Refuge 

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In -

Common carp have negatively impacted the aquatic health ofMalheur 

National Wildlife Refuge - we need your help to bring the birds back. 

alheur National Wildlife Refuge is one of the jewels of 

the National Wildlife Refuge System. It is a premier site 

for birds and birding as it provides invaluable migratory 

stopover and breeding habitat along the Pacifi c Flyway. 

Over the last 60 years, these habitats have been significantly 

altered by a non-native species, the common carp. As a result, 

refuge waters can produce only a fraction of the waterfowl and 

waterbirds they once did. 

Malheur National Wildlife Refuge supports a good number 

ofmigratory ruddy ducks on the Pacific Flyway. Ruddy and 

other diving ducks rely on sago pondweed - an abundant 

submerged aquatic p lant found on healthy lakes. 

u. s. Fi5h IV ldl!fo SaviceiDuvl! Mmh! 

Malheur, Mud and Harney Lakes are magnets for colonial 

nesting waterbirds, or birds that gather in large assemblages 

during nesting season. Ref uge waters support white-faced 

ibis, as well as grebes, pelicans and egrets. 
A Disastrous 


e 


ommon carp were introduced in the 1920s 

as a desirable sustenance fish in many 

places across North America, and in the 1950s 

carp became established in Malheur National 

Wildlife Refuge waters. Since then, carp have 

severely depleted migratory bird food resources 

and diminished water quality. With over 7,2 million 

pounds of carp currently in refuge waters, bird 

productions numbers will remain dramatically 

decreased. 

Why are Carp 


a Problem? 


The greatest impact of carp is their bottom feeding 

behavior: carp eat invertebrates, uproot vegetation and 

disturb the muddy bottom. As carp populations explode, 

food staples for waterfowl and waterbirds disappear. 

The damaging impacts of 

common carp have 

seriously handicapped 

the refuge and its ability 

to fulfill its mission to 

provide feeding, nesting 

and rearing habitat for 

migratory birds. Currently, 

the ecological collapse 

caused by carp has 

reduced waterfowl 

production to about 

2-7% of its former 

capability, Malhear is one ofthe largest lake systems west 

ofthe Rockies. [t is a very dynamic system 

with water levels changing every year. The 

interconnectivity ofthe lakes and wate/ways 

makes carp control an on-going battle. 

The common carp is a member oJ 

the minnow family with resilient 

characteristics: it can resist wide 

temperature ranges, low water clarity 

and high water turbidity, and has 

{{ wide-ranging diel and breeds 

prolifically. Tn the Hamey basin, 

common carp eat all the same foods 

as birds and native fish. 

us. Fish &J VildIife Service 

For the Birds 

Historically, Malheur Lake was home to 

large colonies of nesting waterbirds, host 

to tens of thousands of nesting waterfowl 

and a resting stop for migratory shorebirds. 

In 1908, President Theodore Roosevelt 

established the Lake Malheur Reservation 

"as a preserve and breeding ground for 

native birds." The reservation encompassed 

over 80,000 acres around Malheur, Mud 

and Harney Lakes for migratory waterfowl. 

Today, it is known as Malheur National 

Wildlife Refuge, and protects over 187,000 

acres of habitat, including wetlands, riparian 

areas, meadows and uplands. 

Hi'lOrically, abolll 35% 

oJ the Pacific Flyway's 

canvasback duck 

population used Malhellr 

Lake. In Jact, the lake 

produced approximately 

400, 000 ducks, 75,000 

geese and 3,500 swans, and 

ranked as One of the most 

productive waterfowl areas 

in NOl1h America. 

us.Fjsh &.. IVild/{e Service 

In 1908, William Finley 

photographed a white pelican 

breeding colony on Maiheur 

Lake. Finley - and his photos 

- were instrumental in early 

recognition ofthe importance of 

the lakes, riparian streams and 

marshes in the Hamey basin 

to shorebirds, warerbirds and 

wateifowl. 
A refuge fish biologist and a University 

of Minnesota researcher place a radio 

telemetry tag in a carp specimen. With 

tagging, scielllists can develop population 

estimates as well as locate carp willlering 

and spawning areas. 

u. s. Fish &,. Wildlifi: Serl'ice 

A Goal 

for the 


u ure Challenge of carp control is not insurmountable. 

{ ;:;~lheur National Wildlife Refuge is working to 

restore the basin's aquatic health in order to fulfill its 

mission of providing feeding, nesting, and rearing habitat 

for migratory birds. This will be accomplished by working 

with partners to develop an efficient and sustainable carp 

control program for the entire basin using the best 

available science. 

Current Carp 


Control Techniques 


Refuge staff have been conducting carp control treatments since 1955. 

Since then, ongoing efforts to improve aquatic health on Malheur 

National Wildlife Refuge have included the use of chemicals, fishscreens, 

traps and barriers, and water draw downs. While all of these treatments 

have been effective, carp populations rebound within a few years without 

a basin-wide solution. 

In order for carp control to be a success, continuing studies on carp 

populations and their effect on aquatic food supplies will need to be 

completed. Complete eradication of common carp will not be possible in 

all waterways, but huge strides can be made in control. 
u.s. 


FISH & WILDLIFE 

SERVICE 

A juvenile pied-hilled grehe swims alone on a 

wetland. Grebes feed heavily on insects, small 

fish and crustaceans hy diving below the surface.