UNDERSTANDING THE CHARACTERIZATION OF NITROGEN AS IT IS DISTRIBUTED SPATIALLY THROUGHOUT THE SAN JUAN BAY ESTUARY

In cooperation with the U.S. Environmental Protection Agency this ongoing research and data to understand how nitrogen is distributed temporally and spatially through the San Juan Bay Estuary, a waterway composed of three lagoons: San José Lagoon, La Torrecilla Lagoon, Piñones Lagoon, a main channel: Caño Martín Peña, and a minor canal called Canal Suárez was compiled. The San Juan Bay leads from the Atlantic Ocean into the major canal, Martín Peña. It is here that Martín Peña cuts off the oceans natural flow due to the accumulation of unnatural waste and pollutants, and like a clogged artery this disrupts the balance of San Juan’s delicate eco-system. A June 2015 sample collection trip provided over 200 samples from locations along the San Juan Estuary. These samples included mollusks (mussels, clams, oysters, barnacles), mangrove leaves (Red, Black, White, Bottonwood), various fish species, algae, tree bark, and sediment cores. Over the summer of 2015 each sample, each one with corresponding GPS location, was processed with respect to the sample type. The final and most important samples to be processed were the highly contaminated sediments. The sediment along the estuary are key to an accurate characterization of the nitrogen gradient along the canal because unlike the shellfish and fish, sediment is ambient.

Stable isotope analysis was performed to quantify the amount of nitrogen present, whereas the sediment samples will be further analyzed and characterized with a grain size analysis, silica analysis, and determination of percent carbonate and percent organics with the loss of ignition method. Research and sample processing is ongoing.

The San Juan Bay Estuary is home to 160 species of bird, 300 types of plants, and 124 kinds of fish and is currently threated by problems such as urban runoff, trash “clog-up”, and raw sewage from poor waste disposal strategy. Priority management issues of this estuary include habitat loss and alteration, floatable debris, and species loss and decline but can extend to pathogens, toxins, and human health complications such as gastrointestinal illness and bronchial asthma. It is hoped that the findings of this study will aid Puerto Rico’s government in expediting the dredging of Martín Peña channel making the San Juan Bay Estuary a safer environment for native wildlife and local communities.