Advancements in ichthyoplankton taxonomy in the large marine ecosystems of Alaska: 1979–2021

As fisheries management strategies in the United States become more holistic by including ecosystem data, there is a need to refine taxonomic expertise within large marine ecosystems (LMEs) to support ecosystem management and investigate climate-mediated processes. In this study, we provide an update on the taxonomic resolution of the early life history stages of fishes in the LMEs of Alaska, a highly productive but rapidly changing region, explore patterns of species richness by LME, and contribute new illustrations. The Ecosystems and Fisheries-Oceanography Coordinated Investigations (EcoFI) program at the Alaska Fisheries Science Center (AFSC) collected ichthyoplankton samples for 3 LMEs during 1972–2021: the Gulf of Alaska (1972–2021), the southeastern Bering Sea (1979–2019), and the U.S. Arctic (2004–2019). Through these sampling efforts, we can now identify the eggs of 127 species and the larvae of 353 species, representing 26% and 71%, respectively, of the described species of Alaska. Species richness reached an asymptote in the Gulf of Alaska by the late 1980s but increased in the Bering Sea until 2013, whereas no pattern was present in the Arctic. Illustrations are contributed for 8 species, many of which are early juveniles, which is a potential recruitment bottleneck. The ability to identify individuals with high taxonomic resolution across life history transitions is critical for generating early life history indicators that support sustainable fisheries management.