The parasite that feeds on blood is
threatening large fish and businesses
throughout the Great Lakes


They are eels with bodies resembling eels the mouth of a Sarlacc as well as the same diet as
the vampire.

Sea lampreys belong to their native waters of the Atlantic Ocean and the rivers that are a part of
it. However, more than 100 years ago, they were able to make their way through the Great
Lakes, where they expanded and turned into one of the worst species of invasive in the history
of the United States.

They are parasites. For food, they cling to fish, pierce them, begin sucking the body fluids and
blood and, in many cases, kill their prey. One lamprey could kill as much as forty tonnes of fish.
thousands of them can are threatening our Great Lakes fishing economy, which is estimated to
be around 7 billion dollars annually.

Officials from the wildlife department in the Great Lakes have been culling sea lampreys for
decades, mostly with lamprey-specific pesticides. However, the sea lampreys are threatened in
a portion of their natural habitat that includes Western Europe and the northeastern US. There are four species of indigenous lampreys that reside throughout the Great Lakes, which wildlife
officials are trying to save.

This is a major tension that is common to the field of invasive biology. The way we treat the
species is largely based on the location it’s in regardless of whether humans have put it there.
The appearance of a species is also important. Lampreys in the Great Lakes are, unfortunately,
unfortunate in both ways.

What exactly is the definition of a sea lamprey?

With a length of up to a meter in length, they are the longest of 40 species of lampreys, a
species of animals that are truly ancient. They’ve been living on Earth for over 350 million years
with a total of no less than four major extinctions.

They’re a strange bunch Also. As with sharks, sea lampreys do not have bones, and like salmon
are able to can swim upstream to spawn and are able to live in both fresh and salty water and,
like frogs too, undergo transformation.

There are mouths too. They’re made up of concentric rings of teeth made of the keratin (the
substance that’s in your hair and nails) that they use to attract their prey. After latching on their
prey, they pierce the flesh using the shape of a tongue.

As terrifying as it sounds, lampreys can be a boon to the ecosystems of the East Coast and in
western Europe which is where they’re native According to Margaret Docker, a biologist at the
University of Manitoba who’s been studying lampreys for over 35 years. Lampreys as larvae
provide food for a range of aquatic animals. The larvae reside in the streams, eating dead or
decaying matter that other animals are unable to take in, and help to cycle nutrients through in
the food chain.

After a couple of years (and sometimes, for a longer period) the larval lampreys transform and
become parasites, developing the mouths of their new gills and mouths and functional eyes.
They leave the river in large numbers, Docker said. “A lot of marine mammals and other fish will
wait at the river’s mouth for this flood of lampreys,” she added.

As parasites, sea lampreys aren’t an issue in their natural habitat. They are with “peaceful
coexistence” with other fish, Docker said. Sea lampreys are known to search for larger fish,
which could more easily withstand an attack. They also are protected by many predators in
nature like catfish and other dangers like dams, and there aren’t many.

The way sea lampreys turned into enemies in the Great Lakes

Many species are “invasive” because of humans regardless of whether it’s a hungry snail that is
spreading north because of changes in the climate and jumping Joro spiders who likely flew to
the US by way of a container vessel. Sea lampreys are no exception. They came to the Great
Lakes sometime in the 1800s, probably because of the construction of canals. (Some experts believe that the sea lamprey originates from Lake Ontario. Also, there’s a more extensive
debate regarding the term “invasive.”)

With lots of fish to feast on and no natural predators, the lampreys flourished throughout their
home in the Great Lakes. In the late 1940s, they were found in all five of them, according to the
publication Great Lakes Sea Lamprey: The 70 Year War on a Biological Invader by lamprey
researcher Cory Brant.

In the same period, the regional fisheries declined. It was reported that the US and Canada
were harvesting around fifteen million kilograms of trout from the lake in the lower Great Lakes
each year. In the 1960s, it had fallen down to 300.000 pounds which were only two percent less
than it was. “The sea lamprey threatens complete destruction of the Great Lakes fishing
industry,” the South Bend Tribune reported in the spring of 1953. (Other risks, like overfishing,
contributed to the decline of the Great Lakes fishing industry.)

The wildlife authorities of the region did not hesitate to take on the fight. In 1954 Canada and
the US and Canada joined forces and created an organization known as The Great Lakes
Fishery Commission (GLFC). The purpose of the GLFC was and continues to have been to
eliminate sea lampreys.

A government assault on lampreys

The United States’ battle against sea lampreys is among the most organized and well-funded
initiatives to combat any species that is invasive. The primary weapon used includes lampricides
— specifically, two pesticides targeted at lampreys, yet don’t appear to affect other fish.
(Scientists discovered these in the 1950s after painstakingly examining over 77,000 chemicals.)

Every year, wildlife officials dump about 175,000 pounds of liquid lampricides into rivers that
eventually flow into the Great Lakes, where they kill lampreys, especially in their larvae (they
also harm native lampreys too). The officials also depend on small barriers or dams to stop sea
lampreys from moving into the river to breed.

In a typical year, GLFC — which invests around $25 million annually for sea lamprey
management — kills approximately seven million marine lampreys. This year, the number of
deaths has risen to 1.7 million, as per the kill count on the website.

Lampricides perform their task well. Sea lampreys destroyed over 100 million kilograms of fish
annually throughout the Great Lakes, but today they kill less than 10 million pounds of fish, in
accordance with GLFC. It’s likely to bring numerous benefits for non-commercial fish and other
animals also, say, experts.

However, these gains aren’t without a lot of risks according to Robert McLaughlin, a biologist at
the University of Guelph in Ontario. “Anytime that control is eased, they quickly start to
rebound,” McLaughlin said. “The numbers of them right now aren’t that high, but that’s because
we’ve been controlling them for close to 70 years.”

Wildlife officials are not yet able to eradicate the animals entirely. While lampricides are able to
kill 98 percent of larvae in a stream, there are still some remaining to form an upcoming
generation according to Marc Gaden, communications director and legislative liaison for GLFC.
A single female lamprey could generate more than 100,000 eggs Gaden said. “You just can’t get
every one of them,” said the expert, and the last mile could be extremely costly.

Scientists are currently exploring innovative ways to ward off sea lampreys. One of these is the
use of scents and Pheromones. Certain pheromones draw lampreys, which allow scientists to
draw them into traps. However, the intense scent of dead lampreys dissuades them. (This video
will show the effects of adding lamprey repellent in a tank. It’s not for everyone. grisly).

Controlling sea lampreys has definitely helped fish and the people who depend on their services
throughout the Great Lakes. But it’s important to remember that these efforts are threatening the
native lampreys of the region that are prone to lampricides too and may harm lampreys all over
the world. “In the case of sea lamprey in their native range, there is no doubt that the public’s
imagination has been strongly negatively influenced by the need to control the species in the
Great Lakes,” the authors of the study said.

Sea lampreys are thought to be “critically imperiled” in parts of the eastern US and “critically
endangered” in parts of Europe in Europe, not to mention other species of lamprey that are in
danger of extinction. However they are not endangered, and as Kelly Robinson, an ecology
professor at Michigan State University, puts it, “everybody just thinks lampreys are terrible
because of the Great Lakes.”

If nothing else perhaps you’ll be able to keep in mind how sea lampreys (and other species that
are invasive) aren’t inherently bad even as gross as they might appear. Certain countries regard
them as an important source of food. Even if you’re heading towards the Great Lakes and
planning to go swimming there, don’t be worried. Sea lampreys favor fish over humans with
warm blood.