Coral fracture by derelict fishing gear affects the sustainability of the marginal reefs of Ecuador

Hard coral coverage contributes to increasing the structural complexity of coral reefs, provides biological resources and drives biological and ecological interactions among reef organisms. Declines in the structural complexity and coral diversity of tropical reefs, due to the influence of anthropogenic activities, have been reported around the world in recent decades; however, coral reefs on the continental coast of Ecuador have been poorly studied. From September 2017 to April 2018, the method of permanent belt transects and quadrats was used to assess the status of coral (percentage of live, dead and fractured coral) to determine the contribution of derelict fishing gear to the process of coral fracture, which causes loss of structural complexity on two marginal coral-rocky reefs in the central coast of Manabi-Ecuador: Perpetuo Socorro and Ureles. Three geomorphological zones [crest (5-7 m depth), slope (7-10 m depth) and bottom (10-13 m depth)] were assessed. Results show that the crest zone in Ureles reef was highly affected by the entanglement of nets compared with Perpetuo Socorro, and identify derelict fishing gear as a key driver in the process of the fracturing and fragmentation of coral. Seasonal and site-associated factors also had a significant effect on the structural complexity of the reef studied. Destruction of coral in the crest zones drastically affects invertebrate and fish communities. We recommend a periodical assessment to measure the loss of structural complexity plus the implementation of a recovery program for the reefs studied that involves the education, active participation and collaboration of artisanal fishermen, governmental organizations and universities.