Distribution of blue catfish in Chesapeake Bay tr American Shad (CBP) Rive Invasive What are blue and flathead catfish? • Blue and flathead catfish are n Missouri, and Ohio River basins. • They were introduced into the Ja York Rivers in Virginia during the 19 • They are now common in most Virginia and also in some large Mar • They can live longer than 20 ye greater than 100 pounds. They p thrive in brackish waters as well. • Although both species are consid threat of blue catfish is more populations, rapid range expans amounts of native species. Why are blue and flathead catfish a proble • Blue and flathead catfish are consid economic and/or environmental ha species have few natural predator fish and shellfish. • These catfish are quickly spreading tributary. In some studies on the J to make up 75% of the total fish bi inhabiting that tributary (Schloesse • As adults, both species feed prima crabs. As the catfish in the Bay grow Flathe ributaries from 1996-2012 (Schloesser et al., 2011; Garm Menhaden er Herring B e Catfish in the Chesapeake Bay native to the Mississippi, ames, Rappahannock, and 960s-1980s. major tidal tributaries in ryland tributaries. ears, and can grow to be prefer freshwater but can dered invasive in the Chesapeake Bay, the e concerning because of their increasing sion, and capacity to consume significant em in the Chesapeake Bay? dered invasive (having the potential to cause harm) in the Bay watershed. Adults of these rs in the Bay and consume native species of g throughout the Bay into nearly every major James and Rappahannock they are estimated iomass or 75% of the total weight of all fish er et al. 2011; VDGIF; VCU). arily on fish and shellfish including shad, river her w larger, they will consume more native Bay fish. 1 ead Catfish (State of Pennsylvania) man et al., unpublished data). Blue Crab Blue Catfish (CBP) rring, menhaden, and blue
3
Embed
Invasive Catfish in the Chesapeake Bay · • These catfish are quickly spreading tributary. In some studies on the James and Rappahannock th to make up 75% of the total fish biomass
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Distribution of blue catfish in Chesapeake Bay tributaries from 199
American Shad (CBP) River
Invasive Catfish
What are blue and flathead catfish?
• Blue and flathead catfish are native to the Mississippi,
Missouri, and Ohio River basins.
• They were introduced into the James, Rappahannock, and
York Rivers in Virginia during the 1960s
• They are now common in most major tidal tributaries in
Virginia and also in some large Maryland tributaries.
• They can live longer than 20 years, and can grow to be
greater than 100 pounds. They prefer freshwater
thrive in brackish waters as well.
• Although both species are considered invasive in the Chesapeake Bay, the
threat of blue catfish is more concerning because of their
populations, rapid range expansion
amounts of native species.
Why are blue and flathead catfish a problem in the Chesapeake Bay?
• Blue and flathead catfish are considered invasive (having the potential to cause
economic and/or environmental harm) in
species have few natural predators in the Bay
fish and shellfish.
• These catfish are quickly spreading
tributary. In some studies on the James and Rappahannock th
to make up 75% of the total fish biomass or 75% of the total weight of all fish
inhabiting that tributary (Schloesser
• As adults, both species feed primarily on fish and shellfish including
crabs. As the catfish in the Bay grow larger
Flathead Catfish (State of Pennsylvania)
Distribution of blue catfish in Chesapeake Bay tributaries from 1996-2012 (Schloesser et al., 2011; Garman
Menhaden River Herring
Blue Catfish (CBP)
Invasive Catfish in the Chesapeake Bay
catfish are native to the Mississippi,
They were introduced into the James, Rappahannock, and
the 1960s-1980s.
They are now common in most major tidal tributaries in
ome large Maryland tributaries.
0 years, and can grow to be
They prefer freshwater but can
Although both species are considered invasive in the Chesapeake Bay, the
threat of blue catfish is more concerning because of their increasing
rapid range expansion, and capacity to consume significant
catfish a problem in the Chesapeake Bay?
considered invasive (having the potential to cause
economic and/or environmental harm) in the Bay watershed. Adults of these
natural predators in the Bay and consume native species of
spreading throughout the Bay into nearly every major
James and Rappahannock they are estimated
75% of the total fish biomass or 75% of the total weight of all fish
inhabiting that tributary (Schloesser et al. 2011; VDGIF; VCU).
ed primarily on fish and shellfish including shad, river herring,
As the catfish in the Bay grow larger, they will consume more native Bay fish.
1
Flathead Catfish (State of Pennsylvania)
, 2011; Garman et al., unpublished data).
Blue Crab
Blue Catfish (CBP)
shad, river herring, menhaden, and blue
2
Gut content analysis of blue catfish shows
multiple blue crabs were consumed (VCU)
Blue Catfish (VIMS)
Maryland Record Blue
Catfish (84 lbs, 52 in,
Potomac River, 8/13/12)
James River Record Blue Catfish
(102 lbs; 2009)
Tagging study to estimate the population of
blue catfish in James River (July 2012, NCBO)
What is being done to address invasive catfish in the Chesapeake Bay?
Policy and Management
• The Chesapeake Bay Program’s Sustainable Fisheries Goal Implementation Team (SFGIT) is a group of
Chesapeake Bay jurisdictional managers and other fisheries stakeholders that have recognized invasive catfish as
a problem.
• The SFGIT is committed to developing policy options to mitigate their spread while keeping in mind their
recreational and economic value.
• The SFGIT Executive Committee adopted an Invasive Catfish
Policy statement in January 2012, stating “the potential risk posed by
blue catfish and flathead catfish on native species warrants action to
examine potential measures to reduce densities and limit range
expansion, and to evaluate possible negative ecological impacts.”
• The Invasive Catfish Task Force was established by the SFGIT
to coordinate research, increase public awareness, and recommend
policy options to reduce spread and mitigate the impacts of catfish
on valuable Chesapeake Bay resources.
Science
• The SFGIT has sought management driven research to further
understand blue and flathead catfish’s negative impacts on native
species.
• VIMS is working with commercial watermen on a tag and recapture
study in which 15,000 catfish were tagged in July and 5-7% of the
fish were since recaptured. 900 fish have been processed and they
are now analyzing these data using appropriate models.
• VCU is working on the attached “Catfish Portal” that will show the
current locations of blue and flathead catfish, potential habitable
areas, and areas of concern for protection.
• VCU is also working on a predation study to further determine the
diet composition of blue catfish.
• VIMS is researching contaminant concentrations in blue catfish that
will be used to evaluate the efficacy of using fisheries as a