Marine Mammal Conservation
TREE Foundation with its network of STPF members is able to get first-hand information and rescue stranded whales, dolphins and various shark species including whale sharks. The “TREE Foundation Marine Mammal Stranding and Rescue Team” immediately addresses the situation and records the necessary data and archives the stranded animal data for the state Forest Department.
Introduction
Marine mammals encompass a wide variety of species and have long been a source of great interest to man for millennia.
Mammals are classified into five groups namely:
- Cetaceans (whales, dolphins, porpoise)
- Mustelides (otters)
- Pinnipeds (elephant seal, seal, sea lion, walrus)
- Sirenians (manatee, dugong)
- Ursids (polar bear)
The Marine Mammals found in the Indian Sub continent are the Cetaceans and Sirenians. Few are found in the near shore habitats and many are pelagic (open ocean). The Coromandel Coast along the states of Tamil Nadu and Andhra Pradesh, between Point Calimere and the mouth of the Krishna River in Andhra Pradesh covers southeastern India, in the Bay of Bengal. It consists of sandy shorelines, estuaries, mudflats, mangroves, and sand bars. The program area along the Coromandel Coast, has approximately 700 km of open coastline with sandy beaches, estuaries and near shore coral reefs. These sandy beaches are sporadic nesting sites for the Olive Ridley sea turtle and the inshore waters have been frequented by Indo Pacific Humpback Dolphins (Sousa chinensis).
Causes of Stranding
- Infectious disease, including parasite infestation
- Ingestion of marine debris
- Starvation
- Pollution exposure
- Trauma ( e.g., injuries from ship/boat strikes or fishery entanglements)
- Sound (human-generated or natural)
- Harmful algal blooms and associated biotoxins
- Unusual weather or oceanographic events
TREE Foundation has been recording stranded marine mammals and sea turtles along the Tamil Nadu coast since 2005.
Shortfin Pilot Whale
Tropical Whale
Blue Whale
TREE Foundation have been working with the fishing communities along the east Coast of India for Sea Turtle Conservation and have been involved in undertaking Marine Mammal Studies along the coast. The sighting of dead marine mammals and turtles along the coast are reported by the fishermen as part of the conservation program which in turn assists us in the study of probable cause of death in these stranded marine mammals and sea turtles.
TREE Foundation undertakes to continue the study and to analyze the cause of death which could be due to natural, accident caused or due to entanglement or fisheries interaction. This study has helped understand marine mammals and sea turtle species diversity along our coast since 2009. Many rare species of marine mammals that includes 14 different species of Whale, Dolphins and porpoise and 4 species of sea turtles have been recorded and their morphometric characteristics have been archived. The continued study will help re-establishing the presence of the species available in the archives and will also enable in updating the archives. In addition, the study may help in identifying and recording the presence of other species not found / recorded in the archives as yet.
Upon notification of a stranding, members of the TREE Foundation strandings team will attend to the location. If the location will take some time to reach, a local Sea Turtle Protection Force (STPF) member will be deputed to the scene in the interim whilst waiting for the team to arrive. The respective DFO/Wildlife Warden/Forest Range Officer is informed of the stranding immediately and in advance of the STPF undertaking measurements, species identification and recording data.
We actively encourage the attendance of Department officers at the stranding to oversee our work and witness the safe removal / burial of the stranded animal (if already deceased). With respect to public health removal / burial of the carcass is the essential final step in the overall strandings program involving deceased animals.
Objectives
The primary objective of attending is to assess the viability of:
- Rehabilitation
- Recovery
- Eventual release of the stranded mammal if alive
It should be noted that the great majority of strandings involve already deceased animals. It is our duty to ensure any live stranded turtles are given the best chance at survival and future release.
- If mammal is deceased, to ensure scavengers or beachgoers don't interfere
so that an accurate assessment may be carried out by the strandings team.
Additionally, recording data:
- Provides essential information regarding environmental policy making
- Helps establish the species' local populations
- Provides insight for devising suitable precautionary measures
Marine Mammals recorded over the years
Dolphins
- Risso’s (Grampus griseus)
- Bottle Nose (Tursiops)
- Common (Delphinus delphis)
- Tropical Spotted (Stenella attenuata)
- Indo Pacific Humpback (Sousa chinensis)
- Spinner (Stenella longirostris)
Porpoise
- Finless (Neophocaena phocaenoides)
Whales
- Blue Whale (Balaenoptera musculus)
- Sperm whale (Physeter macrocephalus)
- Tropical whale/ Bryde’s (Balaenoptera brydei)
- Cuvier’s Beaked Whale (Ziphius cavirostris)
- Sei Whale (Balaenoptera borealis)
- Short Finned Pilot Whale (Globicephala macrorhynchus)
- Pygmy Sperm Whale (Kogia breviceps)
- Dwarf Sperm Whale (Kogia sima)
Sharks
- Whale shark (Rhincodon typus)
Learnings from stranded Marine Mammals / Sea Turtles
It helps us to understand ocean biodiversity and gain valuable insights into the lives of the oceanic marine mammals and sea turtles such as:
- Seasonal distribution
- Natural history
- Cases of fisheries interaction
- Population health
- Environmental contaminant levels
- Incidence of disease.
- Species diversity
- In some cases, the only existing information about certain species has been learned only from stranding events.
