This week we focused on the elkhorn slough, a 7-mile-long river delta and estuary, which is a partly enclosed coastal body, on Monterey Bay in California. As one of the largest estuaries in California, it is an essential habitat for over 700 species, and it is protected under private and public ownerships.
The major issues in this slough include tidal erosion, marsh loss and drowning as a result of the changes in tide flow, and source pollution from the agricultural run-off. According to Elkhorn Slough Foundation, “Tidal Erosion is the process by which tidal flows erode banks and channel beds, sometimes called tidal scour. The average rate of bank erosion along the slough’s main channel is twenty inches a year in the upper slough and twelve inches a year in the lower slough. The average width of tidal creeks has increased from eight feet to over forty feet in the last 70 years.” Today, large portions of Elkhorn were diked and drained for cattle grazing, railroad and road constructions, and the creation of freshwater impoundment. The draining leads to massive subsidence, which means when the tidal exchange later returns, the tidal flats are too low for the marshes to return to the area previously occupied, resulting in marsh losses and the drowning of plants in central area of the marsh.
The second half of the class we did role-playing. I was the co-founder of a local Kayak tourist company and talked to other people who played the researcher, farmer and power plant owner. Unfortunately, I had to leave early, so I did not know how we reached a conclusion. Please read Joe’s post if you want to know our solutions.