Abstract: The Southern Ocean, one of Earth's most productive areas, is widely recognized as a major sink for atmospheric carbon and mercury, tightly coupling primary production with the sedimentary sequestration of these elements. The impacts of climate warming on these processes, however, remain unclear. Here, we utilize 20 sediment cores from the Ross Sea, a representative ice-shelf sea in West Antarctica, to examine how Holocene warming and extensive glacial retreat influenced carbon and mercury sequestration. We find that organic carbon (OC) burial has been relatively constant over the past 12,000 years, whereas mercury burial in the Ross Embayment and open ocean exhibited three- and eightfold increases, respectively. Carbon isotopes and accumulation profiles suggest warming boosted glacial- and terrestrial-derived OC inputs to the ocean, while trace elements and biomarkers reveal a declining contribution offshore. Biomarker ratios further indicate greater remineralization of this OC in the open ocean. Consequently, enhanced OC degradation, coupled with rising external mercury inputs, drives mercury enrichment in marine sediments before reaching the seafloor. These findings imply that ongoing warming could trigger a positive feedback loop, accelerating OC degradation into CO(2) and amplifying the impacts of anthropogenic mercury on Southern Ocean ecosystems.

Abstract: Flood control has received significant attention in recent years due to the extensive and devastating damage of flooding to communities and economies. Stormwater management and flood control are closely related, both aiming to manage and mitigate the impact of excess water in urban and natural environments. In this study, low impact developments (LIDs) and pipe replacements were chosen as strategies to manage surface runoff and flooding using a multi-objective optimization (MOO) approach. Six scenarios with varying rainfall intensities were created to explore trends and solutions for minimizing surface runoff, flood areas, and construction costs at a study site, with rainfall adjustments made to reflect future rainfall nonstationary conditions. The findings revealed nonlinear increases in both runoff and flood area reductions as investment increased, with distinct trends between runoff volume reduction and flood area reduction across the six scenarios. Considering flood area reduction, a 25-year-24-h storm scenario resulted in the highest benefit-cost ratio and was recommended to use for future design and planning in terms of stormwater management and flood control. Moreover, spatial analysis revealed the effectiveness of clustering LIDs in subcatchments with largely impervious areas, and integrating LIDs with pipe replacement was crucial to control flooding efficiently. These findings could help city planners in drainage system design and urban planning with the consideration of limited budgets and flood control under future conditions.

Abstract: Strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae), is an important specialty crop in Florida, generating about $500 million in annual revenue. An invasive insect, chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), has emerged as a major strawberry pest, causing considerable yield and revenue loss in recent years. Pesticide application is the leading control option but is not always recommended due to resistance development. Host plant resistance (HPR) can be a novel option to manage S. dorsalis sustainably. Four commercial cultivars, 'Florida Brilliance', 'Florida Medallion FL16.30-128', 'Sweet Sensation 'Florida127', and 'Florida Pearl FL16.78-109', were evaluated for their performance in the 2021-2022 field season under the natural population of S. dorsalis. In 2022-2023 and 2023-2024, 3 more cultivars, 'Strawberry Festival', 'Florida Radiance', and 'Florida Beauty', were added to this list. Twenty bare-root strawberry transplants were planted in each field plot, and each cultivar was replicated 8 times in a randomized complete block design. Damage on trifoliate, number of adults and larval S. dorsalis on trifoliate, number of flowers, and marketable fruit yield were assessed for each cultivar. Results revealed that 'Florida Pearl 109' had the highest insect count and damage index of all 3 year. 'Strawberry Festival' also showed the same trend after its introduction in the second year. 'Florida Brilliance' and 'Sweet Sensation' had the lowest damage index, lowest adult insect count, and higher marketable yield compared to 'Florida Pearl 109' and 'Strawberry Festival'. Therefore, utilizing resistant cultivars can be an effective tool for managing S. dorsalis in the field.

Abstract: Karenia brevis, a toxin-producing dinoflagellate, has been implicated in frequent harmful algal blooms (HABs) in the Gulf of Mexico. Shellfish species, such as Mercenaria campechiensis, have high resilience to K. brevis exposure causing high accumulation and retention of brevetoxins within their tissues. The current study aimed to analyze the accumulation and depuration of brevetoxins in M. campechiensis exposed to 100,000 cells L(-1) for two weeks. The second aim was to identify the potential detoxification enzymes in M. campechiensis as well as potential enzymes representative of stress to see if moderate concentrations lead to stress in exposed M. campechiensis. This was done by exposing M. campechiensis to a continuous flow of K. brevis, followed by a 47-day depuration period. There was an increase in brevetoxin concentration during the exposure with a rapid decrease at the onset of the depuration period. This was followed by a gradual decrease with detectable toxins in the exposed clam tissue for the duration of the experiment. While there was detectable toxin during the depurations, the concentrations were below the NSP level for BTX-2 by day 14 indicating M. campechiensis would potentially be safe for consumption after two weeks following exposure to a moderate K. brevis concentration. Fold change of AChE activity significantly increased in the exposure tank when compared to the controls following the exposure period. Fold change of GST activity from control significantly decreased in the exposure tank compared to the controls on 14 d exposure. Both changes in enzyme activity support the findings that a moderate concentration of K. brevis may induce stress in M. campechiensis. Ultimately, the results of the current study further highlight the importance of the K. brevis regulatory limits as it can prevent possible neurotoxic shellfish poisoning in people who eat contaminated shellfish as it prevents the consumption of shellfish exposed to moderate and high concentrations of K. brevis.