Abstract. Fossil fuel use, cement manufacture and land-use changes are the primary sources of anthropogenic carbon dioxide (CO 2 ) to the atmosphere, with the ocean absorbing approximately 30 % (Sabine et al., 2004). Ocean uptake and chemical equilibration of anthropogenic CO 2 with seawater results in a gradual reduction in seawater pH and saturation states ( ) for calcium carbonate (CaCO 3 ) minerals in a process termed ocean acidification. Assessing the present and future impact of ocean acidification on marine ecosystems requires detection of the multi-decadal rate of change across ocean basins and at ocean time-series sites. Here, we show the longest continuous record of ocean CO 2 changes and ocean acidification in the North Atlantic subtropical gyre near Bermuda from 1983-2011. Dissolved inorganic carbon (DIC) and partial pressure of CO 2 (pCO 2 ) increased in surface seawater by ∼40 µmol kg −1 and ∼50 µatm (∼20 %), respectively. Increasing Revelle factor (β) values imply that the capacity of North Atlantic surface waters to absorb CO 2 has also diminished. As indicators of ocean acidification, seawater pH decreased by ∼0.05 (0.0017 yr −1 ) and values by ∼7-8 %. Such data provide critically needed multi-decadal information for assessing the North Atlantic Ocean CO 2 sink and the pH changes that determine marine ecosystem responses to ocean acidification.

Since 2014, Stony Coral Tissue Loss Disease (SCTLD) has led to mass mortality of the majority of hard coral species on the Florida Reef Tract. Following the successful treatment of SCTLD lesions on laboratory corals using water dosed with antibiotics, two topical pastes were developed as vehicles to directly apply antibiotic treatments to wild corals. These pastes were tested as placebos and with additions of amoxicillin on active SCTLD lesions on multiple coral species. The effectiveness of the pastes without antibiotics (placebo treatments) was 4% and 9%, no different from untreated controls. Adding amoxicillin to both pastes significantly increased effectiveness to 70% and 84%. Effectiveness with this method was seen across five different coral species, with success rates of the more effective paste ranging from 67% (Colpophyllia natans) to 90% (Orbicella faveolata and Montastraea cavernosa). Topical antibiotic application is a viable and effective tool for halting disease lesions on corals affected by SCTLD.

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Fossil fuel use, cement manufacture and land-use changes are the primary sources of anthropogenic carbon dioxide (CO₂) to the atmosphere, with the ocean absorbing 30 %. Ocean uptake and chemical equilibration of anthropogenic CO₂with seawater results in a gradual reduction in seawater pH and saturation states (Ω) for calcium carbonate (CaCO₃) minerals in a process termed ocean acidification. Assessing the present and future impact of ocean acidification on marine ecosystems requires detection of the multi-decadal rate of change across ocean basins and at ocean time-series sites. Here, we show the longest continuous record of ocean CO₂ changes and ocean acidification in the North Atlantic subtropical gyre near Bermuda from 1983–2011. Dissolved inorganic carbon (DIC) and partial pressure of CO₂ (<i>p</i>CO₂) increased in surface seawater by ~40 μmol kg⁻¹ and ~50 μatm (~20 %), respectively. Increasing Revelle factor (<i>β</i>) values imply that the capacity of North Atlantic surface waters to absorb CO₂ has also diminished. As indicators of ocean acidification, seawater pH decreased by ~0.05 (0.0017 yr⁻¹) and Ω values by ~7–8 %. Such data provide critically needed multi-decadal information for assessing the North Atlantic Ocean CO₂sink and the pH changes that determine marine ecosystem responses to ocean acidification