Shark Week 2019
Indonesia’s First Record of ‘Living Fossil’: The Goblin Shark
By Hollie Booth and Muhammad Ichsan | August 2, 2019
Indonesia lies at the heart of the Coral Triangle: the global epicentre of marine biodiversity. It is a hotspot of unique and diverse species, and considered one of the most irreplaceable regions in the world for sharks, rays, and their cartilaginous relatives (Class Chondrichthyes).
An official count puts the number of cartilaginous fishes in Indonesian waters at 221. However, researchers at WCS (Wildlife Conservation Society) recently added to this count through their discovery of a rare deep-sea shark — the Goblin Shark (Mitsukurina owstoni) — at a landing site in Aceh, Indonesia’s Westernmost province.
The goblin shark has previously been recorded in Indo-pacific waters, off northern Australia, but has never been officially recorded in Indonesia. In April 2019, four individuals were accidentally captured in a bottom gillnet fishery operating off the coast of Aceh Jaya.
Sometimes called a ‘living fossil,’ the goblin shark is the only extant representative of the family Mitsukurinidae. This family of sharks is an ancient lineage some 125 million years old, which evolved during the early cretaceous period and would have coinhabited the earth with dinosaurs.
Goblin sharks typically inhabit depths of greater than 100 meters, though they have been caught at more than 10 times that depth. The distinctive elongated snout, which helped to give the goblin shark its name, is important for feeding at the darkened reach of the water column.
Covered with electro-sensory ampullae of Lorenzini, the snout can detect minute electric fields produced by nearby prey (teleosts, cephlapods and crustaceans). Its jaws can then extend rapidly, almost to the end of its snout, to snatch the prey.
“Sometimes called a ‘living fossil,’ the goblin shark is the only extant representative of the family Mitsukurinidae. This family of sharks is an ancient lineage some 125 million years old, which evolved during the early cretaceous period and would have coinhabited the earth with dinosaurs.”
Our team member — Muhammad (WCS’s Sharks and Rays Officer for Aceh province) — has credited the discovery to the local research team in Aceh Jaya, and their close relationship with the fishing community.
Unlike many of its cartilaginous relatives found in Indonesian waters, the goblin shark is not currently considered at risk of extinction. This is primarily due to its wide distribution and its deep-water habitat, which is at lower risk of fishing pressure.
However, this could change with recent rapid expansion of deep-sea fisheries. Many deep-water species have slow life cycles and cannot easily recover from fishing pressure. This is particularly risky for rare species like the goblin shark, for which there is little available life history and ecological information to make informed management decisions.
This underlines the importance of continued basic research for data-scarce shark species and fisheries to ensure they don’t disappear right under our nose, as is thought to be the case for many species in the Western Indian Ocean.
“WCS has been working on shark research and management in Aceh province since 2016. Indonesia’s biggest shark-fishing province, Aceh is home to a unique marine management institution called The Panglima Laot, which roughly translates to ‘Commander of the Sea.’”
WCS has been working on shark research and management in Aceh province since 2016. Aceh is thought to be Indonesia’s biggest shark-fishing province. It is home to a unique traditional institution for fisheries and marine management called The Panglima Laot, which roughly translates to ‘Commander of the Sea’.
An Aceh shark management working group — which consists of government, NGOs, researchers and the Panglima Laot — has recently been inaugurated, to develop a shark management plan for the province.
In Aceh Jaya, where the goblin sharks were discovered, other priority species including hammerhead sharks and wedgefish are regularly caught as valuable secondary catch.
WCS has been working with fishers, local government, and the Panglima Laot to better understand shark catch patterns and collaboratively design fisheries management measures to reduce threats to these vulnerable species.
GPS trackers have recently been deployed on a number of vessels, to better understand the precise locations of shark catch hotspots, and local spatial management rules have been established to reduce fishing pressure in critical shark habitat.
These multi-faceted approaches — which combine management-relevant research with stakeholder engagement to effectively reduce fishing pressure on sharks — are critical to ensuring their survival. These ancient fish have survived in our oceans for millions of years. What a shame for them to blink out in just a few short decades.