SPRING SURVEY PROTOCOL

Protocol for Big Bend National Park Amphibian Monitoring Field Crews

During diurnal visits to springs, we quantify egg masses, tadpoles, and adults using area-constrained and time-constrained searches.  In addition, we record various habitat measurements and conduct water quality analyses.

SURVEY METHODS

Starting from the headwaters of a spring (the source), conduct a minimum of two 50 m survey transects followed by a 30 minute walk along the drainage.  If water ends permanently at any point in the survey, record the total distance of water and stop the survey there.  If water starts and stops, record the lengths of water sections and continue the survey.

There are a few exceptions to starting at the spring source.  For example, at Lower and Upper Boot spring, the exact spring source is unknown.  Therefore, we started transects at the lowest water point and surveyed upstream.  For repeat springs, if the source changes during the season we always attempt to begin surveying at the original source point.  The UTM coordinates are taken at the starting points of the surveys.

50 m TRANSECT SURVEY METHODS

Conduct a minimum of two 50 m contiguous transects (if there is water).

At the beginning of a 50 m transect survey, do the following:

· Record date, location, time begin, and observer # 1 and # 2 names on the data sheet.

· Photograph the spring.  Take one photograph of the source, and one looking downstream and/or one viewing the general area.  We try to include landmarks in the photograph background to orient future researchers.  In 1999, only photograph new springs that were not surveyed in 1998.

· UTM East, UTM North, elevation, and ± meter from the GPS unit.

· Sky code : 0 = clear or few clouds, 1 = partly cloudy or variable, 2 = cloudy or overcast, 3 = fog, 4 = drizzle, 5 = heavy rain.

· Wind speed:  range of wind speed as determined from anemometer.  Face into wind with anemometer held in front of you at breast height.

· Air temperature in shade 1 m above ground level with Hanna K-type thermocouple.

· Water temperature with probe about 2 - 3 cm below water surface and 0.5 m from water's edge with Hanna K-type thermocouple.

· Dissolved Oxygen (DO) using Hach test kit. 

· Collect a 250 ml water sample from spring source area if possible.  With a permanent marker, write the location, date and time on the water sample bottle.  Keep the bottle cool and place in a  cooler with ice packs.   Upon return from the field, either process water sample immediately or place in refrigerator.  Within 48 hours of collection, process water sample in the lab for pH, conductivity, salinity, nitrate, nitrite, and sulfate.  See Water Analysis protocol.

Laying out 50 m tape-Prewalk

At the source of the spring, conduct the first 50 m transect survey heading downstream.   Secure the 0 m end of a 50 m tape at the beginning of the surface water.  Wet soil or mud is not considered surface water.  Observer # 1 walks the 50 m tape out along the spring following the spring’s course while counting the numbers of adult or recently metamorphosed frogs seen or the number of plops heard.  Observer # 2 records Observer #1's observations and separately records anything Observer # 1 missed.  Note at what meter adults were seen or heard and record that number within that meter section on the data sheet. 

Transect Survey

After the pre-walk, the two observers should stay close together.  Observer # 1 tells Observer # 2 what s/he sees and Observer # 2 records the observations, adding any amphibians Observer # 1 failed to see in the Observer # 2 column on the data sheet.  Trade off being first and second observers after each 50 m transect.   Often it is very difficult to conduct observer 1 vs. 2 because of the physical aspects of the spring area.  Note on the data sheet when the observer 1 vs. 2 technique doesn't work.

At each 1 m point along the survey, noted from the 50 m tape, take the ocular tube and record whether or not vegetation is over the water at the cross hair of the tube.   Record vegetation cover for < 1.5 m (looking down) and > 1.5 m (looking up).   If there is vegetation at the cross hair point of the ocular tube, record a "1"; if no vegetation intersects the cross hair, record a "0".   If that section is dry, record a "-".  Vegetation is considered to be any flora that is providing shade, so this includes dead branches or overhanging plants.  Algae or other sub-aquatic plants are not considered as shade-providing vegetation and are recorded elsewhere on the data sheet.   When entering these numbers into the computer, sum the numbers for each 10 m stretch to get a total percentage cover.  For example, if at each meter point, vegetation > 1.5 m hits the cross hair 6 times, but not on 4 occasions, the percent cover greater than 1.5 m for the 10 m stretch is 60%.

Along each meter section, conduct a single meter-long sweep with a dipnet through the water.  To standardize sweeps, use a large, green, aquarium net (20 x 15 cm, 8 x 6 in) with a mesh size of 1.5 mm.  From June through August 1998, we used a larger mesh (4 mm) yet similar-sized net.  Record the number and species of amphibians caught per sweep.  If the water is too shallow to sweep, record a "-".  Record sweeps in each 10 m section of the 50 m transect.  Thus, if you caught nothing in sweeps from 0 - 6 m, then 2 Rber tadpoles (TP) in sweep  6 - 7 m, 3 Rber tadpoles in 7 - 8 m, and water from 8 - 10 m was unsweepable, the recorded data would read "0,0,0,0,0,0,2 Rber TP, 3 Rber TP, -,-".  Always put 2 commas between observations.

For each 10 m section of the 50 m transect, record number of egg masses, tadpoles, metamorphs, adults seen, and/or plops heard.  Record the species if known.  If species is not positively identified, then record as unknown species ("unk. spp.").  For each egg mass, record length and width of egg mass and how far below the surface of the water the egg mass is.  If there are different sizes of tadpoles, record the size classes present (example, 10 Rber TP 20 mm, 30 Rber TP 60 mm).

For each 10 m section, record predators seen and any aquatic animals seen (e.g. snails, surface insects).  The following are aquatic animals and their respective code names:

GWB = giant water bug
PDB = predacious diving beetle
FAI = fairy shrimp
DRAG = dragonfly larvae
HYD = Hydrophilidae (water scavenger beetles)
DAMS = damselfly larvae
ABL = aquatic beetle larvae
SPI = spiders
BKSW = backswimmer
WG = whirlygig beetle
WS = water strider
CWB = creeping water bug
WB = water boatmen

Record other animals seen in the notes section at the bottom of the data sheet, such as snakes, javelinas, mountain lion tracks, bats, etc.

Before starting the 50 m transect, write down 5 random numbers between 1 and 10, one for each 10 meter section.  In this randomly selected meter, record more detailed physical aspects and vegetation attributes.  A single random number is easily obtained by starting and stopping a timer with 100th’s of a second.  Take the one’s place number.   The first random number is the meter that will have vegetation recorded in the 0-10 m section.  For the second random number, add a 1 in front of it to be the random meter in the 10-20 m section.  For the third random number, add a 2 in front of it to be the random meter in the 20-30 m section.  Continue like this until you have a 0’s, 10’s, 20’s, 30’s, and 40’s random number.

At each random number, record the following at that meter:

· Percent pool (P), riffle (R), or seep (S) (e.g. 100P, 60P/40R, 80R/20S).

· Water width at the random meter mark.

· Water depth at the width mid-point of the random meter mark.

Record the following in the 1 m section starting at the random meter mark up to the next meter mark.  For example, if the random meter is 12, record information for the section of water from meter 12 to 13 regardless of width:

· Dominant substrate: bedrock, clay, silt, sand, pebble (2 - 10 mm diameter), gravel (11 - 50 mm dia.), stone (51 - 400 mm dia.), boulder (> 400 mm diameter).

· Percent downstream left and right cover including dominant cover.  Visually approximate percent cover (e.g., if the left side of the water’s edge is covered by Baccharis from 12.0 m to 12.6 m, by rock from 12.6 to 12.8, and uncovered from 12.8 to 13.0, then left cover is 80% and the dominant cover is Baccharis).

· Percent sub-aquatic vegetation.  Visually estimate the percent of sub-aquatic vegetation in the 1 m section of water.  Record the dominant plant (e.g. algae or Charra).

· Percent emergent vegetation.  Visually estimate the percent of emergent plants in the 1 m section of water. Record the dominant plant (e.g. Baccharis, grass, cattail).

If the random meter section is dry, then skip the above measurements.  Write "dry" in this section of the data sheet.

At the end of the 50 m transect, record the dominant vegetation species along the spring.  Try to include five to ten different plants.  Write out common or scientific names of plants.  Record "Yes" or "No" if there is cattail, tamarisk, or willow present.  For tamarisk, record if there are <25, 25-75, or >75 individuals present.  Also, record "Y" or "N" if there are signs of human, livestock, or hog use at the spring and make a short note as to what the presence is (e.g. ruin, cow tracks).  Any other notes may be included at the bottom of the data sheet.  Sometimes we took a photo looking upstream at the end of a 50 m transect.  Record time end.

30 MINUTE WALK AFTER TRANSECTS

If there is still water after the two 50 m transect surveys, conduct a time-constrained survey of 30 minutes (data sheet).  Begin at the end point of the second transect (100 m from source).  Continue surveying downstream until either 30 minutes have passed or water ends.  The 50 m tape should be laid out along the waterflow for each stretch.   Secure one end of a 50 m tape (e.g., under a rock).

Observer 1 will count and point out amphibians to Observer 2 who will record observations, noting any amphibians the first observer did not see in a separate column.   The two observers should walk close together.  Trade off as observer 1 and 2 each 50 m.  Record who is observer 1 and 2.

Record time begin and end of each 50 m.  When amphibians are seen, record the meter point from start of walk and the time.  Record species, and the number of adults or plops, metamorphs, tadpoles, and egg masses.  If water stops and starts, record distances between water stretches.

RECOMMENDATIONS

Start the spring survey of Terlingua Abaja about 300 m upstream from the gauging station where cattail wetlands begin.  This area is better amphibian habitat.

During the initial walk while laying out the tape of a 50 m transect survey, have observer 2 walk next to observer 1, such that observer bias statistics can be conducted on these amphibian counts.

If the random number in a 10 m stretch is dry, go to the next meter in that stretch that does have water in order to provide more information about the spring habitat.

TINAJA SURVEY METHODS

Methods are similar to those used for the spring survey, but because tinajas are not linear you do not work along a 50 m transect, but instead survey each pool of water (tinaja) separately.  Record initial data from the first pool heading downstream and take photographs up and down stream.  Record UTM coordinates at the first pool.  At each tinaja, look for and count amphibians using the Observer 1 and 2 method.  Record predators and other aquatic organisms. 

For the entire pool, record on the data sheet the following vegetation measurements and tinaja physical characteristics:

· Dominant substrate.

· % scum cover: scum is defined as the organic debris on the bottom of a pool.  Visually estimate the percent of the bottom of the pool covered by scum.

· % mat algae: mat algae is floating algae.  Visually estimate the percent of the surface of the pool covered by mat algae.

· Dominant sub-aquatic vegetation: algae or Charra.

· % shoreline cover on left and right banks facing downstream.  Visually estimate the percent of each side of the pool that is covered by vegetation or rock. 

· Dominant left and right shore cover is the plant species or rock that is providing the most shade on the left and right sides of the tinaja.

· Type: shallow tinajas are less than 0.5 m deep, deep tinajas are equal to or greater than 0.5 m deep at the deepest point.

· Water length: length of the pool parallel to the downstream flow of the water or canyon.

· Water width: width of the pool perpendicular to the length measurement.

· Water depth: depth of the pool at the deepest point.

· Distance to next pool: distance between the end of pool 1 to the beginning of pool 2.  This entry is blank for the last pool surveyed.

Sweeps are done differently in tinajas than in springs.  There are two kinds of sweeps in the tinaja survey:  shallow and deep.  Shallow sweeps are made parallel to the water's edge in water less than 0.5 m deep.  Sweeps are 1 m in length and should occur every meter.  The maximum number of shallow sweeps per tinaja is 20 sweeps.  If a tinaja's circumference is greater than 20 m, than spatially distribute 20 sweeps equally around the pool.  Deep sweeps are sweeps made perpendicular to the water's edge in water equal to or greater than 0.5 m deep.   Sweeps are 1 m in length and should occur every meter.  Again, the maximum number of deep sweeps is 20.  If a tinaja is larger than this, spatially distribute the deep sweeps equally around the pool.

Tinajas that are less than 0.5 m deep will have only shallow sweeps.  Tinajas that are completely equal to or greater than 0.5 m deep will have only deep sweeps.  Most tinajas have varying depths. For each sweep, record a "0" or the number of amphibians caught, species code, and life stage.  If a sweep is not possible, record as a "-".  For tinajas of varying depths, the number of shallow sweeps (including dashes) should equal the number of deep sweeps (including dashes).

At the end of the tinaja survey, record the dominant vegetation species along the tinaja(s).  Record "Yes" or "No" if there is cattail, tamarisk, or willow present.  For tamarisk, record if there are <25,   25 - 75, or >75 individuals present.  Also, record "Y" or "N" if there are signs of human, livestock, or hog use at the tinajas and make a short note as to what the presence is (e.g. ruin, cow tracks). Any other notes may be included at the bottom of the data sheet.  Record time end.

The figure shows the location of 84 surveyed and 32 visited but not completely surveyed spring, tinaja, tank, and culvert/pool/pond sites at Big Bend National Park in 1998.   The table shows the # of sites visited and surveyed in each wetland category.

Six springs were visited on a monthly basis over the course of the June-October 1998 field season.  This figure shows the number of Rio Grande leopard frog eggs, tadpoles, and adults recorded at Cattail Falls over time.

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