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Source- This post on Diadromous fish has been created based on the article “Fish moving between marine & freshwater ecosystems have designated protected areas, but no protection in them: Study” published in “Down to Earth” on 29th May 2024.
Why in News?
Recently, a study was published in the British Ecological Society’s Journal of Applied Ecology. The researchers discovered that marine protected areas (MPAs) designated to safeguard diadromous fish species did not align with their core habitats.
This finding highlights the need for better coordination and planning to ensure effective conservation efforts for these migratory fish.
About Diadromous fish
| Aspects | Description |
| About | 1. Diadromous fish are those species that migrate between saltwater and freshwater environments. 2. They move back and forth between the ocean and rivers or streams during different stages of their lives. |
| Types of Diadromous Fish | 1) Anadromous Fish: These fish are born in freshwater. As juveniles, they migrate to the ocean, where they grow into adults. Later, they return to freshwater to spawn (lay eggs). 2) Catadromous Fish: These fish are born in saltwater. As juveniles, they move into freshwater, where they mature into adults. Eventually, they migrate back to the ocean to spawn. 3) Amphidromous Fish: These fish are born in freshwater or estuaries (where freshwater meets the sea). Initially, they drift into the ocean as larvae. Later, they return to freshwater to grow into adults and spawn. 4) Potamodromous Fish: These fish are born in upstream freshwater habitats (upstream areas of rivers). As juveniles, they migrate downstream within freshwater to grow into adults. Finally, they migrate back upstream to spawn. |
| Threats to Diadromous Fish | Diadromous fish face various human-induced pressures: i) Agricultural and pollutant runoffs: Contaminants from agriculture and other sources can harm their habitats. ii) Habitat destruction: Dam construction and land development impact their migration routes. iii) Barriers to migration: Dams, weirs, and other structures hinder their movement. iv) Fishing and bycatch: Overfishing and accidental capture affect their populations. v) Climate change: Altered water temperatures and habitats impact their survival. |
UPSC Syllabus: Science and technology
