Aim Prasertsuk grew up splitting her childhood between Chiang Mai and Portland, Oregon — her Thai father a civil engineer, her American mother a high school biology teacher — and credits the dissonance between those two river systems for making her a biologist before she knew what biology was. She was catching fish in the irrigation channels behind her grandmother's house in Mae Rim by the age of seven. By the time she left for university in the United States, she had already decided she was coming back.
She completed a Bachelor of Science in Fisheries Biology at Oregon State University, followed by a Master's with a thesis focused on salmonid habitat restoration in Pacific Northwest streams. The techniques she learned there — population modelling, electrofishing surveys, aquatic macroinvertebrate sampling as a proxy for water quality — came back with her to northern Thailand in 2017 when she joined a research collaboration between Chiang Mai University and an international conservation NGO monitoring wild mahseer (Tor spp.) populations in the tributary rivers of the Ping and Wang basins.
Mahseer are among Thailand's most ecologically important freshwater fish and among its most threatened. The wild populations that once characterised the fast-flowing, boulder-strewn rivers of the north have been significantly reduced by dam construction, agricultural runoff, and overfishing. Aim's conservation work concentrates on population assessment in rivers that still hold breeding-age fish, and on working with local communities to develop alternative livelihood models that reduce fishing pressure on the species. She is not evangelical about it — she understands that rural communities fish because they need to eat — but she is persistent and practically minded.
On catch-and-release fly fishing
Aim argues that well-executed catch-and-release fly fishing for mahseer, conducted under proper guidelines, is a net conservation positive — it creates economic value for the fish that discourages destructive harvesting, and it generates population data that wouldn't otherwise exist. She is candid, however, that poorly handled C&R can harm the fish, and she writes accordingly.
Her fly fishing practice grew directly out of her fieldwork. Wading rivers for surveys requires exactly the kind of water-reading skill that makes a competent fly angler, and she made the connection deliberately — converting survey methodology into fishing technique, learning to read mahseer lies the same way she read habitat data. She now guides occasional fly fishing trips on rivers she has surveyed, almost always with an explicit educational component: clients learn which fish populations are stable and which are fragile, and why that distinction matters for how they fish.
Her writing on ThaiAngler focuses on northern Thailand's wild river landscape — the species that live there, the rivers that still hold reasonable populations, the seasonal windows when fly fishing is practical, and the conservation context that any responsible visiting angler should understand. She is notably honest about the limits of access: several of the rivers with the most interesting mahseer populations are inside national park boundaries, require permits that can take weeks to arrange, or involve multi-day travel in conditions that eliminate the casual visitor. She does not simplify this or pretend the logistics are easier than they are.
Aim lives in a rented house in Nimmanhaemin with two cats and a tying bench that spills into the kitchen. She speaks Thai with a Chiang Mai accent that marks her immediately as someone who grew up there rather than arrived, and English with a slight Pacific Northwest flatness that reasserts itself when she is tired.