The entertaining spectacle of wild fishes chasing lasers shone onto the seabed could provide scientists with an innovative way of measuring their territory size and therefore helping to sustainably and spatially manage fisheries and associated habitats in the future, a new study suggests.
Research led by the University of Plymouth has for the first time explored how wild fishes behave spatially when reacting to an artificial stimulus, in this instance lasers used for routine monitoring in a Marine Protected Area (MPA).
Focusing on the wrasse populations of Lyme Bay, off the coast of southern England, it found that certain species would ‘chase’ the lasers – mounted on a sled towed above the seabed – apparently as if to try and ward them off and protect their territories.
The researchers then compared chase distance between species, showing that some wrasse would chase the lasers for up to five metres and that there were also differences based on size and gender within species.
Writing in the Journal of Applied Ichthyology, scientists say that understanding the territory size and home range of marine organisms is an important factor to consider for the implementation and management of MPAs.
And while this study focused on wrasse, which are increasingly being used as cleaner fish within salmon aquaculture, they believe the method has the potential to be developed in order to investigate aspects of territoriality and aggression in other species of wild fish.
The project was conceived by Senior Research Fellow Dr Emma Sheehan, and carried out by Pete Davies, who was at the time based at the University of York.
