How Many Fish Are Caught Before Maturity? Inconclusive on Current Data

The earlier finding from 8,790 logged lengths compared with external length-at-maturity values, reporting the immature share of marine native catches, is withdrawn. In the 2026-09-26 snapshot there are 11,611 statistics-eligible length records (2,505 measured with a ruler), but whether the external reference values match the site's records in region and length type has not been verified, and there is no effort or unsuccessful-trip record, so the immature share is currently inconclusive.

Inconclusive: the region and length type of the external length-at-maturity values have not been checked against the site's length records, so no immature share is computed.

Reviewed 2026-09-30 | Data 2025-01-01 to 2026-09-25

The earlier version compared 8,790 logged lengths of 14 species from 2025-01-01 to 2026-09-04 with external length-at-maturity values, and reported the immature share of marine native catches and whether anglers release by size. Those conclusions are withdrawn.

There are three reasons. The external reference values come from different regions and studies, and their length type (total, fork or standard length) may not match the site's records; that match has not been verified. Under the current integrity rules the usable length records differ, and the earlier release-by-size model has not been rebuilt on them. There is no effort or unsuccessful-trip record, and fish released without a record are invisible, so the full catch composition cannot be seen.

So how many fish are caught before maturity is currently inconclusive. This is neither a finding that most are mature nor that most are immature.

Of 14,424 eligible catches from 2025-01-01 to 2026-09-25, 11,611 have a statistics-eligible length, from 2,991 anglers; 2,505 were measured with a ruler.

Of these, 8,305 were released, 3,306 kept and 0 unrecorded.

The earlier reference table lists length at maturity for 14 species; 14 of them have usable length records here, 3,681 in total (1,594 for species the table marks as marine native and 2,087 for freshwater non-native).

Length-at-maturity values verified species by species, ideally from Taiwanese or nearby populations and using the same length type as the site.

More ruler- or image-measured lengths with an estimate of measurement error, hypotheses written down before looking at the data, then a recomputed immature share and release relationship.

Source: a read-only point-in-time snapshot taken 2026-09-26 (38,040 catch records), recomputed offline with no production reads or writes; the length-at-maturity table is the one the earlier study used, kept in the repository.

Records count when the current record, species identity and context rules all pass and both upload and verified capture time are on or before 2026-09-25; shrimp-fishing, managed-pond and non-fish records are excluded. Lengths count only when the record marks them as statistics-eligible.