Description
Multiply positive netLength, netHeight, hours, and activeFraction in (0, 1] for areaTimeEffort.
Fisheries sampling effort can be expressed as net-hours, area-hours, or another declared survey unit. Exclusions and partial operation change the counted effort without automatically correcting catchability or sample bias.
Multiply positive netLength, netHeight, hours, and activeFraction in (0, 1] for areaTimeEffort.
When to use this tool
Use Gillnet Catch Per Area Hour Term when you need a reproducible effort component under a supplied survey convention.
How to use the tool and how it works
- Enter fish, netLength, netHeight, hours, activeFraction. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read areaTimeEffort, catchPerAreaHour. Use the output convention below.
Multiply positive netLength, netHeight, hours, and activeFraction in (0, 1] for areaTimeEffort. Divide nonnegative integer fish by that effort.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| fish | Fish | Required. Safe integer; minimum 0. |
| netLength | Net Length | Required. Finite number; strictly above 0. |
| netHeight | Net Height | Required. Finite number; strictly above 0. |
| hours | Hours | Required. Finite number; strictly above 0. |
| activeFraction | Active Fraction | Required. Finite number; maximum 1; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| areaTimeEffort | Area Time Effort | Required. Finite number. |
| catchPerAreaHour | Catch Per Area Hour | Required. Finite number. |
{
"input": {
"fish": 40,
"netLength": 20,
"netHeight": 2,
"hours": 5,
"activeFraction": 0.5
},
"output": {
"areaTimeEffort": 100,
"catchPerAreaHour": 0.4
}
}Limitations and assumptions
- Lengths use one unit and output is fish per area-hour; this is nominal net effort without selectivity, habitat, or catchability adjustment.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use the complete survey design and suitable detection or catchability methods when estimating population abundance.
References
Similar or alternative tools
- Net Effort Time Area Term
Multiply nonnegative netArea by hours and functioningFraction in [0, 1] for areaHours.
- Fish School Transect Density Term
Compute positive transectLength times stripWidth as sampledArea.