This study was funded by the U.S. Department of Energy (DOE) Water Power Technologies Office. The laboratory studies were conducted at Pacific Northwest National Laboratory, which is operated by Battelle for the DOE under Contract DE-AC05-76RL01830.

1. Acid/base encapsulation
<ol>
	<li>Mix a 1:2 ratio by the weight of H2C2O4 (oxalic acid) and NaHCO3 (sodium bicarbonate) in a mixing cup (see Table of Materials). If the acid-base powder mix is crystallized, grind it down using a mortar and pestle (Figure 1A).</li>
	<li>Retrieve the size 3 vegetable-based capsules and the semi-automatic capsule filling machine to begin the process (see Table of Materials).</li>
	<li>Place the cap sheet flat on a clean, dry surface. Align the encapsulation sheet on top of the cap sheet using the black pegs to fix it correctly in place (Figure 1B).</li>
	<li>Separate the capsule tops and bottoms, unless using pre-separated capsules. The size #3 vegetable capsules, when closed, have overall dimensions of 15.9 mm in length, 5.57 mm in outer diameter (OD), 0.30 mL in volume, and weigh 47 mg.</li>
	<li>Pour capsule tops into the encapsulation sheet (Figure 1C). Gently shake the tops into the holes with a circular motion. While doing this, cover the gap in the wall of the encapsulation sheet with one hand or a powder spreader to avoid spilling the tops (Figure 1D).
	<ol>
		<li>Once the holes are filled, pour the excess capsule tops into a clean cup (Figure 1E). Identify any upside-down capsule tops and turn them over (Figure 1F). Ensure that all capsule tops are facing the correct direction in the cap sheet. It is important to ensure proper orientation, as incorrect alignment may result in capsule tops not properly joining with the capsule bottoms.</li>
	</ol>
	</li>
	<li>Remove the encapsulation sheet and set aside the filled cap sheet.</li>
	<li>Take out the body or &#34;bottom&#34; sheet. Place it on a clean, dry, flat surface. Fix the encapsulation sheet to the bottom sheet, ensuring proper alignment by utilizing the black pegs to position it correctly in place.</li>
	<li>Pour capsule bottoms into the encapsulation sheet and shake as before in a circular motion to fill the holes. Pour off excess capsule bottoms. Identify any upside-down capsule bottoms and turn them over.</li>
	<li>Remove the encapsulation sheet from the bottom sheet and set it aside.</li>
	<li>Pour the acid/base powder mixture onto the filled bottom sheet (Figure 1G). Use a plastic spreader to fill the capsule bottoms with the powder (Figure 1H). Check that all the capsule bottoms are filled (Figure 1I). Remove any unused acid/base powder.</li>
	<li>Place the cap sheet on a flat surface and position the middle sheet on top, aligning it with the black pegs to ensure a correct fit. Ensure to line up all the capsule tops with the corresponding holes in the middle sheet.</li>
	<li>Invert the cap sheet with the affixed middle sheet and align it with the filled bottom sheet (Figure 1J).</li>
	<li>Gently press down on the cap sheet equally on all sides to join the tops and bottoms, fitting both sides of the capsule together (Figure 1K).</li>
	<li>Remove the cap sheet and middle sheet from the bottom sheet. At this point, the capsule bottoms and tops should be properly joined together.
	<ol>
		<li>Verify that each capsule top and bottom are fitted tightly; if not, manually press the capsule top and bottom together to create a tight fit. Remove the filled capsules and place them in an airtight, sealable container (Figure 1L). 
		NOTE: For safe handling, it is essential for users to wear personal protective equipment (PPE) and face protection. Adequate ventilation should be ensured, and precautions should be taken to avoid ingestion, inhalation, and contact with the substance on the skin, eyes, or clothing. Additionally, it is important to prevent the generation of dust. For detailed information regarding safety, please refer to the safety data sheet (SDS) for oxalic acid and sodium bicarbonate. To maintain the integrity of the acid/base capsules, it is advised to store them away from direct sunlight and high humidity. Store the unused capsules in a sealed, airtight container. As long as the capsules are kept dry and free from moisture, they can be used effectively to ensure optimal functionality.</li>
	</ol>
	</li>
</ol>
2. Silicone stopper manufacture
<ol>
	<li>Using a fused deposition modeling (FDM) 3D printer (see Table of Materials), print a mold plate using the STL file provided in Supplementary File 1.</li>
	<li>Place a clear packing tape on the bottom side of the mold plate so that each opening is sealed (Figure 2A).</li>
	<li>Mix a 1:1 ratio by weight (e.g., 50 g each of Part A and Part B) of the commercially available silicone mold material into a mixing cup (see Table of Materials). Using a disposable spoon, thoroughly mix the chemical compound for approximately 5 min, or until it has become uniform.</li>
	<li>Place the mold plate with the packing tape over a piece of paper. The paper will catch any potential silicone spill from the mold plate.</li>
	<li>Begin pouring the silicone mixture into each stopper hole, ensuring they are all filled (Figure 2B). Use a rubber squeegee to spread the silicone into each stopper hole (Figure 2C). Remove the leftover silicone mixture from the surface of the mold plate.</li>
	<li>Let the rubber stoppers dry for 4 h. After making sure the stoppers have fully cured (e.g., the silicone mixture has completely dried and hardened), remove the tape from the back of the mold plate (Figure 2D), and then begin pulling the stoppers out of the mold (Figure 2E).</li>
	<li>Remove any excess silicone attached to the stoppers (Figure 2F).</li>
</ol>
3. Balloon tag assembly
<ol>
	<li>Carefully insert the piercing tool (e.g., straight dental pick) into the silicone stopper (Figure 3A) (see Table of Materials). Insert the piercing tool into a 15 G syringe needle and then remove the piercing tool from the silicone stopper, leaving only the 15 G needle inside (Figure 3B). The piercing tool will create a slit inside the silicone stopper without cutting or removing any material.</li>
	<li>Cut a piece of 50 lb. fishing line (see Table of Materials) to a length of 150 mm. Insert the fishing line through the 15 G syringe needle and into the silicone stopper (Figure 3C).
	<ol>
		<li>While carefully holding the stopper and the fishing line together, remove the 15 G syringe needle from the stopper&#39;s body, leaving the fishing line inside the stopper (Figure 3D). Ensure the fishing line lengths are even on both sides of the stopper.</li>
	</ol>
	</li>
	<li>Insert two acid/base-powder-filled capsules into a latex balloon (Figure 3E) (see Table of Materials). Expand the balloon opening using the rubber-band expansion tool (i.e., castration band pliers) and then carefully insert one silicone stopper into the balloon opening (Figure 3F), leaving the fishing line&#39;s two ends outside the balloon.</li>
	<li>Place two O-rings (1.6 mm wide, 8.1 mm ID, see Table of Materials) onto the rubber-band expansion tool and expand them. Insert the neck of the latex balloon through the two expanded O-rings (Figure 3G). Carefully pull the two O-rings away from the rubber-band expansion tool, leaving them tightly wrapped around the balloon&#39;s neck, centered on the stopper (Figure 3H).</li>
</ol>
4. Balloon tag attachment to Sensor Fish caps
<ol>
	<li>Put one end of the fishing line through one of the small holes in the Sensor Fish cap (see Table of Materials) and bring it through the large hole in the center of the cap (Figure 4A).</li>
	<li>Tie the two ends of the fishing line together, leaving about 13 to 26 mm between the top of the cap and the base of the balloon. Use four overhand knots on top of each other when tying the fishing line.</li>
	<li>Leave the extra fishing line attached, as cutting it too close to a knot could potentially cause the knot to come undone (Figure 4B).</li>
	<li>Test the knot by gripping the fishing line on each side of the knot with the fingers and pulling as hard as possible. Be cautious not to pull too close to the balloon, as it could unintentionally tear the fishing line through the rubber stopper.</li>
</ol>

Optimizing Balloon Tag Assembly to Recover Sensor Fish and Live Fish

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<li>Tuononen, E. I., Cooke, S. J., Timusk, E. R., Smokorowski, K. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Extent+of+injury+and+mortality+arising+from+entrainment+of+fish+through+a+Very+Low+Head+hydropower+turbine+in+central+Ontario%2C+Canada%5BTitle%5D)+AND+%22Hydrobiologia%22%5BJournal%5D)">Extent of injury and mortality arising from entrainment of fish through a Very Low Head hydropower turbine in central Ontario, Canada.</a> Hydrobiologia. 849, 407-420 (2020).</li>
<li>Deng, Z., Carlson, T. J., Duncan, J. P., Richmond, M. C., Dauble, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Use+of+an+autonomous+sensor+to+evaluate+the+biological+performance+of+the+advanced+turbine+at+Wanapum+Dam%5BTitle%5D)+AND+%22Journal+of+Renewable+and+Sustainable+Energy%22%5BJournal%5D)">Use of an autonomous sensor to evaluate the biological performance of the advanced turbine at Wanapum Dam.</a> Journal of Renewable and Sustainable Energy. 2, 053104(2010).</li>
<li>Martinez, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Hydraulic+and+biological+characterization+of+a+large+Kaplan+turbine%5BTitle%5D)+AND+%22Renewable+energy%22%5BJournal%5D)">Hydraulic and biological characterization of a large Kaplan turbine.</a> Renewable energy. 131, 240-249 (2019).</li>
<li>Zhiqun Deng,, et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Six-degree-of-freedom+sensor+fish+design+and+instrumentation%5BTitle%5D)+AND+%22%22%5BJournal%5D)">Six-degree-of-freedom sensor fish design and instrumentation.</a> 7, 3399-3415 (2007).</li>
<li>Deng, Z. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Design+and+implementation+of+a+new+autonomous+sensor+fish+to+support+advanced+hydropower+development%5BTitle%5D)+AND+%22Review+of+Scientific+Instruments%22%5BJournal%5D)">Design and implementation of a new autonomous sensor fish to support advanced hydropower development.</a> Review of Scientific Instruments. 85, 115001(2014).</li>
<li>Deng, Y., Jia, Y., Haoran, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Effects+of+ionicity+and+chain+structure+on+the+physicochemical+properties+of+protic+ionic+liquids%5BTitle%5D)+AND+%22AIChE+Journal%22%5BJournal%5D)">Effects of ionicity and chain structure on the physicochemical properties of protic ionic liquids.</a> AIChE Journal. 66 (10), e16982(2020).</li>
<li>Salalila, A., Deng, Z. D., Martinez, J. J., Lu, J., Baumgartner, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Evaluation+of+a+fish-friendly+self-cleaning+horizontal+irrigation+screen+using+autonomous+sensors%5BTitle%5D)+AND+%22Marine+and+Freshwater+Research%22%5BJournal%5D)">Evaluation of a fish-friendly self-cleaning horizontal irrigation screen using autonomous sensors.</a> Marine and Freshwater Research. 70, 1274-1283 (2019).</li>
<li>Martinez, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((In+situ+characterization+of+turbine+hydraulic+environment+to+support+development+of+fish-friendly+hydropower+guidelines+in+the+lower+Mekong+River+region%5BTitle%5D)+AND+%22Ecological+engineering%22%5BJournal%5D)">In situ characterization of turbine hydraulic environment to support development of fish-friendly hydropower guidelines in the lower Mekong River region.</a> Ecological engineering. 133, 88-97 (2019).</li>
<li>Heisey, P. G., Mathur, D., D'Allesandro, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+new+technique+for+assessing+fish+passage+survival+at+hydro+power+stations%5BTitle%5D)+AND+%22International+Atomic+Energy+Agency%22%5BJournal%5D)">A new technique for assessing fish passage survival at hydro power stations.</a> International Atomic Energy Agency. , (1993).</li>
<li>Heisey, P. G., Mathur, D., Rineer, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+reliable+tag-recapture+technique+for+estimating+turbine+passage+survival%3A+application+to+young-of-the-year+American+shad+%28Alosa+sapidissima%29%5BTitle%5D)+AND+%22Canadian+Journal+of+Fisheries+and+Aquatic+Sciences%22%5BJournal%5D)">A reliable tag-recapture technique for estimating turbine passage survival: application to young-of-the-year American shad (Alosa sapidissima).</a> Canadian Journal of Fisheries and Aquatic Sciences. 49 (9), 1826-1834 (1992).</li>
<li>Mathur, D., Heisey, P. G., Euston, E. T., Skalski, J. R., Hays, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Turbine+passage+survival+estimation+for+chinook+salmon+smolts+%28Oncorhynchus+tshawytscha%29+at+a+large+dam+on+the+Columbia+River%5BTitle%5D)+AND+%22Canadian+Journal+of+Fisheries+and+Aquatic+Sciences%22%5BJournal%5D)">Turbine passage survival estimation for chinook salmon smolts (Oncorhynchus tshawytscha) at a large dam on the Columbia River.</a> Canadian Journal of Fisheries and Aquatic Sciences. 53 (3), 542-549 (1996).</li>
<li>Mathur, D., Heisey, P. G., Robinson, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Turbine-passage+mortality+of+juvenile+American+shad+at+a+low-head+hydroelectric+dam%5BTitle%5D)+AND+%22Transactions+of+the+American+Fisheries+Society%22%5BJournal%5D)">Turbine-passage mortality of juvenile American shad at a low-head hydroelectric dam.</a> Transactions of the American Fisheries Society. 123 (1), 108-111 (1994).</li>
<li>Watson, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Safe+passage+of+American+Eels+through+a+novel+hydropower+turbine%5BTitle%5D)+AND+%22Transactions+of+the+American+Fisheries+Society%22%5BJournal%5D)">Safe passage of American Eels through a novel hydropower turbine.</a> Transactions of the American Fisheries Society. 151, 711-724 (2022).</li>
<li>Al-Tabakha, M. oawia M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Influence+of+capsule+shell+composition+on+the+performance+indicators+of+hypromellose+capsule+in+comparison+to+hard+gelatin+capsules%5BTitle%5D)+AND+%22Drug+Development+and+Industrial+Pharmacy%22%5BJournal%5D)">Influence of capsule shell composition on the performance indicators of hypromellose capsule in comparison to hard gelatin capsules.</a> Drug Development and Industrial Pharmacy. 41 (10), 1726-1737 (2015).</li>
<li>Hydropower Vision. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=%22U.S.+Department+of+Energy%22">U.S. Department of Energy</a>. , https://www.energy.gov/eere/water/articles/hydropower-vision-report-full-report (2016).</li>
<li>Duncan, J. oanne P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Physical+and+ecological+evaluation+of+a+fish-friendly+surface+spillway%5BTitle%5D)+AND+%22Ecological+Engineering%22%5BJournal%5D)">Physical and ecological evaluation of a fish-friendly surface spillway.</a> Ecological Engineering. 110, 107-116 (2018).</li>
<li>Trumbo, B. radly A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Improving+hydroturbine+pressures+to+enhance+salmon+passage+survival+and+recovery%5BTitle%5D)+AND+%22Reviews+in+fish+biology+and+fisheries%22%5BJournal%5D)">Improving hydroturbine pressures to enhance salmon passage survival and recovery.</a> Reviews in fish biology and fisheries. 24, 955-965 (2014).</li>
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	</a> (1994).</li>
</ol>

The authors have no conflicts of interest.

This study concluded that three-capsule balloon tags injected with 5 mL of water at 18.3 &#176;C had a slower start inflation time and consistently larger volume compared to two-capsule and four-capsule balloon tags. When the balloon tags were injected with water at 12.7 &#176;C, the average volume was smaller, and the inflation time was longer. The three-capsule begins deflating first, followed by the four-capsule, and lastly the two-capsule. The inflation and deflation periods associated with each water temperature can...

Hydropower is a significant renewable energy resource worldwide. In the United States, hydropower contributes an estimated 38% or 274 TWh of electricity generated from renewable sources1 and has the potential to add approximately 460 TWh per year2. However, as hydropower development increases, concerns about fish injury and mortality during hydraulic passage have become paramount3. Various mechanisms contribute to fish injuries during passage, including rapid decompression (barotrauma), shear stress, turbulence, strikes, cavitation, and grinding4. Although these injury mechanisms may not have an immediate impact on the overall condition of the fish, they can render them more vulnerable to diseases, fungal infections, parasites, and predation5. Additionally, direct physical injuries resulting from collisions with turbines or other hydraulic structures can lead to significant mortality, emphasizing the importance of mitigating these risks in hydropower development.
One of the most common methods for evaluating fish passage conditions is releasing Sensor Fish and live fish through hydraulic structures6,7. The Sensor Fish is an autonomous device designed to study the physical conditions that fish experience during passage through hydraulic structures, including turbines, spillways, and dam bypass alternatives8,9. Equipped with a 3D accelerometer, 3D gyroscope, temperature sensor, and pressure sensor9, the Sensor Fish provides valuable data on fish passage conditions.
Balloon tags, which are self-inflating balloons attached externally to Sensor Fish and live fish, assist in their recovery after passing through hydraulic structures. The balloon tags consist of dissolvable capsules filled with gas-generating chemicals (e.g., oxalic acid and sodium bicarbonate), a silicone stopper, and a fishing line. Prior to deployment, water is injected through the silicone stopper into the balloon. The water dissolves the vegetable-based capsules, triggering a chemical reaction that produces gas&#160;inflating the balloon. In this neutralization reaction, sodium bicarbonate, a weak base, and oxalic acid, a weak acid, react to form carbon dioxide, water, and sodium oxalate10. The chemical reaction is provided below:
2NaHCO3+ H2C2O4 &#8594; 2CO2 + 2H2O + Na2C2O4
The inflated balloon increases the buoyancy of the Sensor Fish and live fish, enabling them to float on&#160;the water surface for easier recovery.
The number of balloon tags required to achieve flotation and facilitate the retrieval of a sample (e.g., Sensor Fish or live fish) may vary based on the volume and mass characteristics of the sample. The duration of balloon tag inflation can be adjusted by injecting water at different temperatures. Colder water will increase the inflation time, while warmer water will decrease it. Balloon tags have been successfully employed in various locations, including the Farmers Screen, a unique horizontal, flat-plate fish and debris screen structure in Hood River, Oregon11, and a Francis turbine at Nam Ngum Dam in the Lao People&#39;s Democratic Republic12. Another commercially available balloon tag example is the Hi-Z Turb&#39;N Tag13,14. The Hi-Z Turb&#39;N Tag allows inflation time to be adjusted between 2 min and 60 min, depending on the injected water temperature13. This technology has been used in fish studies at many field sites, including studies involving Chinook salmon smolts released at Rocky Reach Dam on the Columbia River and juvenile American shad at Hadley Falls Dam on the Connecticut River15,16. Both technologies utilize acid-base&#160;chemical reactions to inflate the balloon tags for recovery.
This method offers cost-effectiveness and simplicity in manufacturing, with an estimated material cost of only $0.50 per balloon. As described here, the manufacturing process is easy to follow, making balloon tag production accessible to anyone.

<table><tbody><tr><td>3D Printed Silicone Stopper Plate</td><td>NA</td><td>NA</td><td></td></tr><tr><td>ARC800 Sensor Fish</td><td>ATS</td><td>NA</td><td></td></tr><tr><td>FDM 3D printer</td><td>NA</td><td>NA</td><td></td></tr><tr><td>Manual Capsule Filler Machine CN-400CL (Size #3)</td><td>Capsulcn</td><td>NA</td><td></td></tr><tr><td>Mold Star 15 SLOW</td><td>Smooth-On</td><td>NA</td><td></td></tr><tr><td>Oil-Resistant Buna-N O-Ring</td><td>McMaster-Carr</td><td>SN: 9262K141</td><td></td></tr><tr><td>Oxalic Acid, 98%, Anhydrous Powder (C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)&amp;nbsp;</td><td>Thermo Scientific&amp;nbsp;</td><td>CAS: 144-62-7</td><td></td></tr><tr><td>Rubber Band Expansion Tool</td><td>iplusmile</td><td>NA</td><td></td></tr><tr><td>Separated Vegetable Cellulose Capsules (Size #3)</td><td>Capsule Connection</td><td>NA</td><td></td></tr><tr><td>Smiley Face YoYo Latex balloon</td><td>YoYo Balloons, Etc.</td><td>NA</td><td></td></tr><tr><td>Sodium Bicarbonate Powder (CHNaO&lt;sub&gt;3&lt;/sub&gt;)&amp;nbsp;</td><td>Sigma</td><td>CAS: 144-55-8</td><td></td></tr><tr><td>Spectra Fiber Braided Fishing Line (50 lbs.)</td><td>Power Pro</td><td>NA</td><td></td></tr></tbody></table>

balloon tag manufacturing technique for sensor fish and live fish recovery

Fish may experience injuries and mortality when they pass through hydraulic conveyances at hydropower dams, even if these conveyances are designed to be fish-friendly, such as downstream bypass systems, modified spillways&#160;and turbines. The main methods used to study fish passage conditions in hydraulic structures involve direct, in situ testing using Sensor Fish technology and live fish. Sensor Fish data helps identify physical stressors and their locations in the fish passage environment, while live fish are assessed for injuries and mortality. Balloon tags, which are self-inflating balloons attached externally to Sensor Fish and live fish, aid in their recovery after passing through hydraulic structures.
This article focuses on the development of balloon tags with varying numbers of dissolvable, vegetable-based capsules containing a mixture of oxalic acid, sodium bicarbonate powders, and water at two different temperatures. Our research determined that balloon tags with three capsules, injected with 5 mL of water at 18.3 &#176;C, consistently achieved the desired balloon volume. These tags had a mean inflation volume of 114 cm3 with a standard deviation of 1.2 cm3. Among the balloon tags injected with water at 18.3 &#176;C, it was observed that the two-capsule balloon tags took the longest time to reach full inflation. In addition, the four-capsule balloon tags demonstrated a faster inflation start time, while the three-capsule balloon tags demonstrated a faster deflation start time. Overall, this approach proves to be effective for validating the performance of new technologies, improving turbine design, and making operational decisions to enhance fish passage conditions. It serves as a valuable tool for research and field evaluations, aiding in the refinement of both the design and operation of hydraulic structures.

A study was conducted to determine the optimal methods for manufacturing balloon tags, focusing on the volume and temperature of water injected into the balloon. The study examined various input parameters, including the inflation start time, full inflation time, deflation start time, and the volume of the balloon at full inflation. The study was conducted at a desk with an ambient temperature of 21 &#176;C.
A total of 360 balloon tags were prepared for the study. The tags were divided into 36...

Watch this Scientific Journal Video about Developing Cost-Effective and Customizable Balloon Tags for Fish Passage Studies at JoVE.com

Author Spotlight: Developing Cost-Effective and Customizable Balloon Tags for Fish Passage Studies 

A protocol is presented for designing and manufacturing balloon tags to recover Sensor Fish and live fish, allowing assessment of their physical condition and biological performance in hydraulic structures. The method optimizes balloon tag performance by considering factors such as balloon volume, inflation/deflation times, component selection, and the characteristics of the injected water.

Balloon Tag Manufacturing Technique for Sensor Fish and Live Fish Recovery

Fish may experience injuries and mortality when they pass through hydraulic conveyances at hydropower dams, even if these conveyances are designed to be ...

balloon-tag-manufacturing-technique-for-sensor-fish-live-fish

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Engineering

1.6K Views.  Pacific Northwest National Laboratory. A protocol is presented for designing and manufacturing balloon tags to recover Sensor Fish and live fish, allowing assessment of their physical condition and biological performance in hydraulic structures. The method optimizes balloon tag performance by considering factors such as balloon volume, inflation/deflation times, component selection, and the characteristics of the injected water.

Video: Author Spotlight: Developing Cost-Effective and Customizable Balloon Tags for Fish Passage Studies 

Synthesis and Characterization of High c-axis ZnO Thin Film by Plasma Enhanced Chemical Vapor Deposition System and its UV Photodetector Application

In this study, zinc oxide (ZnO) thin films with high c-axis (0002) preferential orientation have been successfully and effectively synthesized onto silicon (Si) substrates via different synthesized temperatures by using plasma enhanced chemical vapor deposition (PECVD) system. The effects of different synthesized temperatures on the crystal structure, surface morphologies and optical properties have been investigated. The X-ray diffraction (XRD) patterns indicated that the intensity of (0002) diffraction peak became stronger with increasing synthesized temperature until 400 oC. The diffraction intensity of (0002) peak gradually became weaker accompanying with appearance of (10-10) diffraction peak as the synthesized temperature up to excess of 400 oC. The RT photoluminescence (PL) spectra exhibited a strong near-band-edge (NBE) emission observed at around 375 nm and a negligible deep-level (DL) emission located at around 575 nm under high c-axis ZnO thin films. Field emission scanning electron microscopy (FE-SEM) images revealed the homogeneous surface and with small grain size distribution. The ZnO thin films have also been synthesized onto glass substrates under the same parameters for measuring the transmittance.
For the purpose of ultraviolet (UV) photodetector application, the interdigitated platinum (Pt) thin film (thickness ~100 nm) fabricated via conventional optical lithography process and radio frequency (RF) magnetron sputtering. In order to reach Ohmic contact, the device was annealed in argon circumstances at 450 oC by rapid thermal annealing (RTA) system for 10 min. After the systematic measurements, the current-voltage (I-V) curve of photo and dark current and time-dependent photocurrent response results exhibited a good responsivity and reliability, indicating that the high c-axis ZnO thin film is a suitable sensing layer for UV photodetector application.

We offered a method to directly synthesize high c-axis (0002) ZnO thin film by plasma enhanced chemical vapor deposition. The as-synthesized ZnO thin film combined with Pt interdigitated electrode was used as sensing layer for ultraviolet photodetector, showing a high performance through a combination of its good responsivity and reliability.

In this study, zinc oxide (ZnO) thin films with high c-axis (0002) preferential orientation have been successfully and effectively synthesized onto ...

How to Build a Vacuum Spring-transport Package for Spinning Rotor Gauges

The spinning rotor gauge (SRG) is a high-vacuum gauge often used as a secondary or transfer standard for vacuum pressures in the range of 1.0 x 10-4 Pa to 1.0 Pa. In this application, the SRGs are frequently transported to laboratories for calibration. Events can occur during transportation that change the rotor surface conditions, thus changing the calibration factor. To assure calibration stability, a spring-transport mechanism is often used to immobilize the rotor and keep it under vacuum during transport. It is also important to transport the spring-transport mechanism using packaging designed to minimize the risk of damage during shipping. In this manuscript, a detailed description is given on how to build a robust spring-transport mechanism and shipping container. Together these form a spring-transport package. The spring-transport package design was tested using drop-tests and the performance was found to be excellent. The present spring-transport mechanism design keeps the rotor immobilized when experiencing shocks of several hundred g (g = 9.8 m/sec2 and is the acceleration due to gravity), while the shipping container assures that the mechanism will not experience shocks greater than about 100 g during common shipping mishaps (as defined by industry standards).

Here we describe how to build a robust spring-transport mechanism for a spinning rotor gauge. This device securely immobilizes the rotor and keeps it under vacuum during transportation. We also describe packaging that minimizes the risk of damage during transport. Tests show our design works for typical shocks during transport.

The spinning rotor gauge (SRG) is a high-vacuum gauge often used as a secondary or transfer standard for vacuum pressures in the range of 1.0 x 10-4 Pa to ...

Basic Methods for the Study of Reproductive Ecology of Fish in Aquaria

Captive-rearing observations are valuable for revealing aspects of fish behavior and ecology when continuous field investigations are impossible. Here, a series of basic techniques are described to enable observations of the reproductive behavior of a wild-caught gobiid fish, as a model, kept in an aquarium. The method focuses on three steps: collection, transport, and observations of reproductive ecology of a substrate spawner. Essential aspects of live fish collection and transport are (1) preventing injury to the fish, and (2) careful acclimation to the aquarium. Preventing harm through injuries such as scratches or a sudden change of water pressure is imperative when collecting live fish, as any physical damage is likely to negatively affect the survival and later behavior of the fish. Careful acclimation to aquaria decreases the incidence death and mitigates the shock of transport. Observations during captive rearing include (1) the identification of individual fish and (2) monitoring spawned eggs without negative effects to the fish or eggs, thereby enabling detailed investigation of the study species' reproductive ecology. The subcutaneous injection of a visible implant elastomer (VIE) tag is a precise method for the subsequent identification of individual fish, and it can be used with a wide size range of fish, with minimal influence on their survival and behavior. If the study species is a substrate spawner that deposits adhesive eggs, an artificial nest site constructed from polyvinyl chloride (PVC) pipe with the addition of a removable waterproof sheet will facilitate counting and monitoring the eggs, lessening the investigator's influence on the nest-holding and egg-guarding behavior of the fish. Although this basic method entails techniques that are seldom mentioned in detail in research articles, they are fundamental for undertaking experiments that require the captive rearing of a wild fish.

A series of basic methods to enable the study of the reproductive ecology of fish kept in aquaria are described. These are useful protocols for collecting fish using SCUBA, transporting live fish, and observing the reproductive behavior of wild-caught fish kept in aquaria.

Captive-rearing observations are valuable for revealing aspects of fish behavior and ecology when continuous field investigations are impossible. Here, a ...

Behavior

Implantation of a New Micro Acoustic Tag in Juvenile Pacific Lamprey and American Eel

Juvenile Pacific Lamprey and American eels were used for laboratory evaluations to determine potential effects from tag implantation. Telemetry technology has been identified as a way to obtain more detailed information on movement and behavior across a broader spatial scale than is possible with other known technology. The purpose of this method is to provide a detailed step by step instruction on tag implantation for both lampreys and eel. For laboratory studies using actively migrating juvenile Pacific Lamprey (120-160 mm), we determined that the presence of the tag did not alter the swimming ability between tagged and untagged Individuals or have any significant tag loss (&lt;3%). Similar results were determined during laboratory testing of Yellow phase American Eels (113-175 mm). No mortality occurred during a 38-day holding period and there was minimal tag loss (3.8%). The presence of the tag did not have any significant effect on the swimming ability or survival of tagged eels compared to untagged controls and there was minimal tag loss.

This article illustrates the procedure for implanting a micro acoustic tag in juvenile Pacific Lamprey and American Eel. Our application is based on laboratory trials, which indicate that acoustic tags can be successfully implanted with no apparent effects on swimming ability or survival and minimal tag loss.

Juvenile Pacific Lamprey and American eels were used for laboratory evaluations to determine potential effects from tag implantation. Telemetry technology ...

Environment

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from individual neurons are critical for understanding how neural circuits function under natural conditions. Traditionally, these recordings have been performed 'blind', meaning the identity of the recorded cell is unknown at the start of the recording. Cellular identity can be subsequently determined via intracellular1, juxtacellular2 or loose-patch3 iontophoresis of dye, but these recordings cannot be pre-targeted to specific neurons in regions with functionally heterogeneous cell types. Fluorescent proteins can be expressed in a cell-type specific manner permitting visually-guided single-cell electrophysiology4-6. However, there are many model systems for which these genetic tools are not available. Even in genetically accessible model systems, the desired promoter may be unknown or genetically homogenous neurons may have varying projection patterns. Similarly, viral vectors have been used to label specific subgroups of projection neurons7, but use of this method is limited by toxicity and lack of trans-synaptic specificity. Thus, additional techniques that offer specific pre-visualization to record from identified single neurons in vivo are needed. Pre-visualization of the target neuron is particularly useful for challenging recording conditions, for which classical single-cell recordings are often prohibitively difficult8-11. The novel technique described in this paper uses retrograde transport of a fluorescent dye applied using tungsten needles to rapidly and selectively label a specific subset of cells within a particular brain region based on their unique axonal projections, thereby providing a visual cue to obtain targeted electrophysiological recordings from identified neurons in an intact circuit within a vertebrate CNS.
The most significant novel advancement of our method is the use of fluorescent labeling to target specific cell types in a non-genetically accessible model system. Weakly electric fish are an excellent model system for studying neural circuits in awake, behaving animals12. We utilized this technique to study sensory processing by "small cells" in the anterior exterolateral nucleus (ELa) of weakly electric mormyrid fish. "Small cells" are hypothesized to be time comparator neurons important for detecting submillisecond differences in the arrival times of presynaptic spikes13. However, anatomical features such as dense myelin, engulfing synapses, and small cell bodies have made it extremely difficult to record from these cells using traditional methods11, 14. Here we demonstrate that our novel method selectively labels these cells in 28% of preparations, allowing for reliable, robust recordings and characterization of responses to electrosensory stimulation.

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Retrograde transport of fluorescent dye labels a sub-population of neurons based on anatomical projection. Labeled axons can be visually targeted in vivo, permitting extracellular recording from identified axons. This technique facilitates recording when neurons cannot be labeled through genetic manipulation or are difficult to isolate using 'blind' in vivo approaches.

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from ...

Neuroscience

Long-term Behavioral Tracking of Freely Swimming Weakly Electric Fish

Long-term behavioral tracking can capture and quantify natural animal behaviors, including those occurring infrequently. Behaviors such as exploration and social interactions can be best studied by observing unrestrained, freely behaving animals. Weakly electric fish (WEF) display readily observable exploratory and social behaviors by emitting electric organ discharge (EOD). Here, we describe three effective techniques to synchronously measure the EOD, body position, and posture of a free-swimming WEF for an extended period of time. First, we describe the construction of an experimental tank inside of an isolation chamber designed to block external sources of sensory stimuli such as light, sound, and vibration. The aquarium was partitioned to accommodate four test specimens, and automated gates remotely control the animals&#39; access to the central arena. Second, we describe a precise and reliable real-time EOD timing measurement method from freely swimming WEF. Signal distortions caused by the animal&#39;s body movements are corrected by spatial averaging and temporal processing stages. Third, we describe an underwater near-infrared imaging setup to observe unperturbed nocturnal animal behaviors. Infrared light pulses were used to synchronize the timing between the video and the physiological signal over a long recording duration. Our automated tracking software measures the animal&#39;s body position and posture reliably in an aquatic scene. In combination, these techniques enable long term observation of spontaneous behavior of freely swimming weakly electric fish in a reliable and precise manner. We believe our method can be similarly applied to the study of other aquatic animals by relating their physiological signals with exploratory or social behaviors.

We describe a set of techniques for studying spontaneous behavior of freely swimming weakly electric fish over an extended period of time, by synchronously measuring the animal&#39;s electric organ discharge timing, body position and posture both accurately and reliably in a specially designed aquarium tank inside a sensory isolation chamber.

Long-term behavioral tracking can capture and quantify natural animal behaviors, including those occurring infrequently. Behaviors such as exploration and ...

Handling and Tagging Techniques for Implanting Juvenile American Shad with a New Acoustic Microtransmitter

The use of telemetry techniques to better understand the behavior and survival of juvenile American shad (Alosa sapidissima), as they migrate through hydropower systems, has been challenging because shad are widely known to be particularly sensitive to handling. The goal of this study was to develop a tagging protocol using a new, acoustic micro transmitter that minimizes the detrimental effects of the tagging process and maximizes post-tagging survival of juvenile American shad. Limiting out-of-water handling and the use of brackish saltwater (7.5 parts per thousand) before and after tagging improved survival for shad tagged using a simple pectoral implantation method. This protocol provides a detailed, step-by-step procedure for tagging juvenile shad with acoustic transmitters. Fish tagged using this procedure and held in the laboratory for 60 days had an 81.5% survival rate, compared to 70% for their untagged counterparts. The successful tagging and handling practices developed in this study could be applied to field telemetry studies of juvenile shad and other sensitive species.

This article provides a detailed procedure for optimal handling practices and implantation of an acoustic micro transmitter into juvenile American shad. The results of our laboratory study suggest that these tagging techniques could be implemented in field studies of juvenile American shad with a high probability of survival.

The use of telemetry techniques to better understand the behavior and survival of juvenile American shad (Alosa sapidissima), as they migrate through ...

Swimming Performance Assessment in Fishes

Swimming performance tests of fish have been integral to studies of muscle energetics, swimming mechanics, gas exchange, cardiac physiology, disease, pollution, hypoxia and temperature. This paper describes a flexible protocol to assess fish swimming performance using equipment in which water velocity can be controlled. The protocol involves one to several stepped increases in flow speed that are intended to cause fish to fatigue. Step speeds and their duration can be set to capture swimming abilities of different physiological and ecological relevance. Most frequently step size is set to determine critical swimming velocity (Ucrit), which is intended to capture maximum sustained swimming ability. Traditionally this test has consisted of approximately ten steps each of 20 min duration. However, steps of shorter duration (e.g. 1 min) are increasingly being utilized to capture acceleration ability or burst swimming performance. Regardless of step size, swimming tests can be repeated over time to gauge individual variation and recovery ability. Endpoints related to swimming such as measures of metabolic rate, fin use, ventilation rate, and of behavior, such as the distance between schooling fish, are often included before, during and after swimming tests. Given the diversity of fish species, the number of unexplored research questions, and the importance of many species to global ecology and economic health, studies of fish swimming performance will remain popular and invaluable for the foreseeable future.

The lives of the majority of fish are predicated on swimming. This protocol describes techniques for capturing a range of swimming modes available to individual and schooling fish, and includes metrics associated with swimming physiology and behaviour.

Swimming performance tests of fish have been integral to studies of muscle energetics, swimming mechanics, gas exchange, cardiac physiology, disease, ...

Biology

Using an Automated 3D-tracking System to Record Individual and Shoals of Adult Zebrafish

Like many aquatic animals, zebrafish (Danio rerio) moves in a 3D space. It is thus preferable to use a 3D recording system to study its behavior. The presented automatic video tracking system accomplishes this by using a mirror system and a calibration procedure that corrects for the considerable error introduced by the transition of light from water to air. With this system it is possible to record both single and groups of adult zebrafish. Before use, the system has to be calibrated. The system consists of three modules: Recording, Path Reconstruction, and Data Processing. The step-by-step protocols for calibration and using the three modules are presented. Depending on the experimental setup, the system can be used for testing neophobia, white aversion, social cohesion, motor impairments, novel object exploration etc. It is especially promising as a first-step tool to study the effects of drugs or mutations on basic behavioral patterns. The system provides information about vertical and horizontal distribution of the zebrafish, about the xyz-components of kinematic parameters (such as locomotion, velocity, acceleration, and turning angle) and it provides the data necessary to calculate parameters for social cohesions when testing shoals.

The use of a 3D automatic video system that can track individual and groups of zebrafish is described. As application example we explore the effects of the NMDA-receptor antagonist MK-801 on shoals of zebrafish.

Like many aquatic animals, zebrafish (Danio rerio) moves in a 3D space. It is thus preferable to use a 3D recording system to study its behavior. The ...

Wireless Electrophysiological Recording of Neurons by Movable Tetrodes in Freely Swimming Fish

The neural mechanisms governing fish behavior remain mostly unknown, although fish constitute the majority of all vertebrates. The ability to record brain activity from freely moving fish would advance research on the neural basis of fish behavior considerably. Moreover, precise control of the recording location in the brain is critical to studying coordinated neural activity across regions in fish brain. Here, we present a technique that records wirelessly from the brain of freely swimming fish while controlling for the depth of the recording location. The system is based on a neural logger associated with a novel water-compatible implant that can adjust the recording location by microdrive-controlled tetrodes. The capabilities of the system are illustrated through recordings from the telencephalon of goldfish.

A novel wireless technique for recording extracellular neural signals from the brain of freely swimming goldfish is presented. The recording device is composed of two tetrodes, a microdrive, a neural data logger, and a waterproof case. All parts are custom-made except for the data logger and its connector.

The neural mechanisms governing fish behavior remain mostly unknown, although fish constitute the majority of all vertebrates. The ability to record brain ...

Balloon Tag Manufacturing Technique for Sensor Fish and Live Fish Recovery

Summary

Explore More Videos

Synthesis and Characterization of High c-axis ZnO Thin Film by Plasma Enhanced Chemical Vapor Deposition System and its UV Photodetector Application

How to Build a Vacuum Spring-transport Package for Spinning Rotor Gauges

Basic Methods for the Study of Reproductive Ecology of Fish in Aquaria

Implantation of a New Micro Acoustic Tag in Juvenile Pacific Lamprey and American Eel

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Long-term Behavioral Tracking of Freely Swimming Weakly Electric Fish

Handling and Tagging Techniques for Implanting Juvenile American Shad with a New Acoustic Microtransmitter

Swimming Performance Assessment in Fishes

Using an Automated 3D-tracking System to Record Individual and Shoals of Adult Zebrafish

Wireless Electrophysiological Recording of Neurons by Movable Tetrodes in Freely Swimming Fish