Cravin’ Crawdads

by Aaron Kania

Lake Vermilion has become home to a large population of Rusty Crayfish. (All crayfish species are known as crawdads, especially if you are going to eat them.) These are suspected to have been introduced when fishermen from the central Midwest brought them to the area as bait and released them into the lake before heading home. Lake Vermilion and the surrounding areas provide ideal habitat for the invader. These non-natives outcompete the native crayfish and reproduce rapidly. Living on the lake and enjoying sunsets on the dock in the evening provides one ample opportunity to conduct thought experiments about the surrounding world. These thought experiments sometimes lead to research, which leads to seeking out knowledgeable neighbors and experts who have experience with such things. These multiple lines of inquiry may occasionally lead to actually experimenting with the subject matter to learn a thing or two first hand.

2022 got off to a slow start on the lake because of the high water. By the time the water receded it was well into June. We had bought two crayfish traps during the winter so were ready. We tried hot dogs, fish carcasses, and chicken bones for bait. The fish definitely worked best, and one night we caught 144 crawdads! Usually there were a dozen or so caught every night in early summer, which tapered off to five or so by September. This was not enough to cook up, so we had to find a way to keep the crawdads until we were ready to have a meal. At first we put them in a bucket but found that crawdads do not live long in a bucket without aeration. So we got a hanging live fish trap that we could attach to the dock. This worked great and we could keep the crawdads alive for several weeks until we had enough to cook up. By the end of summer we had caught more than 800 crawdads. (The Ely record we know of was 6,000 in one spot by Dan, Fall Lake!)

All this catching led to the question of what to do with them. Eat them of course, and not be wasteful. The most time-consuming part is in the preparation. This can be fun for all involved. It generally requires a cold beer or two to start. The first thing to do is purge the crawdads. To accomplish this we moved the crawdads from the live trap to a wheelbarrow filled with water. This gave us a chance to make sure there were no dead crawdads in the trap and also let us salt the crawdads so they would purge the contents of their intestines. From the wheelbarrow it was straight into a pot of boiling water for 15 minutes. We added a full box of Old Bay Seafood Seasoning for lots of flavor. Then we shut off the heat and let them sit in the hot water for another 15 minutes.

The real challenge now begins. If being used in a low country boil, all the other fixings can be added. Hold on–what is a “boil”? Low Country or Cajun boils involve adding other ingredients such as potatoes, corn, and shrimp. The difference between Low Country (Georgia and South Carolina primarily) and Cajun (Louisiana primarily) boils has to do with how the seasoning is added. But the key to a good boil is the group of friends invited over. It is truly about the atmosphere and joy of being out and about on a summer evening with good friends gathered together.

The Scandinavian tradition also involves plenty of friends, but uses dill for the seasoning and aquavit for the social lubrication. Typically a MidSummer’s Eve party, a kräftefest or kräftskiva will be imitated on August 12th, 5pm, at the Ely Folk School this year. The crayfish will be served separately with the rest of the meal being potluck.

The nice part of either a boil or kräftskiva is that a whole lot of friends divide up the work of shucking the crawdads for the ounce of meat in the tail. True believers suck the goodness out of the head, but none of our friends took up that challenge. If the crawdads are not going into a group meal, then usually more beer is necessary and a rainy day helps.

To shuck a couple hundred crawdads takes a few hours. We got pretty good with technique and could shuck each crawdad in 20 to 30 seconds. It took a lot of practice and we each had our own techniques for the process. First, the front half needs to be separated from the tail. Then there is a trick of twisting the tail to pull out the vein along with the flipper of the tail. Next, a crack is made along the tail and the meat pulled out in one piece. The reward here is a bit tough to be enthusiastic about. A couple hours of work yields a quart bag of meat that can be frozen and used like shrimp. A hot, creamy crawdad chowder with cheddar bay biscuits is delicious on a cold day. The real lesson, though, is to have some good friends over to help while sitting in the garage drinking a couple cold beverages in a rain storm. That’s probably the most efficient way to process the crawdads.

Now what to do with all the leftovers? And there are lots of shells after the fun is over. That question led us to a search for solutions. Dumping them in the trash was not a good solution since going to the landfill is not something we do often. Throwing them in the woods was also not a good option due to odor and flies. We did some research into what they do down south and found that composting the shells might work.

A friendly neighbor loaned us a barrel composter on wheels that is easy to turn. After more research we settled on using sawdust as a matrix for the shells. The quantity of four parts sawdust to one part shell seemed to be the best ratio. We added a little garden dirt to speed up the process through the introduction of good bacteria. The final ingredient was a liberal dose of water, and the composting was off to the races. Throughout the course of the summer we mixed up a giant batch of compost with the hundreds of crawdads and a huge bag of sawdust. We rotated the compost barrel whenever we walked by. Thankfully there was no odor to the mixture. The shells broke down quickly. By the end of summer we had two overflowing wheelbarrows full of material. We collected a sample to send to the University of Minnesota Soil testing lab. Those results came back and showed that the crawdads and sawdust turned two waste products into a really high quality soil additive.

What started out as a thought exercise turned into a summer’s worth of fun learning activities. We definitely put a dent in the population of crawdads around our dock. That was not enough time to see if this will help protect the weed patch from crayfish predation and maintain the lake vegetation needed for little fish to grow into eating-size fish. Anglers–you are doing double duty when you eat rusties: providing a meal now and more meals of fish later. What we found in 2022 may lead us to more thought experiments for 2023. The first question will be to find out if more rusty or native crayfish have repopulated our shoreline.

More About Rusty Crayfish

from Liz Anderson, Lake County SWCD

Many people have had run-ins with the feisty crawdad known as the rusty crayfish, but are you aware of its origin story? Hailing from the Ohio River Basin, rusty crayfish were first observed in lakes in the Ely area in the late 1990s, and it’s thought that they hitched a ride with anglers using them as bait. The good news is that since the early 2000s they haven’t spread to any new, unconnected local waters. The bad news is that many of the area lakes are connected, and rusty crayfish have wreaked havoc where they have become established.

Rusty crayfish are omnivores with a voracious appetite. Known as the “lawnmowers of the lake,” rusty crayfish can decimate aquatic plants, affecting fish habitat and wild rice beds. Rusties eat snails, fish eggs, plants, and pretty much anything they can get their claws on. They are much more aggressive than our native Calico and Virile crayfishes and have drastically reduced native crayfish numbers, if not outright ousted them.

Identifying rusty crayfish can range from very easy to somewhat challenging. If you see the namesake markings, the rusty red spots on their sides, it is a surefire indication you have a rusty crayfish. You can also look at their large, front claws and if there are orange tips preceded by black rings, it’s probably a rusty. When pinched closed, most rusty crayfish claws will also have a slight gap or keyhole opening. Unfortunately, crayfish markings can vary and not all rusty crayfish have red spots. Making it even trickier in this area is hybridization between rusty crayfish and other species. If you are unsure of an identification, don’t hesitate to call in the experts! Reach out to your local Soil & Water Conservation District, 1854 Treaty Authority, or the DNR. In most situations, there are limited management strategies for controlling rusty crayfish populations on a lakewide scale, however there are some things that can be done to minimize impacts at a hyper-local level. We have heard anecdotal reports that intensive trapping near shoreline properties can help protect aquatic