According to scientists at Stony Brook University, the water quality around Long Island—from bays to estuaries to lakes—is not suitable for the health of fish and shellfish. Paralytic shellfish poisoning events in May, intense brown and rust tide blooms since then, and regions of low oxygen (called dead zones) have all contributed to the degradation of Long Island ecosystems. Most of the problems can be traced back to rising levels of nitrogen from household sewage and fertilizers.