Hello FIRE Lab followers! My name is Kherlen Shinebayar! I am a student at Swansea University, but originally from Mongolia. I am working with FIRE Lab on several projects related to mapping instream infrastructure, and this summer I will be starting my own research project about fragmentation of rivers in Mongolia and how this influences freshwater fishes that live in those rivers.
We here at FIRE Lab have been sharing with you about different migratory species, and in keeping with that theme, today’s blog post is about migratory fishes of Mongolia. My name also links with today’s blog post – see if you can find the connection! I am excited to share with you about my country and the fishes that live there – let’s get started!
Mongolia is a landlocked country in East Asia. It is sandwiched between Russia to the north and China to the south. Most rivers and lakes are in the north of Mongolia; as such, fishes in Mongolia prefer cold, well oxygenated waters. Most recent figures report 79 species and subspecies of freshwater fishes in Mongolia (WWF, 2019).
Eighteen of the 79 fish species in Mongolia are classified as migratory; 17 of which are potamodromous, meaning they migrate exclusively between freshwater habitats. The Amur sturgeon (Acipenser schrenckii) is the only exception; it is an anadromous fish – living in marine environment only moving to fresh water for spawning.
The remoteness of much of Mongolia and restrictions in funding for scientific research means that there is limited information and understanding about many of these species. The better known and researched species are important fisheries, especially the Taimen (Hucho taimen). The department of ‘Ichthyological and Hydro-biological’ team of the Geoecological Institute of Mongolia depends on local fisherman reports (WWF, 2019), and in 2018 the World Wildlife Fund initiated and developed www.ezagas.mn a website where people could share information about their catch. The website also offers general information about the fish species of Mongolia.
Taimen is the largest Salmonid in the world; heavier, on average, than the largest North American Salmonid, the Chinook Salmon. The Taimen is also a migratory species! It inhabits the River Selenga. Taimen undertake two migratory stages – in spring they migrate upstream for spawning and in autumn they move downstream to lowland river courses and enter lakes. The warming up of the lake water in summer drives the fish away, while in winter the fish return to the lakes.
In summer the Taimen is present in the upper course of the River Kherlen, some 200-250 km downstream from its sources. The fish remain in the upper course of the Kherlen until the end of September because of the abundance of food sources such as minnows. The autumn downstream migration usually starts at the end of September and it depends on water temperature and on the presence of fish on which it feeds.
Like many of the world’s larger bodied migratory fish species, Taimen is a valuable commercial fish species. A special angling licence is now required to capture these fish in Mongolian waters, because the numbers of Taimen have been declining. I am interested in knowing more about how instream infrastructure, such as roads and dams could influence migratory fishes like Taimen, and smaller ones that might be less understood or studied. I hope to address some of this during my research project this summer. Stay tuned for updates about that on a future blog post!
Thank you for reading!
Stay tuned for our next migratory species post in two weeks!