2 min read
Sep 15, 2025
Melissa Morgan is a marine research officer advancing ocean conservation in the Ascension Island Marine Protected Area with an instrument named after the park. Ocean Diagnostics’ automated depth sampler, Ascension, is helping Morgan collect the environmental DNA (eDNA) samples she needs to establish and monitor native and invasive species. This information is key to informing the MPA’s conservation management strategies and action plans.
“The ability to deploy Ascension from a RIB (rigid inflatable boat) is amazing. It's such a comprehensive instrument for what we need it for, and we can actually deploy it easily from a small vessel.”
Biodiversity Loss in Ascension Island MPA
Situated in the middle of the Atlantic Ocean, Ascension Island has a small population that includes military bases from the UK and the US, drawing cargo and military vessels travelling from the UK, Saint Helena and South Africa. It was already widely considered one of the most invasive islands in the world after many non-native plant species introductions, but the marine environment has generally remained pristine until now.
“We're concerned that we're going to have a spread of invasive species. We recently had a cargo ship come in from South Africa with three different species of invasive mussels on its hull. Being a small island, the many small endemic invertebrates cannot compete as they occupy very specific niches within the ecosystem. Better understanding biodiversity and how it’s impacted by these activities can help to inform actions to check vessels more strategically.”
Using eDNA to Map Ascension Island Marine Biodiversity
Like human DNA, environmental DNA (eDNA) holds genetic traces that reveal information about species living in an ecosystem. It’s useful for detecting species without having to catch or directly disturb them.
After two years of developing an eDNA reference library and eDNA sequencing laboratory, the Ascension Island team has created a baseline to identify native versus invasive species and continue to catalogue new species they hadn’t previously known to use the MPA.
“Now we have three to four years of data, so it should be much easier to see if a new species pops up.”
Collecting eDNA Samples at Depth
Initially, the team used Ascension to sample eDNA from the first 5-10 meters of the ocean at 10 different sites around the island to get a general sense of biodiversity present and to screen for any invasive species.
Ascension is a small, portable instrument that can collect seawater eDNA samples down to 400 meters and filter in situ without needing large research vessels or heavy equipment. Its user interface makes it easy for new team members to use without significant technical training, while its rechargeable battery ensures it is always ready for sampling days.
Morgan’s team is now using it in a mesophotic zone project to take deeper samples at the 70-meter range and around black coral reefs to sequence traces of animals present at those depths. Morgan also joined Darwin 200 expedition’s leg from Saint Helena to Ascension Island, deploying Ascension at the two seamounts just inside the MPA. This technology can help unlock discoveries about the deep MPA and how to protect it.
Additional Data Collected with the eDNA Sampler
Using the instrument’s GPS and CTD (conductivity, temperature and depth) sensor, Morgan can further test a new theory that the direction of currents and fluctuations in seawater temperatures influence the movements of megafauna around the island.
She explains, “It's really useful to have a copy of the (CTD) data without having to deploy additional equipment. It’s all built into one nice, small compact device.”
The same data is useful for generating an average for different depths, so the team can plot the data and create heat maps based on the different temperatures. They also hope to test the instruments’ microplastics application after finding 85 percent of sampled seabirds around Ascension Island had microplastics in their stomach despite being 800 miles from land.
Using the eDNA Sampler to Inform MPA Conservation Management
While the international community establishes new MPAs to reach the goal of protecting 30 per cent of the ocean by 2030, teams on the ground need better technology to support ongoing monitoring and efforts. With Ocean Diagnostics’ eDNA depth sampler, MPAs like Ascension Island can more easily collect the data they need to help protect marine biodiversity.