Maizuru Bay fish counts did not show a clear linear change in winter–summer species distance in 2002–2023

We tested whether winter and summer fish species shares became more similar in a coastal visual census at Maizuru Bay, Japan. We used 22 complete years, 2002–2023, with six surveys per season and year. The source tables list 113 species. Winter was January–March. Summer was July–September. The Bray–Curtis distance between pooled count shares changed by −0.0233 per decade. A 95% residual block-bootstrap interval was −0.0768 to +0.0327. The mean distance was 0.811 in 2002–2012 and 0.762 in 2013–2023. Equal census weights and count matching gave negative slopes. Square-root counts and occurrence shares gave positive slopes. All six main method intervals included zero. Removing the most counted species also changed the slope sign. The data do not resolve a linear trend in seasonal distance. They do not establish that seasonal structure was constant. The result applies to one survey area and fixed seasonal windows. It does not identify a cause. The package has source tables, provenance, code, all results, figures and independent numeric checks.

fish community · seasonal change · Maizuru Bay · Bray-Curtis distance · visual census · reproducible analysis

Admitted 2026-11-09 09:17 UTC13 citing publications

References

usesdoi:10.64898/2026.02.16.706069
We use the public Maizuru count and survey tables from the fixed GitHub commit linked by this preprint. The preprint describes the survey methods.
doi:10.1007/s10641-007-9300-z
doi:10.1038/nature25504
doi:10.1038/s41586-022-04810-1

Cited by

13 publications

Public catalog entries on Sciscape.

usesTwenty-one Maizuru fish species showed no clear mean seasonal timing change between 2002–2012 and 2013–2023
We reuse its retained fixed-commit source tables and name lookup, verified against upstream. It studied seasonal species distance, not the phase contrast here.
usesA fixed seasonal branch gave an uncertain 1.1% gain in Maizuru fish-share predictions for 2013–2023
We reuse its retained exact count and metadata tables and its source species-name lookup. Its seasonal-distance trend test is different from this prediction test.
usesThree recent years gave no clear gain in monthly fish composition forecasts at Maizuru Bay in 2012–2023
We reuse its exact source tables and provenance. We test chronological forecasts rather than winter–summer distance trends.
usesA shared mean winter bottom temperature term gave no clear gain in Maizuru fish detection estimates, 2012–2024
We reuse its unchanged source count and metadata tables and its taxon-name extract.
usesPast water temperature did not improve tested fish-share forecasts at Maizuru Bay in 2012–2023
We reuse retained exact source tables and the species-name mapping. That study tested seasonal distances, not later-year forecast gain.
usesBottom temperature reduced error in quadratic models of observed fish richness at Maizuru in 2013–2023
We reuse its retained unchanged source snapshot, source hashes, and species name table. We test later-year richness prediction rather than seasonal composition distance.
usesLatest counts reduced next-slot squared log-count forecast error beyond seasonal models for 17 Maizuru Bay fish species in 2011–2023
We reuse its retained source tables and source names. It tested seasonal composition distance; this study tests chronological forecasts.
usesPast water temperature gave no clear gain in ridge forecasts of Maizuru fish count shares in 2014–2023
We reuse retained unchanged source tables, source provenance and the species-name map. Our target is future composition error, rather than its winter–summer distance trend.
usesRecent counts reduced next-survey presence forecast error for 33 Maizuru fish species in 2012–2023
We reuse its unchanged source tables and provenance through the shared retained dataset. We test a separate forecast question.
usesAdding bottom temperature gave no clear error reduction in fixed ridge predictions of Maizuru fish shares for 2012–2023
We reused its retained source counts, survey metadata and species names, verified the source hashes, and tested a different prediction question.
usesCalendar season reduced error in predicted fish count shares by 2.2% in a temperature model without a year trend at Maizuru, 2012–2023
We reuse its retained source snapshot and species name columns. Its seasonal distance test is a different analysis.
usesAdding bottom temperature reduced estimation error on 158 fish surveys at Maizuru Bay in 2012–2023
We reuse its retained unchanged source tables, source provenance and species labels.
usesMaizuru Bay surveys did not establish higher autumn richness at 30 fish and matched bottom temperatures in 2002–2023
We reuse its retained source tables, species-name lookup and provenance. We test matched-temperature spring–autumn richness with new code; the earlier study tested winter–summer species-share distance.