Migration of great seahorses

Key findings-

• Extensive fishing off the Coromandel coast could be forcing the great seahorse to migrate laboriously toward Odisha. 
• Fishing is less intense in the Bay of Bengal off the Odisha coastline. But the shallow coastal ecosystem of the eastern Indian State may not be the new comfort zone for the fish with a horse-like head.
• The study was based on a specimen of a juvenile great seahorse, or  Hippocampus kelloggi, caught in a ring net and collected from the Ariyapalli fish landing centre in Odisha’s Ganjam district.
• But the great seahorse is not migrating in large numbers, as the Odisha coast does not have coral reefs or seagrass meadows that the species can call home, except within the Chilika region
• Despite the ban on fishing and trading activities on seahorses from 2001, clandestine fishing and trading still take place in India. 
• This creates immense pressure on the seahorse populations that have a high dependency on local habitats to maintain their extensive and long-life history traits.

About seahorses-

• A seahorse (also written sea-horse and sea horse) is any of 46 species of small marine fish in the genus Hippocampus.
• Having a head and neck suggestive of a horse, seahorses also feature segmented bony armour, an upright posture and a curled prehensile tail.
• Seahorses are mainly found in shallow tropical and temperate salt water throughout the world, from about 45°S to 45°N. 

• They live in sheltered areas such as seagrass beds, estuaries, coral reefs, and mangroves. 

• Seahorses range in size from 1.5 to 35.5 cm. They are named for their equine appearance, with bent necks and long snouted heads and a distinctive trunk and tail. 
• Although they are bony fish, they do not have scales, but rather thin skin stretched over a series of bony plates, which are arranged in rings throughout their bodies. 
• Each species has a distinct number of rings.The armor of bony plates also protects them against predators, and because of this outer skeleton, they no longer have ribs.
• The coastal ecosystems of India house nine out of 12 species found in the Indo-Pacific, one of the hotspots of seahorse populations that are distributed across diverse ecosystems such as seagrass, mangroves, macroalgal beds, and coral reefs. 
• These nine species are distributed along the coasts of eight States and five Union Territories from Gujarat to Odisha, apart from Lakshadweep and the Andaman and Nicobar Islands. 
• The population of the great seahorse, which is among the eight species tagged ‘vulnerable’, is declining due to its overexploitation for traditional Chinese medicines and as ornamental fish, combined with general destructive fishing and fisheries bycatch
• Seahorses are poor swimmers but migrate by rafting clinging to floating substrata such as macroalgae or plastic debris for dispersal by ocean currents – to new habitats for successful maintenance of their population.