It is said that the environmental movement began with the first Earth Day. Four decades later, we have seen signs of environmental improvement: rivers no longer catch fire, chemical dumps have been cleaned up and we are breathing cleaner air. But even as we solve past environmental problems, we place renewed pressure on our ecosystem.
In the Chesapeake Bay watershed, our population has doubled over the past 60 years, reaching almost 18 million people. With that population increase comes a rise in polluted runoff from roads, parking lots and farm fields and more discharges from septic systems and wastewater treatment plants. These non-point sources of pollution push nutrients and sediment into our waterways, where they create algal blooms and low-oxygen dead zones, smother our underwater grasses and reduce fish habitat. Our actions on land continue to impact our environment, creating an ecosystem that is dangerously out of balance. Now, pollution is much more insidious.
When we look at the efforts made to restore the Bay and its watershed, we can see what works and what doesn’t. We know that technological upgrades to wastewater treatment plants can lower nitrogen and phosphorous discharges, improving water quality and, in some cases, boosting the growth of underwater grasses. We know that controls on power plant and vehicle emissions can reduce the atmospheric deposition of nitrogen, lowering nutrient pollution in the Bay. And there is evidence that planting cover crops, controlling fertilizer applications and restricting livestock from streams can reduce agricultural runoff and restore local waters.
While these actions demonstrate success, there are other actions that have not led to such improvements. But these experiences are equally important. The environment is a complex system, and what works in one location might not work as well in another. The same practice implemented in the Piedmont, for instance, will not create the same results as that practice implemented on the Coastal Plain. And some areas experience “lag-times” between the implementation of conservation practices and an improvement in water quality. Knowing what factors may cause these differences is important, so we can adjust our behavior and adapt our approaches to local conditions. As we work to restore the watershed, we must constantly ask ourselves, “What have we learned?” And we must know that how we apply these lessons will provide the key to restoring rivers, streams and the Bay.
Note: The opinions expressed above are those of the author and do not necessarily reflect U.S. EPA policy, endorsement, or action.
Cover crops, sediment ponds and streamside trees and shrubs: each of these conservation practices will slow the flow of pollutants into the Chesapeake Bay. But each will take different amounts of time to produce water quality results, according to a panel of experts convened by the Chesapeake Bay Program.
Image courtesy Uncle Kick-Kick/Flickr
In a report released this month, the Bay Program’s Scientific and Technical Advisory Committee (STAC) notes that the impacts of changes in land use and pollution loads into rivers and streams will not always be immediately reflected in changes to water quality. In fact, these so-called “lag-times”—or the stretch of time between the adoption of a conservation practice and the effect of that practice on a particular waterway—could call for patience in awaiting visible results from our restoration work.
Lag times are a natural part of our environment: as rainwater soaks into the ground, it can move nitrogen through the soil, and strong storms can pick up sediment and deposit it elsewhere. Because conditions in the Bay are a result of current human activities and a legacy of activities from the past, it makes sense that management actions taken now could take days or even decades to produce positive results. In fact, scientists know that some practices—in particular, those that take place close to rivers and streams—can produce results faster than others.
But according to STAC, this doesn’t mean that we should scale back on watershed restoration. Instead, an understanding of lag-times improves our understanding of how the ecosystem works, and reminds us to be “patiently realistic about the time-scale for observing results.”
Learn more about lag-times and the Chesapeake Bay.
Denser grass beds in the Chesapeake Bay could boost the region’s blue crab population, according to a new report from the Virginia Institute of Marine Science (VIMS).
While researchers have long known that blue crabs use grass beds as sheltered nurseries and feeding grounds, this study is the first to show that denser, higher-quality grass beds hold more crabs than open beds where patches of mud or sand separate plants.
These findings are based on fieldwork conducted between 2007 and 2008, during which scientists used a powerful vacuum to collect blue crabs from 104 sites along the shores of the lower Bay.
Graduate student Gina Ralph led the study and said in a media release that her work suggests “the quality of seagrass habitat can influence the population dynamics of blue crabs on a baywide basis.” But underwater grass abundance has declined in recent years, due to warming waters and sunlight-blocking sediment pollution. Blue crabs, too, have suffered population declines, as pollution, predators and human harvest put pressure on the iconic species.
Learn more about the link between grass beds and blue crabs.
When the start of a new school year drives students into the library, it’s not always a given that they are looking at books. In fact, one marine research center in Virginia is home to a library filled with fish.
The Nunnally Ichthyology Collection at the Virginia Institute of Marine Science (VIMS) contains more than 100,000 freshwater, estuarine and marine fish specimens for use in research and education. The collection is curated by Eric J. Hilton, an associate professor of marine science who has spent a great deal of his life around collections of fish and reptiles. But this one, he says, is unique: after taking on “orphaned” specimens from two other laboratories, VIMS has become the only institution to actively maintain a collection of Chesapeake Bay and mid-Atlantic fish.
The preservation process starts with the euthanization of the fish. Then, the specimen is soaked in a formalin bath to prevent tissue decay and breakdown.
Once the specimen is completely soaked (larger fish take quite a bit more time to preserve than smaller fish), the formalin is flushed from the body and the specimen is placed in a jar that contains a 70 percent ethanol solution.
Oftentimes, multiple specimens of a single species are collected and catalogued. Because there is always variation in nature, researchers prefer to compare and contrast multiple fish of the same species to gain a well-rounded perspective of what the fish and the area they live in are like. “Looking at [only] one individual from a [single] locality will not give you a good view of that locality,” Hilton said.
Each jar is given its own catalogue number that will follow the specimen far into the future. “With that [catalogue] number comes species identification, and all of the attributes of when and where that fish was caught and how it was caught,” Hilton said. “[The number] is entered into a catalogue that is accessible to people throughout the world.”
VIMS also collects a limited amount of skeletal remains in order to conduct skeletal analyses of certain species. “We hope that someday, people can come to the Chesapeake Bay and ask, ‘What was here in 2013?’ and get to see those species and specimens,” Hilton said. If the collection is properly cared for, its fish could be kept for well over 200 years. In fact, some natural resource libraries in Europe are more than 400 years old.
Because its specimens have been collected over decades, the library contains evidence of changes in the Bay. The southern flounder, for instance, is typically found off the coast of North Carolina and other southern waters. Historically, adult southern flounders have made their way to the southernmost portions of the Bay only during hot summer months when the water is warm. But in recent years, researchers have found young southern flounder in the Bay and have added them to the VIMS collection. This new addition indicates a northward shift of southern flounder spawning grounds, likely due to warming waters and climate change.
The fish collection also stores vital information about the introduction and spread of invasive species like the northern snakehead or blue catfish across the state of Virginia and the Bay watershed. Hilton explains: “We have snakeheads from different drainages, so we can track their invasion. We have some of the first juvenile blue cats, and can get a sense of where and when the invasions start.”
VIMS plans to continue their fish collection efforts for the foreseeable future. After all, as science and technology advance, researchers can conduct new tests on older specimens and learn things about the species or its environment that they might not have known before. “If you stop collecting, you limit what you are able to do,” Hilton said.
To view more photos, visit the Chesapeake Bay Program Flickr page.
Images by Steve Droter.
Captions by Jenna Valente.