Many marine species are migratory, meaning that they move between different waters in search of food, to spawn, or to escape from predators. Some move between the water column, while others are highly migratory. Highly migratory marine species are species that travel long distances across the oceans. They swim thousands of miles crossing international boundaries and even continents.
These fascinating migrations are not limited to a particular species but cut across all groups, from fish, sea mammals, and reptiles to seabirds. Unfortunately, due to their extensive movements, they are prone to overfishing and are among the most threatened species.
Below we will look at some of the highly migratory marine species.
Humpback Whale
Habitat: All oceans of the world
Distance covered each year: 16,000 miles
The humpback whale belongs to the baleen whale suborder and gets its name from the hump on its back. They live in all the oceans and can grow up to lengths of 60 feet and 80,000 pounds in weight. Additionally, it’s also a fascinating animal to watch. They are active and often jump out of the water, slapping the surface with their fins. It is also vocal and known for its courtship songs.
These whales are well known for their long-distance migrations. During summer, humpback whales migrate to feed in the cold productive waters near the poles. In the winter, they migrate to the warm waters to mate and give birth. Humpbacks are powerful swimmers and swim up to 16,000 miles yearly.
Interestingly, despite traveling, feeding, and mating in big groups, these whales are typically loners and prefer to travel alone or in small groups of two to three. In these situations, a pod can consist of a mother whale and her baby. Sometimes two or three whales form a temporary alliance.
Bluefin Tuna
Habitat: Open waters of the Atlantic, Pacific, and Indian Oceans
Distance covered each year: Approximately 10,000 miles
Bluefin tuna is one of the largest tuna species and can grow to lengths of over 10 feet and a weight of over 1,000 pounds.
The bluefin tuna is a highly migratory marine species and travels long distances in search of food and suitable spawning grounds. They swim between the Western Pacific and Eastern Pacific several times a year. Besides, they are fast swimmers, swimming at 43 miles per hour.
Unfortunately, Bluefin tuna is a popular target for commercial and recreational fishermen. This is because of the high price of the meat used to prepare sushi and sashimi.
Leatherback Turtles
Habitat: All oceans except the Arctic and Antarctic
Distance covered each year: 12,000 miles
Another highly migratory marine species is the leatherback turtle. The leatherback turtle is a reptile and the largest of all sea turtles. They can grow to lengths of up to 5 feet and weigh up to 1,000 pounds.
Interestingly, they are the only turtles that do not have a hard shell but instead have a leathery carapace. These turtles occur in all oceans except in the Arctic and Antarctic.
Leatherback turtles migrate long distances yearly, swimming over 12,000 miles between their nesting and feeding grounds. They are also highly skilled divers, with a record of almost 4000 feet, thus diving more profoundly than any marine mammal.
Leatherbacks need to eat a lot of jellyfish to survive, and the abundance of jellyfish varies depending on the season and location. Therefore, by migrating, leatherbacks ensure they have enough food throughout the year.
However, migration is a dangerous journey for them. They face many threats, such as bycatch, being eaten by predators, and worse still, their eggs are harvested for human consumption. Sadly, due to these dangers, their population is declining at an alarming rate.
Blue Marlin
Habitat: Occur across tropical and subtropical waters of the Pacific, Atlantic, and Indian Oceans
Distance covered each year: Over 12,000 miles
The blue marlin is another highly migratory fish. They are pelagic species and mainly occur in warm tropical waters. It is the largest marlin species growing up to 14 feet in length and about 2000 pounds in weight. Amusingly, females are usually larger than males.
Every year, they swim from their breeding grounds in the tropical waters of the Indian and Pacific oceans to the colder waters of the Atlantic. The fish travel in schools, often numbering in thousands, and cover vast distances of up to 12,000 miles.
Unfortunately, this migratory behavior exposes the blue marlin to several threats, such as overfishing, bycatch, and climate change. Worse, it is currently among the endangered species listed by the ICUN.
Swordfish
Habitat: Live in tropical and temperate waters
Distance covered each year: 3,000 miles
Swordfish are also among the highly migratory marine species. They occur in tropical and temperate waters. They can grow up to 15 feet long and weigh up to 1000 pounds.
The blue marlin is another highly migratory fish. They are pelagic species and mainly occur in warm tropical waters. It is the largest marlin species growing up to 14 feet in length and about 2000 pounds in weight. Amusingly, females are usually larger than males.
They travel long distances yearly for food and suitable breeding grounds, often covering about 3000 miles. They are also fast swimmers, swimming 60 miles per hour. But unlike many fish, swordfish are solo swimmers, meaning they do not swim in schools.
Currently, there has been a decline in the global swordfish population. This is primarily due to overfishing, bycatch, and climate change.
Blue Whale
Habitat: Live in all oceans of the world
Distance covered each year: 18,000 miles
Adding to our list is the blue whale. The blue whale is a marine mammal believed to be the largest animal ever. They live in every ocean and mainly prefer upwelling cold waters. They can grow up to 98 meters long and weigh up to 1500 pounds.
It is a highly migratory marine species that migrate seasonally between different areas in search of food and mating opportunities—swimming up to 18,000 miles. Their main migration routes are between their Antarctic breeding grounds and Arctic feeding grounds. However, some blue whales also migrate between the Indian and Pacific oceans.
Blue whales are often seen alone or in small groups of 2-3 animals. These groups usually consist of a mother and her calves. Unfortunately, blue whales are also among the most endangered species. During their migration, they face threats such as climate change, bycatch, and being hit by ships, among others.
Great White Shark
Habitat: Live in the coastal waters of North America, South Africa, and Australia
Distance covered each year: Approximately 2,500 miles
White sharks, also known as great white sharks, are one of the most aggressive predators in the ocean. Although they occur in all oceans of the world, they mostly live in the coastal waters of North America, South Africa, and Australia.
They are mostly grey or blue-grey, with a white belly. They also have torpedo-shaped bodies and large, triangular dorsal fins. White sharks can grow up to lengths of 20 feet and can weigh over 5,000 pounds.
They are highly migratory marine species, swimming almost 2,500 miles from their breeding grounds in North America to their feeding grounds in South Africa and back again yearly.
While white sharks are not considered endangered, their numbers are declining. This is mainly due to the illegal hunting of these animals for their fins and teeth. In addition, they are also accidentally caught by fishermen who are targeting other species.
Salmon
Habitat: Live in the cold, clear waters of the Northern Pacific and Atlantic Oceans. Mainly in coastal areas and near freshwater rivers where they can spawn
Distance covered each year: Over 1,000 miles
Salmon are highly migratory marine species living in fresh and saltwater environments. They are native to tributaries of the North Atlantic and Pacific Oceans. It is a popular food fish that is high in omega-3 fatty acids, can grow up to lengths of 5 feet, and can weigh over 100 pounds.
Typically, salmon are anadromous, and migration is essential to their lifecycle. Therefore, they breed in freshwater, and as they mature, they move to the ocean, where they spend most of their life, then migrate back to freshwater to reproduce.
Amusingly, Folklore tracking studies show that salmon fish return to the same spot where they hatched to spawn. However, some stray and spawn in different freshwater systems.
Unfortunately, in recent years, salmon populations have been declining. This is due to overfishing and habitat loss. Climate change is also playing a role in their decline, as warmer water temperatures and changes in the timing of river flows impact salmon migration.
FAQs
Why is migration important to marine animals?
Migration is important to marine species for reasons such as looking for food and mating. What’s more, migration also helps these species escape from predators and enable them to adapt to different environmental conditions.
What are the benefits of highly migratory marine species?
Highly migratory marine species have many benefits. First, they are a significant food source for thousands of people worldwide. Secondly, they are crucial to the economy and livelihoods of many coastal communities. What’s more, they help keep ecosystems in balance by redistributing nutrients and energy.
What challenges do marine species face while migrating?
There are many challenges that marine species face during migration. These challenges include overfishing, bycatch, and being hit by ships. On top of that, another challenge is climate change. With changes in water temperature, their migration patterns are affected.
How do marine animals migrate?
Some marine animals migrate by swimming long distances in open waters, while others use currents to travel large distances with little effort. Besides, some migrate vertically in the water column, while other species migrate to different areas during different times of the year.
