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Sex may influence environmental diphenhydramine accumulation in Round Stingrays Full text
2018
Lyons, Kady | Burket, S Rebekah | Brooks, Bryan W.
Despite the amount of treated wastewater discharged into the Southern California Bight, few studies have examined pharmaceutical compounds in local biota. The Round Stingray (Urobatis halleri) was selected as a representative elasmobranch species to perform an exploratory study on environmental pharmaceutical exposure. Archived liver samples of males and females from juvenile to adult size classes from several locations (n = 53) were examined for 18 pharmaceutical and illicit drug compounds using isotope-dilution LC-MS/MS. Very few compounds were detected in stingray livers, with diphenhydramine as the only pharmaceutical above quantitation limits. Only stingrays collected from the urban site (mainland California) had detectable levels of diphenhydramine compared to no detections in reference stingrays (offshore island). Sex and sampling location substantially influenced both detection rate and concentrations. Our results suggest that aspects of species' ecology and physiology should be considered for future studies investigating pharmaceutical exposure in elasmobranchs.
Show more [+] Less [-]Influence of thermooxidative degradation on the in situ fate of polyethylene in temperate coastal waters Full text
2018
Karlsson, Therese M. | Hassellöv, Martin | Jakubowicz, Ignacy
Polyethylene is a commonly used polymer in plastic products and is often found as marine litter. Nevertheless there is limited knowledge about what happens to the material when it ends up in the sea. Polyethylene films were therefore thermally oxidised to four different levels of degradation. The films were then placed in stainless-steel cages in the sea off the Swedish west coast for 12 summer weeks. Subsamples were analysed with respect to biofouling, degradation and buoyancy. All levels showed a continued oxidation in the field. The pre-degraded films started fragmenting and the non-degraded films showed a decrease in tensile strain. All levels showed increased biofouling with higher presence of filamentous algae and bryozoans on pre-degraded materials. The density (kg·m−3) of the films was seen to increase slightly, and the apparent density for the pre-degraded films (density of the films with biofilm) showed a strong increase, which resulted in sinking.
Show more [+] Less [-]Pollution signature for temperate reef biodiversity is short and simple Full text
2018
Ling, S.D. | Davey, A. | Reeves, S.E. | Gaylard, S. | Davies, P.L. | Stuart-Smith, R.D. | Edgar, G.J.
Pollution increasingly impacts healthy functioning of marine ecosystems globally. Here we quantify concentrations of major pollutant types (heavy metals/sewage/petrochemicals/plastics) as accumulated within marine sediments on and/or immediately adjacent to shallow reefs for 42 sites spanning coastal population centres across south-eastern Australia. Gradients in pollutants were revealed, but few pollutants co-varied, while increasing wave exposure ostensibly diluted concentrations of all pollutants except microplastics. Examination of reef biodiversity indicators revealed that maximum size of fauna and flora, a key life-history parameter summarised by the Community shortness index, plus declining functional and species richness, were the most sensitive bioindicators of pollutants – for which heavy metals and nutrient-enrichment were most pervasive. Results indicate that assemblages of biogenic habitat formers and associated fauna collapse from “long and complicated” to “short and simplified” configurations in response to increasing pollution, and this community signature may form an effective bioindicator to track human-driven degradation.
Show more [+] Less [-]Marine introduced species in Australia, where to from here? A personal perspective from a practising taxonomist Full text
2018
Hutchings, Pat
While introduced marine species have been arriving in Australia for centuries, it was the advent of container shipping and the discharge of ballast water into Australian ports that highlighted the problem. A summary is provided of how Australia responded to this challenge and continues to. More recently there has been an acceptance that hull fouling is also an important vector of introductions. A major problem in Australia is distinguishing introduced species from as yet undescribed native species. This is a particular problem in northern Australia where the native fauna is poorly documented. Despite the economic and environmental threats posed by introduced species, the impetus to undertake expensive comprehensive surveys has declined and attention is now focusing on targeted surveys especially of known marine pest species and molecular data to identify introductions. Ongoing research is still needed to monitor other species identified as being introduced and their potential to become pests.
Show more [+] Less [-]Manure Phosphorus: Mobility in Soils and Management Strategies to Minimize Losses Full text
2018
Kumaragamage, D. | Akinremi, O.O.
Manure is a valuable source of plant nutrients; however, continuous application to soils may lead to accumulation of phosphorus (P), increasing the risk of P loss into waterways triggering freshwater eutrophication. This review paper summarizes and critically evaluates relevant research findings published within the last 5 years on manure P mobility in soils and management strategies to mitigate losses identifying future research needs. Past and recent research evidence on manure P mobilization and losses from soils have yielded inconsistent and often confounding results, because of the interactive effects of source factors and the existence of concurrent transport pathways. Although far from being conclusive, a few general trends are worth noting; P losses were greater with (a) increasing soluble P applied with manure, (b) vulnerable soils with limited P sorption capacity and/or susceptible to preferential flow/erosion, (c) conditions conducive to P release and transport, and (d) reduced soil-manure P interaction following application. Effective mitigating strategies included (a) generating low-P manure, (b) processing manure to reduce total and/or soluble P, and (c) adopting best management practices (BMPs) during and post-manure application. Future research should focus on a better understanding of the interactive effects of source factors on short- and long-term manure P loss via different transport pathways. Existing mitigation efforts and new directions should focus on reducing P buildup in soil by employing a combination of strategies during generation, processing, and application of manure, coupled with site- and time-specific BMPs selected based on the dominant pathway of P loss.
Show more [+] Less [-]Desalination of Water: a Review Full text
2018
Darre, NatashaC. | Toor, GurpalS.
PURPOSE OF REVIEW: In the face of rising water demands and dwindling freshwater supplies, alternative water sources are needed. Desalination of water has become a key to helping meet increasing water needs, especially in water-stressed countries where water obtained by desalination far exceeds supplies from the freshwater sources. RECENT FINDINGS: Recent technological advancements have enabled desalination to become more efficient and cost-competitive on a global scale. This has become possible due to the improvement in the materials used in membrane-based desalination, incorporation of energy-recovery devices to reduce electricity demands, and combining different desalination methods into hybrid designs. Further, there has been a gradual phasing-in of renewable energy sources to power desalination plants, which will help ensure the long-term sustainability of desalination. However, there are still challenges of reducing energy demands and managing waste products from the desalination to prevent adverse environmental effects. This article reviews the history, location, components, costs, and other facets of desalination and summarizes the new technologies that are set to improve the overall efficiency of the desalination process.
Show more [+] Less [-]Interactive effect of nitrogen source and high CO2 concentration on the growth of the dinoflagellate Alexandrium tamarense and its toxicity to zebrafish (Danio rerio) embryos Full text
2018
Guan, Wanchun | Si, Ranran | Li, Xi | Cai, Jingbo | Chen, Shaobo
Interactive effect of nitrogen source and high CO2 concentration on the growth of the dinoflagellate Alexandrium tamarense and its toxicity to zebrafish (Danio rerio) embryos Full text
2018
Guan, Wanchun | Si, Ranran | Li, Xi | Cai, Jingbo | Chen, Shaobo
The effects and interactive effects of different nitrogen (N) sources (ammonium, nitrate, and urea) and carbon dioxide (CO₂) concentrations were investigated on Alexandrium tamarense, a harmful marine dinoflagellate, by measuring its growth (μ), extracellular carbonic anhydrase (CA), and its toxicity to zebrafish (Danio rerio) embryo. The μ and CA were influenced more strongly by CO₂ concentrations rather than by N sources; significant effects of CO₂ on μ and CA were observed under low CO₂ concentration (LC) conditions compared to high CO₂ concentration (HC) conditions. The ammonium and nitrate media under LC conditions had the maximum μ and CA, which was inhibited under HC conditions. The embryotoxic effects were influenced more strongly by the N sources than by CO₂ concentrations, thus excluding the lower deformation in urea under HC conditions. Moreover, the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione S-transferase (GST), and catalase (CAT) were detected in normal (untreated) zebrafish embryos, and among them, the level of SOD was the highest. In summary, this study provides a clear insight for understanding the effects and interactive effects of N sources and CO₂ concentrations on the growth and toxicity of harmful dinoflagellates.
Show more [+] Less [-]Seawater carbonate chemistry and growth of the dinoflagellate Alexandrium tamarense and its toxicity to zebrafish (Danio rerio) embryos Full text
2018
Guan, WanChun | Si, Ranran | Li, Xi | Cai, Jingbo | Chen, Shaobo
The effects and interactive effects of different nitrogen (N) sources (ammonium, nitrate, and urea) and carbon dioxide (CO2) concentrations were investigated on Alexandrium tamarense, a harmful marine dinoflagellate, by measuring its growth (μ), extracellular carbonic anhydrase (CA), and its toxicity to zebrafish (Danio rerio) embryo. The μ and CA were influenced more strongly by CO2 concentrations rather than by N sources; significant effects of CO2 on μ and CA were observed under low CO2 concentration (LC) conditions compared to high CO2 concentration (HC) conditions. The ammonium and nitrate media under LC conditions had the maximum μ and CA, which was inhibited under HC conditions. The embryotoxic effects were influenced more strongly by the N sources than by CO2 concentrations, thus excluding the lower deformation in urea under HC conditions. Moreover, the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione S-transferase (GST), and catalase (CAT) were detected in normal (untreated) zebrafish embryos, and among them, the level of SOD was the highest. In summary, this study provides a clear insight for understanding the effects and interactive effects of N sources and CO2 concentrations on the growth and toxicity of harmful dinoflagellates.
Show more [+] Less [-]A review of chemical-based sediment quality assessment methodologies for the marine environment Full text
2018
Birch, G.F.
This review of 19 chemical approaches used in assessing sediment quality are classified into empirical, mechanistic and sediment quality indices (SQI) groups. Empirical sediment quality guidelines (SQGs), based on matching chemical and biological-effects data and the mechanistic techniques, founded on equilibrium partitioning principals (EqP), are well established and most used. Empirical SQGs provide a useful screening tool to initially identify locations and chemicals of most concern, but are not regulatory criteria. The EqP approach is causally linked however, the scheme assumes porewater chemistry largely controls sediment toxicity. SQIs are not based on matching chemical-biological data and combine schemes with multiple narrative intents. The 41 SQGs reviewed show a considerable range in upper and lower guideline values. Grain size and organic content should be included into SQGs, however inclusion of suspended sediment into SQGs raises concerns. SQGs are built into decision-tree schemes with other lines-of-evidence and evaluated in a weight-of-evidence framework.
Show more [+] Less [-]Changes in the tissue concentrations of trace elements during the reproductive cycle of Noah's Ark shells (Arca noae Linnaeus, 1758) Full text
2018
Erk, Marijana | Ivanković, Dušica | Župan, Ivan | Čulin, Jelena | Dragun, Zrinka | Puljas, Sanja | Peharda, Melita
Concentrations of 23 trace elements (TEs; essential: Co, Cu, Fe, Mn, Mo, Se, V, Zn; non-essential: Ag, Al, As, Ba, Cd, Cr, Cs, Li, Ni, Pb, Rb, Sr, Ti, Tl, U) in whole soft tissues of Noah's Ark shell (Arca noae) were determined monthly during one year (March 2013–February 2014) at two sampling sites in the central part of the Eastern Adriatic Sea. Our aim was to detect the influence of reproductive cycle and changes in the environmental factors on the variabilities of TEs' contents. Higher concentrations of Pb, Ba, V, Mo, Mn and Fe were found at potentially contaminated site in Pašman channel, whereas higher concentrations of Tl, Ni, Li, Cr, Cd, Ti and Se were found at reference site in Nature Park Telašćica. Since several bioaccumulated TEs were associated to mean gonadal index, in TEs monitoring in A. noae, animal gonadal status has to be considered.
Show more [+] Less [-]Contributions of pre- versus post-settlement processes to fluctuating abundance of crown-of-thorns starfishes (Acanthaster spp.) Full text
2018
Wilmes, Jennifer C. | Caballes, Ciemon F. | Cowan, Zara-Louise | Hoey, Andrew S. | Lang, Bethan J. | Messmer, Vanessa | Pratchett, Morgan S.
Numerous hypotheses have been put forward to account for population outbreaks of crown-of-thorns starfishes (CoTS, Acanthaster spp.), which place specific importance on either pre- or post-settlement mechanisms. The purpose of this review is to specifically assess the contributions of pre- versus post-settlement processes in the population dynamics of CoTS. Given the immense reproductive potential of CoTS (>100 million eggs per female), persistent high densities would appear inevitable unless there were significant constraints on larval development, settlement success, and/or early post-settlement growth and survival. In terms of population constraints, pre- and post-settlement processes are both important and have additive effects to suppress densities of juvenile and adult CoTS within reef ecosystems. It is difficult, however, to assess the relative contributions of pre- versus post-settlement processes to population outbreaks, especially given limited data on settlement rates, as well as early post-settlement growth and mortality. Prioritising this research is important to resolve potential effects of anthropogenic activities (e.g., fishing) and habitat degradation on changing population dynamics of CoTS, and will also improve management effectiveness.
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