Future Projections of Phytoplankton Dynamics and Marine Harmful Algal Bloom Events Due to Climate Change: New Jersey’s Changing Coastal Shelf Ecosystem

Abstract

New Jersey’s coast, encompassed within the Mid-Atlantic Bight (MAB), is characterized by physical and seasonal dynamics that drive phytoplankton growth, abundance, and composition. Phytoplankton are generally highest in abundance during the fall bloom, when the temperature-induced stratification breaks down stimulating mixing and increasing nutrient concentrations in surface waters. The MAB is one of the fastest warming regions of the ocean, which has coincided with small decreases in primary productivity and shifts in the timing of seasonal transitions. The relative contribution of larger groups (e.g., diatoms) to the phytoplankton community has decreased, whereas the relative contribution of smaller groups (e.g., dinoflagellates, green algae) has increased. These trends, including the variation in growth patterns, are likely to continue as climate change progresses. These variations may result in the increase in the harmful overgrowth of the phytoplankton population, known as a harmful algal bloom (HABs). Harmful algal blooms have occurred in NJ marine waters for decades with the potential to negatively impact New Jersey residents and ecosystems. While there is a lack of short- and intermediate-terms studies investigating the future of HABs in the MAB, future conditions associated with climate change will likely increase the potential for marine HAB events.