Where Have all the Fish Gone?

The joys and perils of working on stream and riverine fishes is that the causes for changes in fish assemblages or populations is seldom obvious at first glance. Take a look at this paper which summarizes a very large investigation of declines in fish in Swiss Rivers.

The photo here is of the the Lütschine River

It is a fast- flowing glacier fed river that is popular among tourists who must raft it. Not all Swiss rivers look this way but it is the way we think about foreign lands from travel brochures.

Now click on the link and see what seems to explain "where have all the fish gone" in Swiss Rivers. I was surprised. You may be also.

Post your precis here for articles you read about Ecosystems Issues for Wednesday's discussion.

Have a nice weekend

Following the New River Video

A number of news article and this video on our local New River were produced by Tim Thornton Roanoke Times last year. Articles highlight the diverse pressures and benefits and land ownership in this large watershed. The video mentions the Hawksnest project which divert most of the New River (photo at right) through the Gauley mountain to produce hydropower. The Hawk's Nest tunnel is one of the country's worst disasters involving contraction of silicosis while constructing the hydro project. Silicosis was contracted through inhaling rock (silica) dust while blasting. The Hawk's Nest incident and the Hawks Nest tunnel is quietly hidden and forgotten by most, but see new book just published in 2008.

In these news articles there is a glaring omission of the relicensing process underway to re-consider operations of the Claytor Dam project (see hydrograph at right). Numerous studies are underway to address problems that exist with the hydro operations. You can see the study documents and schedules at the Claytor Lake Relicensing website. All studies are to be completed January 15 2009. After comments from stakeholders it is likely that a new license will be granted to AEP from FERC sometime in 2009. As you can tell the conceptual flow diagrams in papers by Richter et al. (2006) and Poff et al. (2003) have to fit into sometimes rigid FERC institutional processes where timeliness is key.

"Anyone who can solve the problems of water will be worthy of two Nobel prizes - one for peace and one for science."
John F. Kennedy

Saving Water for Whom?

This article came out last week -- and it's emblematic of what happens when we have a drought --- those who scream the loudest seem to get attention and those at the end of the river - those in the estuaries and bays will see less freshwater. Similarly we see major controversy over managing flows below a highly altered river systems in Virginia, Staunton River. Learn more about What's Behind the Water Wars. Here we average minimum of 650 cubic feet per second is required to be released from the dam unless there is a special variance related to drought conditions. Well won't we have a variance every time there is a drought??

“We'll never know the worth of water until the well goes dry.”– Scottish proverb.

This week we explore the many issues surrounding instream flows (in some places referred to as environmental flows) and read about the complexities of water resources management.

I will use the term "instream flow" because it is more common in the legal world though the term environmental flows is emerging throughout the world. The term "instream flow" is used to identify a specific stream flow (typically measured in cubic feet per second, or cfs) at a specific location for a defined time, and typically following seasonal variations. Instream flows are usually defined as the stream flows needed to protect and preserve instream resources and values, such as fish, wildlife and recreation. Instream flows are most often described and established in a formal legal document, typically an adopted state rule. I have personally witnessed the agonizing development of what is today referrred to as instream flow science as it is embedded in policy and law. As the cigarette commercial used to say "you've come a long way baby!"

Today, every state and Canadian province will understand the meaning of instream flow, even if their state statutes do not and some states have several specialists who do nothing but instream flow work. These specialists are organized as the Instream Flow Council which promotes awareness and sound science for protecting, maintaining and restoring aquatic ecosystems .

Sufficient water in streams is necessary to sustain both the natural environment and our community water supplies. We come to expect a continuous supply of freshwater and seldom think of it as an expensive commodity that we must pay for, such as electricity or oil. But that may change and droughts make us think about the finite nature of water -- and globally there are many severe problems outlined in the Report "Blue Gold" by Maude Barlow.

The instream flow council published a book of methods recently and has posted a 194 pages of references related to instream flows. I hope you find at least one interesting article on flow management to inform our discussion next Wednesday.

Click on comment and below and post your precis.

Population Ecology?

I didn't see a posting for the next discussion, but I wanted to get these out of the way. Anyway, here are my summaries:

Dolinsek, I. J., J. W. A. Grant and P. M. Biron. 2007. The effect of habitat heterogeneity on the population density of juvenile Atlantic salmon Salmo salar. Journal of Fish Biology 70: 206-214.

Kalleberg, E. R. 1958. Observations in a stream tank of territoriality and compensation in juvenile salmon and trout (Salmo salar L. and S. trutta). Report of the Institute of Freshwater Research Drottingholm 39: 55-98.

In a manipulative field experiment, Dolinshek et al. (2007) tested the Kalleberg (1958) hypothesis that for juvenile Atlantic salmon visual isolation reduces territory size and subsequently increases density. Dolinshek et al. (2007) hypothesized that if visual isolation is the primary mechanism controlling density in salmon, and not habitat heterogeneity or habitat quality, changes to a habitat that affect visual isolation should have no effect on non-salmonid density because such fish do not defend territories, but should affect density of coincident salmonids. They manipulated streams by adding or removing boulders from test plots. Boulders were assumed to provide sufficient visual isolation. They found that adding boulders increased salmon density, but had little effect on non-salmonids, thus supporting Kalleberg’s hypothesis.



Elliott, J. M. and M. A. Hurley. 1998. Population regulation in adult, but not juvenile, resident trout (Salmo trutta) in a Lake District stream. Journal of Animal Ecology 67: 280-286.

In previous work, Elliott and Hurley (1998) found that one of two extensively documented trout populations studied in the English Lake District was clearly controlled by density-dependent factors in early life stages (competition among individuals that recently emerged from redds). In the second population, which had a lower overall density, this density-dependent relationship was not observed, so they tested whether density-dependence at a later life stage, reproductive females, controlled populations. Specifically, they studied the relationship between how many females laid eggs each year and the number of successfully spawning females that resulted from that year’s recruitment. When female density exceeded 4 per 300 m2 their offspring produced fewer females and eggs. Documentation of later life density-dependence in salmonids is rare and the specific mechanisms remain unknown, though Elliot and Hurley (1998) speculate on a few.



Orth, D.J., and T.J. Newcomb. 2002. Certainties and uncertainties of defining essential habitats of riverine smallmouth bass. Pages 251-264 in M. S. Ridgway and D. P. Phillipp, eds. Black Bass: Ecology, Conservation, and Management. American Fisheries Society, Bethesda, MD.

Sorry to diverge from the Precis approach, but I just could not do this article justice via that summary format. Orth and Newcomb (2002) present concepts germane both to our discussions of habitat ecology and population ecology in stream habitat management.

On Habitat Ecology:

Orth and Newcomb (2002) use the inconsistencies and consistencies of observed habitat associations in Virginia and West Virginia streams to draw conclusions about the physical and biological processes that create and maintain habitats for SMB. For example, physical habitat measures of nest sites (depth, velocity, proximity to banks, etc,) varied by river, but all relationships were related to refugia for both adults and offspring. Nests in deeper habitats with greater cover protected adults from avian prey. Nests were also more common in areas less likely to be affected by violent flows, thus providing flow refugia for eggs. The conceptual connections presented in this example are writ large in Orth and Newcomb (2002) as they look at habitat use for all important life stages of SMB (nesting, early development, juvenile, and adult) and also at habitat needed to sustain a SMB forage base.

On Population Ecology:

In the first portion of their paper, Orth and Newcomb (2002) briefly review some factors known more globally to affect recruitment to and structure of SMB populations. However, in discussion of habitat associations they more narrowly hypothesize links between habitat and population structure, demonstrating the importance of density-independent mechanisms on SMB populations. For example, they hypothesized that SMB population structure is the product of stochastic processes, such as rare and extreme flow events, and habitat quality, such as suitable nest sites. They also discuss the link between habitat for forage and success of populations. For example crayfish density can affect adult SMB density. Thus, habitat quality for crayfish can control SMB populations.

In summary, Orth and Newcomb (2002) expose the danger of the assumption that because an animal appears to be habitat generalist, that population dynamics are not affected by density-independent mechanisms indirectly or directly related to habitat quality.

FLOW: For the Love of Water

This documentary, " Flow: For the Love of Water" will be playing through Thursday at the Lyric Theatre in Blacksburg. 7 and 9:15pm. It is an award winning documentary directed by Irena Salina " builds a case against the growing privatization of the world's dwindling fresh water supply with an unflinching focus on politics, pollution, human rights, and the emergence of a domineering world water cartel."

It is a great intro to our Oct 29th review of instream flow legal and institutional mechanisms.

Click on the Title to read some of the reviews...

Photo: by D. J. Orth, South Fork Roanoke River October 2008 at very low flow

Spatial Scales for River Conservation

Photo by Bruce Molnia USGS Meanders of Shenandoah River, Virginia

On Wednesday we will be reading papers on appropriate spatial scales for conserving riverine resources. My lecture on Wednesday will focus on Population Ecology of Stream Fishes and the emphasis will be on the temporal variation in habitat and the tendency of stream fish populations and assemblages to maintain some semblance of stability in a temporally variable environment (no assigned reading).

Our discussion will complicate this picture by taking a realistic view of the spatial connectivity of habitats. The paper by Kurt Fausch and others is a thorough literature review which proposes a number of principles based on a few example studies that study fish populations in a spatial context. The other papers that have been assigned will provide us additional examples from darters, smallmouth bass, mountain suckers and charr. These papers describe complex studies and numerous types of data and data analysis and are long -- so do not leave your reading to the last minute, hours or day .

Pay close attention to principles described in Table 1 and bring your examples of your personal insights and examples of these premises. Or think about these principles and their applications as you read specific articles about spatial patterns in stream fishes.

This just in: About the Trends in Nutrients in Shenandoah River of Virginia. Here is an example of the spatial complexity of addressing a basic question about the trends in water quality over time.

"There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact." Mark Twain, Life on the Mississippi, 1883

Clinch River Flood Frequency

Thought I might share this. I just did the frequency analysis for the Clinch River at Cleveland Island. How does it compare to what you saw? This basin drains mostly forest and agriculture (pasture).

Exam Help

Photo by Lee Walker.

Wednesday's Exam will consist of Five Questions. Click on Exam Help Above for added advice.

Here are a number of Exam Questions to assist in your studies. Do not assume that the exam questions will be worded exactly as these are.

As compared to other ecosystems, streams are unique in ways that make them both interesting and difficult to study, understand, and manage. What are the most important unique factors as you understand them? Compare and contrast a local stream ecosystem, such as Craig Creek, with the local Pandapas pond.

Describe the term “Leitbild” as it relates to the process of stream habitat restoration. How do we as stream habitat specialists translate that Leitbild into an operational plan?

What are hydraulic geometry relationships for stream channels? Geometry is one of the oldest components of mathematics concerned with questions of size, shape, and relative positions of shapes. How are these relationships derived for streams and how are they intended to be applied? And what are the major factors that lead to variability in relationships.

We use a lot of strange terms in stream rehabilitation, such as root wads, J hooks, cross vanes, weirs, revetments, W-rocks, K-dam, check dam, and others. Can you classify these terms based on their function as stream rehabilitation techniques and describe they are and what they are intended to do?

What is the significance of the concept of bankful stage or discharge? In the field, how does one approach identifying the bankful stage reliably? What are some procedures and indicators that you recommend be implemented?

Fluvial processes create and maintain stream channels that may or may not provide suitable habitat for fish of interest to the public. Describe the basis for the Montgomery-Buffington systems for classifying stream channels based on fluvial processes. For each channel type, explain the features of the channel that provides habitat for a specific life or ecosystem function.

Science is the search for fundamental principles to help us understand and explain phenomena. Based on your studies thus far, can you describe three to five fundamental physical process principles that help us understand and explain the form (dimension, pattern, profile) of stream channels.

Victor Shelford wrote that ‘the first essential is the locate the animal in the environment’ While this is the first step in understanding habitat use, please expand on the notion of microhabitat selection by describing how a stream ecologist would demonstrate habitat selection by a stream animal. In your elaboration on this idea, think about one cue (based on sensory perceptions) that a fish may use in habitat selection and explain the process of by which a fish displays selection.

The cause and effect diagram is used to explore all the potential or real causes (or inputs) that result in a single effect (or output). Causes are arranged according to their level of importance or detail, resulting in a depiction of relationships and hierarchy of events. Develop a cause and effect diagram that depicts the influence of four major factors that influence the shape (hydrologic response) of a stream hydrograph.

Develop an argument to support your belief of the most important standards and criteria to apply in determining ecologically successful stream restoration.

Phillip Roni and coauthors summarized the results of over 350 studies of stream rehabilitation and organized them into themes of roads, riparian, floodplain, instream structures, and nutrients. What was the central thesis of this paper? In this paper they propose an interim strategy for prioritizing future rehabilitation. Do you agree with their proposed highest priority actions? Why or why not?

Let’s assume your stream habitat management division is considering adopting the stream habitat classification system described by Hawkins et al (1993). What is your opinion about the use of this system? What cautions and concerns would your communicate to your supervisor?

What are the most common motives for river and stream restoration? How does motivation influence the need for criteria for defining success?

In order to fully describe ecologically relevant patterns of variation in stream flow, how would you quantify the stream flow regime for a local stream?

If you have questions or comments, post them here. I will monitor your posts but will be at the FLOW 2008 Conference.