Species of Concern
Decision on the Status Recommendation for the Indiana Crayfish
Fish and Wildlife Services Bloomington, Indiana, Ecological Services
Field Office has reviewed the relevant published and unpublished data
for the Indiana crayfish and has prepared a status assessment report
for the species. Based on that review the Bloomington Field Office has
recommended that the Indiana crayfish (Orconectes indianensis)
not be elevated to the status of a Candidate Species, but that it remain
as a regional "Species of Concern." The endangered species
program staff in the Services Region 3 Office support that recommendation.
Therefore, Region 3 has determined that the Indiana crayfish will
not be elevated to the status of a Candidate Species at this time. The
species will be retained as a "species of concern" and Region
3 will remain the lead region for ongoing review of its status.
of concern" is an informal term that refers to those species
which Region 3 believes might be in need of concentrated conservation
actions. Such conservation actions vary depending on the health of the
populations and types and degree of threats. At one extreme, there may
only need to be periodic monitoring of populations and threats to the
species and its habitat. At the other extreme, a species eventually
may require listing as a Federal threatened or endangered species and
become the subject of a Federal recovery program. Species of concern
receive no legal protection under the Endangered Species Act as a result
of this informal designation, and the use of the term does not necessarily
mean that the species will eventually be proposed for listing as a threatened
or endangered species. As funding and staffing levels permit, Region
3 evaluates Species of Concern to determine the extent of their conservation
needs and to determine whether additional legal protection should be
sought for them.
Office status recommendation indicates that the species historical
distribution was limited to the southern portions of Illinois and Indiana.
(An early inclusion of Kentucky in the species range is not supported
by other researchers.) However, there were no systematic surveys carried
out in Indiana prior to 1993. The current Indiana population appears
to be nearly as widespread as it was historically, ranging across portions
of eight counties. The extent of Indiana crayfish distribution in the
State makes it highly unlikely that the species could be extirpated
by a single catastrophic event. The current proximity of the populations
to each other likely would allow recolonization if a population was
extirpated. However, the core of the Indiana distribution the
Patoka River watershed suffers from significant degradation resulting
from coal mining, stream channelization, and poor water quality, and
Indiana crayfish numbers have decreased within the Patoka drainage.
It is believed
that an historical range contraction occurred in Illinois sometime between
comprehensive crayfish surveys conducted in the early 1900's and the
1970's. However, since that time there is no evidence of a further range
reduction. Similar to the situation in Indiana, the Illinois mainstay
of the crayfish the Saline River system is degraded, and
the North and Middle forks of the Saline River no longer support Indiana
crayfish. Threats to water quality and the crayfish in the two states
include pollution from coal mining and oil extraction, siltation, and
stream channelization and clearing.
is insufficient evidence to show that these ongoing threats are causing
an ongoing population decline, the threats are sufficiently serious
to cause Region 3 to retain the species as a "Species of Concern."
recommends that the following management activities be carried out to
improve the status of the Indiana crayfish:
to the apparent reduction in historical range in Illinois and the habitat
degradation in the core of the Indiana range, the species should be
closely watched. A more comprehensive monitoring protocol should be
developed and implemented to document changes in the species population
and distribution and threats to it and to its habitat. This protocol
should include the sampling methodology used by Page in 1985 and 1994
to ensure comparable data; however, sampling intensity should be increased.
and reduce specific threats to the water quality of the streams which
are still inhabited by the Indiana crayfish. Conservation agreements
with private landowners should be developed throughout the watersheds
occupied by the species.
concerning this species should be directed to the Services Bloomington,
Indiana, Ecological Services Field Office which has the lead responsibility
for data collection and analysis for this species. Questions about the
process of listing a species as threatened or endangered should be directed
to the Regional Listing Coordinator at 612-725-3536 extension 241.
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