Text: Adrian Pinder Frequently referred to as the ‘red-fin’ or ‘deep bodied’ mahseer, Tor tor is the nominal species of the genus and was originally described by Francis Hamilton in 1822 from the Mahananda River, West Bengal. Despite being known to science for over 200 years the species is currently assessed as Data Deficient on the IUCN Red List, meaning that further evidence of the species distribution and population status is urgently required to provide evidence informed Red List assessment of its extinction risk and conservation needs.
Although assumed to have a broad distribution from the south Himalayan drainages to the west flowing Narmada River system in Madhya Pradesh, central India, much debate remains as to the true identity of the real Tor tor. For many years Mahseer Trust has been sent
pictures of fish assumed to be T. tor which often look dramatically different in appearance in accordance with their locality.
Examples of Tor spp. all currently referred to as Tor tor:
Top left - Kalisindh River, Madyha Pradesh;
Centre left – Narmada River, Madhya Pradesh;
Bottom left – West Ramganga River, Uttarakhand;
Right – Trishuli River, Nepal.
As early as 2015 our team recognised that this was a priority area of research. Unfortunately, Hamilton’s 1822 description was extremely vague in detail and no voucher specimens were deposited in museums for our examination. Accordingly, the only way to resolve these uncertainties was to obtain a specimen of T. tor from the type locality of the Mahananda River in West Bengal, where Hamilton originally found the species in the town of Siliguri nestled between India’s borders with Nepal and Bhutan. Only with the morphometric and genetic data from the type locality would it be possible to confirm whether the current assumed distribution of T. tor is made up by a single or multiple species of potentially undescribed Tor species. Delayed by availability of funds and the COVID-19 pandemic, it was not until March 2023 that we successfully assembled a team of volunteers in Siliguri with a mission to find the real T. tor. Read on to see what we found…
Without dwelling on the logistical challenges of individual team members making the journey to Siliguri, Adrian (MT Chair, UK), Sushan (MT Nepal Lead), Gen (aquatic consultant/MT collaborator, Nepal), Ian (angling guide/MT supporter, Sikkim) and Shamip (local angler/conservationist) all arrived exhausted and only managing the briefest of greetings and quick bite to eat before hitting the sack for an early start on the first day of the mission.
05:30 hrs - We arrive at Siliguri Regulated Market. A vast bustling area of traders with an extensive fish market. The quantities of freshwater fish arriving are astronomical and it’s genuinely astonishing to get a feel of how productive India’s freshwaters remain despite all the environmental pressures.
This is just one day, at one market, in one town, in India! Productivity yes - but by no means representative of what’s going on in India’s dying rivers. We quickly learn that most of the fish arriving are farmed and being imported from states as far south as Madhya Pradesh in central India.
The team conduct a few questionnaires with vendors to scope the availability of our local target species but we come away with no leads.
06:30 hrs - Refuelled by a mini paper cup of sweet chai, our next stop is Champasari Market where we’ve been told we might find vendors selling fish from the Mahananda and other local rivers. This time the questionnaires and photo flashcards are more revealing with several vendors recognising our fish and one of the younger men saying he sold one four days earlier. We are then introduced to the man’s father who had been selling fish since he was a boy. He tells us that the fish in our picture (suspected to be T. tor) was once plentiful, growing to large sizes (30 kg +) in the Mahananda River. However, these disappeared when the Fulbari Barrage was constructed across the Mahananda just downstream of Siliguri in the 1970’s. He tells us the fish is still available but much rarer now and only available in the much larger Teesta River to the east.
11:00 hrs - Armed with the knowledge that the Mahananda is no longer the river it once was we head off to assess the habitat quality for mahseer and get a nasty surprise. Approaching the river from the east bank at Karaibari, just upstream of Siliguri, all we can see is a barren moonscape shaped by sand mining activities rather than the rivers natural hydrology. Speaking of which, where was the river’s hydrology? Walking the 300 metres channel width from bank to bank there was no water to be seen: not even a damp patch: only dust.
12:00 hrs - Having undertaken a detailed visual study of the catchment from Google Earth in advance of the trip, we are aware that a short distance upstream the Mahananda flows through protected forests. The question at the back of our minds is, if there is any water flowing from the headwaters, could there be a population of T. tor further upstream? Perhaps during monsoon, fish are able to migrate from the Ganges, past Fulbari barrage to access spawning areas upstream. If this was the case, then perhaps we would be able to find young juveniles in these upper reaches.
Another quick check of Google Earth confirms we should be able to access the river at a temple near the village of Sittong. Leaving the relatively straight roads of the lowland tea estates, the road starts to twist and turn up and around the mountains providing fine views of the jungle beneath us. As we descend the other side of the mountain we are treated to our first site of flowing water. Not much of it in these higher streams but flowing water nonetheless. On closer inspection from Sittong Bridge, the Mahananda is crystal clear with beautifully clean substrate and looking perfect as a spawning and rearing ground for mahseer and other stream fishes.
Standing on the bridge our first impressions of this site were positive, until we spotted a group of seven men armed with a home-made electro shocker (hidden in a rucksack) and nets. Ironically, they were fishing around the feet of a religious deity representing Saraswati: Hindu goddess of knowledge. They were
killing and harvesting everything in their path. Their catch consisted of a mix of small stream fishes (e.g. loaches and Garras), which would never get the opportunity to spawn.
Disheartened that the only flowing water to be found was subject to such fishing pressure, the discovery of a hydropower plant just a few metres away did nothing to lift our spirits. We left Sittong to start the long journey back to Siliguri with the conclusion that if mahseer still exist in the Mahananda, they could only potentially survive in the reaches further downstream between the Fulbari Barrage and the River Ganges.
05:00 hrs - Another early start as we make our way through the quiet streets of Siliguri towards Fulbari Barrage where we’ve had a tip off that local fishers would be selling their overnight catches from the riverbank.
The first thing on our minds is – will there be enough flow downstream of the barrage to support mahseer populations? The answer is no.
Upstream however there is no shortage of water. The Mahananda is a wide flowing channel with interconnected backwaters forming an important wetland area for migrating birds. Temporarily baffled by where all the water was coming from, we soon realise that a river linking project between the Teesta and Mahananda has been in operation since the late 1990’s. 100 percent of the flow we are looking at is Teesta water entering the east bank of Mahananda, via the linking canal, a short distance upstream of Fulbari Barrage. But - rather than benefiting the Mahananda and being released through the barrage - the flow is diverted in its entirety into an irrigation canal, leaving the Mahananda on its west bank: the Mahananda is essentially functioning as a crossroads to divert water away from Bangladesh and back into India.
All the travel and two early morning starts does little to aid us to compute our next move, so we shift our focus back to the local fishermen operating gill nets from tiny, corrugated iron skiffs upstream of the barrage. Given what we know about the risks of river linking projects we are not particularly surprised to find the catches are dominated by invasive species. Along with large numbers of common carp, we also come across an emerging threat to India’s aquatic biodiversity, a South American armoured catfish (better knows as Plecos in the aquarium trade). Further interviews with fishers confirm that the Mahananda is a dying ephemeral river and our only hope of finding our target species is to the east in the River Teesta.
07:00 hrs - The team split themselves between a car and a scooter and make their way east following the course of the Teesta Mahananda linking canal. This cuts a path through the beautiful Baikunthapur Forest, home to large numbers of elephant, which are evident from piles of dung on the far bank of the canal. Despite being an artificial water body, the sight of flowing water is strangely a welcome one.
08:30 hrs - The Teesta Barrage is immense with 44 gates spanning a river width of 615 m. Unfortunately, apart from minimal compensation flow, these gates are firmly sealed, resulting in negligible flow linking a small number of pools in the downstream section. Upstream of the barrage is not dissimilar to the Mahananda above Fulbari, only this wetland is vast, extending as far as the eye can see.
There is plenty of evidence of fishing activity with gill netters working from pirogues both upstream and downstream. We make our way to the west bank immediately downstream of the barrage where a small number of boats are docked, and fishermen are chatting.
The fishermen are willing to engage in conversation and the team split up to interview as many people as possible. It seems that they are familiar with the fish and tell us to return tomorrow afternoon when they will get back with their catches.
07:00 hrs - A welcome later start and an opportunity to top our batteries up with a little extra sleep. Despite being told to return at 15:00, we set off for Teesta Barrage with a view to hanging around on the off chance of learning something useful while we await the fishing boats.
A few more interviews are completed and by 15:00 there are a couple of fish vendors set up in the open market area alongside the barrage.
We continue to wait for our fishermen to return but the sky is blackening, and the wind is rising. We get word that a major hailstorm (golf ball size hail) is sweeping in from Bangladesh. We monitor the situation until the wind is too great for the traders and the market is disassembled with people scrambling to stow away wildly flapping tarpaulins. The wind is also carrying a huge amount of dust, making it difficult to see. The collective decision is to cut our losses and try to get back to Siliguri before the storm hits. This turns out to be a good move as we are soon engulfed in torrential rain and surrounded by lightning strikes.
06:00 hrs - Today is our last day and our hopes of finding T. tor are not particularly high. Discussions over dinner the previous evening highlighted that despite losing all its water down the canal, the Teesta was flowing and the river upstream of the barrage could potentially support mahseers. Rather than heading back to the barrage for more disappointment, we head upstream to Sevoke. Here the Teesta emerges from the protected forested foothills of the Himalayas and spills into the flatter lands of the Terai.
At last we have found a large river with a good flow and looking perfect for mahseer. Heartened by this sight, we continue driving upstream until we reach Teesta Low Dam–IV, situated just downstream of the tiny village of Kalijhora.
Ian and Shamip do some asking around and we are given the address of a local fisherman (and dam worker) who might be able to help us. After finding our man, we climb down to the bank of the reservoir with him and some other recreational fishermen who told us they catch several species of mahseer (including golden mahseer, Tor putitora) on a regular basis. As we watched them throw in their groundbait, (inclusive of goats innards lashed onto a rock) Sushan began chatting to the young man from he village. As soon as he saw our picture of the fish we were looking for he pointed and said ‘Tor tor’. As a dam worker we learned that as well as catching these fish, he had observed their annual arrival at the junction between the Teesta and the small tributary which joins just downstream of the dam. His knowledge was enlightening, and he went on to explain that shoals of T. putitora and T. tor (typically between 1 and 5 kg) both arrive during June/July. Despite arriving in synchrony, their spawning is separate with T. putitora spawning at the junction, while T. tor migrate a further 2 km upstream to spawn where the gradient starts to increase rapidly.
He also shared his experience as a fisherman who used to kill everything he caught, until one day, at the age of 15, he caught his first golden mahseer, a fish bigger and more beautiful than anything he’d seen before. Initially he was scared to approach it as its gold colour and black stripe reminded him of a tiger. This was the first fish he ever released. It also stimulated his interest to find out what he could about mahseer from YouTube videos. He has since released every fish he has caught.
Despite staying with the fishermen for a few hours we only saw one fish caught – a tiny Neolissochilus hexagonolepis, often referred to as copper mahseer and locally known as katli.
Our final drive back to Siliguri provided time to accept we were not going to be successful in our quest this time, but we had been given hope that another trip during June/July had the potential to be more productive.
Day 5 - Last chance saloon
Having said our goodbyes, we all set off on our onward journeys, Ian back to Sikkim, me (Adrian) to the airport for a convoluted flight to Kathmandu via Delhi.
The 16-hour bus journey to take Sushan and Gen back home to Kathmandu was not however scheduled to leave until 15:00, providing them with a bit of downtime and the intention of exploring some of Siliguri’s book stores.
Five minutes prior to my taxi arriving to collect me from the hotel I get a missed WhatsApp call from Sushan. Scrabbling to establish contact it transpires that they had stumbled across another fish market and had just purchased two mahseers of 2 kg a piece which had just arrived from the River Teesta. By now I was in the taxi and the excited messages continued to flow. “Can you delay your bus?” was my primary concern. With one of the fish being our target species (still assumed at this stage to be T. tor) and the other potentially being Tor mosal (the next species on our hit list) there was urgent work to be done.
Genetic samples needed to be taken from fin clips and a full suite of morphometric and meristic measurements were required before beginning the process of fixing the specimens in formalin for their preservation and movement to a permanent home in a museum. Thankfully both Sushan and Gen were willing and stayed a further five days, managing to secure additional samples but only the one T. tor.
Having just returned from the trip there is a lot of analysis needed before we can comment on the significance of these findings, but we are excited to share the results as soon as we can.
A roller-coaster of a week for the team. We expect to have results from the genetic sequences for comparison with those lodged in Genbank in early May.
Please also read our report on the landscape visited by our team published by South Asia Network on Dams, Rivers and People here.
For more news on Mahseer Trust work, sign-up for our quarterly newsletters. The April/May 2023 issue has extra reporting from this trip and a focus on Troubled Waters.