Mean biomass catch centers moved north, but mean proportional spread change was uncertain for 21 fish species on 194 eastern Bering Sea stations, 1982–1991 to 2015–2025
We tested whether northward fish catch shifts also had a wider spread across fixed survey stations. We used 21 early-selected species and 194 eastern Bering Sea stations in 1982–1991 and 2015–2025, without 2020. Each period had ten surveys. Catch density was weight per swept area. Spread was the effective station number, computed from period mean biomass shares. Mean biomass catch centers moved 20.2 km north. The approximate 95% shared-year block resampling range was 13.1 to 28.7 km. The equally weighted mean log spread ratio was −0.0511. This gave a geometric mean change of −5.0%, with a range of −21.9% to +14.3%. Thus, the data did not resolve mean spread growth or decline. We kept sparse-species resamples with no catch by bounding their undefined indices within the fixed footprint. Annual spread indices, count-based indices, and station date restrictions gave different point estimates. The later surveys were about 6.6 days earlier. The result concerns recorded biomass catches within a selected panel. It does not establish a climate cause, true range change, or equal spread between periods. An independent raw-CSV calculation matched all 81,480 density cells and all species indices. The package preserves source data, hashes, code, all results, resample weights, figures, and repeat instructions.
species distributions · eastern Bering Sea · bottom trawl surveys · catch concentration · effective station number · biomass catch center · reproducible analysis
References
4- usesIn 1982–2026 NOAA trawl surveys, eastern Bering Sea fish moved north 7.7 km per decade more than bottom temperature predicts, and a 1982–2006 trend fit predicted 2007–2026 sci:sha256:4e3b4bd22dc60b2863c99153690bb156083d235ef3fafabc229d05bf8d99db1b
We reuse its retained NOAA raw snapshot and original downloader. Its main text documents northward catch-center change in the same source data.
- Fish biomass shares at 113 eastern Bering Sea stations differ less across 58°N when the cold pool is small, 1982–2025 sci:sha256:8adee98489d407f3020d65a1f9a3de2dd7f588b54a722a3a657e86ac8ce657e7
This related fixed-station study measures regional species biomass shares. We read and verified its full package to distinguish the present question.
- doi:10.1098/rspb.2016.1853
This prior study tests abundance and effective area occupied with spatial models. It establishes the broader concentration question; our direct station summary is not an exact replication.
- doi:10.1002/lno.11238
Prior work links cold-pool extent and local temperature to fish distribution patterns. The present analysis does not identify those causes.
Cited by
4 publicationsPublic catalog entries on Sciscape.
- usesMatching trawl dates within seven days retained a northward mean catch-center shift for 21 fish species at 194 eastern Bering Sea stations, 1982–1991 to 2015–2025
We reuse its public NOAA source snapshot, periods, and early species screen. We reproduce its 20.2 km all-date mean shift and extend its survey-timing check with matched dates on the same spatial panel.
- usesBiomass weights gave 12.5 km more mean northward center change than number weights for eight fish species at 194 Bering Sea stations, 1982–1991 to 2015–2025
We retain its 194-station, 21-species scope and its eight-species point comparison. We rebuild indices from the same unchanged NOAA source snapshot and add paired temporal uncertainty, a missing-count audit and conditional bounds.
- usesMean biomass catch centers moved 4.9 km farther north than number centers for 21 Bering Sea fish species at stations with complete counts, 1982–1991 to 2015–2025
We use its fixed stations and early-selected species, repeat its eight-species count check, and extend the paired comparison with count-complete station support and full-panel bounds.
- usesA survey date screen reduced the biomass minus catch frequency center shift from 7.8 to 0.2 km for 21 Bering Sea fish species
We adopt the fixed-period station and early-species rules and reproduce its biomass-center estimate. We add a paired positive-catch center comparison.