Even though temperatures are still cold and snowflakes still occasionally flurry in the air, the longer days indicate that spring is on its way. In the oceans, productivity is increasing once more after the water has been well mixed during winter storms and nutrients are abundant at the sea surface.
On the rocky beaches around Kodiak seaweeds are beginning to grow again. Kodiak’s third grade students on their visits to the Ocean Science Discovery Lab are studying seaweeds (among many other things) and I have been prowling the beaches and docks to collect the study materials.
Recently, Mandy Lindenberg and Sandra Lindstrom published a guidebook to seaweeds in Alaska. Color-coded, the book sorts the seaweeds into the three groups red, green and brown, but it also has an additional section for sea lichens and one for sea grasses.
Unlike seaweeds, sea grasses are actually flowering plants with roots, blades and flowers. In seaweeds, the parts resembling root, stem and leaf are called holdfast, stipe and blade. While true roots deliver nutrients and water from the soil to the plant, holdfasts are only for attachment. The blade and stipe of the seaweed take the dissolved nutrients directly out of the water.
Also, while most land plants have many different cells with special functions in their stems and leaves, many seaweeds only have few types of cells.
The students often describe the green seaweeds as slimy and thin. Green seaweeds consist of only one layer of cells and some grow simply by division of cells into long chains. The result looks like green hair, and in fact the names “northern sea hair” or “mermaid’s tresses” reflect this.
Most commonly seen from our shores is the green sea lettuce and it is an easily collected, very nutritious seaweed that can be enjoyed raw or dried. For those interested in collecting edible seaweeds, there is a booklet by Dolly Garza with great descriptions of common edible seaweeds and instructions how to collect, prepare and enjoy them. Spring is a good time to collect them young and tasty.
The very common rockweed or popweed belongs to the brown seaweeds and grows on rocks along the high tide line. Most kids know that you can pop the little bulbs at the end of the blades and they make a small popping sound. For eating it is better to collect young plants without those bulbs. These can be crunched fresh or steeped in boiling water and mixed into salads or stirfries.
Several other brown seaweeds are edible, the most auspicious of these being the large bull kelp. A fresh specimen can be cut up and the stipe can be pickled, while the blades can be used dried or fresh. The larger kelp grow further down on the beaches and are only accessible at low tides.
Some of the red seaweeds stand out by their obvious bright red color. Most of them are smaller than the kelps, growing to about one foot long. Most commonly found washed up on the beaches around town is the red sea fern, which is a very pretty plant. When you look closely, each branch divides into more branches and the very tips of the seaweed are flattened, resembling the structure of a fern leaf. Often, the students describe them as feather-like. Their pretty structure and vibrant dark red color has inspired artists to dry them and use them to make note cards and pictures.
Today, I will try this with a class of High School students, because I strongly believe that we only protect what we care for and we can only appreciate what we know.