Global study warns migratory freshwater fish remain dangerously under-protected under the Convention on Migratory Species. Researchers say data gaps and policy neglect are leaving dozens of transboundary fish species at high risk of extinction
By Salam Rajesh
Freshwater fish are fairly under-represented in the Convention on the Conservation of Migratory Species of Wild Animals – in short, the Convention on Migratory Species, screams the headline of a paper published in the Nature Reviews Biodiversity earlier this month.
The paper, “The untapped potential of CMS for migratory freshwater fishes”, urged member countries that urgent action is needed to unlock the potential of the Convention on Migratory Species (CMS) to advance the conservation of migratory freshwater fishes particularly in biodiversity rich regions of the globe with untapped potentials.
The paper, co-authored by 14 freshwater experts including four associated with IUCN and its Species Survival Commission (SSC)’s Freshwater Fish Specialist Group, finds that freshwater fish are considerably under-represented in the Convention on Migratory Species.
The paper noted that only 23 transboundary migratory freshwater fish species are currently listed in the CMS, despite the fact that at least 87 are at great risk of extinction according to the IUCN Red List of Threatened Species.
Migratory freshwater fish are further under-represented in terms of diversity, with sturgeons and paddlefishes making up all but four of the 23 species in the CMS, the paper noted.
Catherine Sayer, IUCN’s Freshwater Biodiversity Lead and co-author on the paper, says, “As we look towards the next CMS Conference of Parties in March, this is an opportune moment to address the untapped potential to protect freshwater fish through the Convention”.
“Freshwater species are essential to ecological processes such as nutrient cycles and providing food and livelihoods to people, yet they are highly susceptible to habitat loss, fragmentation and overexploitation. Coordinated international action is urgently needed to protect species along their migratory routes”.
The paper basically says that the lack of primary information on freshwater fish is a major reason for the under-representation.
Stressing on this assertion, the authors of the study emphasized that there is no comprehensive assessment of how many fish species migrate in freshwaters and across national boundaries.
At the same time, one-third of all known freshwater fish species are Not Evaluated or Data Deficient on The IUCN Red List of Threatened Species, limiting people’s understanding of whether they should be listed in the CMS.
Additionally, many countries with river basins that cross international borders are not signatories to CMS, particularly in Asia and North America. This reduces the likelihood that species in these regions will be proposed and included in the CMS. For instance, the paper cited that the Mekong River basin is a biodiversity hotspot for migratory freshwater fishes, but no Mekong countries are Parties to the CMS.
Catherine Sayer stressed that creating a full list of migratory freshwater fish and ensuring they are assessed on the IUCN Red List are key next steps. The creation of a specialist group to work together with Range States to propose freshwater species to CMS would also help attract attention to those in most urgent need of protections, she added.
The paper re-emphasized the value of strengthening the links between research, communications, policy development and CMS implementation. The authors also stressed that alongside efforts to include more freshwater fish in the Convention, research to address knowledge gaps about their life history is critical to understand which conservation efforts would be most effective.
Furthermore, the paper highlights the need to raise awareness of migratory freshwater species, as people’s support is key to encourage policy and action on the ground.
The CMS is a United Nations environmental treaty signed by 132 countries and the European Union, providing a global framework for protecting migratory species. Two CMS appendices list over 1100 species that require protections.
All CMS Parties are obliged to prevent the catch of species in Appendix I (with limited exceptions), while Range States are encouraged to work together to conserve species in Appendix II through various CMS instruments, to prevent unsustainable exploitation, protect and restore habitats, remove barriers to migration, and mitigate other threats throughout species’ ranges.
It may be recalled that the IUCN (International Union for the Conservation of Nature and Natural Resources) had recently said more than 47,000 species of the animal and plant lives are threatened with extinction, which is 28 percent of all species assessed globally.
The IUCN Red List Strategic Plan (2021-2030)’s goal is to have 260,000 species of all animal and plant lives assessed and to reassess 140,000 of those species to ensure that the information on their status is up-to-date so as to enable monitoring in trends on their change of status.
The IUCN says that 169,420 species out of the targeted 260,000 species has been assessed so far globally, with 90,580 species still remaining to be assessed as per the IUCN standards.
For Manipur, a small nation state jam-packed within two significant global biodiversity hotspots – the Eastern Himalaya Biodiversity Hotspot and the Indo-Burma Biodiversity Hotspot – a number of freshwater fish had been identified and listed by researchers led by former Manipur University professor and IUCN SSC Freshwater Fish Specialist Group expert Waikhom Vishwanath.
Yet, gap in information of several more freshwater fish in the State’s three major river systems, namely, the Manipur River system, Barak River system and Maklang-Yu River system still remains, necessitating more intensive field-based study on the diversity, and inventory, of freshwater fish within the Indo-Burma Biodiversity Hotspot.
It equally is important to re-evaluate the migratory freshwater fish population, and species, along the Chindwin-Irrawaddy-Manipur River transboundary migratory passage. It is necessary to understand the extent of loss in migratory freshwater fish within Manipur due to human interference in the form of the Ithai Barrage over Manipur River near Ithai Khunou village in Bishnupur District of the State.
State administrators need to re-think on strategies to re-vitalize the migratory freshwater fish population as in the pre-Ithai Barrage era to achieve the goals enshrined in the CMS projection to revive and re-strengthen the populations of transboundary migratory freshwater fish across regions in the world.