SW15-7
Wildlife Diversity Project Proposal
Title: Invasive Crayfish Removal from Tumbling Creek Cave
Location (County): Taney
Project Centroid (UTM Coordinate):
Easting:517254
Northing: 4045953
Project Leader:
Dave Woods
Total Amount Requested: $ 5600
Partner Match: $2100.00
(EXP = $0, EQP=$0, HL=$0)
Explain the need and objective of the project:
Tumbling Creek Cave was designated as a National Natural Landmark in 1981, in part due to its rich
biodiversity. In terms of cave fauna, Tumbling Creek Cave is the most diverse American cave west of the
Mississippi River. In fact, based on species richness, number of troglobites and site endemism, Tumbling Creek
Cave produces twice the biodiversity value of any other known cave in Missouri. The Tumbling Creek
Cavesnail, (Antrobia culveri), a federally endangered species, is an endemic aquatic genus found only in
Tumbling Creek Cave and in the karst aquifer downgradient of humanly accessible cave passages. In the mid1970s the cavesnail population was estimated at 15,000. The current population is now estimated at about
150. In addition, other various aquatic cave obligate taxa have been observed in the Tumbling Creek Cave,
many of which are Species of Conservation Concern, including the Clarus cave springtail, the Ancyla cave
isopod, the Atricola cave isopod, the Grotto salamander, the Onondaga cave amphipod and the Ozark cave
amphipod. Furthermore, a cave crayfish species yet to be identified has been observed in the cave on multiple
occasions. It is thought that once identified, this species occurrence could be evidence of a significant range
expansion for one of the existing cave crayfish species, or a new species altogether.
One factor believed to be a current threat to the cave’s aquatic biodiversity and contributor to the severe
population decline of the Tumbling Creek cavesnail is predation by the ringed crayfish (Orconeactes neglectus
neglectus). While this crayfish has been observed in the cave on occasion in the past, ringed crayfish densities
have increased dramatically since the 1960’s. Crayfish are a known predator of multiple aquatic taxa, including
snails. During the period 2001 to 2011 Dr. David Ashley, of Missouri Western State University, trapped and
released ringed crayfish in the snail study area on 26 occasions. He captured a total of 487 crayfish during this
period with a mean of 18.7 individuals per capture event, which in 1,423 square feet of habitat represents a
crayfish for every 2.9 square feet of habitat. In June 2011 Tom Aley began a program of trapping and removing
crayfish from the cave. There were a total of 27 capture and removal events between June and October of 2011
with total capture and removals producing 107 crayfish, which represents 1 crayfish for every 13.3 square feet
of cavesnail habitat. In addition to trapping efforts, the Ozark Underground Laboratory has added crayfish
screens to the gate on the Bear Cave entrance to the cave system.
In the past the Ozark Underground Laboratory (OUL) and the Tumbling Creek Cave Foundation (TCCF) have
funded all crayfish control work. An FY14 WDF grant was obtained to partially fund a collaborative effort
with the TCCF to capture and remove ringed crayfish from the cave. So far, 40 traps have been deployed and
162 ringed crayfish have been captured and removed from cavesnail habitat using FY14 WDF grant money. In
FY15, efforts will be made to trap further downstream towards the natural entrance of the cave. During the
spring, summer and early fall months, this area of the cave is inaccessible due to the presence of gray bats.
Trapping this section of the cave in the winter months is an effort to prevent ringed crayfish migrations further
upstream towards the more prime cave stream habitats. It is believed that the approach of trapping and removal,
coupled with efforts to reduce re-invasion of crayfish into the cave, is important in the protection of the aquatic
biodiversity of the cave and the recovery of the Tumbling Creek Cavesnail. While the crayfish issue was not
recognized as a primary concern when the Tumbling Creek Cavesnail Recovery Plan was written in 2003, the
SW15-7
multi-agency recovery team currently recognizes crayfish removal as one of the primary actions needed to aid
in the recovery of the cavesnail population.
List priority geographies (COA(s)) and targeted species and/or natural communities this project will
affect:
Tumbling Creek Cave, Tumbling Creek Cavesnail and the most biologically diverse cave community west of
the Mississippi River.
Describe the expected product, result, or outcome:
Capture and removal of ringed crayfish within Tumbling Creek Cave, in concert with the maintenance of
exclusion screens on the cave gate, will reduce or eliminate crayfish densities within the cave and decrease
unnatural predation pressure on aquatic fauna.
Explain the approach/methodology that will be utilized to complete the project:
A total of 40 crayfish traps will be used within the cave. During the spring, summer and early fall months, traps
will be located between the furthest upstream reaches of known crayfish migrations to 200 meters downstream.
In the winter (November – March) when gray bats have left the cave, trapping efforts will extend further
downstream towards the natural entrance of the cave. In the event of heavy precipitation, additional traps will
be placed near the cave entrance and gate to detect crayfish migrations upstream for outside of the cave.
Trapping will be conducted every 2 weeks throughout the year. Bait will consist of hot dogs and/or chicken
wings. Crayfish densities are calculated and recorded to monitor the success of the trapping efforts.
Budget Table:
Category
Amount
Requested
Contract or
Agreement
Personnel Service (Labor)
$5250
Equipment
Expenses
Total
$0
$350
$5600
Cooperative
Agreement
Non-MDC/Partner Match
Value
$2100
Entity
Tumbling Creek Cave
Foundation
$2100
** In no circumstance can MDC staff or other MDC sources of funds be used for match to the WDF**
Provide justification for any labor and/or equipment in this proposal:
On site labor contracted through Ozark Underground Laboratory staff will set and run traps on two-week
trapping cycles. Expense money will be used to maintain exclusion fencing and traps and to purchase bait.
Indicate your willingness to accept less funding and describe the effect on the overall project if certain
portions were reduced. For example, eliminating labor or equipment may not allow the project to be
completed while a reduction in expense dollars would only decrease the footprint of the project area (less
acres).
Complete elimination of labor funding will not allow the project to be completed. Partial elimination of labor
funding will not allow trapping to occur in the cave areas downstream towards the natural entrance. It is
thought that trapping in this location during the winter helps prevent re-establishment in the upstream sections
of the cave, often considered the most prime cave stream habitat. Elimination of expense funding will require
increased partner contribution to provide bait and maintenance materials for traps and fencing.