Coal mining has negative impact on freshwater stream biodiversity

Coal energy is expected to remain a key component of the national electricity portfolio until 2040, according to the Energy Information Administration.  Previous research suggests that coal mining operations can negatively impact the environment.  For instance, mountaintop-mining valley fill operations, common across Appalachia, often result in bioaccumulation of toxic chemicals in fish while other mining operations acidify freshwater streams.  Current federal regulations, like the Clean Water Act (1972) and the Surface Mining Control and Reclamation Act (1977), aim to protect the environment from degradation by providing operational standards to minimize the surface impacts of mining.

However, a recent study, published in Nature Sustainability and co-authored by Freshwater Initiative researcher Julian Olden, found that despite current laws and regulations, mining operations continue to have a detrimental impact on freshwater streams.  Where previous research has focused on a single mining operation or region, this study, led by Xingli Giam at the University of Tennessee (a former UW post-doctoral researcher), provides a quantitative meta-analysis of the impact of coal mining on stream health across multiple regions of the United States, according to a variety of mining operations, and under existing environmental regulations.

The study reported that streams affected by coal mining had, on average, a one-third reduction in biodiversity and only half of the total organism abundance of unaffected streams.  Invertebrate, fish, and salamander species richness (e.g., the number of different species living in the stream) declined by 32%, 39%, and 28%, respectively.  The study also suggests that even where federal regulations had mandated stream restoration, biodiversity and total organism abundance were still lower than unaffected streams.


Stream organisms affected by coal mining operations

The authors argue that for regulations to be effective, they must have broad, public support.  It is necessary to identify bipartisan arguments for conservation that resonate across a wide variety of backgrounds and belief systems.  For example, appeals to improving public health (coal mining has a high human health cost, including lung cancer and kidney disease) and recreational fishing and hunting (streams provide recreational opportunity) may both attract broad support.  Without stricter regulations backed by public support, coal mining operations will continue to degrade stream health across the United States.

You can read the full study here.

Long-term water resources data collection network is shrinking

Though nearly 71% of the Earth is covered in water, less than 3% of Earth’s water is fresh water, and only about 0.3% is readily available to humans in lakes, streams, rivers, and wetlands.  Reliable accounting of this limited resource is therefore fundamental to manage freshwater allocations to both ecosystems and society.  Networks of stream gages, known as “hydrometric networks,” have traditionally provided scientists with long-term records of water flow, water height, and other water quality variables.  However, a recent study finds that the global hydrometric network is not keeping pace with freshwater monitoring needs around the world.  The number of stream gaging stations reporting data to publicly available data repositories, called Water Information Systems, is declining.

Freshwater Initiative researcher Julian Olden is a co-author on a new study which proposes prioritizing stream monitoring by identifying watersheds that rely on hydrologic data for conservation initiatives.  The authors explain that long-term data, and thus a hydrometric network of monitoring stations, is needed for sustainable water management.  Here, knowledge is power: it is imperative to know how much water is available, where it is available, and when it is available.

Long-term hydrologic data collected through hydrometric networks is used to evaluate climate effects on freshwater resources, to track changes in river or stream flow patterns, and to improve flood and drought forecasting.  However, two of the largest Water Information Systems, the Global Runoff Data Centre and the United States Geological Society’s National Water Information System, are shrinking in monitoring capacity due to financial vulnerability, weakening infrastructure, and shifting priorities away from long-term data collection.

The authors argue that shrinking Water Information Systems may compromise human responsiveness to water challenges and the ability to monitor freshwater biodiversity.  It is not possible to respond to global water crises if researchers cannot forecast them for lack of long-term data.  The authors identified watersheds with a “High Monitoring Need” that should be prioritized for their water scarcity, high flood risk, or high biodiversity.  Coupled with policy recommendations for the maintenance of hydrometric networks, this prioritization strategy may secure the continuation of long-term data needed for sustainable water management.

You may visually explore the data used in this study, including stream gage distribution and stressed watersheds in the United States, here.

You may read the full study, published in Nature Sustainability, here.