Another threat is that, due to an invasion by filter-feeding zebra mussels, the Great Lakes are actually getting clearer, says Van Nynatten. This has allowed some species to migrate deeper than they typically would, meaning increased competition — including from other species of sculpin — and predation for the deepwater sculpin.
In 2006, the Great Lakes-Western St. Lawrence populations of the deepwater sculpin were listed as a species of special concern under the Species at Risk Act. This was re-examined and confirmed in 2017. By sequencing the genome now, Lovejoy and Van Nynatten say they are taking a “biodiversity snapshot, freezing it in time.”
Sequencing a genome is a huge undertaking — “500 million little nucleotides all strung together that need to be assembled into what makes up the chromosome of this fish,” says Van Nynatten — and as such, the project is still in its early stages.
Still, Lovejoy has clear goals for the future, including sequencing the genome of the fourhorn sculpin — the close Arctic relative. After that, other populations of fourhorn sculpins that have made the marine to freshwater transition — populations he describes as “little independent, natural experiments.”
Comparing these genomes with that of the deepwater sculpin would undoubtedly reveal more about this unassuming fish turned iconic Canadian species. As would comparing this genomic “snapshot” with future iterations.