Scavengers enjoy porpoise bait

Baited cameras have been in use since the late 1960s to study scavenging animals in the deep-ocean. In this instance a harbour porpoise has been used as bait 2 m below a photographic lander system. The porpoise had died following attack by bottlenose dolphins and was obtained for experimental use from The Scottish Agricultural College Wildlife Unit, Inverness.

There is no sunlight below 1000 m water depth and therefore the animals survive by foraging and consuming food which falls down from the surface waters above. The porpoise therefore provides a tasty and welcome treat, hence all the activity! The porpoise was deployed on the lander system in the Porcupine Seabight, off the southwest coast of Ireland. The images were taken once every 3 hours for 16 days within this sequence, but the actual carcass was deployed for 6 months. Even the scientists involved were surprised to see the carcass completely stripped bare in only 16 days. The mesh is 50 mm squares to enable a sense of scale.

Many species of fish are visible with the movie, which include the deepwater arrowtooth eel, Histiobranchus bathybius, the abyssal grenadier, Coryphaenoides armatus, the blue hake, Antimora rostrata, and the cusk eel Spectrunculus grandis. Many invertebrates were also observed including a high number of squat lobsters, sea cucumbers and an octopus.

Video copyright: Oceanlab, University of Aberdeen

Category:

Science & Technology

Tags:

• Scavengers
• baited camera
• time lapse photography