| The importance of groundwater seepage into estuaries is poorly understood, but it may be a significant part of nutrient cycling. Groundwater seepage also can add nutrient pollutants to an estuary, thereby changing the ecosystem to a state of eutrophic conditions. In a previous 2001 study, seepage meters showed average groundwater seepage into the Indian River Lagoon to be 40 ml/m2/min and 63 ml/m2/min during the dry and rainy season, respectively, in the northern study area and 28 ml/m2/min and 39 ml/m2/min during the dry and rainy season, respectively, in the southern study area. Seepage rates increased between the dry and rainy seasons in the northern study area by 58% and in the southern study area by 41%. Assuming that nutrients in groundwater seepage can be differentiated from recycled lagoon water, nutrient loading of total nitrogen and total phosphorus in seepage water was 11 to 17 times the total nitrogen and 14 to 23 times the total phosphorus of surface water discharge from drainage areas surrounding the lagoon. Nutrient loading from seepage water may also affect the limiting nutrient for primary production in each study area. |
