For the past few years Asian Carp Regional Coordinating Committee partners have
stepped up efforts to better understand the population status and distribution of
grass carp in western Lake Erie. Work completed between May 30, 2017 and July 12,
2017 has led to the collection of fish eggs in the Sandusky River in Ohio, now confirmed
to be grass carp eggs. The eggs were collected by representatives from U.S. Geological
Survey, Ohio Department of Natural Resources and the University of Toledo, and then
identified based on morphological characteristics of the eggs by the University
of Toledo with confirmation by the U.S. Geological Survey. The recent discovery
is not an indicator of the population size of grass carp in the Sandusky River,
but it does underscore the continued need for grass carp early detection and management
efforts in the area.
Current evidence suggests that grass carp, a type of Asian carp, are present in
extremely low abundance in the area, making early detection a critical step in preventing
the invasive fish from gaining a foothold in the environment. The collaborative
efforts of Ohio Department of Natural Resources, Michigan Department of Natural
Resources, U.S. Geological Survey, U.S. Fish and Wildlife Service and the Great
Lakes Fishery Commission are yielding critical new information about the locations
and movement patterns of grass carp.
Work to assess the potential for reproduction of grass carp in Ohio and Michigan
rivers is being led by U.S. Geological Survey and the University of Toledo, with
support from the Ohio Department of Natural Resources and the Michigan Department
of Natural Resources. Work began in the Sandusky River (Ohio) in 2014, the River
Raisin (Michigan) in 2015, and the Maumee River (Ohio) in 2017. Research is focused
on learning more about the reproductive behaviors of grass carp and identifying
potential hatching locations for resulting eggs. Prior to this year, collection
efforts in the Sandusky River yielded eight grass carp eggs in 2015, with no eggs
collected in 2014 or 2016. With a single female grass carp able to produce up to
one million eggs during spawning, the implications of finding 7,649 eggs in the
Sandusky River this year are as of yet still unknown. It is important to note that
no larval grass carp were found since sampling began.
Coordinated fish sampling efforts focused on the Sandusky River and Sandusky Bay
by federal, provincial and state partners were completed the week of August 28.
The work complements the U.S. Fish and Wildlife Service’s Early Detection and Monitoring
Program for Aquatic Invasive Species, which is conducted in targeted areas throughout
the Great Lakes Basin in collaboration with state partners. Sandusky Bay was identified
in 2013 as a “high risk” location for potential aquatic invasive species introductions
in Lake Erie. Information from sampling work, together with results from ongoing
research, will be used to inform planning and implementation of a large-scale, coordinated,
grass carp-focused action in the Sandusky River in 2018. This larger-scale effort
will more fully evaluate potential future actions to remove grass carp and to learn
more about potential opportunities to manage the populations in Lake Erie. Future
decisions about specific actions that could occur in Lake Erie will be made through
the cooperative fishery management process facilitated by the Great Lakes Fishery
Commission, including its Invasive Fishes Executive Committee and the Lake Erie
Committee, in collaboration with the Asian Carp Regional Coordinating Committee.
Information resulting from this interagency effort will inform potential grass carp
response actions in Lake Erie, and may also support efforts to reduce the risk of
introduction of bighead, silver, and black carps in the Great Lakes and beyond.
Grass carp research and management actions are funded by the Great Lakes Restoration
Initiative, U.S. Geological Survey and U.S. Fish and Wildlife Service federal appropriations,
and Michigan Department of Natural Resources and Ohio Department of Natural Resources
agency budgets. Grass carp actions are described in greater detail in the 2017 Asian
Carp Action Plan. Collectively these interagency efforts also support the goals
and objectives of the national Management and Control Plan for Bighead, Black, Grass,
and Silver Carps in the United States.