Accumulation and Effects of Dissolved and Nanoparticle Silver and Copper in Two Marine Seaweed Species

This study investigated the accumulation and effects of metal nanoparticles in two seaweed species, Ulva lactuca and Agardhiella subulata. Both seaweeds were exposed to silver nitrate (AgNO3), silver nanoparticles, and copper oxide (CuO) nanoparticles for 48 h. Metal accumulation occurred in both seaweed species in a concentration-dependent manner after 48 h exposure to each form of metal. In several cases, seaweeds exposed to AgNO3 (the dissolved form) accumulated comparatively higher tissue Ag concentration than seaweed exposed to Ag nanoparticles; and A. subulata had higher tissue Ag concentrations than U. lactuca after exposure to AgNO3 for 48 h. Additionally, clear differences were observed in the regulation of Ag between the two seaweed species. Photosynthetic toxicity (primarily due to decreased maximum electron transport rate) was observed in U. lactuca after exposure to AgNO3, Ag nanoparticles, and CuO nanoparticles. These results increase current knowledge about the differences in dissolved metal versus nanoparticle exposure in marine seaweeds and have implications in marine food webs

Principles of Biology II (Valdosta State University)

This Grants Collection for Principles of Biology II was created under a Round Four ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/biology-collections/1009/thumbnail.jp

Influence of Water Hardness on Accumulation and Effects of Silver in the Green Alga, Raphidocelis subcapitata

Metal pollution from anthropogenic sources can pose a threat to aquatic systems. Silver is released into the environment from various industrial processes. In excess, silver can accumulate and cause adverse effects in aquatic organisms, particularly those in lower trophic levels, such as phytoplankton. Water chemistry parameters, such as hardness, have been shown to modify toxicity of metals because divalent cations compete with the metal for binding sites on the biological membrane. The objective of this study was to assess population growth and silver accumulation in the green alga, Raphidocelis subcapitata, after silver exposure in waters of varying hardness for 7 d. Throughout the exposure period, a decrease in algal cell density was observed with increasing silver concentrations. Silver accumulation in the algae decreased and cell density increased with increasing water hardness. Additionally, at least some degree of protection was observed against silver toxicity due to increased water hardness

The Influence of Acidification and Copper Exposure on Copper Accumulation and Anti-Oxidant Enzyme Responses in the Pond Snail, Lymnaea stagnalis

Atmospheric carbon dioxide is rising at an accelerated rated due to increased anthropogenic activities. Metals have also been a noted problem; however, little research has addressed combined exposure of both pollutants to sensitive, calcifying organisms in freshwater habitats. This study examined copper accumulation (over 7 d) and activity of the antioxidant enzymes, catalase and glutathione peroxidase (over 2 d), in the freshwater common pond snail, Lymnaea stagnalis, after exposure to ambient and increased (2000 µatm) CO2 and copper (control, 5, and 20 µg/L). Results demonstrated increased copper accumulation in soft tissue of snails exposed to copper; however, exposure to increased CO2 did not increase the magnitude of copper accumulation. After 2 d, increased glutathione peroxidase activity was observed in snails exposed to increased CO2 or copper individually; however, synergistic effects from exposure to both parameters were not observed. A greater response in glutathione peroxidase activity was observed in elevated CO2-exposed snails as compared to those exposed to copper. This study provides new insight into exposure to multiple contaminants, which elicit a similar compensatory response in L. stagnali

River Report. State of Lower St. JOhns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2023

https://digitalcommons.unf.edu/sotr/1013/thumbnail.jp

River Report. State of the Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2022.

https://digitalcommons.unf.edu/sotr/1012/thumbnail.jp

Prospective Environmental Life Cycle Assessment of Nanosilver T-Shirts

A cradle-to-grave life cycle assessment (LCA) is performed to compare nanosilver T-shirts with conventional T-shirts with and without biocidal treatment. For nanosilver production and textile incorporation, we investigate two processes: flame spray pyrolysis (FSP) and plasma polymerization with silver co-sputtering (PlaSpu). Prospective environmental impacts due to increased nanosilver T-shirt commercialization are estimated with six scenarios. Results show significant differences in environmental burdens between nanoparticle production technologies: The "cradle-to-gate" climate footprint of the production of a nanosilver T-shirt is 2.70 kg of CO2-equiv (FSP) and 7.67-166 kg of CO2-equiv (PlaSpu, varying maturity stages). Production of conventional T-shirts with and without the biocide triclosan has emissions of 2.55 kg of CO2-equiv (contribution from triclosan insignificant). Consumer behavior considerably affects the environmental impacts during the use phase. Lower washing frequencies can compensate for the increased climate footprint of FSP nanosilver T-shirt production. The toxic releases from washing and disposal in the life cycle of T-shirts appear to be of minor relevance. By contrast, the production phase may be rather significant due to toxic silver emissions at the mining site if high silver quantities are require

Water Contamination Reduces the Tolerance of Coral Larvae to Thermal Stress

Coral reefs are highly susceptible to climate change, with elevated sea surface temperatures (SST) posing one of the main threats to coral survival. Successful recruitment of new colonies is important for the recovery of degraded reefs following mortality events. Coral larvae require relatively uncontaminated substratum on which to metamorphose into sessile polyps, and the increasing pollution of coastal waters therefore constitutes an additional threat to reef resilience. Here we develop and analyse a model of larval metamorphosis success for two common coral species to quantify the interactive effects of water pollution (copper contamination) and SST. We identify thresholds of temperature and pollution that prevent larval metamorphosis, and evaluate synergistic interactions between these stressors. Our analyses show that halving the concentration of Cu can protect corals from the negative effects of a 2–3°C increase in SST. These results demonstrate that effective mitigation of local impacts can reduce negative effects of global stressors