Abandoned Mine Posts

by Andy McAllister, Watershed Coordinator

In this last installment of the Life in Our Streams series, we leave the stream and emerge into the green world of streamside vegetation. A world that is inextricably tied to our aquatic environment.

Vegetation along rivers and streams, called riparian vegetation, plays an important part in maintaining and improving the quality of our rivers and streams. The type, density and width of riparian vegetation provide a crucial link between terrestrial and stream ecosystems.

Native vegetation along the streambank provides food and shelter, while also providing a corridor for the movement of wildlife. Riparian vegetation provides vegetable matter, which breaks down and provides food for aquatic invertebrates. Shade from riparian vegetation helps maintain cool water temperatures in pools. In addition, fallen branches, large woody debris and aquatic plants provide habitat for fish and invertebrates.

Riparian vegetation is important in the prevention of stream bank erosion. Vegetation binds soil and and creates a “roughness” that reduces stream flow rates, particularly during floods. Vegetation at the base of riverbanks is especially important to riverbank stability, particularly on outside bends of meanders and on other banks where flow is deflected.

Vegetated riparian zones maintain water quality by filtering sediment and nutrients, and reducing the amounts of water entering a water course. Any vegetation that provides a dense cover at ground level will be an effective filter. Riparian vegetation of course, has an inherent aesthetic and intrinsic worth that is difficult to value in monetary terms.

Wetlands are another type of highly valued vegetated area. Wetlands can be found adjacent to streams or in isolated pockets. A wetland is land that is seasonally or permanently covered by shallow water, as well as land where the water table is close to or at the surface. In either case, the presence of abundant water has caused the formation of what is called “hydric soil”. Hydric soil is one that is saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions. Hydric soil is one of the key characteristics of a wetland. This type of soil favors the growth of either water loving (hydrophilic) or water tolerant plants. These unique areas represent a combination of terrestrial and aquatic characteristics, and are further categorized by type as marsh, swamp, fen and bog.

A wetland with different types of plants.

Wetlands are very productive ecosystems and can be thought of as “biological supermarkets.” Wetlands provide large amounts of food, which attract many different animal species. In addition to being “biological supermarkets” for other animals, wetlands produce a number of natural products used by humans, including fish and shellfish, cranberries, timber, wild rice, blueberries, as well as medicines that are extracted from wetlands soils and plants.

There are several types of wetland plants depending on where they live in the wetland:
Emergent plants are those that, although rooted under the water, emerge through the water’s surface (eg. sedges)
Submerged plants are those that stay submerged in the water column (eg. bladderwort)
Floating plants are those which live entirely on the water’s surface (eg. duckweed)

Wetland plants that require water and proper hydric soils at all times are termed “Obligates”. Those that are a little more forgiving in their environmental requirements are termed “Facultative”. Often, both can be found in a wetland.

Wetlands also absorb and retain stormwater helping to slow flooding. Wetlands are also useful in filtering out pollutants from Abandoned Mine Drainage (AMD). Long a part of passive treatment technology, wetlands can capture and retain metals from AMD that would otherwise settle out in a stream.

For more information:

The Value of Wetlands from the World Wildlife Fund

by Andy McAllister, Watershed Coordinator

Since the “Life in Our Streams” series began, our journey has taken us through a myriad of life forms inhabiting our underwater world. From the bacteria, smallest of the small, to the bottom dwelling creatures known as benthic invertebrates, all form an important part of the aquatic food web. As we leave the relative protection of the stream bottom and journey into the expanse of the water column travelling toward the surface, other life forms begin to become apparent.

Aquatic organisms are often categorized by where they live in the water. As we’ve already seen, benthic organisms live in or on the stream bottom and feed on plant and animal material that collects on the bottom. Crayfish, mussels, and stonefly and mayfly larvae are examples of benthic organisms.

Pelagic organisms are those that live within the water column. These organisms may float or swim and include everything from tiny plants and animals known as plankton, to fishes, frogs, turtles, and a wide variety of insects.

Fishes are probably the best-known pelagic inhabitants of our streams and rivers.  The fish’s ability to live in the water column depends upon the speed at which it can swim and how long it can sustain that speed. Of course, this ability often varies greatly between species. Continuous swimming expends a tremendous amount of energy, so fishes tend to spend only short periods in full current. Instead, individuals remain close to the bottom or the banks, behind obstacles, sheltered from the current, often swimming in the current only to feed or change locations. Some fish species have adapted to living primarily on the stream bottom, rarely venturing into the open water column. These fishes are flattened top to bottom to reduce resistance to the current and often have eyes on top of their heads to see what is happening above them. These types of fishes are known as “demersal” fishes. An example of a demersal fish is the sculpin.

Other vertebrates that inhabit streams include amphibians, such as salamanders, reptiles (e.g. snakes and turtles) various bird species, and mammals (e.g. otters and beavers). With the exception of a few species, these vertebrates are not tied to water as fishes are and spend part of their time in terrestrial habitats.

Abandoned Mine Drainage (AMD) is just as dangerous for inhabitants of the water column as it is for benthic organisms. Fish in particular are susceptible in several ways. The primary causes of fish death in acid waters are through loss of sodium ions from the blood and loss of oxygen in their tissues. Sodium loss interferes with the process known as osmoregulation, the way in which fish maintain the concentration of their body fluids. As a result of a sodium loss, there is a constant influx of water into the body and loss of salts and ions from the blood outwards. The end product is that the fish would rapidly accumulate water and die. Acid water also attacks the fish’s gills, increasing the gills’ permeability to water, adversely affecting gill function and reducing the amount of oxygen they can absorb.

Low pH levels that are not directly lethal adversely affect fish growth rates and reproduction . Some fish, such as brook trout, are tolerant of low pH. However, it’s the presence of dissolved metals found in many AMD discharges, that decreases the fish’s ability to tolerate low pH. Finally, metals precipitating out in the water column, collects on the gill structures, further restricting oxygen absorption into the blood.

AMD impacts on Pennsylvania’s native brook trout populations for example, are localized. But where it happens, it’s generally severe. In fact, if we were to total up the entire area of brook trout habitat in Pennsylvania that’s impacted by AMD, it would be larger than the state of Connecticut.

For more information:
Conserving the Eastern Brook Trout by the Eastern Brook Trout Joint Venture

Gallery of PA Fishes by the PA Fish and Boat Commission

By Andy McAllister, Watershed Coordinator

As most people who are involved in watershed work know, we watershed folks love acronyms. Even the invertebrates can’t escape our penchant for acronyms. In this edition of Abandoned Mine Posts, we continue our Life in Our Streams series and examine a group of aquatic invertebrates with a unique acronym.

Healthy streams unaffected by pollutants such as acid rain or AMD generally have a high diversity of macroinvertebrate species representing several orders. In these healthier streams, one group of macroinvertebrates is most often well-represented. That group of macroinvertebrates is known as the EPT.

The term EPT, refers to three orders of aquatic insects that are well
known to be indicators of good water quality: Ephemeroptera, Plecoptera, and Trichoptera. These insects are more commonly known as Mayflies, Stoneflies, and Caddisflies. All have an aquatic phase in their life cycle and all of them emerge from their watery home and take to the air when they metamorphose into adults.

Mayflies (Order: Ephemeroptera)

Graceful and elegant, mayfly adults often emerge from the water in large numbers during the spring and spark feeding frenzies among resident trout.  As their order name would imply, their life is ephemeral, lasting a day or little longer.

While mayfly adults do not eat and only live long enough to ensure the survival of the species, mayfly nymphs live on the stream bottom for about a year, consuming anything from small bits of organic debris called detritus, to algae or other smaller invertebrates, depending on the individual tastes of that particular Genus. Several mayfly species are considered to be very sensitive to acidic conditions in a stream.

Stoneflies (Order: Plecoptera)

Often beautifully adorned with intricate color patterns, stonefly nymphs on the other hand, are generally carnivores, preying on anything that is smaller than they are. However as with anything, there are exceptions and while many stoneflies are predators, there are some stoneflies that do prefer to consume detritus and algae. Stonefly adults, once emerged from the stream, can and do eat plant material.

Their existence as adults, while longer than that of the mayflies, is very short. Stonefly adults can live for up to a few weeks. During that time, they mate and lay eggs to ensure the next generation of stoneflies. Many of the stoneflies had traditionally been considered to be fairly tolerant of acidic conditions in a stream compared to other macroinvertebrate groups. However, recent studies suggest that this order of aquatic insects may be more severely affected by acidification than previously believed.

Caddisflies (Order: Trichoptera)

Caddisfly larvae are the engineers of our aquatic world. Most caddisfly larvae live in cases that they construct out of sand, rock, twigs, leaf pieces, and any other kind of underwater debris. The beauty of these miniature constructions can be breathtaking. Some caddisflies generate their creations out of silk, create a net, or construct no case at all.

Caddisflies as a group can tolerate only a slight amount of acidity in
a stream however, there are a few species of caddisfly that are very
tolerant of acidic conditions.

by Andy McAllister, Watershed Coordinator and Bruce Golden, Regional Coordinator

The editors of Abandoned Mine Posts (AMP) recently caught up with Mark Killar, Director of Watershed Services with the Western Pennsylvania Conservancy and asked about the possibility of trout living in AMD-impacted streams.

AMP: Redstone Creek in Fayette County is a stream that runs orange for many miles from huge abandoned mine discharges, yet we’re aware of reports of rainbow trout being caught there. Could that be? Is it a fluke or are they fish that someone dumped into the creek?
Killar: This kind of scenario has been observed in other streams that receive net alkaline Abandoned Mine Drainage (AMD) from abandoned deep mines. As you may be aware, these discharges often contain high amounts of alkalinity due to the limestone layer located above the flooded portion of the mine(s). Although the discharges look ugly because they contain lots of iron and turn the stream orange, they don’t contain acid or aluminum, the two deadly killers of fish and life in the stream. Because fish aren’t affected that much by iron, they can survive in these net alkaline iron polluted streams.

AMP: So, some discharges aren’t as toxic as others? Is it possible that some of these discharges could actually help fish populations?
Killar: Well, one thing that helps out trout in particular is the 50 degree water temperature of the mine water. Especially at low stream flows, the mine discharges have a positive effect on the stream by keeping the water temperature down because they often can make up a significant portion of the stream flow when the streams are usually flowing low. Cooler water means the stream can hold more oxygen, which the trout like and need. Besides that, people wouldn’t normally think there are trout in the orange water so they don’t fish there and the trout get a chance to grow.

AMP: You said that “fish aren’t affected that much by iron”. Does that mean we should simply not be concerned about water that’s just polluted by iron then?
Killar: A study was done on Sewickley Creek some years ago (which also has several large alkaline deep mine discharges on it) and to the surprise of the person doing the study several nice brown trout turned up in a little orange tributary to the stream. It was a very small stream that looked ugly as heck, but again, didn’t have acid or aluminum being dumped into it from the mine discharge. Upon further study, it turned out the fish only had minnows in their stomachs and no aquatic insects, which makes sense in that the heavy coating of iron on the bottom of the stream significantly reduces the number of aquatic insects because it smothers out their habitat. The big question is “What the heck are the minnows eating to keep them alive?” One theory is they come from the smaller unpolluted tributaries or are washed into the unpolluted sections from upstream. A similar situation happened on Loyalhanna Creek near Latrobe where again large net alkaline deep mine discharges polluted it and turned the stream orange. One local fisherman had a secret spot he would fish (in the orange portion of the stream) and would catch some pretty large fish. Again, it was likely that few fisherman would consider fishing in that portion of the stream so the fish had lots of time to grow big.

Visit the Western Pennsylvania Conservancy’s website for information about conservation activities in your area.

For a listing of watershed groups in Western Pennsylvania, visit http://amrclearinghouse.org/Sub/organizations/WesternPennsylvania.htm