Health & Environmental Research Online (HERO)


ISA NOxSOxPM Ecology (2018)

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290 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Development of an epiphyte indicator of nutrient enrichment: A critical evaluation of observational and experimental studies

Author: Nelson, WG (2017) HERO ID: 4127888

[Less] An extensive review of the literature describing epiphytes on submerged aquatic vegetation (SAV), especially . . . [More] An extensive review of the literature describing epiphytes on submerged aquatic vegetation (SAV), especially seagrasses, was conducted in order to evaluate the evidence for response of epiphyte metrics to increased nutrients. Evidence from field observational studies, together with laboratory and field mesocosm experiments, was assembled from the literature and evaluated for a hypothesized positive response to nutrient addition. There was general consistency in the results to confirm that elevated nutrients tended to increase the load of epiphytes on the surface of SAV, in the absence of other limiting factors. In spite of multiple sources of uncontrolled variation, positive relationships of epiphyte load to nutrient concentration or load (either nitrogen or phosphorus) often were observed along strong anthropogenic or natural nutrient gradients in coastal regions. Such response patterns may only be evident for parts of the year. Results from both mesocosm and field experiments also generally support the increase of epiphytes with increased nutrients, although outcomes from field experiments tended to be more variable. Relatively few studies with nutrient addition in mesocosms have been done with tropical or subtropical species, and more such controlled experiments would be helpful. Experimental duration influenced results, with more positive responses of epiphytes to nutrients at shorter durations in mesocosm experiments versus more positive responses at longer durations in field experiments. In the field, response of epiphyte biomass to nutrient additions was independent of climate zone. Mesograzer activity was a critical covariate for epiphyte response under experimental nutrient elevation, but the epiphyte response was highly dependent on factors such as grazer identity and density, as well as nutrient and ambient light levels. The balance of evidence suggests that epiphytes on SAV will be a useful indicator of persistent nutrient enhancement in many situations. Careful selection of appropriate temporal and spatial constraints for data collection, and concurrent evaluation of confounding factors will help increase the signal to noise ratio for this indicator.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Forty years of seagrass population stability and resilience in an urbanizing estuary

Authors: Shelton, AO; Francis, TB; Feist, BE; Williams, GD; Lindquist, A; Levin, PS (2017) HERO ID: 3941193

[Less] Coasts and estuaries contain among the most productive and ecologically important habitats in the world . . . [More] Coasts and estuaries contain among the most productive and ecologically important habitats in the world and face intense pressure from current and projected human activities, including coastal development. Seagrasses are a key habitat feature in many estuaries perceived to be in widespread decline owing to human actions.

We use spatio-temporal models and a 41-year time series from 100s of km of shoreline which includes over 160 000 observations from Puget Sound, Washington, USA, to examine multiscale trends and drivers of eelgrass (Zostera spp.) change in an urbanizing estuary.

At whole estuary scale (100s of km), we find a stable and resilient eelgrass population despite a more than doubling of human population density and multiple major climactic stressors (e. g. ENSO events) over the period. However, the aggregate trend is not reflected at the site scale (10s of km), where some sites persistently increase while others decline.

Site trends were spatially asynchronous; adjacent sites sometimes exhibited opposite trends over the same period. Substantial change in eelgrass occurred at the subsite (0 1 km) scale, including both complete local loss and dramatic increase of eelgrass.

Metrics of local human development including shoreline armouring, upland development (imperviousness) and human density provide no explanatory power for eelgrass population change at any spatial scale.

Our results suggest that the appropriate scale for understanding eelgrass change is smaller than typically assumed (approximately 1-to 3-km scale) and contrasts strongly with previous work.

Synthesis. Despite ongoing conservation concern over seagrasses world-wide, eelgrass in Puget Sound has been highly resilient to both anthropogenic and environmental change over four decades. Our work provides general methods that can be applied to understand spatial and temporal scales of change and can be used to assess hypothesized drivers of change.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Responses of juvenile Atlantic silverside, striped killifish, mummichog, and striped bass to acute hypoxia and acidification: Aquatic surface respiration and survival

Authors: Dixon, RL; Grecay, PA; Targett, TE (2017) Journal of Experimental Marine Biology and Ecology 493:20-30. HERO ID: 3941446

[Less] Diel fluctuations in dissolved oxygen (DO) and pH create hypoxic conditions that alter the quality of . . . [More] Diel fluctuations in dissolved oxygen (DO) and pH create hypoxic conditions that alter the quality of shallow estuarine nursery habitats for juvenile fishes. Understanding how different species in these environments mitigate stress associated with intermittent hypoxia through compensatory behaviors, such as aquatic surface respiration (ASR), is important in determining the effect of these stressors on estuarine ecosystems. Behavioral responses of Atlantic silversides (Menidia menidia), striped killifish (Fundulus majalis), mummichog (Fundulus heteroclitus), and juvenile striped bass (Morone saxatilis) were independently observed during exposure to two levels of diel-cycling DO (3-9 mg O(2)l(-1) and 1-11 mg O(2)l(-1)) each tested with both the corresponding pH cycle (7.2-7.8 and 6.8-8.1, respectively) and static pH (7.5) under controlled laboratory conditions. In treatments in which DO declined to similar to 3 mg O(2)l(-1) none of the species examined exhibited ASR behavior either with or without the associated pH decline. However, ASR was observed during both 4-hour and extended 16-hour exposure where DO declined to similar to 1.0-1.6 mg O(2)l(-1) in M. menidia and both Fundulus species. M. saxatilis did not exhibit ASR and no mortalities occurred during 4-hour low DO/pH treatments or during 16 hour exposure to 1.5 mg O(2)l(-1). During extended 16-hour treatments, DO thresholds for ASR were not found to be different between F. majalis and F. heteroclitus, but both differed significantly from M. menidia. Across both 4-hour and 16 hour treatments, the onset of ASR was observed in M. menidia at or near lethal levels (1.31-1.62 mg O(2)l(-1)). No evidence of a pH (pCO2) effect on ASR or survival was found in any species in response to naturally co-varying DO and pH swings, despite pH as low as 6.8 and high pCO(2) levels of > similar to 12,000 mu atm. These results suggest that utilization of ASR is a species-specific response influenced by the magnitude and duration of hypoxic exposure. ASR may serve as a last-ditch strategy by M. menidia to prolong survival for minutes to hours, but function as a means for F. heteroclitus to mitigate or reduce negative effects of hypoxia on a scale of days to weeks, with F. majalis exhibiting an intermediate response.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Spatial differentiation of marine eutrophication damage indicators based on species density

Authors: Cosme, N; Jones, MC; Cheung, WWL; Larsen, HF (2017) Ecological Indicators 73:676-685. HERO ID: 3941448

[Less] Marine eutrophication refers to an ecosystem response to the loading of nutrients, typically nitrogen . . . [More] Marine eutrophication refers to an ecosystem response to the loading of nutrients, typically nitrogen (N), to coastal waters where several impacts may occur. The increase of planktonic growth due to N-enrichment fuels the organic carbon cycles and may lead to excessive oxygen depletion in benthic waters. Such hypoxic conditions may cause severe effects on exposed ecological communities. The biologic processes that determine production, sink, and aerobic respiration of organic material, as a function of available N, are coupled with the sensitivity of demersal species to hypoxia to derive an indicator of the Ecosystem Response (ER) to N-uptake. The loss of species richness expressed by the ER is further modelled to a marine eutrophication Ecosystem Damage (meED) indicator, as an absolute metric of time integrated number of species disappeared (species yr), by applying a newly-proposed and spatially-explicit factor based on species density (SD). The meED indicator is calculated for 66 Large Marine Ecosystems and ranges from 1.6 x 10(-12) species kgN(-1) in the Central Arctic Ocean, to 4.8 x 10(-8) species kgN-1 in the Northeast U.S. Continental Shelf. The spatially explicit SDs contribute to the environmental relevance of meED scores and to the harmonisation of marine eutrophication impacts with other ecosystem-damage Life Cycle Impact Assessment (LCIA) indicators. The novel features improve current methodologies and support the adoption of the meED indicator in LCIA for the characterization of anthropogenic-N emissions and thus contributing to the sustainability assessment of human activities. (C) 2016 Elsevier Ltd. All rights reserved.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Sex in murky waters: algal-induced turbidity increases sexual selection in pipefish

Authors: Sundin, J; Aronsen, T; Rosenqvist, G; Berglund, A (2017) Behavioral Ecology and Sociobiology 71:78. HERO ID: 3942469

[Less] ABSTRACT: Algal-induced turbidity has been shown to alter several important aspects . . . [More] ABSTRACT: Algal-induced turbidity has been shown to alter several important aspects of reproduction and sexual selection. However, while turbidity has been shown to negatively affect reproduction and sexually selected traits in some species, it may instead enhance reproductive success in others, implying that the impact of eutrophication is far more complex than originally believed. In this study, we aimed to provide more insight into these inconsistent findings. We used molecular tools to investigate the impact of algal turbidity on reproductive success and sexual selection on males in controlled laboratory experiments, allowing mate choice, mating competition, and mate encounter rates to affect reproduction. As study species, we used the broad-nosed pipefish, Syngnathus typhle, a species practicing male pregnancy and where we have previously shown that male mate choice is impaired by turbidity. Here, turbidity instead enhanced sexual selection on male size and mating success as well as reproductive success. Effects from mating competition and mate encounter rates may thus override effects from mate choice based on visual cues, producing an overall stronger sexual selection in turbid waters. Hence, seemingly inconsistent effects of turbidity on sexual selection may depend on which mechanisms of sexual selection that have been under study.

SIGNIFICANCE STATEMENT: Algal blooms are becoming increasingly more common due to eutrophication of freshwater and marine environments. The high density of algae lowers water transparency and reduces the possibility for fish and other aquatic animals to perform behaviors dependent on vision. We have previously shown that pipefish are unable to select the best partner in mate choice trials when water transparency was reduced. However, fish might use other senses than vision to compensate for the reduction in water transparency. In this study, we found that when fish were allowed to freely interact, thereby allowing competition between partners and direct contact between the fish, the best partner was indeed chosen. Hence, the negative effects of reduced water visibility due to algal blooms may be counteracted by the use of other senses in fish.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Eutrophication-induced acidification of coastal waters in the northern Gulf of Mexico: Insights into origin and processes from a coupled physical-biogeochemical model

Authors: Laurent, A; Fennel, K; Cai, WeiJun; Huang, WeiJen; Barbero, L; Wanninkhof, Rik (2017) Geophysical Research Letters 44:946-956. HERO ID: 3942476

[Less] Nutrient inputs from the Mississippi/Atchafalaya River system into the northern Gulf of Mexico promote . . . [More] Nutrient inputs from the Mississippi/Atchafalaya River system into the northern Gulf of Mexico promote high phytoplankton production and lead to high respiration rates. Respiration coupled with water column stratification results in seasonal summer hypoxia in bottom waters on the shelf. In addition to consuming oxygen, respiration produces carbon dioxide (CO2), thus lowering the pH and acidifying bottom waters. Here we present a high-resolution biogeochemical model simulating this eutrophication-driven acidification and investigate the dominant underlying processes. The model shows the recurring development of an extended area of acidified bottom waters in summer on the northern Gulf of Mexico shelf that coincides with hypoxic waters. Not reported before, acidified waters are confined to a thin bottom boundary layer where the production of CO2 by benthic metabolic processes is dominant. Despite a reduced saturation state, acidified waters remain supersaturated with respect to aragonite.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Fisheries, low oxygen and climate change: how much do we really know?

Authors: Townhill, BL; Pinnegar, JK; Righton, DA; Metcalfe, JD (2017) HERO ID: 3942501

[Less] As a result of long-term climate change, regions of the ocean with low oxygen concentrations are predicted . . . [More] As a result of long-term climate change, regions of the ocean with low oxygen concentrations are predicted to occur more frequently and persist for longer periods of time in the future. When low levels of oxygen are present, this places additional pressure on marine organisms to meet their metabolic requirements, with implications for growth, feeding and reproduction. Extensive research has been carried out on the effects of acute hypoxia, but far less on long-term chronic effects of low oxygen zones, especially with regard to commercially important fishes and shellfishes. To provide further understanding on how commercial species could be affected, the results of relevant experiments must support population and ecosystem models. This is not easy because individual effects are wide-ranging; for example, studies to date have shown that low oxygen zones can affect predator-prey relationships as some species are able to tolerate low oxygen more than others. Some fishes may move away from areas until oxygen levels return to acceptable levels, while others take advantage of a reduced start response in prey fishes and remain in the area to feed. Sessile or less mobile species such as shellfishes are unable to move out of depleted oxygen zones. Some species can tolerate low oxygen levels for only short periods of time, while others are able to acclimatize. To advance the knowledge-base further, a number of promising technological and modelling-based developments and the role of physiological data within these, are proposed. These include advances in remote telemetry (tagging) and sensor technologies, trait-based analyses to provide insight into how whole assemblages might respond in the future, research into long-term adaptability of species, population and ecosystem modelling techniques and quantification of economic effects. In addition, more detailed oxygen monitoring and projections are required to better understand the likely temporal and local-scale changes in oxygen.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Seagrass wasting disease: Nitrate enrichment and exposure to a herbicide (Diuron) increases susceptibility of Zostera marina to infection

Authors: Hughes, RG; Potouroglou, M; Ziauddin, Z; Nicholls, JC (2017) Marine Pollution Bulletin. HERO ID: 4122207

[Less] Seagrass meadows suffered large-scale declines in the past century. The 'wasting disease', pathognomonically . . . [More] Seagrass meadows suffered large-scale declines in the past century. The 'wasting disease', pathognomonically associated with Labyrinthula zosterae, reduced populations of Zostera marina on both sides of the North Atlantic in, and since, the 1930s, coinciding with intensive agricultural use of artificial fertilizers and herbicides. This study tests the long-standing hypothesis that nutrient enrichment and a herbicide increases vulnerability to pathogens. Z. marina shoots from the Thames Estuary grown in elevated nitrate concentrations had significantly higher rates of infection by L. zosterae than controls, but not by Aplanochytrium sp., another slime-mould like protist. Z. marina shoots grown in 2μg·l(-1) Diuron solutions and infected separately by L. zosterae and Aplanochytrium sp. had significantly higher wasting indices than controls. The results identified Aplanochytrium sp. as another opportunistic pathogen causing a seagrass wasting-type disease and support the hypothesis that pollution by herbicides and nitrate increases the susceptibility of Z. marina to infections.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Globally changing nutrient loads and harmful algal blooms recent advances, new paradigms, and continuing challenges

Authors: Glibert, PM; Burford, MA (2017) Oceanography 30:58-69. HERO ID: 3941362

[Less] It is now well recognized that there are more harmful algal blooms (HABs), more often, in new and different . . . [More] It is now well recognized that there are more harmful algal blooms (HABs), more often, in new and different places, often lasting longer, and with a range of toxicities, and that many of these blooms are related to nutrient pollution. Nutrient loads are increasing globally, but they are changing regionally in proportion and in the dominant form of nutrient. The fact that nutrient loads have generally increased is, in itself, insufficient for the promotion of HABs. The success of HABs lies at the intersection of the physiological adaptations of the harmful algal species, environmental conditions, and interactions with co-occurring organisms that alter abiotic conditions and/or aggregate or disperse cells, in turn promoting or inhibiting their growth. It is a change in the supply of the right nutrients at the right time that helps to create conditions conducive to specific HABs. Many dinoflagellate and cyanobacterial HABs appear to have adaptations that allow them to exploit environments-and potentially even become more toxic-where nutrients are not in balanced (Redfield) proportions. HABs are also changing in complex ways due to changes in climate and many other changes that affect the timing, amount, or proportions of nutrients. There is much work to be done to understand the physiological ecology of HABs and other co-occurring species. Climate change and altered CO2 levels, and their implications for altered productivity of the global ocean, should motivate both new models and new experimental investigations that support them. Based on current knowledge, the management implications are clear: the most effective actions to reduce HABs and their impacts will be continued efforts to reduce nutrients entering our waters.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Eutrophication and warming-driven green tides (Ulva rigida) are predicted to increase under future climate change scenarios

Authors: Gao, G; Clare, AS; Rose, C; Caldwell, GS (2017) Marine Pollution Bulletin 114:439-447. HERO ID: 3941463

[Less] The incidence and severity of extraordinary macroalgae blooms (green tides) are increasing. Here, climate . . . [More] The incidence and severity of extraordinary macroalgae blooms (green tides) are increasing. Here, climate change (ocean warming and acidification) impacts on life history and biochemical responses of a causative green tide species, Ulva rigida, were investigated under combinations of pH (7.95, 7.55, corresponding to lower and higher pCO2), temperature (14, 18°C) and nitrate availability (6 and 150μmolL(-1)). The higher temperature accelerated the onset and magnitude of gamete settlement. Any two factor combination promoted germination and accelerated growth in young plants. The higher temperature increased reproduction, which increased further in combination with elevated pCO2 or nitrate. Reproductive success was highest (64.4±5.1%) when the upper limits of all three variables were combined. Biochemically, more protein and lipid but less carbohydrate were synthesized under higher temperature and nitrate conditions. These results suggest that climate change may cause more severe green tides, particularly when eutrophication cannot be effectively controlled.