While not harmful to humans, the presence of Brown Tide is a problem for scallops and eelgrass because the bloom blocks out sunlight needed for eelgrass to survive and eelgrass provides vital spawning and nursery habitat for shellfish and finfish.
The Brown Tide blooms persisted in high concentrations for extended periods in all or part of the Peconic Estuary from 1985 through 1988, 1990 through 1992, and 1995 and as a result eelgrass and the bay scallop population declined significantly in the Peconic Estuary.
Figure 1 Grain yield of wheat applied with varying rates of silicate slag under sufficient and high N application rates NERS 2013, NERS 2014, and BH 2014.
NS denotes no significant effect on yield; P values reported are for the regression model between yield and silicate slag for each N rate.
Nitrogen levels decrease in the eastern part of estuary as you move into deeper, open water sites where flushing is greater.
Subwatershed nitrogen yield in kilograms nitrogen load per unit hectare of subwatershed area.No reported cases of the medical condition DSP or PSP have occurred on Long Island.Harmful algal blooms have plagued the Peconic Estuary for many years.Figure from Nitrogen load modeling to forty-three subwatersheds of the Peconic Estuary- Stephen Lloyd, 2014.The western part of the estuary is particularly susceptible to the negative impacts of nitrogen pollution due to the presence of multiple pollution sources and low levels of tidal flushing.Nitrogen pollution has been identified as the greatest threat to the Peconic Estuary due to its far reaching impacts.Nitrogen load by source for the 43 subwatersheds of the Peconic Estuary.An algal bloom consists of any proliferation or rapid increase in one or several species of microalgae (phytoplankton), cyanobacteria (blue-green algae) or macroalgae (seaweed).A bloom is typically considered “harmful” if it creates any health impact to other living organisms or otherwise degrades or impairs a valued quality of the surface waters or habitat within the estuary. Some algal blooms produce toxins that cause severe illness or death in humans, wildlife, or fish.Too much nitrogen is one of the primary causes of the excessive algae growth we see in our local bays.When excessive levels of nitrogen are introduced to the estuary, from sources such as fertilizer and human and animal waste, nuisance algae and “seaweed” blooms are likely to result.