Lobster Fisher Survey: Where Do Young Lobsters Live?
Kristin Dinning, PhD student at the University of New Brunswick, Department of Biology.
We’ve always assumed young lobsters live only on cobble bottom where they’re protected from predators. However, cobble bottom is rare across the lobster’s geographic range whereas mud or sand is more common.
In Fall 2012, to test whether young lobsters can be found outside cobble habitat, I placed collectors (cobble-filled cages) on mud bottom in Maces Bay, NB. When we retrieved the collectors 4 months later there were young lobsters inside, including lobsters too small to have wandered onto mud bottom from cobble areas (over 800 metres away).
This was exciting as it suggested that juvenile lobsters were living on mud bottom in Maces Bay!
Could it be that growing lobster populations and large numbers of young settlers are overcrowding cobble habitats, forcing young lobsters to settle into other habitats?
Or, could the decline in numbers of lobster predators now allow small young lobsters to survive without the protection of cobble shelters?
If so, could other habitats besides cobble become as important in supporting young lobsters until they mature and enter the fishery?
To explore what habitats young lobsters are using, and how this may have changed in recent years, I am looking for lobster fishers to fill in a short survey. The survey asks fishers where they believe small young lobsters are living (total length under 4 inches or 10 cm) and whether this is different from where young lobsters were seen in the past. The survey will be circulated in the next few months and will be available at the annual FSRS conference in February. It is important to identify all the habitats that young lobsters use and indeed it will be critical to hear what the professionals have to say.