Ocean Acidification

Highlights

• CMIP6 models can quantify future climate threats to UHC sites in Northern Patagonia.
• Projected ∼2.1 °C warming by 2100 will accelerate corrosion and wood-boring activity.
• Ocean pH drop (4.5%) will accelerate corrosion and destabilise calcareous concretions.
• Salinity changes remain negligible across all projected climate change scenarios.
• UHC managers profit locally by integrating in situ data with climate model outputs.

Abstract

Climate change presents a significant and increasing threat to Underwater Cultural Heritage (UCH) worldwide. To better understand the risks that this entails, this study examines the archaeological wreck site of the schooner Emma in the Nuevo Gulf, Northern Patagonia, Argentina. It addresses a geographic research gap and the complex interaction of multiple environmental stressors. Using the information from state-of-the-art climate models, we assess the potential impacts in the near and far future of specific environmental parameters including temperature, salinity, dissolved oxygen, and pH, all relevant at the wreck site’s location, and identified to play a driving role in its conservation.

Results consistently demonstrate a clear trend toward a warmer and more acidic marine environment, with the greatest changes projected under the highest-emission scenario. In that case, sea temperature at the wreck site’s depth increases by approximately 14.5% (∼2.1 °C) by the end of this century, which would accelerate corrosion rates of metals and intensify the activity of wood-boring organisms. In parallel, acidification is projected to increase with pH decreasing by approximately 4.5% (∼0.36 units), contributing to the destabilisation of protective concretions and the intensification of metal corrosion. While dissolved oxygen is projected to decrease (∼3.92%) and salinity remains nearly unchanged, the synergy of warming and acidification suggests the wreck of the Emma will face a more aggressive environment by 2100. The methodology integrates a characterisation of the site’s materials, the main deterioration processes involved and the surrounding environmental context. This study also provides UCH managers with a climate-projection-based assessment of future slow-onset climate-related marine environmental pressures and the likely conservation implications that will inform the development of conservation and monitoring strategies for the Emma and other shipwrecks in the Nuevo Gulf and adjacent coastal areas.

Meccia V. L., Sardella A., Elkin D., Murray C., Grosso M., Frère J., Gutiérrez G., Underwood C. & Bonazza A., 2026. Assessing the projected impacts of climate change on underwater cultural heritage in the Nuevo Gulf, Argentina. Journal of Cultural Heritage 82: 61-72. doi: 10.1016/j.culher.2026.09.001. Article.