Nutrient dynamics of emergent Harmful Algal Bloom species of concern in Maryland's coastal ocean waters

The coastal ocean offshore Maryland is important both ecologically and economically. Annually, the MD seafood industry contributes ~ $600 million to the State's economy, and more than 8 million people visit Ocean City. As a popular tourist destination, the ecosystems surrounding Ocean City, Maryland, including Assateague Island National Seashore and the Maryland Coastal Bays, are impacted by human use through recreation, sewage outflow, and agriculture. The Maryland Coastal Bays (MCB) and waterways which surround the Assateague Island National Seashore, are influenced by both land sources as well as tides and currents from the Atlantic Ocean. There is a need to better understand the linkages between the coastal ocean and the MCB, ecosystem changes and impacts of human activity. Coastal ocean monitoring from the past two years has helped determine nutrient dynamics which explain water quality degradation, and an increase in emergent harmful algal bloom species of concern. Research cruises during the summer months of 2018-2019 evaluated environmental parameters (temperature, salinity, pH, etc.), chlorophyll, phytoplankton species composition. These water quality surveys have shown seasonally elevated chlorophyll and nutrient levels; microscopy analyses have revealed the presence of emergent Harmful Algae Bloom (HAB) species; Dinophysis spp., Karenia spp., and Pseudo-nitzschia spp. in the coastal ocean water of Maryland. Sites with elevated nutrient concentrations coincide with the presence of emergent HAB species, and toxin analyses are underway. HAB species show intra-annual variability across the study site, as well as geographic variability with relation to the Ocean City Inlet and Assateague Island National Seashore.