of an endangered fish in southern Arizona? Doug Duncan1, Ross Timmons2, Sheridan Paulus2. 1 Self. 2Arizona Game and Fish Department ...
A new, natural population of an endangered fish in southern Arizona? Doug Duncan1, Ross Timmons2, Sheridan Paulus2 1 Self 2Arizona
Game and Fish Department
Gila topminnow: an old population comes back; and a new site discovered? Doug Duncan1, Ross Timmons2, Sheridan Paulus2 Self 2Arizona Game and Fish Department
1
• Gila topminnow was one of the most common fishes in the GRB (Hubbs & Miller 1941) • are probably one of the most released endangered fishes in AZ, as far as number of sites, by far • Historically found at 3 sites in the San Rafael Valley – Sharp and Sheehy Springs, Santa Cruz River • Heron Spring • AGFD Safe Harbor • San Rafael Valley is a management and recovery unit for GTM
• Gila topminnow were found in the SCR in Mexico in 2006, 2 locations • Parker Canyon site with topminnow is ~11 river km upstream of the confluence with the SCR in Mexico • There is perennial water 2.6 river km upstream – no GTM • Another 12 river km downstream to perennial water • Another 5.4 river km downstream, next perennial and GTM • Another 6.7 km is the 3rd perennial site, and had GTM
• 16 September: Initial detection • 1 October: Timmons & Paulus survey – 7 seine hauls: 2 adult female POOC (3%) out of a total of 58 fish; longfin dace (AGCH 52%), mosquitofish (GAAF 45%). Sampled less than 100m of stream
• 29 October: group survey, 3 sites, 46 POOC, ~1000 GAAF, MISA, LECY, LEMA, AGCH- 1km survey. 7 poeciliid “experts”
How did they get there? • • • •
Compliance in the 80s – no stocking records Natural, historical population from way back? Emigration from Mexico? Recent, subrosa stocking of unknown origin? – Knowingly topminnow, mosquitofish
Conservation implications • Genetics: may not be definitive, identify lineages • Maintain captives • Natural: means we have an in situ population left in the San Rafael!! • If it isn’t San Rafael/Santa Cruz/Sharp, value may be limited • May need to be removed – Contaminate SCR in Mexico
• Need surveys in Mexico
Santa Cruz RiverNogales reach • Historical locality • Wastewater supported • Topminnow thought extirpated until found in 1993 • Regular sampling • Disappeared again after 2003 (ammonia/diesel spill) • Upstream are the fish in Mexico, and Sonoita/Fresno/Coalmine complex • Genetics
TOPMINNOW! • Gila topminnow rediscovered 12 November at 3 sampling sites in this reach SITE
POOC
GAAF
AGCH
SECONDS
Chavez
1
0
1499
989
Tubac
6
16
174
1116
Santa Gertrudis
1
0
208
523
Nogales Wash
0
0
762
673
• • • • • • • • • • •
Sonoran Institute Sally & Jerry Stefferud Coronado National Forest Global Community Communications Alliance School National Park Service Friends of the Santa Cruz River Chuck Minckley Scott Bonar - USGS/UA Coop Unit Arizona-Sonora Desert Museum Arizona Game and Fish Department Dr. Melanie Culver - USGS/UA Coop Unit
