MASS MORTALITY OF LEPIDOCHELYS OLIVACEA OBSERVED AT KOTTAPETA BEACH IN SRIKAKULAM ALONG THE EAST COAST OF ANDHRA PRADESH, INDIA

K.L.N. MURTHY¹ & K.V. RAMANA MURTHY²

1Programme Officer, Centre for Environment Education, Ahmedabad, Gujarat, India 2Executive Director, Green Mercy, Srikakulam, Andhra Pradesh, India

Email: klnmurthy25@gmail.com

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The coastline of Andhra Pradesh is one of the important sporadic nesting habitats of olive ridley turtles (Lepidochelys olivacea). The species is known to nest on the northern Andhra Pradesh coast (Rajasekhar & Subba Rao, 1993; Priyadarshini, 1998) which encompasses three districts namely Srikakulam, Vizianagaram and Visakhapatnam. Olive ridley turtles are categorised as Vulnerable on the IUCN Red List (IUCN, 2010) and are included in Schedule I of the Indian Wildlife (Protection) Act, 1972. This coast may also serve as an intermediate developmental habitat for sub-adult ridley turtles and for juvenile and sub-adult green turtles Chelonia mydas (Tripathy et al., 2003).

About 154 carcasses of Lepidochelys olivacea that were entangled in fishing trawlers were washed ashore at Kottapeta coast, near Bhavanapadu Fishing Harbour in Srikakulam district (18°16’37.17”N & 83°53’47.62”E ) along the coastline of north coastal Andhra Pradesh (Figure 1) on 17th March 2011. The local fisher folk claimed that the big trawl nets used by the adjacent harbour located at Visakhapatnam city were responsible for these deaths.

A team comprising Forest Department officials, local wildlife conservation NGOs and volunteers visited the spot and examined the carcasses. All the dead turtles were adults. The beached turtles were sexed using external characteristics. Of the dead turtles that were sexed, 86% were females, 6% were males and 8% were unidentified carcasses. Curved carapace length (CCL) and curved carapace width (CCW) were measured for all dead turtles.

These turtles were probably migrating towards their mass nesting grounds in Orissa (some of them may also include the resident nesting population) as the coastline of Andhra Pradesh is believed to form part of the migratory route of the turtles that nest in Orissa (Tripathy et al., 2003). The fact that there are many gravid females amongst the dead ones supports the theory (Figure 2). It is evident that non-use of Turtle Excluder Devices (TEDs) in mechanised fishing trawlers was the main reason for these deaths. Depredation of eggs by humans and feral animals is also widespread in the region. In a similar incident, several olive ridley carcasses were found washed ashore in January 2008 at Thikkavanipalem in Parawada mandal, about 45 km from Visakhapatnam city (Rajasekhar & Murthy, 2008).

Incidental capture in trawl and gill nets is a major cause of marine turtle mortality along the east coast of India (Rajagopalan et al., 1996). In fact, fisheries related mortality is usually higher along the northern coast of Andhra Pradesh, which is probably due to the higher density of turtles in the region.

The indigenous TED developed by the Central Institute of Fisheries Technology (CIFT), Kochi is being promoted in Andhra Pradesh by the State Institute of Fisheries Technology, Kakinada (Bhavani Sankar & Ananth Raju, 2003). However, fisher folk have not keen using TEDs and the operation of mechanised trawlers in the offshore waters during the nesting and breeding season is rampant. Apparently, violation of Coastal Regulation Zone (CRZ) regulations and failure of the authorities to keep a tab on the perpetrators caused this ecological mishap. Besides, breeding olive ridley turtles are also threatened by Casuarina plantations, beach erosion, artificial illumination, depredation of eggs and hatchlings along this coastline.

The control measures which can be taken up by the authorities to reduce fisheries related mortality include:

• Declaration of no fishing zones during the nesting season in areas where the concentration of marine turtles is high, especially near river mouths (Godavari and Vamsadhara).
• Enforcement of laws: CRZ Rules, the Andhra Pradesh Marine Fishing (Regulation) Rules, 1995.
• Enforcement of use of Turtle Excluder Devices (TEDs).

Although awareness campaigns in the form of ‘turtle walks’ and community education programmes in fishing villages are organised every year by Green Mercy (a local NGO and a member of Turtle Action Group), involvement of all stakeholders in sea turtle conservation on a larger scale is vital for securing the long term survival of the species and their coastal nesting habitats in the region.

Literature cited:

Bhavani Sankar, O. & M. Ananth Raju. 2003. Implementation of the Turtle Excluder Device in Andhra Pradesh. Kachhapa 8: 2–5.

IUCN. 2010. Lepidochelys olivacea. In: IUCN 2010. 2010 Red List of Threatened Species. Available at: http:// www.iucnredlist.org/apps/redlist/details/11534/0.

Priyadarshini, K.V.R. 1998. Status and nesting of olive ridley sea turtles (Lepidochelys olivacea) along the Northern Andhra coast. CAPART, WWF-India.

Rajagopalan, M., E. Vivekanandan, S. Krishna Pillai, M. Srinath & A. Bastian Fernando. 1996. Incidental catch of sea turtles in India. Marine Fisheries Information Service T & E Series 143: 8–16.

Rajasekhar, P.S. & M.V. Subba Rao. 1993. Conservation and management of the endangered olive ridley sea turtle Lepidochelys olivacea (Eschscholtz) along the northern Andhra coastline. B.C.G. Testudo 3(5): 35–53.

Rajasekhar, P.S. & K.L.N. Murthy. 2008. A note on olive ridley (Lepidochelys olivacea) mortalities at Thikkavanipalem beach in Visakhapatnam, Andhra Pradesh, India. Indian Ocean Turtle Newsletter 7: 22–23.

Tripathy, B., K. Shanker & B.C. Choudhury. 2003. Important nesting habitats of olive ridley turtles along the Andhra Pradesh coast of eastern India. Oryx 37: 454–463.