Breakwaters impact marine turtle nesting activity

Coastal erosion is a significant environmental issue, exacerbated by human activities and rising sea levels due to climate change. One of the measures developed to counteract erosion worldwide is the use of breakwaters: structures designed to protect coastlines from the force of waves. While effective, these structures can negatively impact natural habitats, including those of marine turtles. There are concerns that breakwaters may obstruct both female turtles trying to reach beaches to nest and hatchlings attempting to reach the open sea. However, information on these impacts is limited and often confounded by other environmental factors. This study aims to assess the possible impact of breakwaters on marine turtle nesting activity by taking advantage of a particular circumstance at a major nesting site (Chrysochou Bay, Cyprus), where nesting activity was monitored before (2015–2017) and after (2019–2021) the installation of 10 breakwaters. A total of 5405 nests were recorded over these periods. Despite a general increase in nest numbers in the rest of Chrysochou Bay, a marked decrease was observed landward of the breakwaters. Our findings provide conclusive evidence that emerged breakwaters impact marine turtle nesting activity.