Undergraduate student Hailey Bond collects samples from the insect emergence traps.
Drought Experiment 2023
Dr. Dana Warren, Dr. Catalina Segura, and graduate student Maddie Maffia are exploring how decoupled drought conditions affect streams and the species that live in streams. Under low-flow conditions, trout and salamanders aggregate in pools or cooler water, increasing competition for macroinvertebrate prey, and causing reduced growth and survival. Under increased temperature conditions the metabolic activity of trout and salamanders are elevated, increasing their respiration rate, and causing population declines from reduced dissolved oxygen (DO) availability. To examine how the trout and salamanders respond and interact to the reduced flow and increased temperature stream conditions, researchers conducted a drying and warming experiment in a tributary of McRae Creek at the HJ Andrews Experimental Forest. In the 2021-2023 summer field seasons, they created separate sections of stream with (a) low flow and (b) elevated temperatures (using passive heating of water traveling through black coils of tubing before returning the water to the stream). In the experimental and control stream sections, they measured trout and salamander abundance, individual growth, and survival using 3-pass depletion methods, while also measuring water level, temperature, and DO using longitudinally distributed sensors. Also see photos from the 2021 and 2022 field seasons. Also see photos from the 2021 and 2022 field season.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_001
Researchers process fish and salamanders captured during a 3-pass depeletion electrofishing survey in a tributary of McRae Creek.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_002
Coastal giant salamanders in a recovery tank before they are released back into the stream.
Photographed by: Adrian Puga
Date: 7/20/2023
Photo number: afo_003
Cutthroat trout being measured at the proccessing station before being released back into the stream.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_004
Researchers process fish and salamanders captured during a 3-pass depeletion electrofishing survey in a tributary of McRae Creek.
Photographed by: Zach Perry
Date: 7/20/2023
Photo number: afo_005
Researchers process fish and salamanders captured during a 3-pass depeletion electrofishing survey in a tributary of McRae Creek.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_006
PIT tag and elastomer tag gear used at a processing station to measure growth.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_007
Hailey Bond (left), Madelyn Maffia (center), and Dana Warren (right) electrofish a small pool in a tributary of McRae Creek.
Photographed by: Adrian Puga
Date: 7/20/2023
Photo number: afo_008
Coastal giant salmanders from a tributary of McRae Creek.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_009
Upper section of the low-flow reach prior to diverting half of the flow.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_010
Middle section of the low-flow reach prior to diverting half of the flow.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_011
Middle section of the low-flow reach prior to diverting half of the flow.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_012
Middle section of the low-flow reach prior to diverting half of the flow.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_013
Lower section of the low-flow reach prior to diverting half of the flow.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_014
Empty lines running along the bank of the low-flow reach prior to the start of the experimental setup.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_015
Structurally complex pool habitat in the low-flow reach.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_016
Empty lines running along the bank of the low-flow reach prior to the start of the experimental setup.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_017
Section of the low-flow reach prior to the set up of the flow diversion.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_018
Bottom of the fishing section in the low flow reach prior to the start of the experimental setup.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_019
Coil system used to passively warm diverted water before it re-enters the increased temperature reach.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_020
Researchers set up the flow diversion that diverts approximately 50% of the streamflow and creates the reduced flow (low-flow) reach.
Photographed by: Adrian Puga
Date: 7/20/2023
Photo number: afo_021
Researchers set up the flow diversion that diverts approximately 50% of the streamflow and creates the reduced flow (low-flow) reach.
Photographed by: Adrian Puga
Date: 7/20/2023
Photo number: afo_022
Water travels through black tubing that is exposed to the sunlight to passively warm it and then re-enters the stream in the experimentally warmed (+Temp) reach.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_023
Sampling fish and salamanders in a tributary of McRae Creek.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_024
Graduate student Maddie Maffia and Professor Dana Warren attempt to electrofish under a deep undercut bank.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_025
An upstream net that closes the system during electrofishing prevents the movement of fish and salmanders into and out of the system.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_026
A terrestrial coastal giant salamanders.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_027
Sampling fish and salamanders in a tributary of McRae Creek.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_028
Sampling fish and salamanders in a tributary of McRae Creek.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_029
Sampling fish and salamanders in a tributary of McRae Creek.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_030
A young pacific giant salamander in the a tupperwear before being weighed.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_031
Hailey Bond collects length measurements of a salmander.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_032
Dana Warren collects the weight of a salamander.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_033
Undergraduate student Adrian Puga records data as fish and salmanders are processed.
Photographed by: Catalina Segura
Date: 7/20/2023
Photo number: afo_034
Undergraduate student Hailey Bond with an electofishing backpack.
Photographed by: Adrian Puga
Date: 7/20/2023
Photo number: afo_035
Diverted water being carried through a large plastic line in the low-flow reach.
Photographed by: Maddie Maffia
Date: 7/20/2023
Photo number: afo_036
The upper portion of the reference reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_037
Large trees in the riparian area of the upstream reference reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_038
Coil system used to passively warm diverted water before it re-enters the increased temperature (+Temp) reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_039
Graduate student Maddie Maffia sets up the siphon pump to divert water through the coil systems.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_040
Undergraduate student Hailey Bond takes notes while checking the outflow of the lines.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_041
Graduate student Maddie Maffia walks along the streambed where tubing diverts water.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_042
Maddie Maffia and Hailey Bond set up the siphon pump to divert and warm water through the coil system.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_043
Undergraduate student Hailey Bond in the reference reach of the stream, where there are no experimental treatments.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_044
Graduate student Maddie Maffia waits for the siphone pump to move water through the ~200 meters of lines.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_045
Graduate student Maddie Maffia fixes a hole in the line as it sprays water.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_046
Graduate student Maddie Maffia repairs a hole in one of the lines.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_047
Graduate student Maddie Maffia checking the coils to make sure water is moving through them.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_048
Graduate student Maddie Maffia takes notes on the water pressure of each of the lines.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_049
The upstream reference reach, where there is no reduced flow or increased temperature treatment.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_050
A frog hangs out on a DO sensors in the reference reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_051
Sensors (DO and PAR) installed in the reference reach, where no treatments are used.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_052
Maddie Maffia and Hailey Bond checking the lines in the low-flow reach
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_053
Maddie Maffia checks the warmed water as it re-enters the warmed reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_054
Diverted water being carried through a large plastic line in the low-flow reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_055
Undergraduate student Hailey Bond checks tubing as it runs along the low-flow reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_056
Diverted water being carried through a large plastic line in the low-flow reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_057
Undergraduate student Hailey Bond empties emergence traps in the low-flow reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_058
Undergraduate student Hailey Bond empties emergence traps in the low-flow reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_059
Graduate student Maddie Maffia ensures the flow diversion still has enough flow for fish passage.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_060
A wood jam creating great habitat cover in the low-flow reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_061
Maddie Maffie and Hailey Bond in the low-flow reach.
Photographed by: Lina DiGregorio
Date: 8/2/2023
Photo number: afo_062