Fig. 1
From: Insights on long-term ecosystem changes from stable isotopes in historical squid beaks
Sampling locations and time series of Gonatus fabricii and Todarodes sagittatus. Contemporary time series represents 2016, 2017 and 2019 in G. fabricii (reused from Golikov et al. 2022 [54]) and 2016–2018 and 2023 in T. sagittatus; rationale behind the pooling is provided in Methods. Geographic objects used in the text are marked on the map