Zebra and Quagga Mussels: Non-Physical Barriers (NPB) for Fish Protection and Avoiding Mussel Impacts
We recently led NPB evaluations (Bowen et al. 2008) that showed a NPB effectively deterred threatened chinook salmon smolts. In addition, others in Reclamation have had some limited success with other NPBs, e.g., electrical (Clarkson 2004). We have also led field investigations of NPBs that were not effective for target fish species. These mixed results lead us to our research question:
* Where and how effective are NPBs at deterring listed and candidate fish species of interest to Reclamation?
We are also aware of research to use NPBs (electrical) to control _Dreissenids_, (e.g., zebra and quagga mussels) (Smythe and Dardeau 1999). Other work which we have not yet reviewed suggests ultraviolet (UV) light might kill _Dreissenids_ (Wright et al. 1997). These works lead us to our second research question:
* Where and how effective are NPBs at reducing _Dreissenid_ impacts in water-related facilities?
It appears that some overlap exists here. It is possible an electrical barrier for fish, e.g. the Central Arizona Project electrical barrier, could keep _Dreissenids_ from ascending into the Gila River. It is possible that pulsed power could reduce _Dreissenid_ densities and move fish predators out of Reclamation facilities. This overlap brings us to our third research question:
* Where and how effective could NPBs be at deterring fish while reducing mussel impacts in Reclamation facilities?
We propose to evaluate NPBs by assessing: NPB type, deployment scenario, and effectiveness for species of interest. We propose a literature-based summary of NPB installations and outcomes and a synopsis of facility types where 1) NPB installation could deter fish entrainment and 2) NPB installation could reduce mussel impacts. Lastly, we propose to include an evaluation of when a single NPB could both deter fish and reduce mussel impacts.
Need and Benefit
Two monitoring tracks have been extremely important in Reclamation in the last few years: fish protection and mussel presence and effects on infrastructure. Fish protection has many applications. One application, fish barriers, has allowed Reclamation to keep fish out of dangerous areas, reducing loss of listed species. The second track, mussel presence and effects, has become extremely important with the invasion of quagga mussels into the states of Utah, Colorado, Arizona, and California. In addition, the threat of mussel invasion into California's Central Valley has caused increased alarm in the Mid-Pacific Region.
Our research with NPBs suggests that fish can be kept out of many areas that are potentially fatal for them. NPBs can cost less to build than positive barrier screens. Therefore, NPBs could produce extensive cost savings for Reclamation's screening of diversions. There may be many other potential applications of NPBs, (e.g., reducing entrainment into power-generating turbines), and our literature review will identify those. Essentially though, Reclamation needs to protect listed fish species; this is required by the Endangered Species Act (ESA). And the benefits that NPBs provide are to help us protect those fish at reduced cost.
_Dreissenids_ threaten Reclamation's ability to deliver water in an economically sound manner. Heavy infestations can clog pipes, pumps, and other infrastructure. Reclamation needs to control _Dreissenid_ colonization and reduce growth rates after colonization has occurred. The benefits from avoiding colonization are no constrictions of water flow. The benefits from reducing _Dreissenid_ growth rates are reduced maintenance costs.
Possible Synergism: NPB, e.g. electrical, could protect fish and reduce the likelihood that a mussel veliger would colonize a structure. There may be many methods for using NPBs to protect fish and reduce colonization rates on Reclamation structures. The need to determine if these opportunities could reduce costs to Reclamation is extensive because the cost savings could be substantial.
The benefits are obvious as well. If NPBs can protect fish and reduce the chance of mussel colonization, then money can be saved. Or NPBs could protect fish and reduce the _Dreissenid_ growth rate. These reductions could allow a slower replacement rate to Reclamation structures; slower replacement rate would mean lower costs.
Contact the Principal Investigator for information about these documents.