Review: How to be a Deep-Sea Fish with Thom Linley

Review: How to be a Deep-Sea Fish with Thom Linley

Friends were entertained and enlightened by stories from Te Papa Curator of Fishes Thom Linley about his explorations of the deep sea and the fascinating creatures he has encountered.

Thom has worked with deep-sea fish for 10 years. His work involves dropping a camera down to places no one has seen before. Which means he is the first human to see a range of species of the deepest fishes, including those living in the Kermadec Trench. His work features on shows such as Blue Planet II and he co-hosts The Deep-Sea Podcast.

Our perception of deep-sea fish gained from watching shows and seeing photos may be that they’re big and dangerous alien-like monsters. Thom disabused us of this notion by showing us specimens of these fish; they’re actually rather small and not scary at all.

The deep sea covers 54% of our planet. There are a number of problems with surviving in an environment down to 10,000 metres. Thom took us through some of the solutions fish have evolved.

Deep below the sea no sunlight trickles down. Although it may look freaky, having massively sensitive bigger eyes helps deep-sea fish compensate for the lack of light and conquer the darkness.

Fish living from 4,000 metres to 8,000 metres deep face pressure from the water and are squeezed from all sides. To survive, their bodies contain a chemical called TMAO which counteracts the effects of pressure.

Very little food makes it down to the depths making the fight to survive challenging. Smell is a primary sense in finding food. Thom shared images of fascinating fish he has studied such as the arrowtooth eel which will eat anything it finds. The deep-sea lizardfish with its huge jaws is a predator. Deep-sea fish save energy by living life slow, but there is much to learn, for instance how they reproduce and communicate.

Living down at 10,000 metres, the world’s deepest fish is the bibby which Thom describes as ‘cute’, helping to change perceptions these creatures are strange and scary. He spends a good deal of time engineering strong equipment that will survive the pressures of the deep. Seeing delicate little fish swimming around this equipment is something you don’t expect to see.

Thom gave us intriguing insights into life down in the deep sea, an environment on our planet that very few will ever see.


Loralee Hyde

Photo caption: Te Papa Curator of Fishes Thom Linley explaining the features of a deep-sea lizardfish. Credit: Loralee Hyde.