Header background

Blog

resources, reviews and more

Output Goal Tables for Backpacks, Towbarges, and Boats

In the movie The Santa Clause, the elves were inundating Santa with new technologies aimed at keeping him safe from extreme conditions.  In response, Santa wanted to know “but what if I fall off the roof?”  In other words, forget for now the advanced gizmos; falling of the roof is the most important and basic issue for his work.  Well, maybe that’s a bit true about our list of blogs.  I think they are well done and address important matters.  Taken together, this list is pretty comprehensive.  That said, in talking with many biologists, a major initial concern is having straightforward guidance for making suitable volt and amp settings given conditions (e.g., water conductivity).   Here’s a brief blog that builds upon and applies information from other blogs to provide example voltage and current output goal tables.  These charts are generated for sampling fish assemblages using common electrofishing gear types.  They are meant as guidelines for setting controls as opposed to strict instructions.

These tables are constructed based on these conditions,

  • a “fish catching” waveform is used to sampling assemblages (e.g., pulsed direct current, square wave, 60 – 120 pps, 20 – 40% duty cycle);
  • limited electrode configurations of typical resistances;
  • fish conductivity of 115 µS/cm; and
  • the power transfer model is appropriate.

Threshold voltage and amperage estimates are derived from field work in various classes, unpublished data from several sources (in particular, see Table 2 in the blog “Final Electrofishing Field Blog in the Series” by Jan Dean; http://electrofishing.net/2018/01/06/final-electrofishing-field-blog-in-the-series/), and a published source (Burkhardt, R.W.and S Gutreuter. 1995. Improving electrofishing catch consistency by standardizing power. North American Journal of Fisheries Management 15:375-381).

 

Procedure at the sampling site,

-measure ambient water conductivity (or specific conductivity and water temperature and convert to specific [see blogs on water conductivity and meters]);

-deploy electrodes in “fishing” fashion within typical habitat conditions; for backpacks, we suggest deploying electrodes as you would while sampling in about 1 – 1.5′ depth;

-consult the goal table;

-standardize by volts or amps;

-if you are using amperage, then adjust voltage until the current goal is reached as indicated on your gear’s peak ammeter;

-if you are using voltage, adjust voltage until the voltage goal is reached as indicated on your gear’s peak volt meter;

-if you have time to run a trial test, go outside but near your sample area and assess subjectively your electrofishing success; if unsatisfactory, adjust settings

-record ambient conductivity, threshold voltage or amperage used (preferably both outputs)

-optionally, record the major reaction of fishes (escape, inhibited swimming, attraction, immobilization)

-optionally, record your assessment of the quality of the sampling, such as “successful” or “unsuccessful”

 

A big point is that these tables may not be accurate enough for your particular equipment or sample sites.  Try them and adjust as needed.  We’d appreciate feedback on your experiences using these tables or your output goal tables.  Please reply to alan_temple@fws.gov

Please note that these values are peak not average.  Volt settings and metering on electrofishing equipment nearly always peak.  However, there are average ammeters are on some models as GPP and Type VI control boxes, among others.

One more thing about these charts.  Amperage is the best output to use for standardization (see recent blogs by Jan Dean).  Using current as the output goal allows broader application to different electrode types.  However, in low conductivity water, or when using low power units as backpacks, voltage may be a better choice to use instead of current.

To assist you in modifying these tables with different conductivity values, or if you have your own threshold values, a link to EF Goal Power Excel file is here EF Goal Power 2015

or you can download the Electrofishing App on the electrofishing.net homepage.

A link to a Word document copy of this blog is here: Output Goal Tables for Backpacks Towbarges Boats

 

Example Backpack Output Goals

Waveform:         PDC (fish catching settings, e.g., 60 pps, 25% duty cycle)

Electrodes:         Ring anode, rattail cathode

R100:                     275 Ohms

Fish Cond.:          115 µS/cm

 

Water Conductivity (Ambient)

Applied Voltage Goal (Peak)

Applied Amperage Goal (Peak)

50

394

0.71

75

303

0.82

100

257

0.93

125

230

1.04

150

211

1.15

175

198

1.25

200

188

1.36

225

181

1.47

250

175

1.58

275

170

1.69

300

165

1.80

325

162

1.90

350

159

2.01

375

156

2.12

400

154

2.23

425

152

2.34

450

150

2.44

475

148

2.55

500

147

2.66

525

146

2.77

550

145

2.88

575

143

2.98

600

142

3.09

625

142

3.20

650

141

3.31

675

140

3.42

700

139

3.53

725

138

3.63

750

138

3.74

775

137

3.85

800

137

3.96

825

136

4.07

850

136

4.17

875

135

4.28

900

135

4.39

925

134

4.50

950

134

4.61

975

134

4.71

1000

133

4.82

 

 

 

Example Tow-barge Output Goal Table (1 anode)

Waveform:         PDC (fish catching settings, e.g., 60 pps, 25% duty cycle)

Anode:                 One Ring

Cathode:             Plate on bottom of barge

R100:                     147 Ohms with one anode

Fish Cond.:          115 µS/cm

 

Water Conductivity (Ambient)

Applied Voltage Goal (Peak)

Applied Amperage Goal (Peak)

 

50

543

1.8

75

417

2.1

100

354

2.4

125

316

2.7

150

291

3.0

175

273

3.2

200

259

3.5

225

249

3.8

250

240

4.1

275

233

4.4

300

228

4.6

325

223

4.9

350

219

5.2

375

215

5.5

400

212

5.8

425

209

6.0

450

207

6.3

475

204

6.6

500

202

6.9

525

201

7.2

550

199

7.4

575

197

7.7

600

196

8.0

625

195

8.3

650

194

8.6

675

193

8.8

700

192

9.1

725

191

9.4

750

190

9.7

775

189

10.0

800

188

10.2

825

187

10.5

850

187

10.8

875

186

11.1

900

186

11.4

925

185

11.6

950

184

11.9

975

184

12.2

1000

183

12.5

 

 

 

Example Tow-barge Output Goal Table (2 anode)

Waveform:         PDC (fish catching settings, e.g., 60 pps, 25% duty cycle)

Anode:                 Two Rings

Cathode:             Plate on bottom of barge

R100:                     87 Ohms with two anodes

Fish Cond.:          115 µS/cm

 

Water Conductivity (Ambient)

Applied Voltage Goal (Peak)

Applied Amperage Goal (Peak)

 

50

642

3.68

75

493

4.24

100

418

4.80

125

373

5.36

150

343

5.92

175

322

6.47

200

306

7.03

225

294

7.59

250

284

8.15

275

276

8.71

300

269

9.27

325

263

9.82

350

258

10.38

375

254

10.94

400

250

11.50

425

247

12.06

450

244

12.61

475

241

13.17

500

239

13.73

525

237

14.29

550

235

14.85

575

233

15.40

600

232

15.96

625

230

16.52

650

229

17.08

675

228

17.64

700

226

18.20

725

225

18.75

750

224

19.31

775

223

19.87

800

222

20.43

825

222

20.99

850

221

21.54

875

220

22.10

900

219

22.66

925

219

23.22

950

218

23.78

975

217

24.33

1000

217

24.89

 

 

 

Example 2-boom Boat Output Goal Table

Waveform:         PDC (fish catching settings, e.g., 60 pps, 25% duty cycle)

Anode:                 Two booms Wisconsin rings 4 – 6 droppers (amperage goals can be used for                                                  two spheres fully immersed)

Cathode:             Boat hull (16 – 18’ length)

R100:                     35 Ohms

Fish Cond.:          115 µS/cm

 

Water Conductivity (Ambient)

Applied Voltage Goal (Peak)

Applied Amperage Goal (Peak)

 

50

502

7.17

75

385

8.26

100

327

9.35

125

292

10.43

150

269

11.52

175

252

12.61

200

239

13.70

225

230

14.78

250

222

15.87

275

216

16.96

300

210

18.04

325

206

19.13

350

202

20.22

375

199

21.30

400

196

22.39

425

193

23.48

450

191

24.57

475

189

25.65

500

187

26.74

525

185

27.83

550

184

28.91

575

182

30.00

600

181

31.09

625

180

32.17

650

179

33.26

675

178

34.35

700

177

35.43

725

176

36.52

750

175

37.61

775

175

38.70

800

174

39.78

825

173

40.87

850

173

41.96

875

172

43.04

900

171

44.13

925

171

45.22

950

170

46.30

975

170

47.39

1000

169

48.48

 

 

 

 

 

 

 

Footer background

Drop us a line

Yay! Message sent. Error! Please validate your fields.
Clear
© 2015 Thread One Page. Imagery: Tom Rayner, Alan temple, Richard Pearson, Paul Godfrey, Roger Scott, John Rayner.