Climate Change Impacts and Future Risk on UK Seahorse Species, Short-Snouted Hippocampus hippocampus and Long-Snouted Hippocampus guttulatus

Abstract

For the two European seahorse species, the short-snouted Hippocampus hippocampus and the long-snouted Hippocampus guttulatus, there are knowledge gaps that need further research. These research gaps become increasingly pressing under climate change, where uncertainty in how coastal ecosystems will change is compounded by uncertainty in how these seahorses will respond to changing pressures. Under climate change, these species could experience northward range shifts, expanding their range in United Kingdom (UK) coastal waters, potentially requiring the UK to take a leadership role in European seahorse conservation in the future. This review aims to synthesise current scientific research to provide an overview of how these seahorse species are likely to respond to climate change. Using the most recent Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6), predictions for future change along with the likelihood and severity of seahorse species response are combined to provide a confidence ranking in the climate change risk for these species in the UK. When considering individual factors, such as sea surface temperature, these seahorse species show some resilience, but climate change is the cumulative impact of multiple stressors, which existing research has not been able to capture. Overall, further research on seahorse response to environmental variables is needed across Europe.