Abdul Wahab Khan | NT Staff Reporter
PANAJI: Seaweeds on the Dona Paula coast are facing a slow death due to marine pollution and warming oceans, former scientists from the National Institute of Oceanography (NIO) have revealed and sought immediate steps for protection and harvesting of these seaweeds.
Being the oldest family of plants on earth, seaweeds or the marine algae, which grow in sea or on rocks below the high-water mark, absorb a high level of nutrients and thus form an important source of food, feed, fertilizer and chemicals.
“Just as trees in forests provide living space for birds and other animals, so do the seaweeds in the oceans. There is a large amount of biodiversity associated with seaweeds but it seems to be washing away and becoming extinct due to marine pollution and many new non-endemic species entering our waters due to shipping activities,” said Dr Vinod Dhargalkar, a former NIO scientist.
It has long been recognised that the release of waste into the marine environment not only affects the composition of water and sediments but adversely affects the flora and fauna too.
According to an NIO study carried out in the past by three former scientists, V V Agadi, N B Bhosle and A G Untawale, 17 species of marine algae collected from five localities were found to be positive to metal pollution with considerable variations in their concentration. The scientists had warned against affecting the metabolic rates in the algae.
Asserting the need for harvesting of seaweeds to protect and save them from depletion, Dr Untawale said that they are fast-growing and do not use up scarce water resources during production – a major benefit in drought-plagued India. The seaweeds can be grown cheaply on the edge of India’s long coastlines and they do not take land away from other food crops like rice or wheat.
A survey along the Goa coast was conducted by NIO in 1975 and 255 tonnes (fresh weight) of seaweeds were reported from Dona Paula to Chapora region. The study was carried out by Dr Untawale and Dr Dhargalkar. They had reported 75 seaweed species and estimated 2,000 tonnes (fresh weight) of seaweeds available on the entire coast of Goa.
According to a new study conducted by Bombay Natural History Society, 70 more new species of marine algae have been discovered. These add up to the 75 species recorded by NIO in the past. Of the total 145 species, 64 are of red algae, 41 of green algae and 40 species of brown algae, which are commercially important. Seaweeds start growing in the months of September and October and the peak season is during April-May.
The recent study was conducted by Bombay Natural History Society’s N Pereira and M R Almeida over a period of three years from 2008 to 2010 at 16 different stations including Chapora, Terekhol, Dona Paula, Vagator, Anjuna, Baga, Reis Magos, Siridao, Mormugao, Bogmalo, Holant, Betul, Cabo de Rama, Palolem, Talpona and Polem. Among the 70 species of seaweeds discovered in this study, 52 were found in the Dona Paula estuarine and these species can be used as a source of food, feed, fertilizers and for industrial use.
A scientific article related to the Bombay Natural History Society’s study was published in the journal of geo marine sciences in 2014 and it had a mention of two new migrated species of seaweed – Erythroglossum lusitanicum, a Delesseria member endemic to the Mediterranean Sea, and Cladophora prehendens, which is endemic to Australia – which were found in Goa during the research. These species of seaweed were so far not reported in India.