Fishers in the Northeast began noticing an unusual shift in the summer of 2023. Some familiar catches, including shortfin and longfin squid, declined, while cold-water species such as mackerel bounced back from years of decline. A new study published in the Journal of Geophysical Research: Oceans finds that a pulse of cold, fresh water brought unusually cold conditions to the region, disrupting fisheries from New England to the Mid-Atlantic.