Coastal ecosystems are subject to effluents from neighboring land areas as well as disturbances such as hurricanes. Excessive rainfall over land and river discharge into coastal zones brings an abundance of pollutants and nutrients from agriculture that sometimes cause explosive phytoplankton blooms. Hurricane Isabel made landfall east of Cape Lookout, North Carolina, as a Category 2 (Stafford-Simpson scale) hurricane on 18 September 2003. The storm's center tracked to the northwest, passing west of Chesapeake Bay in the early morning of 19 September. Hurricane Isabel brought the highest storm surge and winds to the region since the Chesapeake-Potomac hurricane of 1933 and Hurricane Hazel in 1954. The storm surge reached a high of 2.7 m, and sustained wind speeds reached about 30 m s with gusts of 40 ms"1. Hurricane Isabel was responsible for physical and biological changes in the Chesapeake Bay on a variety ofspatial and temporal scales. Short-term responses included a reduction of hypoxia by mixing, nutrient (nitrogen) inputs to the upper water column, and a large-scale phytoplankton bloom (3000 km2), while long-term responses included an early onset of hypoxia in spring 2004, high abundance of the calanoid copepod Eurytemora affinis in spring 2004, and an increased recruitment of Atlantic croaker. These events highlight the importance of hurricanes in the function of this large estuarine ecosystem. The study used aircraft remote sensing technology to quantify chlorophyll (Chl a).
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