Florida Department of
Environmental Protection
Standards and Assessment
Rapid Periphyton Survey
(RPS) Sampling Method
October 2012
Rapid Periphyton Survey (RPS)
• The Rapid Periphyton Survey (RPS)
quantifies the extent (coverage) and
abundance (thickness) of attached algae
in a 100m stream segment.
• Follow DEP SOP FS 7230
• Conduct in conjunction with Stream and
River Habitat Assessment (SOP FT 3100)
and Linear Vegetation Survey (LVS; SOP
FS 7320)
RPS Method Overview
• Establish 100m reach of stream
• Place flags every 10m, to create 11 crossstream transects.
• Beginning at “0” transect, evaluate 9 roughly
equidistant points across the stream.
• Point 1 will be ~ 0.1m from the right bank,
point 5 is in the middle of the stream, and
point 9 is ~ 0.1m from the left bank
RPS Method Overview cont.
• A canopy measurement should be taken
between points 4 and 6, ideally at point 5.
• If these points can’t be reached, do not take
a canopy measurement at that transect
(mark “x” on datasheet).
Conceptual Layout
100 90
80 70 60
50 40 30
20 10
0
100m
 Width is adjusted by system.
 9 observations every 10 m (11 transects, including 0m and 100m)
for a total of 99 observation points.
 Canopy measurement, facing upstream, between points 4 and 6,
ideally at point 5.
Assessing Algal Occurrence
• After scanning the area for safety, choose
points 1-9 haphazardly – that is, choose the
actual point without looking (and potentially
biasing your selection)
• Measure average algae thickness,
perpendicular to substrate, at each point.
Thickness Ranks
Small snag
Rank
N
3
4
5
6
Algae Thickness
rough surface with
no algae, slimy, or
algae up to 1 mm
>1 mm to 6 mm
6 mm to 20 mm
20 mm to 10 cm
>10 cm
Average thickness is
>1mm to <6 =
Rank 3
Thickness Ranks
1.5 cm long , Rank 4
12 cm long , Rank 6
Thickness Ranks 4-5
Thickness Rank 6
Assessing Algal Occurrence
• If substrate cannot be reached and substrate
depth is greater than Secchi depth (photic
zone), record “N” because DEP studies have
shown that no algae occur at those depths.
• If substrate cannot be reached or seen but
depth is less than Secchi depth, record “X”
• If you can see but not reach substrate, estimate
rank based on similar reachable areas
• Do NOT leave any box blank.
Assessing Algal Occurrence
• After completing the survey, count the
number of sample points with ranks 4, 5, or
6. If these are greater than 20% of the total
points, collect a sample of the dominant type
of algae for taxonomic identification.
• Follow SOP FS 7240 for algal mat collection.
• Keep sample on ice until it is delivered to the
lab (no chemical preservation).
40
4
7
5
8
6
9
7
1
8
2
Water 8sample
9
3
RQ:
1
90 2
Point
Transect 3
1=right
(m)
4
9=left
50
5
Site:
6
7
100
1
SCI/Biorecon
(circle 1)
7
Algal mat sample
FDEP Rapid9Periphyton Survey (DEP
County:
Canopy
Cover
Transect
(m)
90
1Date:
2 Algal
Algal
Thickness
Point
Thickness
3 Rank
Canopy
1=right 4 Rank
Cover
9=left
(N - 6)
5 rough, no
1N
6 algae; slimy;
2
algae to 1 mm
7
43
40
5
1 6
2 7
5
3 8
9
6
8
7
9
1
8
1
2
9
5
6
64
7
5
100
6
2
8>1mm - 6 mm
9
1 >6 - 20 mm
2
>20 mm 3
10 cm
4
5
6
>10 cm
Habitat Assessment
Linear
Survey Revised 6/12/12
SOP
FSVeg.
7230)
SCI/Biorecon (circle 1)
Investigators:
Water sample
Algal
Point
Thickness
Transect
Canopy
RQ:
1=right
Rank
(m)
Cover
9=left
(N - 6)
total p
% poi
3
Secch
4
80
# poin
Algal Thickness
2
Rank
1
3
2
3
Check accompanying data
collected at same site/date.
4
4
60
Form FD 9000-25
8 (N - 6)
2
Habitat5Assessment
Linear 6Veg. Survey
RPS Datasheet FD 9000-25
Algal
6Thickness
7 Rank
9
3
80
5
1
8 4
9 5
0
4
Algal mat
4 sample
5 N
6
7
8
rough, no
algae; slimy;
algae to 1 mm
3
>1mm - 6 mm
4
>6 - 20 mm
9
1
2
Check
collec
Algal
Habita
Linear
>20 mm -
SCI/Bi
Water
3
3
3 5
RQ:
7 4
7
10
cm
4
4
Record
"N" for points deeper than the Secchi depth; algae
are presumed
8
8
10
5
50
5
90
5
6
>10 cm
absent. Record "X" for points shallower than Secchi depth for which substrate
Alg
9 6
9
6
6
cannot be seen or reached with the hand. Note if thickness estimated for deep
7
7
1 7
points which can be seen but not reached.
8
8
2 8
Record "N" for points deeper than the Secchi depth; algae are presumed
Record canopy
cover
as
the
number
of
small
densiometer
quadrants
(out
of
96)
9
9
3 9
absent. Record
"X" for points shallower than Secchi
depth for which substrate N
that HAVE
canopy
cover.
Measure
facing
upstream
at
point
4,
5,
or
6.
1
1
1
cannot be seen
or reached with the hand. Note if thickness
estimated for deep
4
2 algal mat sample following DEP SOP FS 27240 if the
2
Collect an
percentage
of
points which can be seen but not reached.
3
70
5
3 sampled points with a thickness rank of
3 4, 5, or 6 is >20%.
3
total
6
Record canopy cover as the number of small densiometer quadrants (out of 96)
Estimating Canopy Cover
• Use a concave spherical densiometer
• Hold instrument level and away from body so that observer’s head is just
outside the grid.
• Divide each of the 24 etched boxes into 4 imaginary boxes. Imagine a
“point” in the center of each of the 96 smaller boxes.
• Count the small squares or points that ARE COVERED with vegetation.
Record this number on the datasheet.
level
Estimating Canopy Cover
71 squares with canopy cover
Record “71” for canopy cover on RPS field sheet
Estimating Canopy Cover
Densiometer measurement should indicate available light
on the sampling date.
Winter
Summer
Hypothetical view of one (of 24) box of the densiometer when
branches are bare (winter) and full of leaves (summer).
Although there is something in each box in both cases, the
“point” is covered for 2 in Winter and 4 in Summer.
Things you might confuse with periphyton –
do not include in RPS
Macroalgae:
Nitella
Chara
Bryophytes: mosses and liverworts:
Liverworts
Sphagnum moss
Fontinalis
Rapid Periphyton Survey
• SOP FS 7230
– Revision date September 19, 2012
• Use in support of numeric nutrient criteria
implementation described in Section 2.7 of
the Stream Condition Index Primer.
http://www.dep.state.fl.us/water/bioassess/docs/sci-primer.pdf
Thickness
Rank?
• Datasheet available on DEP website
http://www.dep.state.fl.us/water/sas/qa/forms.htm