AGRRA: Survey Equipment Construction © Jose Alejandro Alvarez © Jose Alejandro Alvarez Revision: 2017‐07‐20 Images in this presentation are Copyright © by Ken Marks and by other photographers as noted. Copyright © Ocean Research & Education Foundation Permission is granted to use this Powerpoint presentation for educational purposes with the AGRRA Program and, with attribution, for other valid educational purposes. All other uses are strictly prohibited. Tools Needed for Equipment Construction • hacksaw • drill and assorted bits (e.g., 5 mm / 3/16”, 6 mm / 1/4”) • clipper • pliers • screwdriver • metric measuring tape (or use metric fish survey tape reel) Useful Tools (if available) An inexpensive PVC cutter like this BrassCraft model makes quick, easy, and clean cuts through PVC pipe and is highly recommended. A cable tie tension tool like this Stanley FATMAX model tightens and cuts flush cable ties much cleaner and quicker than using pliers and cutters. Both of these tools were purchased from a home improvement store and are well worth the investment when making up multiple sets of gear. Needed for each BENTHOS surveyor • PVC tubing, ½ inch internal diameter (½” ID) ~ 2 m • female threaded connector, ½” ID 1 • male threaded connector, ½” ID 1 • 90° elbow, ½” ID 4 • PVC cement < 100 gm / 4 oz. • braided 3/16” diameter lead‐core rope at least 10.2 m • braided nylon cord at least 1 m • black vinyl electrical tape ~ 3 m • large cable ties ~ 15 (11 black) • smaller colored cable ties 90 (preferably 2 colors, with 45 of one and 45 of the other) • carabiner (or other secure clip) 1 • clipboard (or slate of similar size) 1 • rubber bands up to 12 • braided nylon string (alternative for some rubber bands) ~ 75 cm • appropriate UW‐BENTHOS datasheet 1 / dive • pencil at least 2 + needed for each detailed BENTHOS and CORAL surveyor • flexible, 15 cm plastic ruler (or equivalent) 1 Benthos Survey Equipment slate/clipboard meter stick 25 × 25 cm quadrat 10 m transect line underwater datasheet attached pencil and ruler Measuring Pole Construction Will consist of two, marked poles. The two halves combine to make a 1 meter long measuring pole. PVC tube, ½” ID Use PVC cement to glue one end of a ½” ID PVC tube to a threaded female connector. When the glue has set, measure and cut the tube for a total length of exactly 50 cm from the outer end of the connector. female 50 cm total length connector (Shown after addition of the 10‐cm interval marks.) Glue a second PVC tube (must be at least 50 cm long) into a male threaded connector. Thread the male connector into the female connector (should be firm, but not overly tight). When the glue has set, measure and cut the second PVC tube so the overall length of the combined pole is exactly 100 cm. male connector female connector threaded firmly together Starting at the female connector end, wrap the tubes with black vinyl electrical tape to make alternating 10‐cm bands. If desired, add smaller 5‐cm bands at each end of the meter pole. 5‐cm female connector = black male connector 10‐cm = unmarked 5‐cm When combined, both halves join to create a full 1‐meter pole. The pole half with the female connector is exactly 50 cm in total length. The other half pole is slightly longer due to the protruding threads on the male connector. 50 cm female connector 1 meter total length Quadrat Construction Cut four pieces of ½” ID PVC tube so the inner dimension of the quadrat will be 25 cm × 25 cm. Glue all joints of 90° elbows. Try to make sure quadrat remains relatively flat while gluing together. 25 cm 25 cm Quadrat Construction To make sure the inner dimensions of the completed PVC quadrat will be 25 cm × 25 cm, it is useful to cut two pieces of PVC to act as templates. A piece 24 cm long is used as a guide for cutting the PVC to length and a piece 25 cm long is used when fitting and gluing the quadrat together. Quadrat Construction Using the 24 cm template, cut four pieces of ½” ID PVC tube for each quadrat being constructed. Quadrat Construction Using slower setting PVC cement can be helpful during complicated assemblies like quadrats. Regardless of the glue type used it is necessary to work quickly and efficiently during assembly as the quadrat needs to be flat (planar) and the inside dimensions set to 25 cm before the glue sets. Use the 25 cm template to check the inner dimension between the sides. Make the measurement at the tubing and not the connectors. Quadrat Construction Use a hammer or rubber mallet to tap the corner connectors so that they slide onto the PVC pipe far enough so that the 25 cm template is snug inside the quadrat. Placing the quadrat vertically on a hard smooth surface and holding it in place with a foot will free the hands to be able to hold the template and hammer. Check inside dimensions at all four sides and make sure the quadrat is flat (planar) before the glue sets. Drill several holes through the sides to allow water penetration (otherwise quadrat will float). Attach a carabiner (or other style of clip) to the quadrat with one or more cable ties. Cut off the cable tie “tails” as short as possible with clippers or a tensioning tool. drilled hole clipped cable tie Transect Line Construction 300 ft spool of 3/16” braided, lead‐core rope, used for transect lines, may be sourced from commercial fishing supply companies such as http://www.memphisnet.net (stock number: LL201). Start by unspooling and accurately measuring the actual length of the line (usually a little over 91 m / 300 ft). Each transect line needs to be 10 m plus enough extra to form an eyelet at each end (minimally around 10.2 m). If there is enough line, divide the total length by 9 (otherwise divide by 8) to calculate the length of each transect line. First mark the proposed cut points with tape bands to verify the measurements before making any cuts to avoid errors. (Alternatively, sequentially cut 8 lines each 11 meters.) Form a small eyelet at each end of the transect line and secure it with several, very tight cable ties. Tighten cable ties with a pair of pliers and clip off the “tails” or (recommended) use a cable tie tensioning tool to do this in one step. Cut pieces of braided nylon cord or parachute cord (each about 75 cm long) and tie their ends together to form a loop. Secure to each end of the transect line as shown. clipped cable ties braided nylon cord or parachute cord looped through eyelet at end of transect line As an additional means of securing the ends of the transect line during the survey dive, small fishing weights (4‐6 ounce) can be attached to the loops at the end of the transect line with cable ties. Secure a large black cable tie for the 0‐m mark at one end of the transect line. Measure out and add additional black ties every meter up to the final 10‐m mark near the other end of the transect line (for a total of 11 black cable ties). Tighten each cable tie with pliers to secure its location and clip its “tail” or (recommended) use a cable tie tensioning tool to do this in one step. clipped cable tie at each meter mark Measure out, and add smaller, colored cable ties every 10 cm between the 11 black meter marks (for a total of 90 colored cable ties). If possible, use two colors that alternate every meter for ease of use underwater. Tighten all colored cable ties with pliers and clip their “tails” or (recommended) use a cable tie tensioning tool to do this in one step. meter mark Smaller colored cable tie every 10‐cm mark 10 cm loops at each end of transect line 90 cm 80 cm 50 cm 60 cm 70 cm 20 cm 30 cm 40 cm 0 m 10 cm 1 m 2 m 3 m 4 m small colored cable ties at 10‐cm intervals, when 5 m 6 m possible two colors that alternate every meter for convenience of benthic surveyors. 7 m 8 m 9 m 10 m large black cable ties at unusually long “tail” 1‐meter intervals before first meter mark Attach the loop at one end of the transect line to the carabiner. vent holes vent hole loop clipped to carabiner (Note vent holes drilled in quadrat to keep it from floating.) Wind the transect line around the quadrat to keep it from tangling. Secure the free end of the transect line with a simple looping knot. loop tied off around quadrat side Clipboard Example Attach a mechanical pencil and a flexible plastic ruler (for macroalgal heights) to the plastic slate or clipboard with a braided nylon cord with the pencil and ruler secured to either end. Bring a spare pencil in a secure location (BC pocket or tucked into wetsuit). Trim the tip of the flexible plastic ruler (from Fisher Scientific) at the 0 cm end so that is easier to reach the base of dense clumps of macroalgae. Secure the appropriate underwater datasheet to the slate with rubber bands. A strip of electrical tape placed at the top and bottom of the sheet can help to keep it from moving during the survey dive. Slide slate and meter stick between transect line wrapped around the quadrat for ease of transport. TIP: Surveyors should wear spare rubber bands around their wrists to replace any that break during a dive.