1. Eutrophication comparisons between Chesapeake Bay and Puget Sound Tiffany Huang Oceanography 497 B School of Aquatics and Fisheries

2.  An ecosystem response to human activities that fertilize bodies of water with N and P.  Ex: untreated sewage discharge, runoff from farms or lawns  Can often lead to changes in animal and plant populations, degradation of water habitat and quality.  N and P are essential components of structural proteins, enzymes, cell membranes, nucleic acids, etc.  N and P are present at low concentrations in Estuaries. Ecological Consequences: -biodiversity, visibility, mobility functions, fitness, and certain organisms can die off Eutrophication Background

4.  1600-1700 – subsistence farming, abandoned, moved onto another plot, low human population  1740-1930 – new agricultural technology, used fertilizers, human population increased, demand for wood, chemically developed nitrogen fertilizers replaced natural fertilizers  1930-present – eastern shore drained for cropland, large increase in anoxia since mid 20 th century. Chesapeake Bay

5.  Largest estuary in the U.S. (~300 km )  Land clearing, colonization, erosion of soil led to eutrophication led to hypoxia  Hypoxia increased significantly in last 50 years.  Eutrophication effects are spreading from near-shore areas and semi-enclosed basins to offshore regions.  Spreading of hypoxia may have contributed to major changes in fisheries populations Chesapeake Bay

7.  In 1970’s, discovered first marine dead zone  Today the bay’s dead zones estimate to kill 75,000 tons of bottom dwelling organisms  Overharvesting, pollution, sedimentation, and disease turned bay’s bottom into muddy wasteland Chesapeake Bay

8.  Glacial fjord in Puget Sound ~ 80 miles from Seattle  Long narrow shape results in estuarine circulation pattern and stratified water columns  More susceptible to eutrophication  Low oxygen concentrations have been documented since 1950’s, but over last 10 years conditions have worsened  Southern HC has experienced up to 12 months of hypoxia & Northern HC exhibited oxygen levels at which biological stress begin to occur. Puget Sound : Hood Canal

9.  September 2002, fish on west side of HC observed to be under stress from low concentration of DO  October 2003, DO conditions worsened, 30% rockfish were killed  HCDOP studied the causes of low DO concentrations in HC with USGS  Found out that the horizontal transport and upward mixing of DIN in the lower layer are driven by physical forces that are not fully understood. Puget Sound : Hood Canal

11.  Upgrading waste water treatment plants to enhance nutrient removal  Improved management of animal waste  Reducing and retrofitting impervious surfaces  Restoring wetlands  Planting forests (nitrogen influx didn’t increase in estuary until ~40% of land was deforested)  Prevent fertilizers, pesticides, detergents, and other organic wastes (lawn clippings) from entering streams, groundwater, and other water sources. Solutions to Eutrophication