| Published: January 12, 2021

How Saltwater Intrusion Effects Farmers

Do you remember that 1950s movie called “The Blob”, where a squishy substance overtook people’s homes and possessions? Well it’s back - not in the classic film’s sense, but in the form of saltwater. Were you aware that agriculture producers were coming to terms with their own version of “horror” just off of Maryland’s Eastern Shore (and coastal regions around the country)?


According to Wikipedia, "Saltwater intrusion is the movement of saline water into freshwater aquifers, which can lead to groundwater quality degradation, including drinking water sources, and other consequences."

This seemingly slow-moving saltwater issue is forcing farmers to abandon fields when they first see signs of encroachment - which has doubled in speed and reach over the last several years. This invasion is cause for the need of more support for farmers and natural resources alike.

There are five reasons for seeing saltwater intrusion and inundation:

  1. Storms and high tides are causing extensive flooding in areas, not just in farmland, but also seeping into aquifers, and moving down into shallow water tables
  2. Sea level rise
  3. Droughts
  4. Subsidence
  5. The connectivity of the landscape (ditches) to salty water bodies.

Saltwater Intrusion on the Chesapeake Bay

In a statement from The George Washington University (GWU) Department of Biology, “The Chesapeake Bay is ground zero for sea-level rise. Due to a combination of climate change and natural subsidence of already low-lying land, the bay has some of the highest rates of sea-level rise in the world – approximately three times the global average.”

Dr. Kate Tully, Assistant Professor of Agroecology, University of Maryland (UMD) Department of Plant Science, has been studying sea level rise and saltwater intrusion on Maryland’s Eastern Shore. “Our study is noting widespread saltwater intrusion over many counties on Maryland’s shore,” she says. “We are seeing this all across the states of Delaware and Virginia, as well.” In Somerset County, Maryland, over a thousand acres of farmland have converted to salt marsh over the last eight years, and the pace of this loss is only expected to rise in coming years.

Saltwater intrusion is hard to predict, making it difficult for farmers to determine which fields to tend. This uncertainty is motivation for more data collection. Tully, Dr. Keryn Gedan at GWU, and Dr. Pinki Mondal at the University of Delaware are “working to produce maps of salt levels in soils and hand-dug wells, soil types, hydrogeologic layers, and ditches” (source: UMD).

In a recent interview clip by WJZTV, Tully expressed the importance of acting quickly. “We need to act now. The damage is already happening, but we often speak about climate change and sea levels as a future concern. Farms are already being lost at a fast rate.” Tully adds, “All crops on the Eastern Shore are not adapted to high salt levels. The issue is Maryland’s shore is only two feet above sea level, salt is pushed onto the fields and isn’t able to drain out.”

Tully’s motivation for saving Maryland’s natural resources stems not only from the bountiful food source the bay provides or the thriving wildlife population, but from the preservation of history. “Our history is going underwater,” she says. “Many of the first settler landmarks are becoming lost. Some of the farmers I work with can trace their land back to the 1630s, and they are the first to go underwater.”

Researchers are continuing to look for solutions to this issue while providing assistance to farmers. While they cannot turn back the tides, partnering with environmental agencies will allow them to prepare the Chesapeake Bay for upcoming changes. “We want to be able to help farmers find a crop that can provide income, if possible,” explains Tully. “I attend many roundtable stakeholder meetings. There are incentive programs for farmers, but we want to make it easy for producers to enroll, with as little paperwork as possible.” The Natural Resources Conservation Service (NRCS) is working hard to gain help for farmers by assisting to implement new plans and strategies. Tully also emphases how native marsh grasses store carbon, reducing nutrient loading into the bay. In the face of saltwater intrusion, it is critical to provide farmers with options that can support a clean and healthy environment while not putting them out of business. Tully and her team are tackling this challenge.

Tully concludes, “Aside from the constant forward march of the saltwater invasion, one fact we know for sure is that we need more research on this topic, and we need it fast.”

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