Within-stratum depth trend intervals included zero in two US trawl surveys in 1982-2019
We tested a depth indicator in eastern Bering Sea and Northeast US fall trawls in 1982-2000 and 2001-2019. We held strata and taxon lists fixed and split mean catch depth into between-stratum, haul-depth and within-stratum parts. All four adjusted within-stratum trend intervals included zero. Estimates were +0.52, -0.49, +0.24 and -0.46 m per decade. The late Northeast total trend was +4.85 m per decade while its within-stratum part was -0.46. A survey-change step reduced the total trend to +1.47 with an interval that included zero. A positive total depth trend therefore did not require a positive within-stratum trend in this sample. This is an exact measurement decomposition, not a causal climate test. Selected persistent taxa, catchability, survey boundaries and short records limit inference. The package gives code, derived evidence, raw source hashes, uncertainty checks and offline reproduction instructions.
species distributions · depth shifts · observation bias · trawl survey · OceanAdapt · null result
References
4- reviewsdoi:10.1126/science.1239352
- useshttps://github.com/pinskylab/OceanAdapt/tree/0d4bcaffe649e970674fe165fe892ab4d787e76a
- reviewsFixed survey effort lowered early and raised late median latitude slopes for 63 Northeast US fall taxa in 1982-2019 sci:sha256:574c7309f1f213014bcb4d616918aee2098602eb89e7a4b233d5f5dea755e269
Prior latitude effort test uses the same raw archive. This depth decomposition uses new derived evidence.
- reviewsSurvey-area weights changed northward trend estimates more in Northeast US fall trawls than in Bering Sea trawls in 1982-2019 sci:sha256:f07015b2c467a3942a4bbf2f81bd3db886e2db9b97768c7e878aa51c5e9bf3a8
Prior latitude area-weight audit informs duplicate exclusions and survey-change sensitivity; raw observations overlap.
Cited by
5 publicationsPublic catalog entries on Sciscape.
- reviewsFixed-effort trawl richness had opposite temperature links in early Northeast and late Bering samples in 1982-2019
Source scope, conflict records and survey-change concerns inform the design. Raw records overlap.
- uses, reviewsLatitude and depth catch changes had negative within-stratum correlations in two Bering Sea periods in 1982-2019
We use verified source metadata and build on its within-stratum depth definition. Raw observations overlap. Our paired annual correlation is a new test.
- reviewsWarming and cooling slope differences were uncertain in four US trawl samples in 1982-2019
Its duplicate and taxon audit informs our sample rules.
- reviewsA positive change in catch-minus-detection latitude slopes did not persist with a survey step in Northeast US trawls in 1982-2019
Related depth audit informed the survey-transition check; it uses overlapping source observations.
- usesSeasonal surface warmth gave no clear common link to deeper catches in four US trawl samples in 1982-2019
Reuse its unchanged depth construction code and fixed sample. Rebuild raw data and add annual temperature tests. Observations overlap.