Sunday, March 11, 2018

Clupeids From Freshwaters of Virginia, by Don Orth

Herrings and shads have existed on the North American continent since the Paleocene (66-56 MYBP).  The state fossil of Wyoming is an extinct clupeid fish Knight eocaena.  Clupeomorph fishes arose in the early Cretaceous Period.  All members of the Clupeidae are silvery and laterally compressed and have sharp scutes on their bellies. The countershaded coloration, silvery mirror scales, and schooling behavior are effective anti predator devices.  In the freshwaters of Virginia, you may encounter six clupeid fishes. Four are anadromous species that spend most of their life cycle in salt water while the other two are freshwater. All the herrings and shads are highly prolific and their abundance may change erratically. The anadromous species are particularly important because they transfer marine-derived nutrients to freshwater in addition to serving as prey for numerous coastal birds, mammals, and fishes.   

The American Shad Alosa sapidissima is the largest of the clupeids. The flesh and roe of the American shad is highly sought as food, hence the specific epithet means "most savory."   The lower jaw shape and mouth are key characteristics to distinguish them from Hickory Shad Alosa mediocris.   American Shad spawn in rivers from Canada to Florida.  American Shad commercial fisheries were important to the history of the American colonies.  John McPhee's The Founding Fish (2002) blended descriptions of the natural history of the American Shad with American history and our obsession with this fish.  George Washington fished for American Shad in the Potomac River.  During the Revolutionary War, Washington and his troops were spending winter near the Schuylkill River at Valley Forge and replenished their food supplies with an early run of American Shad. 

Unfortunately, landings of American Shad peaked in 1897 and have declined ever since.   Major causes of declines were overfishing, construction of dams, pollution, concentrated commercial fisheries near the mouths of rivers (Mansueti and Kolb 1953).   By 1943, an estimated 77% of American Shad entering Chesapeake Bay were harvested.   In the 1950s and 1960s, the shad sport fishing increased due to popularity of spin fishing.  Recruitment overfishing was occurring for many decades before regulations were imposed (Foerster and Reagan 1977).  In the 1980s and the 1990s landings from ocean intercept fisheries doubled and mean age and incidence of repeat spawning among American Shad started to decline (Limburg et al. 2003).  Conservation efforts and dam removals were slowly implemented  and recent monitoring efforts show no signs of recovery (Lipsky et al. 2016; Hilton et al. 2017).  Stocking alone has been inadequate to increase wild populations of American Shad in the James River (Aunins et al. 2014) as concerns about inter-basin transfer of American Shad remains a serious problem.  Currently there is a harvest moratorium on American Shad in Virginia waters, although some limited bycatch is permitted.  
American Shad caught on fly rod.  Source
Head of American Shad showing shape of lower jaw.  Photo by Mitchell Blake. 
Hickory Shad is the next largest clupeid fish in Virginia. They are also known as the shad herring or the fall herring and spawn in rivers from Maryland to Florida.  Hickory Shad resemble American Shad but their distribution and feeding niche are different.  Note that in the photo below their lower jaw extends past the upper jaw when closed.  This is the easiest way to reliably distinguish Hickory Shad from the American Shad.  Hickory Shad also has fewer gill rakers than the American Shad and its diet is mainly fish and crustaceans while the American Shad is planktivorous. Sand lance, anchovies, cunners, herring, scup, silversides, and other small fish, squid, fish eggs, and even small crabs have been observed in Hickory Shad guts.   The species epithet mediocris translates to mediocre, referring to its desirability as a food fish.  
Hickory Shad. Photo by
Hickory Shad (top) and American Shad (bottom).  Photo by
Blueback Herring Alosa aestivalis, once known as the glut herring, historically ranged from the Gulf of St. Lawrence to the St. Johns River, Florida.   It has a blue-green colored back and silvery sides and easily confused with the Alewife.  The Alewife Alosa pseudoharengus, also known as the Gaspereau and the Branch Herring, historically ranged from Labrador to South Carolina.  Distinguishing the two species is often confusing and fisheries have lumped the two into 'river herring.'  River herring were listed as species of concern by the National Marine Fisheries Service in 2006 and a harvest moratorium was enacted in 2012.  

The two species can be distinguished.  The back of the Alewife is typically gray-green. The Alewife has a larger eye; it is broader than the distance from its forward edge to the tip of its snout.  The lining of the belly is sooty or black in the Blueback Herring and pale gray or pinkish white in the Alewife.   

The distribution and abundance of both Alewife and Blueback Herring have been highly altered by overfishing, dams, culverts, and introductions.  Both Alewife and Blueback Herring have been introduced in freshwater reservoirs to provide a land-locked populations to support many piscivorous sport fish.  However,  anadromous populations appear most at risk.  Each major Atlantic slope river supports genetically distinct populations, which show declines in abundance and mean size (Palcovacs et al. 2014).    Declines are most dramatic and widespread for the Southern New England Stock of Alewife.  Efforts are underway to reduce the incidental catch of river herrings during their coastal migrations where they overlap with Atlantic Herring Clupea harengus trawlers (Turner et al. 2017). Recently, hybridization between the Blueback Herring and Alewife raised  an additional management concern (McBride et al. 2014).  In New England,  the most heavily dammed region of the world, the freshwaters support only 6.7% of historical capacity of anadromous alewife biomass and abundance (Mattocks et al. 2017). 

Blueback Herring (top) and Alewife (bottom). Photo by Chris Bartlett.
Gizzard Shad Dorosoma cepedianum occurs in freshwater and brackish waters.  It has a deep body, with a silvery-green coloration above fading to plain silver below.  The small mouth is subterminal to inferior and it filter feeds on phytoplankton when young and switches to zooplankton as it grows larger.  A better common name might be the Bluntnose Shad, as the small blunt snout distinguishes it from other shads and herrings.   Gizzard Shad have a distinguishingly long dorsal fin ray occurs at the back of the dorsal fin.  But the 'gizzard' name refers to the muscular gizzard that aids in the breakdown of consumed foods.  Gizzard Shad may deplete zooplankton when very abundant and switch to detrital feeding.  As detrital deposit feeders they resuspend benthic nutrients into the water column where they may stimulate plankton growth.   

Gizzard Shad are readily consumed by Walleye and Black Bass, but may quickly grow beyond the size available to many predators.  Consequently, they are not the ideal forage fish for gape-limited piscivorous fish.  However, Bald Eagles, Ospreys, and Great Blue Heron can capture and eat a large Gizzard Shad. Coleman Sheehy photographed a Great Blue Heron that just captured a Gizzard Shad from James River in Richmond, Virginia.  In tidal freshwater and oligohaline sites, diet of the Osprey was 28% Gizzard Shad (Glass and Watts 2009).
Gizzard Shad. Photo by Uland Thomas. 

Gizzard Shad are widely distributed and have been introduced in many other drainages outside its native range.  They are native to all drainages in Virginia except the New River. However, they were introduced into the New River in the late 1980s.  Gizzard Shad school in large numbers and are caught with cast nets and used for cut bait by those fishing for catfish.  They rarely are hooked by anglers.  However, this rare photo proves that they can be. 
Small Gizzard Shad caught via microfishing in Lake Erie.  Photo by Sean Phillips. 
Threadfin Shad Dorosoma petenense are smaller, southern versions of the Gizzard Shad with different coloration and mouth shape. The principal distinctions are the mouth, which has a terminal position,  and the bluish-gray dorsum and yellowish coloration in caudal fin.  The upper jaw does not project beyond the lower jaw. Threadfin shad have a prominent purple to black spot on the upper side of the body just beyond the operculum and a distinguishingly long dorsal fin ray occurs at the back of the dorsal fin.   The Threadfin Shad are distributed in the lower Mississippi and other Gulf drainages, south to Guatemala.  Because of their small size, they have been introduced widely as a forage fish.  In Virginia, there are populations in Lake Anna, Back Bay, and the James drainage. Threadfin Shad are sensitive to cold temperature and often die in mass during cold winters in the northern part of the range (McLean et al. 1985). 
Threadfin Shad. Photo by Uland Thomas. 
Clupeid fishes are adapted for life in well-lit pelagic zones of lakes, rivers, and the ocean. Throughout life these fishes are eaten by numerous piscivores, including our national bird, the Bald Eagle (Markham and Watts 2008).  Anadromy, coupled with high fecundity, permits development of large populations.  Although these fishes are adapted for heavy predation mortality, the major long-term threats to population viability appear to be connectivity with spawning and rearing habitats and by catch from ocean fisheries.  

If you have been reading carefully, you should be able pass these two quizzes. 

Quiz One

Six clupeid fishes found in freshwaters of Virginia.  Name each one.
Quiz Two
One of these is an Alewife, the other is a Blueback Herring.  Which is which?

Glass, K.A., and B.D. Watts. 2009.  Osprey diet composition and quality in high- and low-salinity areas of lower Chesapeake Bay. Journal of Raptor Research 43:27-36.
Hilton, E. J., R. Latour, P. McGrath, B. Watkins, and A. Magee. 2017. Monitoring the abundance of American shad and river herring in Virginia's rivers 2016 Annual Report. Virginia Institute of Marine Science, College of William and Mary.
Limburg, K.E., K. A. Hattalaand, and A. Kahnle. 2003. American shad in its native range.  Pages 125–140 in K. E. Limburg and J. R. Waldman, editors. Biodiversity, status, and conservation of the world's shads, American Fisheries Society, Bethesda, Maryland, Symposium 35.
Markham, A.C., and B.D. Watts. 2008.  The influence of salinity on the diet of nesting Bald Eagles. Journal of Raptor Research 42:99-109.
Mattocks, S., C.J. Hall, and A. Jordan. 2017.  Damming, lost connectivity, and the historical role of anadromous fish in freshwater ecosystem dynamics.  BioScience 67(8):713-728.
McLean, R.B., J.S. Griffith, and M.V. McGee. 1985. Threadfin shad, Dorosoma petenense Günther, mortality: causes and ecological implications in a South-eastern United States reservoir.  Journal of Fish Biology 27:1-12.
McBride, M. C., T.V.Willis, R.G. Bradford, and P. Bentzen. 2014. Genetic diversity and structure of two hybridizing anadromous fishes (Alosa pseudoharengus, Alosa aestivalis) across the northern portion of their ranges. Conservation Genetics DOI 10.1007/s10592-014-0617-9.
Palcovacs, E.P., D.J. Hasselman, E.E. Argo, SR. Gephard, K.E. Limburg, D.M. Post, T.F. Schultz, and T.V. Willis.  2014. Combining genetic and demographic information to prioritize conservation efforts for anadromous alewife and blueback herring.  Evolutionary Applications 7:212-226.
Turner, S.M., J.A. Hare, J.P. Manderson, J.J. Hoey, D.E. Richardson, C.L. Sarro, and R. Silva. 2017. Cooperative research to evaluate an incidental catch distribution forecast.  Frontiers in Marine Science

Friday, March 9, 2018

Swampfish: A Lesson in Preadaptation, by Don Orth

When I think of dark stained waters, my mind always brings up an image of the Creature from the Black Lagoon, a 1954 movie.  But the star of that movie, Gill-Man, was humanoid with gills and webbed hands. The fishes of the dark stained waters of the coastal plain are Swampfish Chologaster cornuta.   A movie about the Swampfish would have to take us into the subterranean world of the cavefishes. Let's learn more about the world of the Swampfish. 
Gill-Man, the main character from Creature from the Black Lagoon 
Swampfish are small fish (1- 2 ½ inches) that live only two years.  They are easily distinguished from other local fishes by the brown coloration dorsally and creamy-yellow belly with three dark longitudinal stripes on each side.   The body shape is distinctive with a combination of flattened head, small eyes, upturned mouth, no pelvic fin, and a rounded caudal fin.  
Swampfish  Photo by Scott Smith 
The Swampfish is found in acidic blackwater swamps, sloughs, and streams of the coastal plain from southeast Virginia to east-central Georgia. These waters are stained from high levels of organic matter and often have dense aquatic vegetation and coarse woody debris.  The best way to sample Swampfish is with a dipnet because they are so closely associated with cover, a reaction known as thigmotaxis.   The largest series of Swampfish collected from Virginia were taken during application of the ichthyocide, rotenone (Jenkins and Burkhead 1994).

The family Amblyopsidae is most closetly related to the Pirate Perch.  The Swampfish ancestor was likely adapted for life in the changing coastal plain habitats  and changing sea levels after the Cretaceous-Palogene extinction event. There are currently between 7 and 9 species of Amblyopsidae, all of which are geographically isolated from the Swampfish and at least partially cave-adapted. The most recent cavefish, the Hoosier Cavefish, was discovered in Indiana by Chakrabarty et al. (2014). Now there's a movie plot.  Cue the music!  Millions of years before emergence of cavefish, there were ancestral swampfish that give rise to the diversity of amblyopsids we see today.   Rise of the Cavefish -- that's a good movie title. 
 Range map of the Swampfish (Niemiller and Poulson 2010). 
Many of the weird characteristics of the Swampfish seem be preadaptions for life in caves. Feeding may be nocturnal or crepuscular.  Amphipods, chironomid larvae, and cladocerans were the most frequent diet items reported by Ross and Rohde (2003). Swampfish have tiny black spots for eyes and are negatively phototactic. They possess numerous rows of neuromasts, or sensory papillae, on their head, body, and caudal fin. Nostrils are tubular. The vent (anus) is located in the throat position, similar to the Pirate Perch, its sister group. Why?  Keep reading!  The mature male possesses a strange appendage on the snout; its function is still unknown. It may be revealed in the movie.  The small size, small eyes, nocturnal behavior, and enhanced sensory receptor for feeding and orientation in a dark environment are preadaptations for cave-dwelling descendent species (Poulson 1963). All species of Amblyopsidae occur in regions that were not glaciated.  The cave-dwellers in the family occur in regions of karst where the limestone and dolomites have dissolved to create caves with sufficient water to support a simple food web (Noltie and Wicks 2001). 

What about the vent location? Young are born with the vent (i.e., anal–genital pore) positioned just anterior to the anal fin and it migrates forward as the Swampfish matures (Ross and Rohde 2003). You read that correctly.  All excreta, egesta, and gametes are released near the head region. This vent location facilitates transfer of eggs directly to the gill chamber cave-dwelling Northern Cavefish Amblyopsis spelaea (Eigenmann 1909).  However, the Swampfish with a similar vent location never carried eggs or yolk-sac fry in its gill cavity (Ross and Rohde 2003).  Interesting plot twist for the movie.  
View of the dorsal surface of the snout in male and female Swampfish from April sample.  Ross and Rohde (2003).
Unlike the small, isolated populations of cavefishes, the Swampfish populations appear to be more secure.  Channelization and removal of streamside forest and riparian vegetation have altered the lowland swamps and streams, but the populations are resilient.  Native fish enthusiasts can easily collect and keep Swampfish, which adapt well in dimly lit aquaria with peat moss to increase acidity (Goldstein 2000).  They may keep you entertained until the release of Rise of the Cavefish. 

Agassiz, J.L.R. 1853. Recent researches of Prof. Agassiz. American Journal of Science and Arts 16: 134.
Eigenmann, C.H. 1909. Cave vertebrates of America, a study in degenerative evolution. Carnegie Institute of Washington Publication 104:1-241.
Goldstein, R. J. 2000.  American aquarium fishes.  Texas A&M University Press. College Station, Texas. 
Jenkins, R.E. and N.M. Burkhead. 1994. Freshwater Fishes of Virginia. American Fisheries Society, Bethesda, Maryland, 1079 pp.
Niemiller, M.L., and T.L. Poulson. 2010. Subterranean fishes of North America: Amblyopsidae.  Pages 169-280 in E. Trajano, M.E. Bichuette, and B.G. Kapoor, editors.  Biology of Subterranean Fishes.  CRC Press, Science Publishers.
Noltie, D.B., and C.M. Wicks. 2001. How hydrogeology has shaped the ecology of Missouri’s Ozark cavefish, Amblyopsis rosae, and southern cavefish, Typhlichthys subterraneus: insights on the sightless from understanding the underground. Environmental Biology of Fishes 62:171-194.
Poulson, T.L. 1963. Cave adaptation in amblyopsid fishes.  American Midland Naturalist 70:257-290.
Chakrabarty P., J.A. Prejean, and M.L. Niemiller. 2014. The Hoosier cavefish, a new and endangered species (Amblyopsidae, Amblyopsis) from the caves of southern Indiana. ZooKeys 412: 41–57. doi: 10.3897/zookeys.412.7245
Ross, S.W. and F.C. Rohde. 2003. Life history of the swampfish from a North Carolina stream. Southeastern Naturalist 2: 105-120.

Thursday, March 1, 2018

Ten Things You Must Know about Stream Restoration, by Don Orth

In a world dominated by humans, managing fisheries must include restoring modified aquatic ecosystems and habitats.  Numerous approaches exist to achieve ecosystem restoration, habitat restoration, flood control, property protection, sediment management, water quality improvement, and aesthetic or recreational benefits (Wheaton et al. 2008).  Although many riverine specialists are involved in this work, we all must play a role in educating citizens on the basics of stream and riverine restoration.   In this essay, I summarize the ten things you and others must know to be effective stewards of streams and watersheds. 

1.   Stream restoration is not new.  Stream habitat improvement was the pastime of the wealthy from 1892-1931 (Thompson and Stull 2002; Bennett et al. 2008).  Government programs, such as the civilian conservation corps, provided cheap labor and expanded stream modification efforts from 1932 to 1941.   Most work done by a variety of entities from 1942 to 1967 had high failure rates, leading a long period of stagnation. Some installed structures hae high failure rates, while others persisted for long periods. For example, one log and rock dam constructed along the Upper Beaverkill River, New York, in the 1890s persisted for over 100 years (Thompson and Stull 2002).  Recently, stream restoration projects have increased in extent and number of projects, thereby creating a new industry (Bernhardt et al. 2005).   Though stream restoration techniques have a long history, what is new is the development of a stream restoration industry attempting to address more complex issues.   
Ad in American Forests on use of dynamite for stream realignment.
 2.  Most restoration projects manipulate the stream channel in short reach. Many of these small projects are of questionable value or un-evaluated.   Bernhardt et al. (2007), from a survey of 317 individual river restoration projects in the U.S.A, reported that only 46% of restoration projects even had success criteria.  Lack of criteria and the lack of monitoring undermines the credibility of stream restoration efforts for achieving positive outcomes.  Meta-analyses of macro-invertebrate and fish responses to stream restoration are not demonstrably positive (Stewart et al. 2009; Miller et al. 2010; Smucker and Detenbeck 2014; Kail et al. 2015; Roni et al. 2015; Rubin et al. 2017).  While many projects report a positive effect, one-third of projects had no or a negative effects (Kail et al. 2015).  The likelihood of failure appears to be high.  We cannot continue to assume that current practices of stream restoration provide “demonstrable physical, chemical, or biological functional improvements” (Doyle and Shields 2012, p. 500).   Part of the explanation lies in the scale of improvement. 

3.  Place matters!   Streams vary a lot, and basic physics of sediment supply and transport influence what and where treatments will be appropriate.  Streambeds are mobile, however, some are more than others.  Geomorphologists distinguish between colluvial, alluvial, and bedrock controlled channels as they develop their theories.  Furthermore, the upstream human-modifications of watershed and associated hydrologic and geomorphic changes may negate any potential channel restoration benefits (Doyle and Shields 2012).  Fish responses to stream restoration were significantly reduced as agricultural land use increased in the watershed (Kail et al. 2015).  Most evaluations of fish response to wood placement have shown positive responses for salmonids; those that did not did not address watershed issues (Roni et al. 2015).  Our scientific understanding of fish and macro-invertebrates, and past management of their habitats is based on small spatial scales and short time frames, whereas natural processes and human influences on large spatial scales and long time frames interact to create and maintain suitable habitat (Stoll et al. 2016). These studies and others support the need for improved strategies for prioritizing restoration projects (Stoll et al. 2016).   
Log and rock dam along the Upper Beaverkill River was built in the 1890s. (Thompson and Stull 2002).
4. Water quality criteria do not protect aquatic life.    Early guidelines for developing water quality criteria recognized the complexities of multiple stressors and variable field data, but laboratory based studies proceeded more rapidly. Consequently, the guidelines developed by experts established laboratory experiments as the primary source of water quality criteria (Buchwalter et al. 2017).  One model organism, Ceriodaphnia, is highly sensitive to pollutants; however, the water quality criteria developed from lab studies of Ceriodaphnia were not protective of many faunal groups, such as mayflies, stoneflies, crayfish, and mussels.   There are many instances where entire faunal groups were extirpated from an effluent that was deemed safe based on lab-based criteria (Pond et al. 2014).  Furthermore, we understand that the mechanisms of exposure and speciation of toxicants is critically important and cannot be ignored (Buchwalter et al. 2017).  Only a diverse body of scientific evidence can establish water quality criteria based on a more realistic weight-of-evidence approach.   

Stroubles Creek is a highly modified urban stream that drains Blacksburg, Virginia.  It displays all symptoms of the urban stream syndrome and much of the stream channel is buried underground.  Only short segments within town limits are daylighted and available for adoption. Photo by D.J. Orth. Inset illustration by Shannon L. White.
5.  Natural channel design is oversold.   This geomorphic, form-based method does not result in restoration of native biodiversity in degraded streams (Pond et al. 2014).  A process-based restoration approach that considers multiple stressors with stakeholders has the best chance of success (Beechie et al. 2010).  Restoration is also an oversold term.  Very seldom are we really involved in an “action of returning something to a former place or condition.”    Out-of-stream management practices may improve ecological conditions; however, in urban streams these practices will not return to reference conditions (Smucker and Detenbeck 2014).    

Stream mitigation banks (SMB) have necessitated the quantification of benefits created by projects so that credits can be banked and traded.  This “ growing field of SMB has the potential to reinforce the shift away from a stream restoration science, whose goals, standards of training, and legitimate content are defined by public sector scientists” (Lave et al. 2010, p. 694).   The private sector has provided incentives to deliver flood alleviation and public opinion is in favor of quick fixes for flood reduction (Langford and Shaw 2014).

"I suppose it is tempting, if the only tool you have is a hammer,
 to treat everything as if it were a nail." 
Abraham Maslow 1966

Fries Dam on New River was completed in 1903 and still operates as hydroelectric generating facility.  Photo taken September 21, 2015 by D.J. Orth.
6.  Recovery times exceed study durations.   Ecosystem processes take time to allow streams to “self heal.”  While most practitioners recognize this and design to enhance these natural processes, the published studies on stream restoration effects are usually too short.   Scrimgour et al. (2014) and Marttila et al. (2016) document the slow recovery in boreal streams after more than 14 years.  Just as it may be difficult to find a “silver bullet” for evaluating restoration success (Pander and Geist 2013), it is equally difficult to know the appropriate study duration without more long-term research on stream restoration.      
7.   Dams and barriers change everything.  Many dams and road-crossings have already had dramatic effects on our waterscapes, and the influence is only now apparent. Legacy effects are a dominant influence on present-day aquatic communities, and many dams now exceed their design lifespan.   Yet, stream restoration is based on the assumption that all components of the aquatic and riparian communities (both strong and weak dispersers) have opportunities to recolonize and re-establish aquatic communities.  In contrast, many rare or sensitive fishes have not recolonized streams due to movement barriers (Nislow et al. 2011; Quist and Schultz 2014).  Only recently have stream restoration efforts considered the need for extensive inventories of barriers and dams (Januchowski-Hartley et al. 2013).  Barrier mitigation should be a much higher priority for stream restoration. Culverts have shorter design lifespans than dams and ecological designs for culverts permit a longer life span, reduced maintenance, and improved flood event resiliency (O’Shaughnesy et al. 2016).  Future examination needs to be made for prioritizing dam removal or renew or adapt dam operations to future climate scenarios (Ho et al. 2017).  It’s way past time to evaluate the present value of our aging dam infrastructure and plan for a decommissioning and removal of dams.  It is time for large-scale reconnection of flowing waters. 
Pygmy snaketail dragonfly, Ophiogomphus howei, one of rare dragonflies in upper New River drainage.  Photo by Denis Douceta
8.  Invertebrates get no respect.  While biomonitoring of stream water quality with macro-invertebrates has a long-standing history, invertebrates do not get the same level of attention in stream restoration efforts.  We live in an ichthyocentric world, and some regions are simply salmocentric.  However, many major groups of invertebrates, including freshwater snails, mussels, crayfish, stoneflies, and dragonflies, are at far greater risk than salmonids; furthermore, a small percent of species have even been evaluated (Collier et al. 2016).   It took a generation to convince people that “fish need water too” and we need to begin efforts to understand, and then communicate, the functional roles and ecological requirements of stream invertebrates before it is too late.  Developing a conservation strategy for at-risk invertebrate species may be useful for evaluating and prioritizing stream restoration projects (Smith et al. 2015).      

 In Oregon's Bridge Creek Watershed, researchers built a number of beaver dam analogs to encourage increased beaver activity and restore healthy river habitat. Photo by Nick Weber.
9.  Stream restoration may require beaver restoration.  Beavers dominated the waterscapes of North America before European colonists arrived. Stream restoration practitioners are using the beaver in many situations to restore riparian and wetland ecosystems that support declining populations of Pacific salmon and trout (Pollock et al. 2015).  Although there are many human and beaver conflicts in our human-dominated landscapes, the use of beavers as partners along with human stakeholder involvement can provide numerous benefits to the landowners. 
10.  Multiple lines of evidence are needed in diagnosing stream problems.  Available evidence suggests that current stream restoration practice is not adequate (Doyle and Shields 2012).  The only recent clear example that demonstrates that restoration is a useful conservation tool for fishes was the work on the Okaloosa Darter Etheostoma okaloosae on Elgin Air Force Base (Reeves et al. 2016).  “Modern science teaches us that a single line of evidence is not adequate and that a body of diverse work is the most effective way to establish convincing principles that stand up to the test of time.” (Buchwalter et al. 2017, p 290).  Remediation of stream degradation is very expensive.  Before any proposed remedy is implemented, a formal analysis of causes based on multiple lines of evidence should be completed.  Some case studies exemplify this process that can lead to identifying causes and appropriate remediation (Norton et al. 2009).  

Fisheries Biologist Bill Tate conducts an underwater census for Okaloosa Darter Etheostoma okaloosae from a creek on Eglin Air Force Base, Florida.  The Okaloosa Darter increased in abundance and distribution in response to stream restoration treatments    Photo by Carlton Ward Jr.,
True restoration success depends on prioritizing certain actions over others (Beechie et al. 2010; Roni et al. 2015; Stoll et al. 2016).  First and foremost, we should protect high quality habitats.  This requires systematic conservation planning to prioritize aquatic sites for protection and improve the overall regional habitat quality.  Next, we should improve water quality and quantity, and restore watershed processes.  The final step, only after the other actions, is to work toward improving instream habitat.  This means we often will need to say “no” to certain unwarranted stream restoration projects.       

Stream restoration is a rapidly evolving science (Bennett et al. 2008) and the private sector is driving the science (Lave et al. 2010).  There is need for support of the science of stream restoration in order to inform the practice.  Research with long study durations and a priori power analysis would be very instructive for future stream restoration (Vaudor et al. 2015 ).

The practice of stream restoration science must be more holistic, as restoration strategies are based on multiple societal values and beliefs (Wheaton et al. 2008).  Furthermore, we need to address causes and restore processes rather than patch symptoms in the channel (Vietz et al. 2015). Integration of stream channel and riparian habitats into restoration is an integrated effort (Turunen et al. 2017) that requires multiple indicators of restoration success (Pander and Geist 2013).  Doing the restoration “thing right” will involve many scientific specialists; however, deciding what the “right thing” to do will involve dealing with people in the local social and cultural contexts.  Involving more local citizens in river restoration can serve to promote citizen awareness of both the need and value of intact river ecosystems. 

"Some problems are so complex that you have to be
highly intelligent and well informed just to be 
undecided about them."  Laurence J. Peter 

Restoring degraded streams, especially in highly urbanized watersheds, is often a ‘wicked problem.’ Rigorous evaluation is still needed to learn from successes and failures, and reduce uncertainties (Wheaton et al. 2008; Bouwes et al. 2016).  Doyle and Shields (2012) advocated for a greater emphasis on avoidance and minimization of streams to account for high uncertainty in current stream restoration practice.      

Beechie, T.J., D.A. Sear, J.D. Olden, G.R. Pess, J.M. Buffington, H. Moir, P. Roni, and M.M. Pollock.  2010.  Process-based principles for restoring river ecosystems. BioScience 60:209-222. doi:
Bennett, S.J., A. Simon, J.M. Castro, J.F. Atkinson, C.E. Bronner, S.S. Blersch, and A.J. Rabideau. 2011. The evolving science of stream restoration.  Stream Restoration in Dynamic Fluvial Systems: Scientific Approaches, Analyses, and Tools. Geophysical Monograph Series 194:1-9.
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