Maine's Sugar Kelp Has 4 Distinct Populations

A new study has found four distinct populations of sugar kelp in Maine, a crucial discovery for the state's kelp aquaculture industry. The study, led by researchers at Bigelow Laboratory for Ocean Sciences, provides the most comprehensive assessment to date of the genetic diversity and population structure of sugar kelp along Maine's coast.

The team collected genetic material from sugar kelp at 11 sites spanning Maine's 'outer coast'. The findings, published in the Journal of Phycology, show moderate levels of diversity within each study site and identified the four distinct populations, shaped by the oceanography of a complex and dynamic coastline.

The study's senior author, Doug Rasher, a senior research scientist, highlights the importance of regional management strategies to protect and leverage the genetic resource of sugar kelp. Genetic diversity in sugar kelp can bolster resilience to marine heat waves, which is critical for the long-term sustainability of Maine's kelp forests.

## Why it matters Maine has the largest kelp aquaculture industry in the country, and the annual harvest of reproductive tissue from the wild relies on the health of the state's kelp forests. The loss of these forests has cascading impacts on coastal ecosystems and compromises the wild resource that the aquaculture industry depends on. Understanding the complex structure and potential genetic barriers of remaining kelp forests is essential for responding to this loss and ensuring the long-term viability of the industry.

The study's findings have significant implications for the management and restoration of Maine's kelp forests. By recognizing the four distinct populations of sugar kelp, conservation efforts can be tailored to protect and leverage this genetic resource, ultimately supporting the resilience of the state's kelp forests and the aquaculture industry that relies on them.