Cooperative efforts are not only bettering Chesapeake Bay bass fisheries. They're also laying the groundwork for future strategies to sustain and enhance these waters that are vulnerable to erosion and saltwater intrusion, as well as projected sea level rise (SLR) related to climate change.
"We're partnering with Maryland B.A.S.S. Nation (MBN) and others to build a reef in tidal freshwater at National Harbor on the Potomac River, the first tidal freshwater reef in Maryland," said Joe Love, tidal bass manager for the Maryland Department of Natural Resources (DNR). "That type of work might help provide stable reproductive habitat if grasses or wetlands are lost over time.
"In general, it's best to protect habitat, but it's hard to fight the tide," he added. "As habitats change over time, I'm optimistic that innovative work will undoubtedly be accomplished to help protect our tidal freshwater fisheries."
Love also pointed out that MBN has been working with his agency to stock bass in tidal areas of the Middle and Gunpowder rivers. "While Middle River used to be a great bass fishery, urbanization of that watershed likely led to greater saltwater intrusion, nutrient influx, and reduced productivity for bass," he said.
History confirms that good bass spawning habitat can be lost over time in coastal fisheries. For example, SLR, nutria, and saltwater intrusion have degraded a once prime area in the Blackwater National Wildlife Refuge on the Eastern Shore, the biologist explained.
And it is the Eastern Shore that will be punished the most by future intrusion and SLR. "More wetland is predicted to be lost from our Eastern Shore than anywhere else in the bay," Love said.
But the most valuable habitat for bass lies in the Potomac River and upper bay (Susquehanna River). Unfortunately, it also is the most vulnerable, according to an extensive survey of 141 nursery habitats on the Chesapeake Bay watershed that Love conducted with the help of other MDNR biologists and funding from the federal Sport Fish Restoration Act.
"They have highly productive nurseries, and are the two biggest fisheries in Maryland tidal waters," he said. "Because of those things, even a relatively small impact form SLR on the Potomac River and the upper bay can have a bigger impact on the fisheries there than on the Eastern Shore, where habitat quality and availability already severely limit population growth rates for largemouth bass."
For the study, Love added that he focused on "how much impact there could be, worst case scenario" in terms of increased salinity, loss of grass and increased influence by tides.
"To be honest, though, I'm not sure how severe those impacts would be," he said. "Will there only be a little loss of grass? Will salinity only rise a little bit?
"I'm not sure about the degree of influence or even how those influences will affect the fisheries. But we need to start thinking about that for these costal bass fisheries and asking those questions."