Biodiverse coralligenous and coral habitats in the northwestern province of Balıkesir’s Ayvalık nature park, one of Türkiye’s most unique underwater ecosystems, are increasingly at risk due to environmental stress and a lack of protection, marine scientists have warned.
A two-year study led by Nur Eda Topçu Eryalçın from Istanbul University’s Faculty of Aquatic Sciences examined coralligenous habitats — complex, reef-like structures formed by calcifying algae — across nine sites at depths of 30 to 42 meters.
Researchers identified 82 species, confirming the area’s rich biodiversity, but found that conservation measures are falling short.
“These habitats function like underwater rainforests,” Eryalçın said. “They provide shelter, breeding grounds, and nursery areas for many species, while also acting as carbon sinks.”
Despite its protected status, the marine area faces multiple human-induced pressures. Fishing activities, anchoring, diving tourism and pollution continue to degrade the ecosystem.
In several locations, sediment levels exceeded healthy thresholds, smothering marine life and weakening habitat structure.
The study highlights that gorgonian corals, soft corals that form tree-like structures, play a crucial role in maintaining biodiversity.
“Areas with dense gorgonian formations host greater species diversity and experience less sediment stress,” Eryalçın noted. Such formations are rare in the eastern Mediterranean, making Ayvalık a particularly important site.
However, researchers say the lack of a clear and actively enforced marine management plan undermines conservation efforts.
“On land, protection is strict and effective. At sea, governance is unclear, and enforcement is limited. Legal protection alone is not enough,” Eryalçın said, pointing to European marine reserves as examples of more structured management.
