Collapse

Abstract

Anthropogenic contaminants can place significant stress on vegetation, especially when they are taken up into plants. Plastic pollution, including nanoplastics (NPs), could be detrimental to tree functioning, by causing, for example, oxidative stress or reducing photosynthesis. While a number of studies have explored the capacity of plants to take up NPs, few have simultaneously assessed the functional damage due to particulate matter uptake. To quantify NPs uptake by tree roots and to determine whether this resulted in subsequent physiological damage, we exposed the roots of two tree species with different water use strategies in hydroponic cultures to two concentrations (10 mg L−1 and 30 mg L−1) of model metal-doped polystyrene NPs. This approach allowed us to accurately quantify low concentrations of NPs in tissues using standard approaches for metal analysis. The two contrasting tree species included Norway spruce (Picea abies [L.] Karst), a water conservative tree, and wild service tree (Sorbus torminalis [L.] Crantz), an early successional tree with a rather water spending strategy. At both exposure concentrations and at each of the experimental time points (two and four weeks), NPs were highly associated and/or concentrated inside the tree roots. In both species, maximum concentrations were observed after 2 weeks in the roots of the high concentration (HC) treatment (spruce: 2512 ± 304 μg NPs per g DW (dry weight), wild service tree: 1190 ± 823 μg NPs per g DW). In the aboveground organs (stems and leaves or needles), concentrations were one to two orders of magnitude lower than in the roots. Despite relatively similar NPs concentrations in the tree aboveground organs across treatments, there were different temporal impacts on tree physiology of the given species. Photosynthetic efficiency was reduced faster (after 2 weeks of NPs exposure) and more intensively (by 28% in the HC treatment) in wild service trees compared to Norway spruce (ca. 10% reduction only after 4 weeks). Our study shows that both, evergreen coniferous as well as deciduous broadleaf tree species are negatively affected in their photosynthesis by NPs uptake and transport to aboveground organs. Given the likelihood of trees facing multiple, concurrent stressors from anthropogenic pollution and climate change, including the impact of NPs, it is crucial to consider the cumulative effects on vegetation in future.

Editor’s summary

Assessment of the status of fisheries stocks is a key component of their management. Although there has been much debate around how to do fishery assessments, there has been a general belief that estimates are roughly accurate. Edgar et al. used publicly available data on 230 of the best-known fisheries species to test whether stock biomass estimates made in the year of the estimate were as accurate as specifically calculated hindcast models (see the Perspective by Froese and Pauly). They found that, especially in overfished species, historical estimates were higher than later estimates, indicating the presence of excessively positive assessments of stock status. —Sacha Vignieri

Abstract

Effective fisheries management requires accurate estimates of stock biomass and trends; yet, assumptions in stock assessment models generate high levels of uncertainty and error. For 230 fisheries worldwide, we contrasted stock biomass estimates at the time of assessment with updated hindcast estimates modeled for the same year in later assessments to evaluate systematic over- or underestimation. For stocks that were overfished, low value, or located in regions with rising temperatures, historical biomass estimates were generally overstated compared with updated assessments. Moreover, rising trends reported for overfished stocks were often inaccurate. With consideration of bias identified retrospectively, 85% more stocks than currently recognized have likely collapsed below 10% of maximum historical biomass. The high uncertainty and bias in modeled stock estimates warrants much greater precaution by managers.

Marine fish populations or “stocks” are subject to fishing pressure along the world’s coastlines by local fishers and further offshore by industrial fleets, whose huge capacity is capable of decimating the fish that they target. Fishing operations are therefore typically constrained by catch limits derived from stock assessments—i.e., reports on the condition of a fish stock and its estimated future abundance. Theoretically, catch limits should ensure sustainability by not exceeding the productive ability of fish populations and by allowing depleted stocks to rebuild. In reality, the fraction of overfished stocks continues to increase, and reported global catches stagnate despite increasing fishing effort, implying that fish abundance is declining (1). On page 860 of this issue, Edgar et al. (2) report a likely explanation for the apparent inability of standard stock assessment models to provide sound catch limits. Their findings underscore the importance of accurate stock estimates for sustainable fisheries management.

Abstract

Extreme weather events lead to significant adverse societal costs. Extreme Event Attribution (EEA), a methodology that examines how anthropogenic greenhouse gas emissions had changed the occurrence of specific extreme weather events, allows us to quantify the climate change-induced component of these costs. We collect data from all available EEA studies, combine these with data on the socio-economic costs of these events and extrapolate for missing data to arrive at an estimate of the global costs of extreme weather attributable to climate change in the last twenty years. We find that US 143 billion per year of the costs of extreme events is attributable to climatic change. The majority (63%), of this is due to human loss of life. Our results suggest that the frequently cited estimates of the economic costs of climate change arrived at by using Integrated Assessment Models may be substantially underestimated.

https://corporate.exxonmobil.com/-/media/global/files/global-outlook/2024/global-outlook-executive-summary.pdf

https://corporate.exxonmobil.com/sustainability-and-reports/global-outlook#ExploretheGlobalOutlook

cross-posted from: https://lemmy.world/post/19093543

Latimes.com

"Antarctic ecosystems could be disrupted by animals, diseases and rubbish floating from Africa and Australia as rising temperatures melt sea ice buffers, new research suggests..."