Coccolithophore Relief: An Art and Science Interrogation of Ocean Acidification

Organisms that remove carbon from the world’s carbon cycle are becoming ever more important as we try to constrain our carbon emissions to slow climate change. Marine phytoplankton, like coccolithophores, are responsible for 50 percent of global carbon fixation. Through photosynthesis, which also produces oxygen as a by-product, they fix carbon dioxide throughout their lives in the surface waters of the ocean. Even in their death, they help remove carbon from the system. Coccolithophores make armoured plates (coccoliths, hereafter referred to as ‘liths’) from calcium carbonate, which together form a sort of external skeleton for each organism. When they die, they sink and join bottom sediments, in effect exporting and burying carbon in deep-sea sediments.We decided to share the story of coccolithophores, including their important environmental role and their sensitivity to ocean acidification, with the public. We intentionally developed a project involving social arts practice to help people reflect on the importance of these small things. This included the beauty of the tiny liths that make up the  coccolithophore’s amour, the importance of each little lith to collectively make a healthy organism (that in turn has an important global role), and the effect of our individual small actions contributing to climate change. Engaging communities in social arts practice, by involving hands-on making with cognitive activity, gives time and space for such criticalreflection.5 Joining key features of the scientific narrative with congruent aspects of the art-making can serve to reinforce understanding and potential behaviour change

EFFECTS OF SEA LEVEL RISE ON TIDAL FRESHWATER, OLIGOHALINE, AND BRACKISH MARSHES: ACCRETION, NUTRIENT BURIAL, AND BIOGEOCHEMICAL PROCESSES

Tidal wetlands provide critically important ecosystem services such as storm surge and flood attenuation, pollution retention and transformation, and carbon sequestration. The ability of tidal wetlands to maintain surface elevation under accelerated sea level rise is critical for their persistence. Saltwater intrusion can further threaten tidal freshwater marshes by decreasing primary production and organic matter accumulation as well as cause shifts in microbial pathways, leading to increases in organic matter decomposition and an overall decrease in marsh elevation. The objectives of this research were to examine accretion dynamics across the estuarine gradient of the Nanticoke River, a major tributary of the Chesapeake Bay, and determine the relative contribution of organic and inorganic matter to accretion in the marshes; determine the accumulation rates of C, N, and P across the estuarine gradient; and examine the effects of sulfate intrusion on biogeochemical transformations and marsh surface elevation in tidal freshwater marsh soil. Results of the collective studies suggest that the mechanisms controlling accretion dynamics and nutrient accumulation are complex and are likely driven by site-specific factors rather than estuary-wide factors. Accretion rates and nutrient accumulation rates were highly variable across the estuarine gradient, but were largely dependent on both organic matter accumulation and inorganic sedimentation. Only 8 out of the 15 subsites had accretion rates higher than relative sea level rise for the area, with the lowest rates of accretion found in the oligohaline marshes. Organic matter accumulation is especially important in marshes with low mineral sediment supply, particularly mid-estuarine oligohaline marshes, but may not be enough to help keep these marshes above relative sea level. The tidal marshes along the Nanticoke River removed approximately 15% and 9% of the total N and P load entering the system, but their ability to continue to remove nutrients may be compromised due to rising sea levels. Shifts in microbial pathways and increases in organic matter decomposition due to saltwater intrusion further threaten the ability of these marshes to keep pace with sea level rise, potentially resulting in the loss of an extremely valuable ecosystem