The sea trout, or Salmo trutta, is the same species as the river-based brown trout. However, sea trout are the group of trout that venture out to the sea to engage in feeding. They have anadromous nature, migrating between freshwater and saltwater. Depending on where they are, they have many different names. These include peal, sewin, mort, finnock, white trout, spotted seatrout, speckled trout, and salmon trout. The trout is a popular fish among anglers.
They are a vital ecosystem member with their delicate flavor and vibrant fight. They are a prized catch for both anglers and seafood lovers. Join us as we explore the world of these fascinating fish, exploring their life cycle, behavior, and the challenges they face in a changing world.
Appearance
The sea trout is typically silver with a black-spotted pattern. Their dorsal surface ranges from olive-green to bluish-gray, providing camouflage. However, once the fish comes into the rivers to breed, they turn back to a brown color. Once they migrate out to sea again, they turn back to their silver state with black spots.
On average, sea trout can become relatively large sea creatures, measuring up to 60 cm in adulthood and remaining as small as 35 cm. However, in favorable circumstances, they can reach up to 130 cm. When fully grown, they can range from 0.5 – 2.4 kilograms in weight, with them being known to reach 20 kg in very specific habitat conditions.
They have an adipose fin, which is common among all trout species. The most distinctive element of the sea trout’s appearance is its long missile-like body. It is considered to be very similar to the Atlantic Salmon in many physical aspects.
The dorsal and anal fins maintain balance and prevent rolling, while the pectoral and pelvic fins provide lift, steering, and braking capabilities. The powerful caudal fin, or tail fin, generates the thrust necessary for their swift bursts of speed.
Did you know…
During the breeding season, male sea trout stand out with their kype, a hooked lower jaw, and vibrant coloration, often with reddish tones. Females, on the other hand, lack the kype and retain a more silvery appearance. Body shape can also provide clues, with females potentially exhibiting a rounder form, especially when carrying eggs.
Habitat
The sea trout mainly inhabits the Atlantic Ocean, the Baltic Sea, The North Sea, the Black Sea, the Arctic Ocean, and the Caspian Sea. However, in recent years, they have been introduced into many countries and regions, such as Chile, Argentina, and Oceania.
They are most abundant in depths of less than ten feet and prefer temperatures between 60 and 80° F. Water temperatures below 45° F appear to cause large-scale mortalities. It typically lives in salt water.
They are found in grassy flats, estuaries, or shallow waters at night. During colder months, they form big schools and are usually found in waters as deep as 164 feet.
Diet
The sea trout are opportunistic carnivores. They mainly feed on fish, small crabs, and other crustaceans like shrimps and prawns. It moves between the rivers and the sea during their life history.
One or two prominent canine teeth are usually present at the tip of the upper jaw. Small sea trout feed primarily on small crustaceans. Medium-size trout feed on shrimp and small fish. Large fish feed almost exclusively on other fish like mullet or baitfish.
Reproduction
Spawning occurs inshore from March through November. They move into deeper, still waters during colder months. The female population is found in abundance, and larger than its male counterparts. This is due to the number of eggs they lay during spawning. A female sea trout will produce around 800 eggs per kilogram of body weight, with larger and older fish releasing the most.
The life cycle of the sea trout is very seasonal. They engage in spawning in the winter, which occurs in the rivers, then migrate to the sea when their body clock tells them to.
When the spawning process is complete, the young fish can live in the rivers for up to 5 years before venturing out to sea. When they migrate, they can travel up to 40 km per day.
Threats
One of the biggest threats originates in its native rivers. Throughout Central Europe, in particular, many hydroelectric plants and dams have cut off their migration patterns. This intervention has limited the amount of brown trout moving into the seas and oceans.
With electrical power becoming more and more in demand, it is safe to assume that hydroelectric plants will continue to be built, Thus making the outlook for these trout populations rather bleak. Due to flooding in certain areas, many sea trout spawning grounds have been decimated.
Like any fish, the sea trout has predators above them on the food chain. Larger carnivorous fish, fish-eating birds, and mammals such as bears are all a threat and view them as prey.
7 More Quick Facts about the Sea Trout
- Female sea trout are larger than males.
- Populations have been introduced in Chile and Argentina.
- It is the same as brown trout but migrates to saltwater.
- Sea trout spawn upriver during the winter months.
- Artificial baits and lures are effective for catching trout year-round.
- Larval stage of a tapeworm, the “spaghetti” worms get embedded in the flesh along the backbone and can only reach maturity in sharks.
- It is a member of the croaker family (Sciaenidae) and is related to the Atlantic croaker, red drum, black drum, and sand seatrout.
FAQs
What is the difference between trout and sea trout?
The sea trout and brown trout are essentially the same species. Sea trout, known for their anadromous migration between saltwater and freshwater, often display a silvery coloration with dark spots, intensifying during spawning. They typically reach larger sizes due to their marine diet. Brown trout is golden-brown with dark and reddish spots. While some populations migrate like sea trout, many remain resident in freshwater streams, rivers, and lakes, resulting in a generally smaller size.
Are sea trout endangered?
Although humans have impacted the sea trout population through overfishing, habitat loss, and hydroelectric dams, it is generally considered not threatened by the IUCN.
How does sea trout taste?
Sea trout is known for its delicate, slightly sweet flavor and firm, flaky texture. It’s often compared to salmon, though some find it milder and less oily.
What role do hatcheries play in sea trout conservation?
Hatcheries can support sea trout populations by raising and releasing young fish into depleted or recovering habitats. This helps boost wild stocks, enhance fishing opportunities, and aid in restoring populations impacted by habitat loss or overfishing.
