Major Breakthrough in Underwater Heritage: Discoveries in the Bay of Algeciras

Researchers in Spain have recently unveiled a remarkable discovery that could reshape our understanding of underwater heritage. A total of 34 sunken ships, dating from the 5th to the 20th century, were found in the Bay of Algeciras. This significant finding not only sheds light on historical maritime activities but also raises awareness about the threats posed by port development and climate change to these invaluable sites.

The Herakles Project: Unveiling the Unknown

The groundbreaking discoveries stem from the Herakles project, which ran from May 2020 to March 2023 under the guidance of researchers Felipe Cerezo Andreo and Alicia Arévalo González from the Universidad de Cádiz. Over the course of the project, a staggering 151 new archaeological sites were identified, many of which had not been documented in scientific literature before. These findings include not only ships but also various underwater structures spanning different historical periods.

Among the newly discovered vessels, the Puente Mayorga IV, a late 18th-century gunboat, stands out as the first to utilize modern invasive research methods. The project also revealed artifacts from the Punic period, the Roman era, the Middle Ages, and the modern era. Notably, the oldest ship found, Timoncillo I, dates back to the 5th century BCE, showcasing the rich maritime history of the region.

Historical Significance of the Bay of Algeciras

The Bay of Algeciras and the Strait of Gibraltar have long been pivotal in European maritime history. This strategic region serves as a vital link between the Mediterranean Sea and the Atlantic Ocean, facilitating trade and military routes across continents. Despite extensive archaeological research on land, the underwater realm of the bay remained largely unexplored until recently. Prior to 2019, only four underwater sites were known, with just one—the 17th-century shipwreck Ballanera—considered a significant shipwreck.

The recent discoveries not only enrich our understanding of maritime history but also highlight the diverse range of vessels and artifacts that have shaped the region’s past.

Modern Threats to Underwater Heritage

While the discoveries are exciting, researchers caution that the bay’s underwater heritage faces numerous threats. Activities related to port development, industrialization, and tourism pose significant risks. Changes in marine currents and the proliferation of invasive species, such as the alga Rugulopteryx okamurae, are accelerating the degradation of archaeological sites. Even with formal protection through archaeological easement status, many finds have already suffered damage.

To combat these threats, modern geophysical methods and digital documentation techniques were employed during the Herakles project. These approaches allowed for efficient data collection while minimizing disruption to the marine environment. As a result, researchers not only discovered new artifacts but also assessed their preservation status. Alarmingly, 56% of the finds are currently in satisfactory condition, while 44% require urgent conservation measures.

Addressing Gaps in Knowledge

Despite the impressive findings, significant gaps remain in our understanding of shipwrecks, particularly from the 16th and 17th centuries. The loss of the Gibraltar archive after British occupation has contributed to this knowledge gap. Furthermore, most studies have focused on coastal areas, leaving less than a quarter of the entire bay explored. Deepwater zones are particularly vulnerable, as anchors and chains from large vessels can cause irreversible damage to historical heritage.

Several sites require special attention, including Timoncillo I (5th century BCE), Guadarranque III (1st century BCE), Rinconcillo (medieval period), and various Puente Mayorga vessels from the 17th to 19th centuries. All these sites are located at depths of less than 10 meters and are at risk due to environmental changes.

Growing Interest in Underwater Archaeology

In recent years, there has been a surge of interest in underwater archaeology across Spain and other Mediterranean countries. Notable discoveries include the remains of a Roman merchant ship near Cartagena in 2024 and several medieval anchors off the coast of Málaga in 2025. These findings underscore the importance of a systematic approach to studying and preserving maritime heritage.

New technologies not only facilitate the discovery of previously unknown sites but also enable ongoing monitoring of their condition. This is particularly crucial in light of climate change and the increasing volume of maritime traffic, which pose ongoing challenges to the preservation of underwater heritage.

The discoveries in the Bay of Algeciras represent a significant leap forward in our understanding of maritime history and the urgent need to protect these underwater treasures. As researchers continue to explore and document these sites, the hope is that greater awareness and proactive measures will be taken to safeguard our shared underwater heritage for future generations.