Prolonged exposure to elevated temperature leads to severe thermal stress in the broad-nosed pipefish, Syngnathus typhle

Changes in water temperature may have profound effects on physiology, metabolism, and fish behaviour. However, much of the existing research is based on relatively short-term experiments. In the context of climate change, where water temperatures are increasing seasonally, and the frequency and duration of extreme heatwave events are rising, incorporating longer exposure periods will provide a better understanding of the potential effects of warming on marine species. Here, we tested the effects of prolonged exposure to elevated temperature on broad-nosed pipefish, Syngnathus typhle. Fish were exposed to ambient (20 degrees C) and high (24 degrees C) temperatures for a four-month period, during which activity levels, growth and survival were monitored. Fish under high temperature were less active when compared to fish under ambient temperature, grew less, and survival was dramatically decreased. These findings have significant implications for the long-term sustainability of broad-nosed pipefish populations, as the species may struggle to adapt to future ocean conditions.