Meet the Animals

Salmon Survival: Confronting the Invasive Predator in the Great Lakes

Introduction to the Great Lakes

The Great Lakes, a magnificent natural wonder, are a group of five freshwater lakes located in northeastern North America. These vast bodies of water, which have captured the imagination of people for centuries, offer a rich and diverse ecosystem that supports numerous species of plants, animals, and microorganisms.

In this article, we will explore the formation of the Great Lakes, their geography, the water flow that connects them to the Atlantic Ocean, and the fascinating history of salmon in these incredible natural wonders.

Formation of the Great Lakes by glaciers

The story of the Great Lakes begins over 14,000 years ago at the end of the last ice age, when vast glaciers extended across North America. These massive sheets of ice carved deep valleys, leaving behind large basins that would later become the Great Lakes.

As the climate warmed and the glaciers began to melt, enormous quantities of water were released, filling these basins with melted ice water.

The geography and water flow of the Great Lakes

Covering an area of approximately 94,000 square miles, the Great Lakes are a collection of interconnected bodies of water. Lake Michigan, the only Great Lake that is entirely within the United States, is connected to the Illinois River by the Chicago Sanitary and Ship Canal.

The Illinois River, in turn, connects Lake Michigan to the Mississippi River. This intricate network of waterways allows for the flow of water from the Great Lakes to the Gulf of Mexico via the Mississippi River.

To the east, the Great Lakes are connected to the Atlantic Ocean by the St. Lawrence River. This vital waterway provides an essential shipping route, enabling the transport of goods and resources to and from the heartland of North America.

History of salmon in the Great Lakes

Salmon, which are a popular game fish, were not originally native

to the Great Lakes. In fact, their history in these waters is a fascinating tale of decline, conservation efforts, and successful stocking programs.

In the early 20th century, salmon populations in the Great Lakes declined dramatically due to overfishing and habitat destruction. Concerned conservationists recognized the need to take action, leading to the introduction of several species of salmon in

to the Great Lakes through stocking programs.

Types of salmon in the Great Lakes

Today, the Great Lakes support four main types of salmon: Chinook salmon, Coho salmon, Pink salmon, and Atlantic salmon. Chinook salmon, also known as King salmon, are the largest species of salmon in the Great Lakes.

They are known for their impressive size and powerful fighting abilities, making them a favorite target for anglers. Coho salmon, on the other hand, are known for their acrobatic nature, leaping out of the water during their spawning runs.

The flesh of Coho salmon is prized for its delicate flavor and is often considered one of the most delicious varieties of salmon. Pink salmon, also known as humpbacks, are the smallest and most abundant species of salmon in the Great Lakes.

They are known for their distinctive humped backs and pale pink flesh. Lastly, the Atlantic salmon, although not as common as the other species, has made a successful return

to the Great Lakes.

These majestic fish, known for their silver color and graceful swimming, were once extinct in the region but have been reintroduced through stocking efforts. In conclusion, the Great Lakes are a remarkable natural wonder that offers a rich and diverse ecosystem.

From their formation by glaciers thousands of years ago to their interconnected geography and the fascinating history of salmon in these waters, there is much to learn and appreciate about the Great Lakes. So, whether you are a nature enthusiast, a fisherman, or simply someone who appreciates the beauty of our planet, take the time to explore and discover all that the Great Lakes have to offer.

Chinook Salmon: The Majestic Kings of the Great Lakes

Chinook salmon, also known as King salmon, are the largest and most revered species of salmon in the Great Lakes. These magnificent fish, with their impressive size and powerful fighting abilities, have captivated the hearts of anglers and nature enthusiasts alike.

In this section, we will delve into the characteristics and size of Chinook salmon, as well as their appearance and behavior during the spawning season.

Characteristics and size of Chinook salmon

Chinook salmon are aptly named as they truly are kings of the Great Lakes. With an average weight ranging from 20 to 30 pounds, these fish can reach incredible sizes, with some individuals tipping the scales at over 50 pounds.

The largest Chinook salmon ever caught in the Great Lakes weighed a staggering 47.5 pounds, a record that still stands to this day. Size isn’t the only impressive characteristic of the Chinook salmon.

These fish possess a streamlined, torpedo-shaped body that allows them to swim swiftly through the water. They also have a distinctive silvery color, which can vary depending on their environment and age.

Younger Chinook salmon tend to have a brighter silver hue, while older individuals develop a darker, more speckled appearance.

Appearance and behavior of Chinook salmon during spawning

During the spawning season, Chinook salmon undergo remarkable transformations both in appearance and behavior. As they prepare to spawn, their bodies undergo several noteworthy changes.

The bright silver color that once adorned their scales gives way to olive, red, and purplish hues. Their bodies become thicker and more muscular, and the males develop a hooked jaw known as a kype.

As Chinook salmon make their way upstream to spawn, their behavior also undergoes a dramatic shift. They become more aggressive and territorial, and the males engage in fierce battles as they vie for the attention of females.

These battles can be seen in the water, with splashes and thrashing as the males assert dominance. The females, on the other hand, prepare spawning beds known as redds by fanning the gravel with their tails.

Once the moment is right, the female deposits her eggs in the redd, and the male fertilizes them by releasing milt. After spawning, the adults show signs of exhaustion and may die shortly after completing their mission.

However, their legacy lives on as the fertilized eggs hatch, giving rise to a new generation of Chinook salmon. Coho Salmon: The Acrobats of Lake Michigan

Coho salmon, also known as silver salmon, are another prized species found in the Great Lakes.

While they may not match the size and power of their Chinook salmon counterparts, Coho salmon offer their own unique charm and captivating traits. In this section, we will explore the size and weight of Coho salmon, as well as their appearance during the spawning season.

Size and weight of Coho salmon

Coho salmon are generally smaller than Chinook salmon, with an average weight ranging between 3 and 5 pounds. However, in Lake Michigan, these fish can grow larger, with some individuals reaching weights of 15 pounds or more.

Despite their smaller size, Coho salmon are highly sought after by anglers due to their acrobatic nature and delicious flesh.

Appearance of Coho salmon during spawning

During the spawning season, Coho salmon undergo striking physical changes. As they make their way upstream to spawn, their silver scales transform into dark blue to green hues.

This change in coloration is often accompanied by vibrant reds and maroons on their bodies. Their backs become darker, almost black, while their sides are adorned with numerous spots that can vary in size and intensity.

Another distinctive feature of Coho salmon during spawning is the presence of a hooked nose called a kype, similar to Chinook salmon. This development in the males signifies their readiness to compete for a mate and protect their spawning grounds.

The coloration and physical changes in Coho salmon during the spawning season make them a visually captivating sight to behold. In conclusion, Chinook and Coho salmon are two remarkable species that call the Great Lakes home.

Chinook salmon, with their size and power, reign supreme as the kings of these majestic waters. Coho salmon, on the other hand, impress with their acrobatic nature and striking appearance during the spawning season.

Whether you are drawn to the might of the Chinook or the beauty of the Coho, both species offer an extraordinary fishing experience and provide a thrilling connection to the wonders of nature. Pink Salmon: The Abundant Visitors of the Great Lakes

Pink salmon, also known as humpbacks, are the smallest and most abundant species of salmon in the Great Lakes.

Although they may not match the size and power of their Chinook and Coho counterparts, pink salmon bring their own unique charm and an exciting opportunity for anglers. In this section, we will explore the distribution and fishing spots for pink salmon in the Great Lakes, as well as their size and spawning cycle.

Distribution and fishing spots for Pink salmon in the Great Lakes

Pink salmon have a distinct distribution within the Great Lakes, with Lake Huron being the primary hub for these fish. They are known to run up a number of tributaries in Lake Huron, such as the Carp River and the St. Mary’s River, during their spawning season.

These tributaries provide excellent fishing opportunities for anglers seeking to catch these energetic and acrobatic fish. The Carp River, located in northern Michigan, is one of the most popular fishing spots for pink salmon.

During the spawning season, anglers can be seen lining the banks, casting their lines and eagerly awaiting the arrival of these small yet spirited salmon. The accessible nature of the Carp River and its plentiful pink salmon population make it a prime destination for anglers of all skill levels.

Similarly, the St. Mary’s River, which connects Lake Superior and Lake Huron, provides another fantastic opportunity to target pink salmon. This river system offers a diverse range of fishing spots, from the rapids near Sault Ste.

Marie to the calm stretches further downstream. Anglers can find success throughout the river, capitalizing on the pink salmon’s annual migration upstream to complete their spawning cycle.

Size and spawning cycle of Pink salmon

Pink salmon are smaller in size compared to other species of salmon in the Great Lakes. On average, they typically range from 3.5 to 5 pounds, with larger individuals occasionally reaching weights of 8 pounds or more.

While they may not offer the same physical challenge as their larger counterparts, pink salmon make up for it with their feisty and relentless fighting spirit, providing an exciting fishing experience. In terms of their spawning cycle, pink salmon have a unique pattern.

They have the ability to complete their life cycle in either a one-year or three-year timeframe, depending on environmental conditions. Odd-numbered years typically see an abundance of pink salmon, as many individuals follow the three-year cycle to reach maturity.

During these years, these charming fish flood the rivers of the Great Lakes, creating a spectacle that attracts anglers from far and wide. When pink salmon spawn, the females create redds by fanning the riverbed with their tails and depositing their eggs.

Following this, the males release milt to fertilize the eggs. This remarkable act of reproduction ensures the continuation of the pink salmon population in the Great Lakes.

After spawning, pink salmon often succumb to exhaustion and die, providing vital nutrients to the ecosystem and sustaining the circle of life. Atlantic Salmon: The Return of Greatness

Atlantic salmon, once a native species in the Great Lakes, experienced a decline in their population and came dangerously close to extinction.

However, through dedicated efforts and stocking programs, these magnificent fish have been reintroduced, reclaiming their place in these waters. In this section, we will explore the introduction and stocking of Atlantic salmon in the Great Lakes, as well as their size and behavior.and stocking of Atlantic salmon in the Great Lakes

Atlantic salmon were once abundant in the Great Lakes but faced a great decline due to overfishing, habitat destruction, and pollution.

By the 1900s, the native population of Atlantic salmon had become nearly extinct. Recognizing the importance of preserving this iconic species, stocking efforts were initiated to reintroduce Atlantic salmon in

to the Great Lakes.

One significant contributor to the stocking of Atlantic salmon in the Great Lakes is the Lake Superior State University (LSSU) laboratory. LSSU has played a crucial role in raising Atlantic salmon and releasing them into select rivers and streams.

These efforts have successfully reestablished Atlantic salmon populations in parts of Lake Huron, Lake Michigan, and Lake Superior, bringing hope for the future of this remarkable species.

Size and behavior of Atlantic salmon in the Great Lakes

Atlantic salmon in the Great Lakes typically range in size from 3 to 6 pounds, with larger individuals occasionally reaching weights of 20 pounds or more. These fish exhibit remarkable strength, agility, and speed, making them a highly desirable target for fly fishermen and experienced anglers seeking a rewarding sport fishing experience.

One of the appealing aspects of fishing for Atlantic salmon in the Great Lakes is the diversity of habitats they utilize. These fish are known to inhabit fast-moving rivers with cold, oxygen-rich water.

Anglers seeking to catch Atlantic salmon can venture to rivers such as the Salmon River in New York or the St. Mary’s River in Michigan, casting their flies into the swift currents in pursuit of these elusive fish. When reeling in an Atlantic salmon, anglers can expect an exhilarating battle.

These fish are renowned for their acrobatics, often leaping out of the water and putting on a dazzling display of aerial maneuvers. The sheer power and determination of an Atlantic salmon make every encounter a memorable and thrilling experience.

In conclusion, pink salmon and Atlantic salmon have left their mark on the Great Lakes, each offering unique characteristics and fishing experiences. Pink salmon, with their abundance and spirited nature, provide an exciting opportunity for anglers of all skill levels.

Atlantic salmon, on the other hand, represent a remarkable success story of conservation and reintroduction, offering a challenging and rewarding pursuit for those seeking a true trophy fish. Whether casting for pinks or chasing after Atlantic salmon, the Great Lakes provide a rich and diverse salmon fishing experience that captivates and inspires all who venture to these storied waters.

Sea Lamprey: The Invasive Predator of the Great Lakes

The Great Lakes, a haven for diverse aquatic life, have unfortunately faced the introduction of non-native species that disrupt the delicate balance of its ecosystems. One such invasive species is the sea lamprey, a parasitic fish native to the Atlantic Ocean.

In this section, we will explore the introduction and impact of sea lamprey in the Great Lakes, as well as the threats they pose to salmon populations.and impact of sea lamprey in the Great Lakes

Sea lampreys are a highly destructive and invasive species that found their way in

to the Great Lakes through canals and waterways constructed in the early 20th century. With their unique, suction-like mouths and razor-sharp teeth, they attach themselves to other fish, often causing severe injury or death.

This parasitic feeding habit has had devastating consequences for the native fish populations in the Great Lakes. The impact of sea lamprey on the Great Lakes ecosystem is significant.

These invasive predators target a range of fish species, including valuable game fish such as lake trout, whitefish, and salmon. Their parasitic feeding causes profound physical harm, leading to open wounds, infections, and ultimately, the death of their hosts.

Threats posed by sea lamprey to salmon populations

Salmon populations in the Great Lakes have been particularly vulnerable to the threats posed by sea lamprey. The impact of sea lamprey on salmon can be devastating, significantly affecting their numbers and overall health.

Some of the key threats include:

1. Mortality: Sea lampreys are responsible for the deaths of thousands of salmon each year.

Once attached, they feed on the fish’s bodily fluids, weakening them and making them susceptible to disease and predation. 2.

Impact on edibility: The injuries caused by sea lampreys render the affected salmon unpalatable and unfit for human consumption. The parasitic feeding leaves behind unsightly wounds and exposes the flesh to bacteria, spoiling the quality of the meat.

3. Competition for resources: Sea lampreys compete with salmon for limited food resources in the Great Lakes.

With their parasitic feeding habits, they further strain the ecosystem by depleting the available prey base, making it harder for salmon to find adequate nourishment. 4.

Hybridization and genetic contamination: In some cases, sea lampreys attach themselves to spawning salmon, increasing the risk of hybridization between these species. This hybridization can dilute the genetic integrity of the native salmon populations, leading to further challenges in their conservation and management.

5. Threat of extinction for native species: The presence of sea lampreys has caused significant declines in several native fish species, pushing them closer to the brink of extinction.

These include Lake trout, which have experienced significant declines due to lamprey predation. Efforts to control and manage sea lamprey populations in the Great Lakes have been ongoing for many years.

These efforts involve trapping, sterilization, and the use of chemical lampricides to target the sea lamprey larvae in the rivers where they spawn. Despite these measures, the sea lamprey remains a persistent threat to the native fish populations in the Great Lakes.

In conclusion, the presence of sea lamprey in the Great Lakes is a stark reminder of the damage that can be inflicted by invasive species. Their parasitic feeding habits and impact on native fish populations, including salmon, are a cause for concern.

As we continue to work towards effectively managing and controlling these invaders, it is crucial that we remain vigilant in protecting the delicate balance of the Great Lakes ecosystems and ensuring the survival of our valuable native fish species. In conclusion, the Great Lakes face various challenges posed by different species.

The introduction of non-native sea lamprey has had a significant impact on the ecosystem, especially salmon populations. With their parasitic feeding habits, sea lampreys cause mortality, render salmon unedible, and compete for resources.

They pose a threat to the genetic integrity of native species and push them closer to extinction. These issues highlight the importance of invasive species management and conservation efforts in the Great Lakes.

With continued vigilance and proactive measures, we can work towards preserving the delicate balance of the ecosystem and safeguarding the future of these iconic water bodies.

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