Lipophrys pholis is larger, grows faster and is in better condition in protected than in unprotected rocky shores

1. Intertidal fish are a key component of littoral food webs, contributing to the diets of birds and commercial fish species. Ascertaining their growth and condition can therefore help understand the health status of local communities.2. Lipophrys pholis is a fish of the rocky intertidal with a wide distribution throughout the North-eastern Atlantic (NE Atlantic) that has been recommended for use as an indicator in the environmental biomonitoring of marine ecosystems. However, it is unclear yet if this species is sensitive to the reserve effect.3. In this study, the size, growth and body condition of specimens caught at protected and unprotected rocky shores of two contrasting marine provinces of the NE Atlantic were analysed to address whether 4. L. pholis is sensitive to the reserve effect. L. pholis were larger, grew faster in weight and were in better condition in the protected shores of both provinces. A faster growth rate was observed in the populations of the warmer province.5. Inshore waters of unprotected sites in the Northern European Seas sampled in this study have recently been incorporated into a protected area. Thus, these results can help assess the success of the marine conservation programme and the time L. pholis needs to improve its population's health at these shores.6. Regulating access to shores to avoid trampling and harvesting is a protection measure that can help enhance the health and conservation of L. pholis populations.