October is national seafood month!
What do you think of when you hear the word “seafood?” Chances are you think about tasty sea creatures like shrimp and salmon—the creators of the above seafood month icon surely do. But what about sea vegetables? They are just as much sea and just as much food as shrimp and salmon. (They may even be more sea than salmon, which spend a lot of time in freshwater!) Also known as seaweed and marine algae, sea vegetables are a type of healthy, vegetarian seafood that is seriously underrated. Sea vegetables are similar to land vegetables in that they need sunlight, water, and nutrients to grow, but unlike their terrestrial counterparts, sea vegetables don’t have roots; the whole body, called the thallus, takes up nutrients directly from the water in which it bathes. One of the best parts about sea vegetables is that in California, they are free—you don’t need a license to harvest them recreationally!
The western U.S. has miles and miles of undeveloped coastline with abundant, healthy algae readily available for harvest at low tide. Here, I describe the full process of putting seaweed on your plate and focus on a few of my favorite northern California seaweeds, many of which are available throughout the entire west coast. For more information on edible seaweeds throughout California and beyond, check out these pages on commonly harvested marine algae in California and common seaweeds of the Pacific Northwest.
Accessing sea vegetables
Most sea vegetables grow on intertidal rocks. The first step finding them is to locate an accessible intertidal area with rocky substrate. Check local tidepooling and natural resource websites for suggestions, but make sure the site you pick is not in a Marine Protected Area, state park, or state beach where harvest is not allowed. Next, plan your visit during a low tide, ideally when the tide level is zero ft. or lower. There are lots of websites with this information, but I like to use NOAA’s tide predictions. Arrive at least one hour before the low tide and plan to leave about 2 hours after (the tide will be coming in faster at that point and you don’t want to be out on the rocks when the ocean returns!) Finally, check the marine forecast to avoid storms and big waves.
Harvesting sea vegetables
To harvest sea vegetables, you just need a few simple tools: a bucket or bag to hold your harvest (Ziplocs work great), scissors or a sharp knife, weather-appropriate clothes, sturdy shoes, and some natural resource knowledge. Algae are (partly) the base of the intertidal food web, so it is important to harvest them sustainably by leaving behind a large portion of the thallus (remember, that's the name for the body of a seaweed) and only cut what you will keep. Additionally, there are laws prohibiting selling marine algae without a commercial algae harvesting license and there is a 10-lb. limit per person per day for recreational harvest, which does not require a license. Harvest is not allowed in any of California’s Marine Protected Areas, and due population declines, harvest or even disturbance of sea palm (Postelsia palmaeformis) and seagrass (Phyllospadix spp. or Zostera marina) is prohibited. (Fun fact: seagrass and eelgrass are not algae, but true flowering plants! And you don't want to eat them anyway.) Similar rules may apply in Oregon and Washington. Finally, always avoid harvesting near polluted areas like large storm drainage pipes and sewage outfalls.
Cooking with sea vegetables
While I could probably get away with calling myself an expert on finding and harvesting sea vegetables, I am by no means an expert on cooking with them. I only started doing it this summer! However, I think it's fantastic to eat wild-harvested foods and I want to encourage people to give it a shot. So here's my disclaimer: all the cooking info is written by an amateur sea vegetable chef and is probably at least a little inaccurate.
Normally, I love eating raw vegetables, but unless you’re a sea snail, most sea vegetables are not meant to be eaten raw! They are extremely chewy and can be a little slimy. To prepare your seaweed, as soon as you get home, rinse it in tap water to remove surface impurities (and any tiny, clinging herbivores!). If you don’t plan to use your seaweed right away, you should dry it, though it can be stored fresh in the refrigerator for a few days, after which point it will become very slimy. Drying can be done in the oven (on warm), in the sun, or in a dehydrator, then store the seaweed in an airtight container for months or even years.
You can cook most sea vegetables by frying or roasting in a pan or in the oven for just a few minutes. You don't need to rehydrate them for this, but oiling them is a good idea. They’re done when they’re crispy and very brittle and they may change color. If you want to make noodles (e.g. wakame noodles), you should use hydrated seaweed so it is easy to cut. You can rehydrate your dried seaweed by soaking it in warm water for about 10 minutes. Either way, if you're concerned about your seaweed having harmful bacteria on it, don't eat it raw; cooking will kill bacteria. After cooking, you can eat your seaweed plain; grind it up to use as a salty seaweed sprinkle topping; use it like any other vegetable in your recipes—I like to add it to stir fries; or plop a dried alga in your boiling pot of soup, rice, or beans to add flavor. Find more great cooking tips in this Sea Greens 101 article by Heated!
Common northern California sea vegetables
Here are some pictures and facts about my favorite northern California sea vegetables!
Nori
Scientific name: Pyropia perforata
General category: Red algae (Phylum Rhodophyta)
Description: Grayish green to brownish purple and often very frilly. Smooth and one cell thick; you can see through it!
Used in sushi, but ground up and flattened into sheets
Nori makes great chips when fried in coconut oil!
Photo: CDFW
Scientific name: Ulva lactuca
General category: Green algae (Phylum Chlorophyta)
Description: Smooth, bright green and in broad sheets. Two cells thick; you can see through this one as well!
Fry or roast, but not as good for chips
Can be added fresh to salads
Wakame
Fresh wakame (left) and dried. Photos by CDFW (left) and Gina Contolini
Scientific name: Alaria marginata
General category: Brown algae; more specifically, wakame is in the kelp family (Phylum Ochrophyta, Family Laminariaceae)
Description: Dark green, wide, smooth ribbons with thick midrib; very long (up to 19 ft!)
Wakame is used traditionally in miso soup; it can also be used to flavor rice or soup stock
Since it is so long, it is great for making noodles!
Kombu
Scientific name: Laminaria setchellii
General category: Brown algae, kelp family (Phylum Ochrophyta, Family Laminariaceae)
Description: Dark greenish brown. Slender, erect stipe (stem) leading to wide, smooth blade with many dangling finger-like strips.
Good in soup stock or to add in rice or bean water.
Photo: CDFW
Sweet kombu AKA sea cabbage
Scientific name: Hedophyllum sessile
General category: Brown algae, kelp family (Phylum Ochrophyta, Family Laminariaceae)
Description: Dark greenish brown; long, thick blades with no stipe. Looks similar to kombu tips; however, sweet kombu can have smooth or wrinkled blades.
Great as a soup stock or add in water when cooking rice or bean
Photo: CDFW
Sea oak AKA sea fern
Scientific name: Stephanocystis osmundacea
General category: Brown algae (Phylum Ochrophyta)
Description: Dark greenish brown with stiff stipe and many branches. Branches have pneumatocysts (floats) that look like many small beads strung together.
You can eat it raw, but I haven’t tried!
Often pickled
Photo: CDFW
Dulse
Scientific name: Palmaria mollis
General category: Red algae (Phylum Rhodophyta)
Description: Reddish pink with many small blades (under 1 ft.) that are thick, leathery, and usually lobed
Great sauteéd with other vegetables or fried like chips!
Photo: Algaebase.org
