Area weighting gave uncertain changes in annual sea temperature slopes of catch latitude in four US trawl samples, 1982-2019

We tested whether survey-area weights change the link between annual sea surface temperature and catch latitude. We used fixed strata and persistent taxon labels in Bering Sea and Northeast US fall surveys in 1982-2000 and 2001-2019. First-difference models gave paired slope changes of +2.11, +0.39, -0.98 and -3.44 km north per C. All four adjusted bootstrap intervals included zero. A constant catch field also gave no clear temperature link to survey allocation. A three-month temperature window gave a negative change in early Northeast records, but this did not repeat in the other samples. These results do not establish negligible observation bias or a climate cause. Short records, selected taxa, coarse surface temperature and catchability limit inference. The package gives code, derived evidence, raw-file checks, hashes and offline reproduction instructions.

species distributions · observation bias · survey weighting · sea surface temperature · trawl survey · null result