This post is one of a series on projects supported by the Aquarium’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists, and grassroots organizations all around the world as they work to address the most challenging problems facing the ocean.
MCAF funded a project led by Priyankar Chakraborty, a MSc student from Bharati Vidyapeeth Institute of Environmental Education and Research (BVIEER), Pune, India. In this piece, Priyankar writes about recent reports of Sawfish sightings in the Sundarbans region, the impacts of COVID-19 on the project and some of the findings from local fishers. To read Priyankar’s previous blog on the Sawfishes of the Sundarbans click here. Note: this blog has been backdated for archival purposes.
Sawfish observations on the rise
Are sawfishes faring better in the Indian Sundarbans as a response to COVID-19 lockdown?
By Priyankar Chakraborty; Translated by Satyabrata Ghosh
Three phone calls in two months made me feel jubilant when all three reported catching and releasing a sawfish. Why are sawfish sightings more common now than before?
According to the fishers (who went out to fish amid the COVID-19 lockdown and wishes to remain anonymous), many fishes, including elasmobranchs, are now more common in the Indian Sundarbans. The reason attributed by two fishers is that the COVID-19 lockdown prevented mechanized fishing trawlers from going out to the sea. This provided most fishes, including sawfishes, a breather and allowed them to move further inland.
But one fisher thinks that the recent event of the super cyclone ‘Amphan’ (pronounced ‘Umpun’) is the reason why there is a sudden rise in the availability of elasmobranchs, including sawfishes. According to him, the cyclone resulted in floods that raised the water level of the rivers. This brought saltwater deep inside the mangroves, increasing their salinity, allowing sawfishes to access new areas.
All three sawfishes were discerned as female by the fishers. They weighed from 5 kg to 8 kg. Due to lockdown in place, I couldn’t visit the field to ground-truth the identity of the sawfishes caught by showing pictures to the fishers.
One fisher said that the sawfish he caught had an unusual rostrum (distinctly narrower than the ones he saw before) and smaller teeth with a little gap between them. The fish he caught could be an Anoxypristis cuspidata which sports a narrow rostrum and is known from the area but not recorded for ages.
The location where the sawfish with the narrow rostrum was caught, using a handline during high tide(Photograph by Asim Gayen).
All three fishers said that they released the sawfishes upon capture because of what they learnt from the workshop I held last year in disseminating the importance of sawfishes to the ecosystem and the mangroves. They said that other fishers in the region have also caught sawfishes, guitarfishes and sharks in the past couple of months. But they are not sure if they released them back.
A specimen of a juvenile Anoxypristis cuspidata collected in 1908 from the Sundarbans region. No specimen-based scientific record of this species exists from the area in recent years. This specimen remains in the collection of the Zoological Survey of India (Photograph by Priyankar Chakraborty).
It remains to be found if any quantifiable evidence exists between the scarcity of fishing boats at sea and the number of sawfishes in the mangroves. I cannot venture out in the field to assess the situation until the COVID-19 lockdown gets lifted. But we think that this hopeful anecdote continues for a family of fishes that are among the most threatened in the world.