Tapping the ecological and economic potential of shipwrecks in Sri Lanka

The wreck of HMS Hermes recognised among the top 100 wrecks in the world and top 10 wreck dive sites in Asia

Colourful marine life surrounding the wreck of SS Sagaing 7819

In a groundbreaking exercise, marine archaeologists, researchers and several Government and private agencies including universities come together to document the biodiversity of Sri Lanka’s shipwrecks and make information accessible through the National Shipwreck Database of Sri Lanka (NSDSL). The effort will add value to the shipwreck diving experience in Sri Lanka while giving muscle to the country’s marine tourism promotion strategy

By Randima Attygalle

Marine Tourism has changed its face today with many island-nations exploring ‘unconventional marine tourism products’. The world at large is revisiting the untapped opportunities and resources of the ocean. Shipwreck-diving is an effective strategy to promote Sri Lanka’s marine tourism, fetching around $ 200 to 400 million annually. As a coveted trade route the strategic position of the island has enabled a sizable cluster of wrecks. None of our other regional counterparts, including India, the Maldives, Malaysia, Thailand or Indonesia have the number or the variety of shipwrecks as we do – a bonus which needs to be capitalised on.

Where biodiversity and heritage meet

Shipwreck sites are nationally important as part of marine heritage and as biodiversity hotspots. They have multiple benefits. Serving as artificial reefs for marine life, they also attract international divers. The effort to document the biodiversity of Sri Lanka’s documented shipwrecks by a group of marine archaeologists, researchers and several Government and private agencies including universities is a groundbreaking exercise. 

The challenging process of collating the biodiversity of recorded shipwreck sites is also a means of fusing ‘biodiversity’ and ‘heritage’ arms together, says Maritime Archaeologist Rasika Muthucumarana. Representing the Maritime Archaeology Unit (MAU) of the Central Cultural Fund (CCF) which gives leadership to the collaborative venture, Muthucumarana is one of the lead researchers in the effort. “Up to now shipwreck sites have been studied and documented by marine biologists and maritime archaeologists in two different compartments. With plans underway to collate the biodiversity reports of identified wrecks here at home, to the National Shipwreck Database of Sri Lanka (NSDSL), these two schools would come on board on a common platform. The exercise adds value to the shipwreck diving experience in Sri Lanka, offering a more holistic understanding of the wrecks,” he says.

The National Shipwreck Database of Sri Lanka

Preliminary surveys on the biological diversity of shipwrecks around the country commenced in 2018 with SS Sagaing, an iron wreck purposely sunk by the Sri Lanka Navy. The purpose of the survey was to document the recruitment and colonisation of marine organisms on the vessel’s surface after two months of re-sinking the ship in the Trincomalee harbour. This was the foundation for forging a new relationship between marine archaeology, marine biology, and information technology.

The National Shipwreck Database of Sri Lanka (NSDSL) was launched in 2021 as an online database, providing details of known shipwrecks in Sri Lankan waters and preserving their heritage value for future generations. The database (https://nsd.ccf.gov.lk) uses multimedia formats to present information in an interactive manner. The data is collected by the MAU of the CCF, with contributions from other sources such as, professional divers and research institutes. The technical support for the database comes from Eng. Anuradha Piyadasa, Director, Institute for Archaeology & Heritage Studies (IAHS). Information on 108 shipwrecks and six aircraft are available at present in the database. 

Sri Lanka – a shipwreck hotspot

The economic value of a shipwreck site is enormous, although as an island-nation, we still have not fully realised it, observes Muthucumarana. “The Maldives for instance, offers sophisticated tourism products today, but they are not a wreck hot-spot as we. Given the size of our island, we have wrecks in close proximity, an advantage that even India doesn’t have despite its huge coastal belt,” he added.

Throwing light on the role of shipwreck in marine habitats, Blue Resources Trust Coral Reef Program Director Nishan Perera says: “Shipwrecks provide hard substrate for benthic and sessile (immobile) marine invertebrates. This in turn can create a small but biologically diverse ecosystem. Wrecks also provide shelter for fish with complex habitats that include ledges, caves, etc. More complex habitats tend to increase fish diversity. Wrecks also act as fish aggregation devices (FADs) especially, when they are located in sandy areas away from reefs, similar to an oasis in a desert.”

Perera, a marine biologist with a background in coral reef ecology, tropical fisheries and marine protected area management, is among the lead contributors to the exercise of collating the biodiversity of shipwrecks. He says, “Although shipwrecks and other artificial structures are not coral reefs and cannot fully replicate the ecological processes of natural habitats and are not a substitute for natural habitats, they do play a useful role as marine habitats. Their effectiveness, however, would depend on their location and oceanographic conditions such as currents, depth, water quality, etc.”

Ecological and economic benefits

Understanding the biological value as well as commercial value (fisheries, dive tourism etc.) is important when taking decisions on the removal or salvage of wrecks, the marine biologist points out. “In addition, understanding recruitment patterns (how animals colonise a habitat) and what occupies them is important in designing any future artificial reef programs – whether sinking ships or building artificial structures with other materials.”

Perera says, there is very little quantitative data in the country, such as, what species, density, etc. related to benthic and fish communities on wrecks. “Through our work at Blue Resources Trust, we have started documenting fish species on wrecks off Colombo and Pasikudah at a qualitative level (what species are present). Last year we initiated quantitative surveys of three wrecks off Colombo and compared the data with three reef sites in Colombo to understand similarities and differences between natural and artificial habitats and figure out the reasons for any changes.”

Explaining the process of documenting the biodiversity of a wreck, Perera says surveys are done using transects. Traditionally, a diver will visually assess species and numbers within a defined area and a defined time. One of the challenges with many wrecks in this process is that they are located a bit deep which restricts the time a diver can spend underwater, explains Perera. “This means you can do only limited work in a day which increases costs with more days required. Also there are safety concerns so that more experienced divers are needed. Visual census requires divers with a high degree of skill to identify species underwater. For our surveys we trialled a diver operated video method which allows faster data collection in the field. The video is then analysed using software and a data analyst. This allows validation of data and reduces errors. But this method also has its own negatives so there is no perfect method.”

Adding biological and ecological data to the NSDSL will add another layer of information for the wrecks, especially, for more recent wrecks that may not carry much archaeological significance, but provide many ecological benefits as well as economic benefits, observes Perera. He cites the example of the Thermopylae Sierra wreck in Colombo which is important for local fisheries and dive tourism and has been featured in international dive magazines as an iconic dive site. “Many people may be unaware that most underwater segments of the documentary ‘Wild Sri Lanka’ were filmed on shipwrecks in Colombo. Sri Lanka has the potential to develop as a wreck diving destination. However, we need to promote this as a specific identity and also protect the attractions. Additionally, creating baseline data would help with time series comparisons to see how a wreck matures over time as diversity tends to increase with time.”

Conserving the ecosystem

In terms of biodiversity and thereby a boon to the fisheries industry, the wealth of shipwrecks in Sri Lanka play a crucial role as artificial reefs, notes Dharshana Jayawardena, underwater explorer and author of ‘Ghosts of the Deep – shipwrecks of Sri Lanka & Diving to maritime history.’ 

“In an otherwise barren ocean, shipwrecks are a resplendent oasis of life. Once sunk, a wreck gradually transforms into a marine habitat, first by inhabitation of various coral species and secondly, through settlement of other marine life.” The number of species that can be found in a shipwreck can be staggering, adds Jayawardena. “As such, they are rich grounds for fishing and a multitude of fishermen rely on shipwrecks for their day’s catch. In addition, the spillover effect of marine life from these shipwrecks to nearby reefs or wrecks perpetuates the spread of marine life further,” he says.

The National Shipwreck Database is a significant and necessary tool in formulating the marine tourism strategy for Sri Lanka, observes the underwater explorer who goes on to note that relevant government agencies involved in tourism promotion and development can now access all the information about shipwrecks in the country and pick those that can be developed for tourism. “For example, a World War II diving itinerary can be created by using the wrecks of the ships sunk in World War II, during the Japanese attack on Ceylon in 1942. This resulted in several shipwrecks, including the flagship HMS Hermes, the world’s first purpose-designed aircraft carrier. The HMS Hermes is already recognised among the top 100 wrecks in the world and top 10 wreck dive sites in Asia.”

As much as we promote these shipwrecks as revenue generating assets, we also need to protect this wealth. “Today, illegal forms of fishing such as spearfishing, blast-fishing are decimating the natural ecosystems around these wrecks. The NSDSL has a key role to play here too. Relevant agencies such as the Departments of Fisheries and Wildlife can utilise this data to come up with a management plan and combat illegal forms of fishing in the country that are destroying our future potential,” concludes Jayawardena. 

Pic credit – Rasika Muthucumarana and Dharshana Jayawardena