Description
Calculate a supplied survey net's depth span.
Fish records distinguish morphometric length definitions, relative image scales, annulus labels, detection times and survey-effort geometry. A supplied conversion factor need not apply across species or sizes. Local labels, ratios and nominal swept areas organize observations without identifying a fish, determining age or estimating abundance.
Calculate a supplied survey net's depth span.
When to use this tool
Use Fish Survey Net Depth Span when you already have topDepth, bottomDepth and need to calculate a supplied survey net's depth span.
How to use the tool and how it works
- Enter topDepth, bottomDepth. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read depthSpan. Use the output convention below.
Require topDepth>=0 and bottomDepth>=top; return bottom-top.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| topDepth | Top Depth | Required. Finite number; minimum 0. |
| bottomDepth | Bottom Depth | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| depthSpan | bottomDepth-topDepth under a nonnegative downward depth convention. | Required. Finite number. |
{
"input": {
"topDepth": 2,
"bottomDepth": 8
},
"output": {
"depthSpan": 6
}
}Limitations and assumptions
- Units and depth reference must match; no actual net geometry, survey coverage or safe deployment is verified.
- 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
Inspect original specimens, images, reference definitions and survey logs when verifying observations. Use a complete species-appropriate measurement or population method for age, abundance or condition questions; local scales and effort terms preserve only their stated basis.
References
Similar or alternative tools
- Fish Net Soak Time Unit
Convert a supplied net-soak duration to fixed-length hours.
- Fish Tag Detection Gap
Measure a nonnegative gap between supplied fish-tag detections.