Eating Aliens: One Man's Adventures Hunting Invasive Animal Species (12 page)

I walked to the beach and into the tide pools around the rocks and short stone jetties. At first I didn’t see any green crabs in the tide pools. Then I started turning over rocks and found them hiding. The trick was to scoop them up with both hands, each hand closing in from a different side so that they scoot away from the one hand and into the other. Their little claws didn’t pinch enough to do me any harm.

My hope was to gather up a good half gallon of the crabs and have enough to bring some home. But I had made a mistake that no experienced fisherman would: I ignored the tide. The surf began to roll in soon after I began my walk, flushing out the tide pools and gradually merging them with the open water.

I enjoyed the walk along the Sound a little longer. A couple of white egrets paced the edge of the mudflats, probably hunting the same crabs I was. Red-winged blackbirds stopped on fence posts and cocked their heads at me. Joggers along the boardwalk looked at me like I was an idiot: a grown man with his jeans rolled up to his knees, wading in tide pools and playing with crabs. I’m accustomed to those looks. . . .

Back near the parking lot, there was a picnic area with heavy iron grills set into the ground. I retrieved a bag of charcoal from my trunk and supplemented it with some driftwood. Once the fire was going, I set a pot with a bit of water in it on the grill and tossed the dozen or so crabs in to steam. I had nothing more than hot sauce, lime juice, salt, and pepper to season them. Old Bay Seasoning would have been nice.

The result was edible, though not nearly as good as the crabs served at Miya’s. Keeping them alive for a few hours, to enable them to purge anything from their digestive system, would no doubt have improved the flavor. But this was definitely a food source that could be exploited simply by walking along the beach.

On your plate, shore crabs are a more challenging thing to contemplate putting in your mouth than is, say, a lionfish fillet. But going for a walk on the beach or dropping a few strings onto a mudflat is a lot easier and less dangerous than spearing a lionfish. Gathering shore crabs was possibly the easiest hunting I’ve ever done.

Asian Carp

Big silvery torpedoes of some twenty pounds launched themselves out of the water as high as ten feet in a fast graceful arc right into the middle of the boat. They smacked into the aluminum and flopped around in bloody confusion as I tried to pounce on one, even as another came hurtling in.

Asian carp have become a sore point for me over the past year.

On my parents’ property, in rural Virginia, there are two ponds. I grew up in that house from the age of thirteen and spent many a day on those ponds, fishing and observing the wildlife. I knew everything that lived in each pond: the snapping turtles and bullfrogs, muskrats and fish, the stonefly larvae and the various aquatic plants. Pond ecology is a tidy thing to study up close — a small system, but often a complex one nonetheless.

One day in early autumn, shortly after returning from my trip to hunt invasive lizards in Florida, I walked to the lower pond and saw something highly improbable. An enormous fish that looked to be about three feet long was basking, clearly visible, just beneath the surface. Nothing that belonged in a Virginia pond in the foothills of the Blue Ridge Mountains could grow anywhere near that size.

At first, my fisherman’s heart thumped at the sight of a fish that big. But then I gradually realized what it probably was. A carp. A nonnative fish, which some reckless fool must have dumped into the pond.

Further observation suggested that there were around a dozen of the fish there. They spooked easily, rolling in the water and slapping it, almost like a beaver would, when I approached. The pond was mostly barren of plants and had turned a brown, muddy color. It was no longer the healthy ecosystem I had grown up watching.

I asked my parents if they knew where the fish had come from. They asked around, and it turned out that neighbors had stocked the pond with grass carp for the purpose of combating the duckweed, which they thought unsightly. Considering that they owned only a few yards of frontage on the pond and that Virginia law requires the signed consent of all landowners before stocking a pond or lake with carp, what they did was, in fact, illegal.

The carp had to go; the question was how. The neighbors threatened me with unspecified consequences if I removed “their” carp from our pond. I rather enjoyed the thought of what would unfold if they called the game warden to complain about my fishing for carp on my family’s land, in a pond that they had illegally stocked.

There are four species of invasive carp in the United States. The one I encountered in the family pond was the grass carp. Grass carp are native to Asia and were brought to this country in the 1960s for aquatic-weed control. They’re very successful in this role; they’ll eat just about any old plant.

The trouble is that carp don’t have any idea of when enough is enough. They keep eating long after they’ve eaten the weeds they were brought in to control. Often the surface weeds aren’t their first choice, and it’s only after wiping out most of the important native aquatic plants that they get around to eating the things people are trying to get rid of.

This has obvious consequences for the rest of the ecosystem. Removing native plants means they’re not available as a food source for other aquatic herbivores. Also, the plants are no longer providing cover for smaller fish and invertebrates, increasing the amount of predation on them by other species and gradually reducing their numbers. These changes produce a domino effect that creates other ecological problems.

Once the easy food is gone, the carp need to root around for more. Their constant search stirs up sediment that clouds the water. This decreases the amount of light reaching the bottom and further impedes growth of the aquatic plants necessary for the healthy functioning of the pond ecosystem.

Unfortunately, human beings tend to be more concerned with the aesthetics of nature than with its health. A surface covered with scum may not be the best thing for a pond, but dumping a bunch of heavyweight fish that can grow up to fifty pounds will eventually make things worse. State governments have recognized this, and in most places it’s now illegal to introduce viable — that is, able to reproduce — grass carp into the wild.

Nonviable carp, on the other hand, are sometimes stocked. Grass carp can be made to be triploid through artificial means. A triploid grass carp has an extra set of chromosomes that cause it to be sterile. This condition is usually induced by spinning the eggs in a centrifuge very quickly and then stopping; the rapid change in pressure naturally results in the extra chromosomes. Triploid carp are considered safer for weed control because they can’t reproduce and get out of control.

Although they can’t reproduce, they can still wreak havoc for years on the water system they’ve been introduced into. And even when triploid carp are purchased in good faith, there’s no guarantee that they are, in fact, what they’re advertised to be.

Carp breeders are known for being meticulous about ensuring that all the fish they sell are unable to breed. Many of them test every single carp before making a sale. Not every egg turns out triploid, and success rates for a batch range from eighty to one hundred percent. There’s decent government oversight of the breeders, and they’re seldom a problem. The middlemen who buy from the breeders, however, are somewhat of a mixed bag.

Carp expert Duane Chapman, of the United States Geological Survey, let me in on a little secret about triploid grass carp: They aren’t always triploid. The value of a standard grass carp is much lower on the market than that of a triploid grass carp. An unethical middleman may buy a certain quantity of certified triploid grass carp and a larger amount of standard grass carp. In the event of an inspection, he presents the certification for the triploids. In that way, he sells the standard carp fraudulently as triploid. The total sales figures are obscured, and it’s unlikely the transaction will be questioned by the authorities. Even if fraud is detected, it can be very difficult to build a case.

As you can see, stocking what are believed to be sterile, triploid grass carp isn’t guaranteed. Viable carp are being introduced to the wild via the triploid exception. If there’s any route by which the carp can escape from a pond into moving water, which is what they need in order to spawn, trouble is around the corner. Even when a drainage stream looks too small for the carp to escape through, this can change rapidly with a heavy rain.

Even when stocked carp are definitely triploid and don’t pose a risk of escaping and breeding in the wild, they still wreak havoc on the pond ecosystem they’re introduced into. The fish are often stocked when they’re about twelve inches long. Say that twenty carp are stocked. A year later, the weeds are gone and the carp might be twenty inches long. But they keep getting bigger. In another year those twenty carp might be thirty inches long. They’re having a bigger effect on the habitat every year. If the desired effect (weed removal) was already achieved, then, rationally, the number of carp should be reduced. There’s no need to keep a thousand pounds of carp rooting around in the pond if half that biomass was doing the job the year before.

I began experimenting with various fishing methods for the grass carp in my family pond. At first I tried hooks baited with corn, which many people swear by. The fish weren’t the slightest bit interested. Even when I chummed an area with it and came back the next day, the corn was untouched. Next I tried ambushing them with my cast net, ready to throw it over a fish as soon as it came within range. Carp are just too wary and pay too much attention to what’s happening above the surface for that to work. They were always out of the path of the net by the time it hit the water.

Maybe snagging them would work. In warm weather, carp like to bask at the surface. While bass fishing, I discovered that I could cast over a fish’s back from far away and it wouldn’t react to either the lure or the hook sliding over it. Now, I bought the biggest treble hook I could find and tied it onto an eighteen-pound test line on my heavy surf rod with a weight under it. Just my luck: the temperature dropped right when I did this and the carp stopped basking.

I was running out of ideas on how to clear out these carp when I drove to Connecticut to try the shore crabs. My cousin Patrick McNamara lives only a few hours away in Massachusetts, and he is a diehard fisherman. The man compresses a five-day work week into four twelve-hour shifts in order to have three solid days to fish. He’s been known to sit on a beach in freezing rain for days on end to catch a run of striped bass. If anyone could help me break my losing streak on carp, it was Patrick.

From Connecticut I drove to Wilmington, Massachusetts, with one quick stop at a tackle shop. Within minutes of my arrival, Patrick suggested we try to catch the evening bite in a trout stream a few minutes away. I don’t think I’d even dropped my backpack from my shoulder. I’d come to the right place.

We hit the trout stream and took home a few nice rainbows. I had just finished gutting them when he had me back in the car to go fish for eels and bullhead catfish on Silver Lake — in the dark. The next morning we drove to the Concord River to a spot Patrick promised was loaded with carp.

His friend Justin Torname came along. We brought our heavy surf rods in anticipation of heavy carp. I also brought one of Patrick’s much lighter spinning rods, in case there was anything else to fish for.

Patrick’s bait of choice was oatmeal. I didn’t see how it would stay on the hook, but it was a simple matter to roll the stuff into a little ball and slip it onto the hook. Even underwater, the ball held together for a long time.

Patrick had the first bite. He grabbed the rod from its holder in the riverbank and started muscling in the fish. The rod was bent over so far that I thought it would break. Within a few minutes, he’d fought the thirty-inch fish to shore. Justin scooped it up with my landing net.

Seeing a new species up close and personal is always amazing to me. This fish had a yellowish face and a downward-oriented mouth with a couple of short barbels (small protrusions on the lip). What we were looking at was a common carp, not a grass carp. Not the same species, but close enough to get excited. Common carp are native to central Europe and are just as invasive as their cousins are. I killed it quickly with a knife to the brain. (I consider this to be more humane than the standard decapitation, and it exposes less surface area on the interior to potential bacterial contamination.) It’s a testament to the size of these fish that it took me a good five minutes to extract the four-inch hunting knife from the carp’s head.