Connie: Fish exclusion is needed anywhere where fish can be removed from their natural
environment and entrained into a water diversion. This can be at an irrigation diversion, a
water supply pipe intake, an intake at a hydropower facility or open looped pumped storage.
Tim: What we try to do with fish exclusion devices is to come up with ways that fish
can avoid these particular structures or avoid any kind of danger to their lives or interruption
to their lifecycle.
Mike: A lot of our original fish exclusion type facilities are based on sort of old technology
now and as technology has advanced and the science has advanced, we�ve learned a lot
about how fish behave and how fish behave in response to our facilities.
Jennifer: We need to improve fish exclusion to address some of the issues that our agencies
and water users have been facing for years.
Continued deliveries and being able to provide the water for
the public to use is important.
Tim: This is a real issue all over the United States, whether it be a coastal area or an
inland area, whenever species have to migrate from one type of habitat to another and there
are structures that they encounter along their journey, that's an issue that we need to
solve.
Connie: And if enough fish are entrained this can reduce populations and it can lead to
depleted biodiversity. We want to improve fish exclusion because we want to assist with
fish recovery efforts. We do have solutions that work for certain species and certain
life stages but we're looking for ideas that can be applied more broadly to a larger
number of fish species.
Tim: Fish exclusion devices really fall into two main categories: physical exclusion devices
and nonphysical. Now nonphysical devices really focus on behavior of fish so those would include
things like strobe lights or electricity, electric fences that a fish could move physically
through the barrier but because of their operation, it changes the behavior of a fish and gets
them to move in another direction. Now, physical barriers are a little more obvious, they're
things like screens and louvers, any kind of physical barrier that literally prevent
a fish from moving into some sort of intake.
Connie: Physical screening techniques can be costly to install and to operate and maintain,
there are issue with the screens becoming clogged due to sediment, debris, biofouling
or ice and you have to make sure that the velocity across the screen is uniform so that
fish do not end up getting stuck to the screen. For behavioral barriers there are a number
of limitations: there is a varying degree of effectiveness for behavioral barriers depending
on the fish species and the life stage, they do not exclude larval fish or eggs, the fish
can become used to the stimulus so it isn't as quite effective and it might also affect
other species that are in the system.
Mike: What works at one facility, such as a screening structure may not work at another
facility. Better fish exclusion technology essentially allows us to operate our facilities like the
way we'd like to operate them for water and power deliveries.
Connie: An ideal solution would be less costly that the techniques that we use now, can be
more effective than the techniques that we use now and help reduce some of the operation
and maintenance issues.
Jennifer: I think a prize competition can help us with fish exclusion because we can
get out of the box ideas. We can engage our public, we can engage anyone in the United
State or anyone across the world to give us new ideas.
Tim: So we're hoping this prize really jet starts innovation in this area.
Connie: The Bureau of Reclamation is partnering with the Department of Energy's Water Power
Technologies office, the Pacific Northwest National Lab, the US Army Corp of Engineers,
U.S. Geological Survey, U. S. Fish and Wildlife Service, NOAA Fisheries, and the state of
Washington's Department of Fish and Wildlife. We're partnering with these agencies because
we are all interested in finding new and improved ways to exclude fish from diversions. This
is a difficult problem and I'm interested to see if the public has solutions.