SeagrassNet Protocol (in pdf format for printing ~ Adobe Reader is required.)
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SeagrassNet
= Seagrass monitoring Network
Goal:
To measure change in seagrass on a permanent transect: Distribution
via seagrass bed position relative to the transect Species composition via transect plant collection Abundance
via Cover, canopy height, shoot density, above- &
below-ground biomass
Parameters
to monitor and monitoring methods
Herbarium
sheet of each seagrass species (with flowering parts)
·
Collect
each quarter and well document for the International Seagrass Herbarium
at the Museum of Natural History, Smithsonian, Washington, DC Mail
to:
Jackson
Estuarine Laboratory, UNH,
85
Adams Point Road,
Durham,
NH 03824 USA
· Obtain
and complete herbarium label from www.SeagrassNet.org and attach to
each herbarium sheet Photographic record (1 photo of each 1/4
m2 quadrat taken from above and including the sampling quadrat
identification number label)
·
Send used cameras to the global seagrass photo archive
Mail
to: Mr. Len McKenzie
Northern Fisheries Center PO
Box 5396
Cairns, QLD
4870 Australia Seagrass cover, a visual estimate of 1/4 m2
quadrat (50 x 50 cm)
·
Estimate
percent cover for all species combined on a scale (0-100%) in each of
the quadrats (use % cover in order to preserve as much information in
the raw data as possible, rather than using a Braun-Blanquet scale)
·
Estimate percent cover for each species on a scale (0-100%)
in each of the quadrats
·
Measure canopy height of the dominant
species in quadrat ignoring the tallest 20% of leaves and identify any
grazing evidence. Express results as
canopy height for the species. Biomass ·
Collect a 0.0035 m2 core (7 cm diameter) to
establish a cover vs. biomass regression. or all of the quadrats with
cover estimates (above), take a biomass core outside the quadrat within
1m of the quadrat, in an area of the same seagrass species and cover
as the quadrat (to your best judgment).
When placing the core tube, take care to insure that all shoots
originating in the core area are inside the tube. · The
biomass sample is divided into Leaves (all aboveground green plant parts),
Rhizome plus roots (all live plant parts of the horizontal rhizome and
roots that are attached), and Stems (all plant material extending vertically
above the horizontal rhizome with attached roots). Epiphytes are scraped
from the leaves. Leaves are rinsed in fresh water, dried to
constant wt (60° C for 24hr) and weighed.
Process biomass samples (g dry wt m-2), enter on waterproof
data forms, and submit data to SeagrassNet. Send a hard copy of all data sheets to UNH. Sexual reproduction
·
Count the number of flowers, fruits or seeds or flowering
stems in a core for all seagrass species. Express results as Flower/Fruit/Seed
per area. Shoot density by species
·
From the biomass cores, count all shoots of all species
in the 0.0035 m2 core (7 cm diameter).
Express results as total shoots m-2 and by species Maximum depth of distribution
·
Maximum depth is defined as the depth at which the deepest
shoot is found within a 50 m band of the transect perpendicular to shore.
(For locations with very deep Halophila spp. the deep edge for this monitoring
can be defined as the deepest growing strap-bladed seagrass.)
·
Measure the distance from the left (0m), center (25m),
and right (50m) positions on the deep cross-transect (station C)
·
Measure depth, record a GPS location, and simultaneously
record the local time.
·
Indicate if the site is intertidal or a tide pool. Minimum depth of distribution
·
Minimum depth is defined as the depth at which the shallowest
shoot is found in the 50 m band, independent of the density of the bed
(may be intertidal).
·
Measure the distance from the left (0m), center (25m),
and right (50m) positions on the shallow cross-transect (station A)
·
Measure depth, record a GPS location, and simultaneously
record the local time. · Indicate
if the site is intertidal or a tide pool. Tidal information ·
Record what type of tides (diurnal, semi-diurnal) are
found in the area and the tidal range (spring high to spring low) for
the site. ·
Record
whether the minimum depth of distribution is in the intertidal (between
the spring high and spring low tidal levels) or subtidal zone (below
the spring low tide level). Environmental data· Water
temperature (continuously measure temperature, °C) -- Tidbit data loggers
at the shallow (A) and deep (C) stations. The sensors are attached to
the permanent marker and left in the field for 3 months ·
Light level (% surface light at deep and shallow depths)
-- Hobo light sensor. Put light meters out at the shallow and deep stations
for 2 weeks at the time of each quarterly sampling, plus one land-based
meter at a nearby spot without shade · Salinity
(measure at every visit and determine the range over the study area,
ppt). Collect water samples at the 3 stations (A, B, & C) and read
salinity on the refractometer back at the laboratory. ·
Surface sediment characteristics: estimate sediment type
at three points on each cross transect (Left, Center, & Right
on each cross-transect) and collect a syringe core of sediment
at each station on the primary transect (A, B, & C). ·
Surface sediments are collected to obtain:
grain size (% gravel/sand/silt+clay) organic content (%loss on
ignition), and carbonate content (% loss after acidification).
Necessary equipment and materials
copy of the SeagrassNet sampling manual
herbarium supplies and press 0.25
m2 quadrat (50 x 50 cm) 30
cm rulers (2) 50 m measuring tapes (2)
marking pens, pencils and sharpener
quadrat identification number
labeler and white board marker percent
cover standard and species ID sheet waterproof
data sheets (3 per transect) disposable
underwater camera (2)
GPS unit (1) permanent
station marker (cement/stone monument or screw anchor) (2) salinity
refractometer (1) plastic
container for salinity water samples (3) recording
thermometer, Onset Tidbits (3) light
unit, Onset Hobo (3) sensor
storage and mailing box (green) biomass
core sampling tube (7 cm diameter)
plastic bags (36 for biomass, 3 for sediment), marking pens etc. syringe
sediment core sampler (1) aluminum
foil (for drying biomass samples) computer
with internet access mask
and booties boat
if needed
Sampling
intervals
4 times/yr (including times of max/min cover, every 3 months
if possible) Sampling
stations and replicates
1) Locations ranging from pristine (1 required) to stressed (optional)
2) Transects per location
·
Perpendicular to shore at the center of a 50m band running
from the shallow edge of the bed to the deep edge
·
Three cross-transect stations per transect (with the
assumption that stations are independent)
1.
Deep edge of the continuous bed
2.
Shallow edge of the continuous bed
3.
Halfway in depth between deep and shallow
3) Walk or swim the entire transect
from shore to the deep edge and locate each permanent marker with the
GPS (do not walk on sampling area).
·
Collect and record all seagrass species seen along this
transect
·
Record any interesting observations (e.g., depth limit
of species, etc.)
4) Swim or walk the three cross-transects from 0 to 50m (best
done when setting out the measuring tape).
Always set out the cross-transect tape from eft to right when
facing the sea. When walking the transect stay at least 2 meters
from the tape except when actually sampling.
·
Record the names of all species and collect voucher specimens
of each from within 0.5m of the line
·
Determine the dominant species
5)
Sampling
·
12 samples per cross-transect
·
Select 12 random replicates (using the random numbers
provided) for the dominant species
·
Estimate % cover for each of the sample replicates (n=12)
& % of each species within the quadrat
·
Measure canopy height ignoring the tallest 20% of leaves
·
Collect a biomass coreoutside the quadrat within 1m of
the quadrat in an area of the same seagrass species & cover as the
quadrat (to your best judgment)
·
Measure seagrass density and above and below biomass
on each core
·
Number of samples per station is 12 samples (for 1 cross-transect)
·
Number of samples per transect is 36 samples (for 3 cross-transects) 6)
Submit all data to SeagrassNet via the WEB site: www.Seagrassnet.org
7) Mail
Dr. Fred Short, SeagrassNet
Jackson Estuarine Laboratory, UNH
85 Adams Point Road
Durham, NH 03824 USA
8) Mail the cameras and dry biomass samples to:
Mr. Len McKenzie
Northern Fisheries Center
PO Box 5396
Cairns, QLD 4870
Australia
9) Wrap-up
·
Wash all gear in fresh water and dry
·
Review supplies for next quarter's sampling and request
new materials
·
Store gear for next quarter
2001 SeagrassNet Sampling Activities
October
Sampling -- at low tide
1.
On October spring tide, put out the light sensors at A
and C on the transect and on land. Check
the temperature sensors.
2.
In October two weeks later collect the light sensors and
collect the temperature sensors
3.
Put out the new temperature sensors at A and C
4.
Collect
salinity samples from A, B, and C.
5.
Conduct
the seagrass survey and sampling. 6. When finished express mail to UNH: Green box with light and temperature sensors. Original data sheets (keep a copy) 7.Mail:
Cameras with photos of each quadrat to Northern Fisheries Center |