Where birds meet the tides: the importance of protecting Asia's coastal mudflats, with Sayam Chowdhury (SE 2014)

In recognition of the upcoming 25th anniversary of the Gates Cambridge Scholarship at Cambridge, this article will be the first in a short series of interviews profiling the fascinating work and achievements of Gates Cambridge Scholars at Selwyn College. Learn more about the Gates Cambridge 25th anniversary celebrations here.

Intertidal mudflats are areas of coastlines that are exposed exclusively during low tide. Historically, these wetlands have not received much appreciation — but Selwyn PhD student and Gates Cambridge Scholar Sayam U. Chowdhury 's work has helped reveal their importance not just to local wildlife & communities, but migratory birds from abroad too. We asked him about his personal journey, and how his research will help conservation efforts worldwide.

Sayam, tell us a bit about your background.

I am currently in the fourth year of my PhD and hope to complete it in the next few months. I lived most of my life in Bangladesh, particularly in Dhaka but travelled extensively across Asia. Growing up in a rural town in the deltaic plains of Bangladesh, I watched the natural environment vanishing in front of my eyes to meet the demands of a growing population. Responding to the growing need for conservation and my passion for wildlife, I became a conservation biologist with interests in the ecology and conservation of threatened species in Asia, and in applied issues of understanding and mitigating the impact of ecological changes on biodiversity. I felt this was especially important in a densely populated country like Bangladesh.

So, where did your Cambridge journey begin?

To expand my skills and develop a career as a conservation biologist, I applied to the Chevening Scholarship in 2014 and completed an MPhil in Conservation Leadership from the University of Cambridge, at Selwyn College. The MPhil journey largely complemented my career, helping me further understand the complex conservation problems that the natural world faces and find science-based solutions through rigorous research.

I started my PhD at Selwyn College in October 2020, with a scholarship from the Gates Cambridge Trust.

How was your time at Selwyn?

I have lived in Cambridge throughout my PhD except for the period when I was away for fieldwork, mainly in Bangladesh. I was initially admitted to another college for my PhD, but I asked to return to Selwyn, having greatly enjoyed it during my MPhil degree. I value Selwyn — it has always felt inclusive and welcoming of diverse backgrounds. The nature surrounding Selwyn also means a lot to me.

I’ve had many engaging discussions with the Green Officers about nature-friendly initiatives, including the bee hotel now installed in Selwyn’s garden. These gardens also support at least 30 species of birds, and the pond is home to smooth newts.

One of my fondest memories at Selwyn is of an encounter with a fox. After a formal dinner, I was sitting outside near the bar when a fox crossed Old Court and approached me, almost as if it wanted to communicate.

Tell us more about your academic work at Cambridge.

Asia's intertidal mudflats are essential ecosystems, supporting over 50 million migratory birds, including 33 threatened species. These coastal wetlands serve as crucial stopovers for shorebirds migrating between Arctic breeding grounds and wintering sites in South and Southeast Asia. However, they face mounting threats from commercial development, pollution, river damming, and climate change, leading to significant habitat loss.

My PhD research focuses on understanding the habitat requirements of shorebirds in Bangladesh and other parts of Asia, especially the factors driving population declines of migratory species, such as intense human activity. I aim to identify effective conservation strategies to protect these vital habitats and the communities that rely on them. For example, part of my research focused on mapping out how tidal flats are exposed and inundated, which can help guide where to focus conservation projects such as mangrove restoration and afforestation, ensuring the right species are matched to the right habitats for the best chance of success.

Beyond wildlife, intertidal wetlands offer essential services — storing carbon, shielding coastlines, and supporting local food production — which benefit millions of people worldwide. By filling gaps in knowledge of shorebird ecology, my work aims to guide long-term conservation actions to preserve these ecosystems and the diverse life they sustain.

What is your vision for how your work will affect people and the world?

My research aims to improve the lives of people and wildlife.

The data I collect can be used to predict potential new habitats for shorebirds as sea levels rise and coastal development threatens existing sites. Conservationists and policymakers can use this information to inform policies that preserve biodiversity, and in the longer term ensure the bird population’s long-term stability.

However, this research goes beyond just supporting shorebirds. Firstly, as mentioned earlier, it has wide-ranging benefits for environmental policy, restoration projects, and the resilience of coastal communities.

Secondly, understanding tidal elevations and exposure patterns helps manage flood and erosion risks to communities around the flats.

Thirdly, tidal flats often act as nurseries for fish and marine life that many fisheries — and local livelihoods — depend on. Identifying and predicting biodiversity-rich areas can help support sustainable fisheries management.

Ultimately, my goal is to help set conservation priorities that meet biodiversity targets and encourage policies to safeguard these vital ecosystems, benefiting both wildlife and the communities that rely on them.

You’re nearly at the finish line of your PhD. Do you have plans for postdoctoral research?

I have genuinely enjoyed this journey more than I expected, thanks in part to the incredible support from my supervisors, my research group in Cambridge and the highly capable field researchers in Asia, as well as many dedicated collaborators.

Yes, I hope to remain in academia to build on my PhD research and potentially expand its scope globally. In my postdoctoral work, I aim to balance shorebird conservation with climate-focused coastal restoration in Asia, integrating tidal flats more fully into broader conservation discussions. Current global efforts, such as a $4 billion investment in mangrove restoration, seek to mitigate climate change; however, they often overlook that prioritising mangroves at the expense of tidal flats poses significant risks to both migratory birds and local communities.

Through my research, I can help identify areas where tidal flats should be preserved. I believe we can develop more effective strategies and policies to address sea-level rise, guide the construction of more resilient coastal infrastructure, and ensure that tidal flats continue to support shorebird populations as climate change progresses. In doing so, I hope to contribute to a global understanding of coastal ecosystems and to help foster sustainable habitats for both wildlife and local communities.

If you would like to join Selwyn for your postgraduate study, you can learn more about postgraduate scholarships at Selwyn on the Cambridge University student funding website here.

One of the scholarship options open to applicants from outside the UK is the Gates Cambridge Scholarship. Each year Gates Cambridge offers c.80 full-cost scholarships to outstanding applicants to pursue a postgraduate degree in any subject available at the University of Cambridge. Learn more on their website here.

All photos used with permission of Sayam Chowdhury.