This research focuses on developing and evaluating cost-effective balloon tags for fish passage studies in hydraulic structures. Our aims to assess the effectiveness of different balloon tag configurations for the recovery of sensor fish and live fish after they pass through these hydraulic structures. The balloon tag protocol we develop offer a cost effectiveness, customizability, and adjustable inflation times.
It is a low cost solution for large scale studies with limited budgets. It helps to understand the impact of hydraulic structures on fish and can be tailored to different species and environments. We have developed a cost-effective balloon tag manufacturing process.
This will enhance our understanding of balloon tag performances under different conditions, enabling tailored testing and facilitating environmental impact assessments for developing and operating fish friendly hydropower systems. To begin, in a mixing cup, combine oxalic acid and sodium bicarbonate, maintaining a weight ratio of one to two. If the acid-based powder mix becomes crystalline, grind it into a fine powder using a mortar and pestle.
To fill the capsules using a semi-automatic capsule filling machine, place the cap sheet on a clean, dry surface. Align the encapsulation sheet over the cap sheet, separate the capsule tops and bottoms unless using pre-separated capsules. Pour the capsule tops into the encapsulation sheet and shake the sheet gently in a circular motion to fill the holes with the tops.
Collect the leftover capsule tops in a clean cup. Detach the encapsulation sheet from the completely filled cap sheet and keep the cap sheet aside. Identify and flip the capsule tops that are upside down.
Next place the body or bottom sheet on a clean, dry, flat surface. Fix the encapsulation sheet to the bottom sheet and secure the alignment with the black pegs. Pour the capsule bottoms onto the encapsulation sheet and shake as described previously to fill all the holes.
Then pour off the excess capsule bottoms from the sheet. Remove the encapsulation sheet from the filled bottom sheet. Flip any capsule bottoms found upside down.
Now disperse the acid base powder mixture onto the filled bottom sheet. Using a plastic spreader, fill the capsule bottoms with the powder. After positioning the filled cap sheet on a flat surface, mount the middle sheet on its top.
Invert the cap sheet affixed to the middle sheet on the filled bottom sheet, ensuring a proper mutual alignment. Press gently, but equally on all sides of the cap sheet to join and fit the tops and bottoms of the capsules. Then remove the cap sheet and the middle sheet from the bottom sheet, leaving the capsule tops and bottoms joined.
Check each capsule to ensure its top and bottom are fitted tightly. If not, manually press and tighten the top and bottom together. Finally, transfer the filled capsules to an airtight sealable container.
To begin, mix both commercial silicone mold material components in a mixing cup, maintaining a one-to-one weight ratio. Stir thoroughly with a disposable spoon for about five minutes until the mixture becomes uniform in appearance. Then position the 3D printed mold plate fitted with packing tape over a sheet of paper.
Pour the silicone mixture into each stopper hole, ensuring all the holes are filled. Using a rubber squeegee, spread the silicone evenly into each stopper hole before clearing any leftover silicone. Leave the rubber stoppers to dry for four hours.
Once the stoppers have fully cured, as indicated by the complete drying and hardening of the silicone mixture, take off the tape from the back of the mold plate and pull the stoppers out of the mold. Finally, clean any surplus silicone attached to the stoppers. To begin the balloon tag assembly, carefully insert the piercing tool into the silicone stopper.
Then insert the piercing tool attached to the stopper into a 15 gauge syringe needle. After that, remove the piercing tool from the silicone stopper, leaving only the needle embedded in the stopper. Cut a six inch piece from a 50 pound fishing line.
Insert the fishing line piece into the silicone stopper through the 15 gauge needle while holding the stopper and the fishing line together. Carefully retract the needle from the stopper, leaving the fishing line inside the stopper. Next, insert two acid-based powder filled capsules into a latex balloon.
Using a rubber band expansion tool like a castration band plier, gently expand the balloon opening. Then carefully insert one silicone stopper into the balloon opening, making sure to keep the two ends of the fishing line outside the balloon. Place two O-rings onto the rubber band expansion tool and expand them.
Push the neck of the latex balloon through the two expanded O-rings. Carefully pull the two O-rings away from the rubber band expansion tool, leaving them tightly wrapped around the balloon's neck centered on the stopper. Insert one end of the fishing line through one of the small holes in the sensor fish cap and pull it through the large hole at the center.
Tie both ends of the fishing line together, leaving a 0.5 to one inch gap from the top of the cap to the balloon base. Keep the extra fishing line attached as cutting it too close to a knot might cause it to untie. Studying the average inflation time for balloon tags with different volumes of water at two different temperatures revealed that full inflation occurred faster when using water at 18.3 degrees Celsius as compared to 12.7 degrees Celsius.
A slower dissolution of the capsules at lower temperatures caused delayed inflation. Among the tested conditions, the three capsule balloon tags injected with five milliliters of water at 18.3 degrees Celsius exhibited consistent size with a mean volume of 114 cubic centimeters. At 18.3 degrees Celsius, the four capsule balloon tags demonstrated a faster inflation start time.
However, the full inflation times for the two capsule and four capsule balloon tags were nearly identical. The three capsule balloon tag began deflating first followed by the four capsule and finally, the two capsule balloon tags.
