DOI: 10.5061/dryad.8pk0p2nnv
title: Signature of climate-induced changes in seafood species served in restaurants

description: Climate change is causing shifts in biogeography of marine species,
 towards higher latitude, deeper waters, or following local temperature
 gradients. Such species distribution changes are affecting global
 fisheries through increasing the dominance of warmer-water preferred
 species as ocean temperature increases. Previous modeling analyses
 projected that climate-induced changes in seafood availability would
 affect the entire seafood chain. However, observed climate impacts on
 seafood retailers and consumers have rarely been demonstrated. Seafood
 restaurants usually rely on the supply of locally caught species, and thus
 the impacts of changing catches on the food they serve, and consequently
 on their diners, may be reflected in their menus. In this study, 362
 restaurant menus from Vancouver, British Columbia, Canada, were collated
 and analyzed over four different time periods (1880–1960, 1961–1980,
 1981–1996, and 2019–2021). Moreover, 148 present-day menus from two other
 cities north (Anchorage, AK, USA) and south (Los Angeles, CA, USA) of
 Vancouver were also collected. An index, herein called Mean Temperature of
 Restaurant Seafood (MTRS), was calculated from the average temperature
 preference of the species of seafood identified in the menus for each time
 period or location. Overall, the MTRS of menus from Vancouver increased
 from 10.7 ± 0.7 °C to 13.8 ± 1.0 °C (95% confidence intervals) between
 1888–1960 and 2019–2021. Present-day MTRS was among the highest in Los
 Angeles (16.5 ± 1.7 °C) and lowest in Anchorage (9.6 ± 1.0 °C). The
 temporal and spatial variations in MTRS are significantly related to
 observed patterns of average sea surface temperature and the Mean
 Temperature of the Catch. This suggests that restaurant menus may be used
 as a complementary information source regarding changes in marine
 ecosystems and fisheries and the seafood sector’s responses to these
 changes. This study also highlights the value of using unconventional
 information sources and their applications in the detection of climate
 impacts on oceans and their dependent human communities.
description: Copies of publicly available restaurant menus from Vancouver (Canada), Los Angeles (USA) and Anchorage (USA) dated since the 19<sup>th</sup> century were collected from the Internet and museum archives. Archives of menus from restaurants in Vancouver collected from The University of British Columbia (UBC) library, Victoria Island University library, the City of Vancouver Archives, and the Museum of Vancouver Archives were surveyed (N = 228). Only menus that have specified a year of publication or a range of years were recorded. The menus were categorized into three different time periods: 1888-1960, 1961-1980, and 1981-1996. In addition, a total of 134 present day (2019 -2021) menus from Vancouver, 72 menus from Los Angeles menus, and 76 from Anchorage were collected online using the restaurants’ websites or other websites where restaurant menus were made available publicly, including TripAdvisor(https://www.tripadvisor.ca/), KAYAK (https://www.ca.kayak.com/), and OpenTable (https://www.opentable.ca/). The name of the restaurant, year and the seafood specified in the name of the dish or food ingredients were recorded if the information was available on the menus.