Tides of Memory: Monitoring and Preserving Lagos’ Underwater Heritage

The coastal city of Lagos, located in the southwestern Algarve (Portugal), possesses a rich underwater cultural heritage shaped by over two millennia of maritime activity. Its sheltered bay, fluvial-marine interfaces, and geomorphological features have supported successive periods of navigation, trade, and coastal defence—from Roman anchorage points to early modern shipbuilding and World War maritime incidents. Despite this, many underwater sites remain insufficiently documented and unprotected.

This presentation explores the scientific and civic strategy implemented by Neptune Search, a non-profit association founded in 2021 to safeguard Lagos’ submerged archaeological heritage through non-invasive conservation methodologies, environmental monitoring, and community engagement. Drawing from interdisciplinary research, the association is developing predictive models of corrosion and degradation based on seasonal sampling of physical-chemical parameters and visual assessments of reference artefacts in situ. Sampling is conducted across georeferenced stations during full tidal cycles, with analysis guided by established conservation frameworks (e.g., Pearson, Hamilton, MacLeod).

Archaeological interpretation is grounded in past mapping campaigns and typological identification of over 300 artefacts, including 107 anchors. Current efforts focus on validating and reassessing these sites, many of which are threatened by climate change, anthropic pressure caused by tourism, seabed disturbance, and insufficient public policy. In parallel, the association is working to democratize access to this heritage through outreach with schools, maritime-tourism agents, and local stakeholders, emphasizing the social relevance of underwater heritage.

By aligning geoarchaeology, conservation science, and participatory heritage practices, Tides of Memory presents a model for balancing technical rigour with public responsibility—advancing the sustainable protection of underwater heritage in Mediterranean-Atlantic contexts. Additionally, there is evidence of healed trauma—particularly cranial trauma—among some of the individuals buried at Apollonia, though the relationship between migration and skeletal evidence of violence remains ambiguous, indicating how methods, such as isotope analysis and dental morphometrics, may shed light on whether migrants were more likely to assimilation or be victims of violence. Understanding more about whether migrants contributed significantly to Appolonia’s population would also provide new insight regarding migration to one of the largest and most vital colonies on the western Black Sea Coast during Classical Antiquity.