four rivers. The results showed that the parasitic and post-parasitic juvenile stages were bottlenecks for recruitment efficiency. Juvenile survival rates had a more significant positive effect on recruitment efficiency in rivers with a high glochidia density. Juvenile survival rate was decreased by the synergistic interaction of nutrients and fine sediment, although factors limiting glochidia density were not found. The nutrient concentration of rivers in the study region was well explained by the proportion of agricultural land cover and urban areas in the watersheds, but no relationship was detected between fine sediment abundance and land use. This study suggests that nutrient management at a catchment scale can be effective for re-establishing the recruitment of M. togakushiensis, particularly in rivers with a high content of fine sediments. The results also emphasise the importance of considering both parasitic and post-parasitic juvenile stages of mussels to maximise the positive effects of stressor mitigation.

scholarly journals Multiple stressors and disturbance effects on eelgrass and epifaunal macroinvertebrate assemblage structure

2021 ◽  
Vol 657 ◽  
pp. 93-108
Author(s):  
S Cimon ◽  
A Deslauriers ◽  
M Cusson
Keyword(s):  
Nutrient Enrichment ◽  
Field Experiments ◽  
Multiple Stressors ◽  
Shoot Density ◽  
Assemblage Structure ◽  
Interactive Effects ◽  
Anthropogenic Pressure ◽  
Ecosystem Structure ◽  
Density Reduction ◽  
External Forces

Multiple forms of environmental change and anthropogenic pressure co-occur in coastal marine ecosystems. These external forces affect ecosystem structure, functioning, and, eventually, services to humans. Studies that include more than 2 simultaneous stressors are still needed to understand potential interactions among multiple stressors. We evaluated single and interactive effects of density reduction of Zostera marina L. (a habitat-forming species), shading, and sediment nutrient enrichment on the response of Z. marina and its associated epifauna over 10 wk. Shading had the greatest effect on reducing the eelgrass relative leaf elongation rate (RLE), non-structural carbohydrate reserves, and eelgrass shoot density. A reduced eelgrass density sustained higher epifaunal densities and increased the eelgrass RLE. Sediment nutrient enrichment increased eelgrass shoot density but decreased epifaunal richness, diversity, and total abundance. Our disturbance and pair of stressors differed in their influence on diversity measures, but all affected assemblage structure. Most of the changes to the epifaunal assemblage and diversity likely occurred due to altered habitat availability and epiphytic algae load. We observed additive, antagonistic, and negatively synergistic interactions among our treatments, while most of the cumulative effects showed dominance by one stressor over another. Our results highlight the importance of field experiments that are based on multiple disturbances and stressors to determine their interaction type on communities.

scholarly journals Experimentally decomposing phytoplankton community change into ecological and evolutionary contributions

2021 ◽  
Author(s):  
Giannina S. I. Hattich ◽  
Luisa Listmann ◽  
Lynn Govaert ◽  
Christian Pansch ◽  
Thorsten B. H. Reusch ◽  
...  
Keyword(s):  
Phytoplankton Community ◽  
Community Change
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