Orissa and the Gahirmatha beach - a world treasure
Orissa is home to a high diversity of marine and reptilian life.
Of the seven species of marine turtles, five species are found in
India. Of these, four are reported to occur in the coastal waters
of Orissa. These are the Leatherback, the Green, the Hawksbill and
the Olive Ridley, of which the Olive Ridley is the most common.
Orissa supports the Olive Ridley's three most important breeding
beaches in India - which are witness to the famous mass nesting or
arribada year after year. The earliest report of the arribada at
the beaches of Gahirmatha was made in the 1970's . Over the last 2
decades, 2 more major mass nesting grounds of Ridleys have been
discovered along the Orissa coast - the rookery at the mouth of the
Devi River and the rookery at the mouth of the Rushikulya river in
the district of Ganjam.
Today, Gahirmatha is the last place in the world, where the
arribada has been taking place consistently over the past ten
years.
Gahirmatha is the world's largest nesting ground of sea turtles
. From 1975 onwards a 100,000 to 700,000 nesting turtles came to
Gahirmatha every year. The nesting beach is a protected area that
forms part of the Bhitarkanika Wildlife Sanctuary and National
Park. The near shore breeding area was also given protected area
status by the State Government in 1997 and is known as the
Gahirmatha (Marine) Wildlife Sanctuary. The coastal waters off this
beach, where the turtles spend 6-8 months a year from October to
April, was designated as the first marine wildlife sanctuary of
Orissa and a major portion of the Gahirmatha coastline has also
been included in the Bhitarkanika National Park .
The Olive Ridley Turtle
Olive Ridley turtles (Lepidochelys olivacea), named for the
olive colour of it's heart-shaped shell is one of the smallest of
the marine turtles, with adults reaching 2 to 2½ feet in length and
weighing 80 to 110 pounds. The species can be identified by the
uniquely high and variable numbers of scutes and is a widely
distributed species . It can get to about 60-100 years old, and
attain sexual maturity between the 8-12 years. Nesting takes place
1 to 3 times in a single season and produce anywhere between 80-170
eggs each time. The Olive Ridley is omnivorous, eating shrimp,
jellyfish, crabs, snails, fish, algae and sea grass. The ridleys
are most well known for their mass synchronized nesting behaviour,
known as arribadas, with literally thousands of turtles nesting
simultaneously in season.
Recent genetic studies suggest that these Olive Ridleys that
nest in Orissa and India's east coast are distinct from other
populations and could even be the ancestors to populations in other
ocean basins. This theory emphasizes the need to conserve this
population.
The Olive Ridley, like all other species of turtles, is
protected in India under Schedule I of the Wildlife Protection Act,
1972 (Amended 1991). All species of marine turtles are listed as
'endangered' as per the International Union for the Conservation of
Nature (IUCN) red data book.
Marine turtles are also protected under the Convention on
International Trade in Endangered Species of Flora and Fauna
(CITES) and the Convention on Migratory Species (CMS), and the
trade of sea turtles is prohibited through these international
agreements. India is a signatory to all these conventions.
Threats to the Olive Ridley Turtle
Over the last decade close to 100,000 adult turtles have
suffered from human activities at the coast of Orissa, with
mechanized fishing being the principle cause. Turtles are very
vulnerable, as only one in every 1000 hatchlings survives to
adulthood. The present high mortality rates have been continuing
for several years. Each year that passes without improvement will
lead to the loss of thousands of breeding turtles and a decline in
the population.
Destructive coastal development
New Port: The proposed construction of a new Port at Dhamra, 20
kms from Bitharkanika sanctuary is the most recent and serious
threat to the Olive Ridley Turtles and for the survival of the
unique ecological biodiversity of the region.
The construction work for the Dhamra Port will severely disturb
the ecosystem. Once the port is functional, the increased volumes
of shipping traffic and the resultant pollution from oil spills,
chemical leaks, and other effluents will pollute the waters and
destroy the turtle congregation zones.
Offshore drilling exploration for gas: Offshore exploratory
drilling for Gas and Oil in the turtle migration and congregation
zones is another recent and probably the most serious threat. The
granting of permissions for drilling without appropriate impacts
assessment and a study of turtle migration patterns and routes is
of special concern.
Artificial lights: Artificial light from anchoring vessels,
ports and other coastal development activities disrupt the breeding
and nesting of the Olive Ridleys. Turtle hatchlings are extremely
sensitive to artificial light. Even the faintest light can
disorient them enough to make it impossible for hatchlings to find
the sea. Also adults rely on light cues for orientation. For
example the light pollution from the DRDO facility on Wheeler
Island, disorienting turtle hatchlings.
Pollution: Besides the increasing volumes of untreated urban
sewage, agricultural chemical runoff and waste, the effluents from
chemicals and pesticides factories along the coast especially at
Paradip continue to irreversible contaminate the coastal rivers,
creeks and beaches.
Unsustainable Fisheries
Illegal fishing: Besides, the local licensed mechanized fishing
boats, hundred of illegal motorised vessels, both trawlers and gill
netters, from West Bengal, Andhra Pradesh, Burma and Thailand fish
in these waters and are difficult to police during the 'fishing
holiday season' that coincides with the congregation periods.
When these vessels speed through the masses of turtles, they
disturb the egg carrying females and mating pairs that leads to
breeding failure. Moreover, the turtles get wounded or killed by
the slashing of propellers of the mechanized boats and every year
hundreds of turtles get entangled in trawl and gill nets and die of
drowning .
Climate Change
Erosion of coastline: Due to the frequent cyclones and extreme
weather conditions alternating between floods and droughts, the
coastline of Orissa is changing drastically, creating new river
mouths, breaking beach stretches and massive changes in the
topography that will eventually impact the nesting behaviour of the
turtles.