Each block represents a percent cover which helps us determine the density of algae seen in each aerial photograph. |
Everything you will need to do your own biomass estimates! |
To measure biomass you will need:
- 1 quadrat (1/2 meter squared is ideal, but any size will do);
- Measuring tape;
- 1 scale (one with a hanging clip that can weigh at up to 500 grams is ideal);
- Box cutter or razor blade to cut macroalgae overhanging quadrant sample area;
- Salad spinner to remove excess water from the macroalgae;
- A zip-lock bag to hold and weigh the sample;
- paper and pencil to record your readings, and;
- A camera to capture images of your findings!
Step by step instructions on measuring biomass:
Kids, be sure to have an adult help you out!
We sampled Sandy Point on Tuesday, and the Wilson Park Fishing Area (pictured here) and Bissel Cove on Wednesday. |
Take your quadrat and drop it at random within your sample area.
Quadrat laid along shore at random. |
Using your box cutter or razor blade, cut along the edge of your quadrat to trim away pieces of macroalgae that are not in your selected area. If a piece is only half in your selected area you will need to carefully cut away the section that is not in your area.
Using a razor blade, carefully cut away excess macroalgae from your sample. |
A salad spinner is the quickest and easiest way to get rid of excess water. |
Once you have cleaned and dried your sample you will need to separate it into the different types of macroalgae. Make a pile for each of the classes (green, red and brown)
Our sample has been separated. Notice we did not find any brown algae so only green and red are shown. |
Once you have your sample separated, you will need to weigh each sample. First weigh the bag so you can subtract that weight from your total. Weigh each color separately and record your measurements on a piece of paper. Once you have measured all three individually, put all three in the bag and measure the total. This will help verify your measurement and account for any evaporation.
Note: some samples may be too large to measure all in one, so you will need to break it into two part measurements.
Weigh the algae using a hanging scale and plastic bag. |
Repeat these steps four more times to get a total of five samples. Using these numbers you will be able to calculate the total biomass of your shoreline. You will need to calculate the area of your shoreline and your quadrat as well as the percent of the total for each color and sample. Below are some equations you will need for your calculations.
Area = length multiplied by height. (Be sure to use consistent measurements, for example meters (m) and centimeters (cm) OR foot (ft) and inches (in) for all calculations.
M² = length(meters) x height (meters)
Average weight = sum of all samples divided by total number of samples
Grams (g) = {[sample 1(g)] + [sample 2(g)] + [sample 3(g)]} ÷ 3 (samples)
Percent = individual sample weight divided by total sample, multiplied by 100%
% = Green sample (g) ÷ total sample weight (g) x 100 percent
Total cover = total area multiplied by average weight, divided by sample area
M² = total area of shoreline(meters squared) x average weight (grams)
÷ area of quadrat (meters squared)
÷ area of quadrat (meters squared)
1 comment:
Great article! I'm doing a lot of research into biomass and it's benefits so I've found your article really helpful! Thank you.
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