Recently I went to a Happy Hour for the ubiquitous “oysters on the half shell” special. I was lured in by the glass of champagne and the caviar topping for the oysters, because pure decadence. I had just learned how to shuck oysters – well, “learned” may be a very strong word to use here. But I also wanted to pick up tips and tricks from the Oyster Shucker – those incredibly skilled fellows who crack open oysters with a grace and ease to which I can only aspire.
Seeing sacks of oysters being dragged in, and then pried open one-by-one, before being nestled into little beds of ice, made me smile. I smiled, not just because I enjoy eating them, which I do; I smiled because it feels like just last week was the BP oil spill and the collective (regional) concern that the oyster business may not ever fully recover. I smiled because in the hands of a capable shucker, opening an oyster starts with a tap of the knife on the shell and culminates with a sound akin to opening a fresh jar of pickles. I smiled because oyster plates and oyster shuckers are as much a part of local culture as crawfish boils and beer.
But as I sat at the counter, it occurred to me that it’s a near miracle that we even have an oyster population considering how fragile they are. Oysters are sensitive to water quality and coastal pollution. Oysters are filter feeders. Oysters are unable to move on their own and only get moved around because of waves, which leaves it at quite a disadvantage to other filter feeders such as the formidable Asian carp.
The Asian carp can grow to 110 lbs and consume 20-40% of its body weight daily in plankton. This is a problem, not just for the oyster, for two reasons. First because Asian carp can produce up to a million eggs each year, and this means they can simply out-number and out-compete native species. Second because plankton is the base of the food chain and it’s integral to the balance of energy in an aquatic ecosystem, that simply cannot withstand the ensuing demand. And they jump – which isn’t necessarily a problem for the oyster, but it is incredibly dangerous if you get hit by one, which has happened.
Thing is, I can’t figure out why we even still have Asian carp. Here’s the backstory:
Back in the 1970s, Catfish farmers in Arkansas imported Asian carp to eat algae in the ponds. All went well until there was a flood and they escaped into the wild. Because Asian carp don’t have a natural predator, they just kept populating. Rivers. Streams. Lakes. Brackish waters. Any and all water that has plankton in it.
We, as a nation, have thrown a lot of effort (and money) into suppressing the Asian carp invasion. Up in Chicago to protect the Great Lakes, an electrical barrier (think underwater fence) was installed in 2014 at a projected cost of roughly $25M. It was intended to keep the Asian carp from swimming upstream into Lake Michigan. Initially, barges interrupted the signal and the fish swam through it … so, now there are three. But that wasn’t the only plan.
In 2014, the Army Corps of Engineers suggested using herbicides “to prevent the transfer of species”. Ultimately, the introduction of herbicides and other pollutants into fresh and marine waters can have a toxic effect on the plankton and the recovery is dependent upon the resiliency of the ecosystem. However, it wouldn’t necessarily reduce the risk of Asian carp spreading into Lake Michigan. And it would cost $68M per year.
In 2015, the National Resources Conversation Service got support from federal, state, and local agencies to install a berm (think levee) to keep the flood waters from crossing the watershed and dumping Asian carp along the way. It was intended to be a three-kilometer (1.86 miles) wall measuring 23 meters (75.5 feet) wide by 3.5 meters (11.5 feet) high and costing $3.5M. I can’t speak to the width, but I can say that the height is reasonable because the Asian carp can jump up to 10 feet (3 meters) out of the water when scared. Through construction of the berm, the stop-gap was a movable chain link fence that could be closed during flooding to keep the fish out. And now the berm is complete, it is nearly 2-miles-long, 80-feet wide, and averages 7.5 feet high, and cost $4.4M.
All that is to say that Asian carp has proven itself to be a prodigious foe. In fact, the Asian Carp Regional Coordinating Committee said that since 2009, more than $386 million has been spent on research, monitoring and control efforts. But all this is to save the Great Lakes’ $7B per year fishing industry, so it is reasonable to fight it. But all I can think is WHY are we doing this?!?!?!?
I understand the nature of and need for business. I am a stanch proponent of defending our environment so let me explain. Not long ago, I watched an adorable puppy video that was the perfect illustration of over thinking things. The cutest little husky puppy was sitting in his crate chewing on the wires, so he could get out to play with a toy that was on the other side of the wire wall … while the door…sat open…behind…him. And I can’t help but think that is exactly what we are doing with Asian Carp.
To substantiate my point, I will offer this empirical evidence: Asian Carp is not an invasive species in Asia.
Why not? Cause they eat it. It’s a fish!
I do admit that it is a “hard sell” because the Asian Carp has long been confused with its bottom feeding carp cousin – common carp. Carp is carp to a lot of people and although I “get” that sentiment – these are very different animals.
The common or European carp was introduced in the mid-1800s to the Mid-West as game fish from Europe. European carp is known as a pest fish for a variety of reasons. They root along the floor of a body of water, uprooting vegetation and causing the deterioration of habitat. When they feed, they increase turbidity (kick up dirt making the water cloudy) thereby releasing bottom sediments and phosphorus normally locked in the bottom sediment. They are omnivores and eat animal and plant material, including crustaceans, benthic worms, crawfish, and bottom dwelling aquatic insects. And they have been noted to concentrate in large numbers where cannery or slaughter-house wastes are emptied into streams.
The Asian carp, conversely, is a plankton only eating, filter feeder fish. The USDA even found the mercury concentration in Asian carp fillets is below the EPA screening value. It’s boney and irksome to clean if you are unaccustomed to its bone structure. But it’s not the same as it’s bottom-feeding, crustacean eating cousin. In fact the real reason it is no longer considered simply a pest fish and regulated en masse under the Lacey Act and has its own prohibition now is because of the volume of plankton it is eating. If left unchecked, the Asian carp will dominate the plankton supply, upend the aquatic ecosystems, and leave nothing for the native species.
But it makes no sense to me to sacrifice the oyster by not eating the carp. Surely there is enough room in our bellies for both.