Species distribution modelling of benthic amphipod crustaceans in the deep North Atlantic under climate change.

Climate-driven changes in environmental factors influence vulnerable North Atlantic deep-sea (> 200 m depth) benthic ecosystems, leading to species range shifts, habitat loss, or extinctions. Amphipod Crustaceans play a crucial role in deep-sea ecosystems, contributing to food web stability and nutrient cycling. However, their large-scale distributions on species level remain poorly understood. In this study, we created species distribution models (SDMs) of 55 North Atlantic deep-sea amphipods in the present day, medium-term (2050-2060) and long-term (2090-2100) future, utilising best, likely, and worst shared socioeconomic pathways (SSPs) scenarios. The results show species-specific responses to climate change. Over half of the amphipod species expand their habitat in some scenarios, while others face habitat loss. Contrasting habitat likeliness is represented by species of the same genera. Additionally, some species experience habitat shifts, particularly northward and towards the Greenlandic coast. Glacial meltwater influx and increased nutrient availability could enhance habitat suitability in certain regions. Poleward shifts are theorised to be temperature-driven. These changes influence biodiversity, food web dynamics, and ecosystem stability. This study provides a baseline for assessing future changes in North Atlantic amphipod distributions. The findings emphasise the need for conservation strategies and taxonomy in predicting ecosystem responses to climate change.