Crabs
There are numerous species of crabs in the waters off the coast of the Pacific Northwest.
Crabs come in a wide range of sizes. The species that are targeted by fishermen are those that have both large and have a high enough ratio of meat to shell. In the Pacific Northwest, the most famous (by a long shot) is the Dungeness crab.
Crabs are decapods, crustaceans with ten legs (the claws are modified legs). Taxonomically, we can place our region’s crab species in two infraorders within the order Decapoda.
True crabs: true crabs are in the infraorder Brachyura. We can group the species found here into two types, rock crabs and spider crabs.
King crabs: king crabs are in the infraorder Anomura and are descended from hermit crabs.
In the Pacific Northwest, for culinary purposes, we have three species of rock crab, one species of spider crab, and four species of king crab. In addition, we also have an invasive species of true crab that may have culinary potential.
Cooking with crabs
Crabs are primarily eaten for their meat. Crab meat is sweet and mild, and found mostly in the claws and legs.
The roe and the tomalley are also eaten. The tomalley is the crab’s hepatopancrea; it provides similar functions to a liver and pancreas in mammals.
The shells can also be used to flavor broths.
Safety precautions
Like other shellfish, crabs are susceptible to toxins from algae blooms, which can bioaccumulate in crabs to levels that are unsafe for human consumption. Local authorities monitor algae blooms to prevent illness occurring from consuming shellfish. Be mindful and check with them if you’re catching your own.
Crabbing regulations and size
To prevent overfishing, each state has its own regulations with regards to crab fishing; besides setting seasons, these are generally catch limits as well as sex and minimum size requirements.
Crabs are measured according to their carapace (central shell), not including their legs. Minimum size requirement refer to this measure.
Species
Rock crabs
Dungeness crab (Metacarcinus magister)
Red rock crab (Cancer productus)
Brown rock crab (Romaleon antennarium)
Snow crabs
Tanner crab (Chionoecetes bairdi)
King crabs
Brown box crab (Echidnocerus foraminatus)
Puget Sound king crab (Echidnocerus mandtii)
Oregon hair crab (Paralomis multispina)
Scarlet king crab (Lithodes couesi)
Green crabs
European green crab (Carcinus maenas)
Dungeness crabs
Three species of rock crab are commercially fished for in the Pacific Northwest. Of these, by far the most important is the Dungeness crab, which supports a major fishery in California, Oregon, Washington, British Columbia and Alaska.
Dungeness crabs (Metacarcinus magister) can reach 10 inches in size, but are more commonly 6 or 7 inches across. Ranging from Alaska to Baja California, these crabs are found in large numbers throughout the Northwest Coast. They are valued for their high ratio of meat to shell which sits at about 25% of their weight. Juvenile Dungeness crabs are often confused with the smaller graceful rock crab (Metacarcinus gracilis). The season for Dungeness crabbing starts in late fall or early winter (nowadays, usually winter).
Habitat ranges
Although most of the crab species covered here have ranges that cover an extensive area of the West Coast, their population densities vary a lot within those ranges. A crab species can be plentiful in one city area, but completely absent just miles away; it depends a lot on the exact nature of the coastline.
Rock crabs
In addition to the Dungeness crab, two other native rock crab species are targeted, though in much smaller numbers. These are the red rock crab and the brown rock crab.
Both are caught in greater numbers in California, but a fishery is present in our region as well.
The red rock crab (Cancer productus) is a crab with large, black-tipped claws. Red rock crabs measure up to 8 inches across, though they’re usually less than 6 inches. They share a similar range to Dungeness crabs. Red rock crabs are not commercially targeted as frequently as Dungeness crabs, which have more meat and are easier to crack open, but they are flavorful and good to eat.
Because, for whatever reason, some people call them “Japanese crabs”, there is a misconception that the red rock crab is invasive, but this is factually untrue since they’re native and common.
The brown rock crab (Romaleon antennarium) ranges from Alaska to Baja California, but is most abundant in Central California; they are rarely seen north of Coos Bay, Oregon. Brown rock crabs are similar and closely related to red rock crabs. They also have black-tipped claws, but are a bit more brown in color and have more hair on their legs.
Snow crabs
Tanner crabs (Chionoecetes bairdi) are the most common, in the Northwest Coast, of several species of long-legged spider crab that are referred to commercially as “snow crab”. Tanner crabs are found from the coast of Oregon up to Alaska and down to northern Japan. They can reach a shell width of up to 8 inches, but they are usually closer to around 5 inches, with most of the meat in the legs.
There is a major fishery for tanner crabs in Alaska, but not in the Northwest Coast region, where they are less common and found in deeper waters. Though they have sometimes been targeted historically, these crabs are caught and sold mainly as bycatch today.
The main species called snow crab, Chionoecetes opilio, is found further north than our region. There are also a couple of species of deepwater snow crabs, Chionoecetes tanneri and Chionoecetes angulatus, that are found from California north to Alaska, but they are not fished commercially and they are not easily fished due to their deepwater habitat.
King crabs
Brown box crabs (Echidnocerus foraminatus) are a deepwater species of crab that is found from Alaska to southern California. Their carapace can reach widths of 4 to 6 inches across and they have a good meat-to-shell ratio and large claws. In Oregon, box crabs have been briefly commercially targetted in the 1980s and again the late 1990s when crab prices increased due to a shortage of Dungeness crab. Currently, in Oregon, the fishery is managed but very small and considered experimental. They can be caught year-round (except the month of November, to prevent Dungeness fishing).
Native from Alaska down to northern California, the Puget Sound king crab (Echidnocerus mandtii) is a large deepwater crab that reaches carapace widths up to 10 inches across. It is very similar to the brown box crab, but takes 7 years to mature and not enough is known about its lifespan and population health. Fishing limits are low for the species and they are a protected species in Washington.
A deepwater king crab species distributed down to southern Calfiornia, the Oregon hair crab (Paralomis multispina) is fished and consumed in small numbers in Japan. It’s included in Oregon fishery regulations, but again, information is limited and these are regulated as bycatch.
A deepwater king crab species, the scarlet king crab (Lithodes couesi) is included in Oregon fishery regulations, but information is very limited. Lithodes couesi is similar to the commercially caught red king crab (Paralithodes camtschaticus) but smaller in size and rarely targeted.
European green crabs
The European green crab (Carcinus maenas) was first introduced to the San Francisco Bay in 1989, from where it spread to the Pacific Northwest coast in the 1990s. It is considered invasive and its numbers have quickly increased throughout the region.
Green crabs compete with other species and can affect other crab populations. Because of their small size, they are not fished commercially, but they can be fished in California and Oregon. Washington prohibits their possession and requires reporting sightings of them. Trapping of the crabs has been increased in response to growing numbers of the invasive animal. Interestingly, their numbers tend to decrease when there are more red rock crabs in a habitat, as the rock crabs prey on them.
The green crab is also known as the five-spine crab, in reference to the five spines found on either side of the eyes. These are the best way to identify the crab, since they aren’t always green and can be confused with juvenile Dungeness crabs. They are small, growing only 1 to 3 inches in carapace width.
Cooking with small crabs
Because they are invasive, there is some merit to catching European green crabs to eat, but their small size makes them less attractive than commercially harvested species. There are, however, some ways to work with small crabs.
One method is to eat them when they are soft-shelled. Crabs have soft shells after they molt into a new shell. Soft-shelled crabs can be eaten whole and are commonly fried. Carcinus aestuarii, a closely related species of green crab, is eaten this way in Venice. There, crabbers separate crabs that are about to molt from their catch and hold them in special underwater cages, periodically checking to see if they have molted and are soft enough to eat. C. aestuarii roe is also a delicacy in Italy, eaten raw or used as a flavoring ingredient.
In France, the whole crabs are used to make bisques and soups. Similarly, in Vietnam, small crabs known as “cua đô’ng” are fished from rice paddies and used to make a noodle soup called “bún riêu”. To make the soup, the whole crab is pulverized. The mustard is removed before crushing the shells and used to flavor the broth. This method could easily be applied to other small crabs such as the European green crab.
Another Vietnamese and Thai technique is to salt and ferment small crabs to make preserved crabs. The resulting liquid can be used as a seasoning ingredient and the cut up crabs are used in salads and other dishes.
