Green Minute News continues its conversation with Marine biologist Vardhan Patankar on various issues plaguing the marine mammals as also marine biodiversity.
Q1. There have been rising incidents of dolphin deaths with their carcasses found on the beaches of Peninsular India. Elaborate.
I think it’s difficult to say if there is an increase in death of dolphins in recent years.
The phenomena of marine mammals getting washed ashore is called “stranding”.
The instances of stranding have been occurring for a long time, but it is media reportage that has improved over time. In order to find out if the number of stranding have increased, we need a good database to compare with.
Having said that we cannot rule out that there could be an increase in the number of stranding due to expansive fisheries in the country, underwater noise, water pollution, ship strikes, red tides, prey loss or habitat loss, or climate-change induced changes.
Q2. Elaborate on the relationship between fishing and marine wildlife?
Marine wildlife is a generic term used for describing wildlife that lives in our oceans.
This includes animals and other organisms that live in our seas; whereas fishing is the term used for extraction of marine wildlife. I would say that fishing can be equated to hunting. In fact, marine hunters employ the most advanced technology to chase down their prey.
ILLEGAL TRADING OF SHELLS AND CORALS, ONE OF THE CAUSES FOR DEPLETION OF MARINE SPECIES
They use nets that are several kilometres long and they drag their nets along the ocean floor and scrape up everything in their path including small crabs and juveniles of fish. Many of these vessels have freezers and other facilities to process their catch at sea. This is totally oppositive to what artisanal fishers’ practice by stalking their evening meal with a bamboo trap or wooden harpoon – even though artisanal fisheries get broadly referred as fishing.
Q3. What is the impact when the river water is blocked from reaching the oceans?
By blocking rivers from reaching the ocean there could be enormous damage to coastal ecosystems and dependent communities. If rivers are blocked, we lose a great deal of biodiversity, beauty, natural amenity and cultural values associated with estuaries and coastal systems. Many species are ‘specialist’, which means that they live only in specific habitat such as interface between river and sea.
A BLEACHING EPISODE – RISING SEA TEMPERATURES CAUSE MASS BLEACHING IN THE CORAL REEFS OF ANDAMAN ISLANDS IN 2016
Also, there are dependent communities and by blocking rivers, there is a direct impact on these species. In addition, rivers are known to clear pollutants and excess nutrients. This can accumulate over time and increase the salinity and acidity of the water and could in-turn impact associated biodiversity and communities.
Q 4. How do we ensure the protection marine mammals?
Marine mammals have to surface to breathe every few minutes and there is often accidental entanglement of marine mammals in gill nets. In this regard, we need to work with fishermen by raising awareness and ensure that they release marine mammals when caught in their nets.
Currently, there is dearth of reliable information on marine mammals’ ecology in India. To ensure their protection, we need to understand the reason behind death of marine mammals and we need effective policies (such as regulation on speed of the vessels at marine mammal frequented sites, marine protected areas) that protects marine mammals at sea.
THERE IS NEED FOR PROTECTION TO MARINE MAMMAL SPECIES (SOURCE : WIKIMEDIA COMMONS)
Raising awareness about marine mammals, training researchers in conducting marine mammals’ studies, experts advising national guidelines and local action, giving due recognition and legal protection to important marine mammal areas (IMMAs) are a few ways to protect marine mammals. Afterall, we protect what we value, and what we value we protect.
Q 5. Deep sea trawling is a major threat to many species. How serious is this problem in our country?
In India, trawling boomed in 1970s and it continues to deplete marine resources. As per available information, there are about 72,559 mechanised fishing boats across the country, of which trawlers comprise 35,228 (49 percent). Most mid and large size trawlers are armed with heavy metal rollers that are dragged across seafloor for kilometres, indiscriminately scooping up everything in their path.
HELIOPORA CORAL INSIDE MARINE NATIONAL PARK
Huge winches haul the catch on the deck. A hundred years of structure on the bottom – corals, sponges, sea fans etc which provides vital spawning habitat for a variety of marine mammals gets damaged. Adding to this is the fine mesh size of the nets that do not let juveniles and sometimes even eggs and larvae to escape. Many fishes, seaweeds, crabs, sea stars and countless other marine life gets killed in the process that ends up as “bycatch”.
OVERFISHING CAUSING DESTRUCTION TO MARINE HABITAT
(SOURCE: WIKIMEDIA COMMONS)
While research institutions such as the Central Marine Fisheries Research Institute (CMFRI), Department of Animal Husbandry and Dairying (DAHD) and the Marine Products Exports Development Authority (MPEDA) have been monitoring fish catches over the last 60 years, presumably with an eye to establishing quotas and sustainably managing the stock, currently, trawling is one of the major reasons for degradation of marine systems.
(Vardhan Patankar in Conversation with R S Tejus)