Get to know Sugar Kelp

Sugar kelp is a brown seaweed that is light to medium brown in colour. It has a single blade that lacks a midrib in its blade, like other members of the Laminaria genus. The cylindrical stripe can grow up to 50 cm long and approximately 9 mm in diameter. The stripe supports one undivided blade that is moderately thick and up to 3.5 m in length and 18 cm wide. The blade has a ruffled appearance that is more prominent along the edges. Often, there are two rows of bullations near the base which creates a puckered or blistered texture.

Habitat

Sugar kelp grows on the rocks of the low intertidal and shallow subtidal zones along protected to semi-protected shorelines as it does not thrive in heavy surf. It can often be found in the lower part of the intertidal zone well below a band of Ribbon Kelp (Alaria marginata). Sugar kelp’s ideal temperature range is between 10-15°C, but it has been known to survive beneath ice in the winter and up to around 24°C in the summer (talk about resilience!).

Names

It grows fastest in the late winter through to spring and growth slows or even stops in the summer months. (Fun fact: this growth pattern results in annual growth rings in the stripe that can help to age a plant just like aging a tree). Sugar kelp is quick growing at about 1.25 – 6 cm per day.

Sugar kelp is eaten by species such as the Dusky Tegula snail (Tegula pulligo) and sea urchins along the BC coast. Research may suggest that chemicals released by Sugar kelp attract the urchins.

Where it Grows

Aleutian Islands, Alaska, to Santa Catalina Island, California; Japan; Arctic Ocean; Russia; North Atlantic; North Sea

Indigenous Uses

Sugar kelp was used along with Giant kelp (Macrocystis integrifolia), eelgrass (Zostera marina) and seagrass (Phyllospadix spp.) along with bundles of western hemlock boughs (Tsuga heterophylla) or other conifer boughs to harvest herring. The fonds or branches were anchored in the water and used to gather the precious food. They were then removed from the water and hung up to be dried and used all winter. Eggs on the seaweed were eaten together. This practice was performed by many Coastal Nations, a specific example being the Hesquiahat Nation.