Project concept – Tiger of the Water: Saving the hump-backed mahseer

Tiger-of-the-Water-Conserving-the-hump-backed-mahseer

Project Mahseer is a collaborative initiative to conserve the enigmatic and highly threatened mighty mahseers of the family Cyprinidae. In doing so, the project will contribute towards the protection and sustainable management of some of Asia’s most iconic river systems. The initial priority for Project Mahseer is the conservation and recovery of the hump-backed mahseer, a species endemic to the Cauvery River Basin in southern India. Its population has plummeted since the turn of the century and it is now listed as Critically Endangered on the IUCN Red List of Threatened Species. Project Mahseer aims to deliver the necessary conservation actions to save this remarkable species and its habitat for future generations.

 
HOW YOU CAN HELP
Latest Updates
Download Project

This map shows the remaining fragments of river within the Cauvery River Basin where hump-backed mahseer are still recorded. This area totals just 5.5km2 and represents a 90% reduction in the range of the hump-backed mahseer.  (c) Bournemouth University

Mighty mahseer

Mahseer are an iconic and alluring group of fish distributed across 11 countries in Central, South and Southeast Asia. One interpretation of the name mahseer is from the translation of the Indo-Persian words mahi, meaning ‘fish’ and sher, meaning ‘tiger’, and mahseer are often referred to as ‘the tiger of the water’ (with body sizes reaching more than 54 kg). These fish have long been a cultural icon of economic, recreational and conservational value across their range (Siraj et al. 2007), represented in ancient Indian literature and revered as gods (Pinder et al. 2015). They also remain an important food fish and a delicacy for many of the local communities who share the same environments. The global interest in mahseer, however, relates more to their status as some of the most tenacious and sought-after game fish on the planet (Thomas 1873). They have long attracted anglers from around the globe, and earned a reputation for their strength, stamina and splendour. They also lure anglers to some remote and spectacular locations.

Mahseer span tropical to cold-water environments, but many species prefer clear, fast flowing rocky streams and intermittent deep pools, ascending these rivers to spawn (Sakar et al. 2015). For this reason, they are often found in mountainous and rugged terrain. The Latin generic name for many mahseer species, Tor, comes from the name of the altitudinal zone from 600 m – 1,200 m where they are often found. Mahseers’ diet varies depending on the specific species, but research has suggested they are mostly omnivorous and consume algae, submerged plants, insects, freshwater molluscs and snails, and small fishes (Dinesh et al. 2010). They have even been recorded shoaling beneath fruiting trees waiting for seeds and berries to drop into the water channel.

 

Conservation status

0km2
Hump-backed mahseer are now estimated to be restricted to reaches of river channel totalling an area of just 5.5km2.
0kg
Hump-backed mahseer can reach 45kg in weight.
0%
Of rivers in Asia are assessed as being in poor health (ADB 2013).

Mahseer populations have undergone dramatic declines across much of their range.  Since 1871 reports have hinted at declining mahseer populations in different parts of the Indian subcontinent (Nautiyal 2014), and as far back as 1976 the Indian National Commission on Agriculture stated that there was a general decline in mahseer populations across the country because of indiscriminate fishing of brood and juvenile fish and the adverse effect of river valley projects (Ogale 2002).

Further research has since identified that the main causes behind mahseer population declines are:

  • Overexploitation: Indiscriminate fishing has removed mahseer from their native waters, and when the abundance of larger adult fish declined, juveniles and fingerlings were targeted (Nautiyal 2014). The use of destructive fishing gears, in particular dynamiting and poisoning, has also had a particularly negative impact on these species and their habitats. For example, in the Kerala part of the Western Ghats, populations of mahseer fell by 60 – 70 % in a decade as a result of unmanaged exploitation (Raghavan et al. 2011).
  • Loss of habitat: Anthropogenic activities such as sand and boulder mining, deforestation, water abstraction and river engineering projects have decimated mahseer habitats and populations across their range. Many of these drivers of habitat loss can be abated and mitigated to conserve these habitats for mahseer, along with the many other threatened species which occupy and depend upon the same rivers.
  • Barriers to migration: Mahseer are migratory species and rely on free-flowing rivers. Most mahseer species have been observed to have two to three migration cycles each year, navigating upstream to spawning and nursery grounds and then traversing back down rivers to feeding grounds at a lower altitude (Nautiyal 2014). In many cases, dams and barrages have inhibited these movements, fragmenting populations and preventing access to critical spawning sites.
  • Degradation of habitat due to pollution: Pollution is a threat to many river systems across the world, and in 2013 the Asian Development Bank rated more than 80 % of Asia’s rivers as having poor health because of pollution and damming (ADB 2013). For example, in the Western Ghats region, home to three mahseer species, pollution is the primary threat to freshwater biodiversity, with approximately 50 % of fish, 21 % of odonates and 20 % of molluscs threatened by effluent from either urban, domestic, agricultural or industrial sources (Molur et al. 2011).

Compounding these threats, are the implications of the introduction of invasive non-native species and climate change. As a result; of the 16 species of mahseer assessed on the IUCN Red list of Threatened Species, five are threatened with extinction, three are assessed as Near Threatened and eight are Data Deficient (IUCN 2018). None are described as being of ‘Least Concern’.  Conservation action is clearly required to prevent the further decline and extinction of these remarkable species.

Collaborative conservation: Project Mahseer

Project Mahseer is a collaborative initiative catalysed by SHOAL to save this remarkable group of fish from extinction. The project will focus on conserving these species across their range, in turn contributing towards conservation of some of Asia’s most biodiverse and threatened river systems.

The project will engage with a wide range of partner organisations, including non-governmental organisations (NGOs), government stakeholders, universities, scientists, businesses, anglers and local communities to devise and implement conservation solutions which reduce pressure on surviving mahseer populations, and help to recover populations in areas where they have undergone rapid decline. The initial objective is to focus on the conservation of the Critically Endangered hump-backed mahseer; however, it is hoped this will be the first of many projects which is undertaken under this new initiative. Project Mahseer intends to be a long-term initiative operating over a long-time horizon. This is both due to the enormity of the challenge to save mahseer in their 11 range countries, but also to ensure that the impacts of supported conservation interventions are sustainable and enduring.

Project Mahseer: Long term objectives

  • To prevent the extinction of any species of mahseer.
  • To use mahseer as flagship species for the conservation of some of Asia’s most biodiverse yet threatened river systems.
  • To engage anglers across Asia in conservation, and encourage the development of new conservation projects which benefit freshwater fish and people who depend on them.
  • To connect individuals around the globe interested in conservation projects to species of interest for which they can make a tangible difference.
  • To raise awareness of the challenges facing freshwater fish and the changes to river systems which are driving declines in their populations.
  • To demonstrate the effectiveness of a multi-stakeholder approach to freshwater conservation.

References

Asian Development Bank(2013) Asian Water Development Outlook 2013, Asia-Pacific Water Forum

Dinesh K., Nandeesha M.C., Nautiyal P. and Aiyappa P. (2010) Mahseers in India: A review with focus on conservation and management, Indian Journal of Animal Sciences, Vol.80, No.4, Suppl. 1, pp.26-38

IUCN (2018) The IUCN Red List of Threatened Species. Version 2018-2

Molur S., Smith K.G., Daniel B.A. and Darwall W.R.T. (Compilers). (2011) The status and distribution of freshwater biodiversity in the Western Ghats, India, Cambridge, UK and Gland, Switzerland: IUCN, and Coimbatore, India: Zoo Outreach Organisation

Nautiyal P. (2014) Review of the Art and Science of Indian Mahseer (Game Fish) from Nineteenth to Twentieth Century: Road to Extinction or Conservation? Proceedings of the National Academy of Sciences, India – Section B: Biological Sciences, Vol. 84 (2), pp.215-236

Raghavan R, Ali A, Dahanukar N, Rosser A, 2011, Is the Deccan Mahseer, Tor khudree (Sykes 1839) (Pisces: Cyprinidae) fishery in the Western Ghats Hotspot sustainable? A participatory approach to stock assessment, Fisheries Research, Vol. 110, pp.29-38

Pinder A.C., Raghavan R. and Britton J.R. (2015) The legendary hump-backed mahseer Tor sp. Of India’ River Cauvery: an endemic fish swimming towards extinction? Endangered Species Research, Vol. 28, pp.11-17

Pinder A.C., Manimekalan A., Marcus Knight J.D., Krishnankutty P., Britton J.R., Philip S., Dahanukar N. and Raghavan R. (2018) Resolving the taxonomic enigma of the iconic game fish, the hump-backed mahseer from the Western Ghats biodiversity hotspot, India, PLoS ONE, Vol. 13, No.6

Ogale S.N. (Year) Mahseer Breeding and Conservation Possibilities of Commercial Culture. The Indian Experience, in Petr T and Swar D.B, Cold water fisheries in the Trans Himalayan countries, FAO Fish Tech Paper 431, FAO, Rome, pp.193-212

Sakar U.K., Mahapatra N.K., Saxena S.R. and Singh A.K. (2015) Mahseer in India: An Overview on Research Status and Future Priorities, Journal of Eco physiological Occupational Health, Vol.15 (No.1 and 2), pp.45-52

Siraj S.S, Esa Y, Keong B.P, Daud S.K, 2007, Genetic characterisation of the two colour-types of Kelah (Tor tambroides) using random amplified poluimorphic DNA (RAPD), Journal of Malaysian Applied Biology, Vol.36 (1), pp.23-29

Thomas H.S. (1873) The Rod in India. Mangalore: Stolz