And the Survey Says....

On Nov. 15-17, 2011, representatives from the USFWS (Ventura), CDFG (Region 6, Bishop), NP (Mojave National Preserve) shoulder to shoulder with AAE students and some alumni conducted the first mark-recapture population estimate since the introduction of Mohave tui chub to the Lewis Center Refuge back on October 2, 2008.

At dusk on Tuesday Nov. 15, 8 traps, baited with a piece of white bread, were placed in both Deppe Pond and Tui Slough. A total of 16 "custom made" traps were employed in this two day trapping effort.

[Top] Daniel and Jacob open a trap
[Bottom] Sam, Alex and Gabby process fish

Wednesday morning was cool, clear, windless and beautiful. At about 8:45 am with the air and water temperatures at about 50 degrees traps were pulled one at a time starting "up stream" in Deppe Pond. By about 9:20 am, only 6 small fish (all < 63 mm) were caught in Deppe Pond and all of those were in one trap. Tui Slough was next. By the third trap (all placed in the "upstream" shallow section of the slough) only a couple dozen fish had been collected from Tui Slough. The work began with the pulling of the fourth trap, placed at a transition zone where the Slough goes from 2-3 feet deep to 5-6 feet deep. More than 580 fish of the 636 fish collected Wednesday morning came from from traps 4-8.

[Top] Bryce measures a small chub
[Bottom] Judy Hohman (USFWS) Steve Parmenter (CDFG),
Susan Williams (NAWS, China Lake) gather and discuss data

On Thursday morning with weather, air and water conditions similar to Wednesday's, traps were first pulled at about 8:14 am. By about 10:30, 9 new fish were collected from Deppe Pond (all <64 mm in length) and 153 new fish were collected from Tui Slough along with 201 recaptures (fish that had their left pelvic fin clipped the day before).

After the math was done, 789 (636 + 153) Mohave tui chub were caught; 15 (6+9) were collected, processed and released back into Deppe Pond and 773 ((636-6) + (153-9) -1) were collected, processed and released back into Tui Slough (one casualty of the process was retained and preserved).

During both days, fin clips were collected (50 from chub collected from Tui Slough and 15 from chub collected in Deppe Pond) for DNA analysis. We expect to have the results from this analysis sometime after the September of 2012. To view a video documenting this event click here.

[Top] What a 200+mm Mohave tui chub looks like
[Bottom] Releasing collected fish back into Tui Slough after processing

11/21/2011 Daily Press News Release: Students Work to Save Endangered Fish