The Baltic Sea and its fish species

The brackish water environment and fish species composition of the Baltic Sea is unique and combines fish of both freshwater and marine origins. For many fishes, the slightly salty water conditions result in an increased growth rate and many record-sized fish being caught in the sea basin during the years, perhaps most notably large specimen of sea trout, salmon and pike.

The Baltic Sea is often pointed out as a good example of the EU environmental management. Yet there are still considerable challenges and we strongly believe that further support of sustainable fishing tourism is a modern and needed step forward, towards making the best of the natural fish resources that our precious sea provides.

We ensure sustainable fishing in some of the most pristine and beautiful sections of the Baltic Sea Region. We always make sure that our fishing is well-balanced and adapted to local and natural boundaries at each destination.

Fish species

Sea trout – fast growing silver treasures of the Baltic Sea

Sea trout (Salmo trutta) is a symbol of the Baltic Sea Fishing, as it holds the potential for expressing the weight of conservation activities in inland waterways as well as improved sportfishing opportunities along the Baltic Sea coasts. What’s more, the Baltic is home to some of the world’s largest trout.

Also called brown trout, this species shows a lot of varieties, i.e. ecological forms with different migration behaviour. One fish that is born in a woodland stream, not connected to a larger waterway or lake, remains a small-sized trout throughout its life. If the brook flows into a lake however, the trout has more diverse opportunities and can undertake a migration out into the lake to eat smelt (Osmerus eperlanus) and vendace (Coregonus albula) and become a large and shiny lake trout. If, finally, it is born in a waterway that flows into the sea, the opportunities of the trout rise exponentially and it can achieve its full growth potential.

The largest known Baltic trout weighed 15.26 kilos and was caught in Emån, Sweden by a sport fisherman Lennart Westerlund in 1993. Incidentally, it is the world’s second-largest sportfishing-caught trout specimen ever fished on-record. The reason for this is an abundance of food in the estuarial areas. Moreover, the brackish salinity of the Baltic Sea is nearly perfect for trout and salmon (Salmo salar), and in fact, the lifecycles of both species are reminiscent of each other, but the former is much more likely to spawn numerous times and prefer larger rivers. Sea trout are born, spend their early years, and spawn along gravel and stone bed bottom of flowing waterways.

Unfortunately, over the course of several centuries, trout habitats have been severely diminished by various forms of dam installations. Dam removal is one of the activities that the BSF guides donate funds to in addition to river restoration and anti-poaching activities.

Pike – top ambush-hunting predator

Pike (Esox Lucius) fishing in the Baltic Sea is world-famous thanks to the large number of outsize individuals. Fish weighing over 10 kilos are an annual occurrence, and fish surpassing 20 kilos have also been caught. The most famous catch in Swedish waters was made by Fehmi Varli on June 17, 1986, in Ulvsundet, Järnafjärden, outside Södertälje. The pike weighed a whopping 26.57 kilos.

The pike is a predominantly predatory fish throughout its lifecycle and primarily consumes various species of carp, but in the Baltic Sea herring (Clupea harengus) is also a significant component of its diet.

Pike spawn early in the spring, and in case there’s ice, the spawning occurs in connection with its break-up. The water temperature is between 2-5 degrees, and along the Baltic coasts, the spawning usually occurs in April. Flooded terrain is preferred for spawning, and the fish can spawn far up on what is otherwise dry land. The pike spawn in secluded coves and inlets, but they are also happy to use flowing waterways and coastal wetlands flooded by the inflow of freshwater in the spring.

Perch – the striped warrior

For fish-eating individuals, Baltic herring, sticklebacks and various carp fish are attractive prey which they often hunt in shoals. Another culinary delicacy comes to our tables thanks to the perch (Perca fluviatilis) – a common fish species and one of the most popular. This is not surprising to many, as perch are both fun and interesting to fish.

Perch spawn in the spring and spawning grounds are often positioned in shallow and vegetation-rich bays as well as in streams and small waterways. Perch fishing can occur year-round but it reaches its peak during late summer/ early autumn, when perch abundance translates to hundreds of catches per fishing trip, which is highly common.

Perch grow fast in the Baltic, unlike in lakes, where the narrowed availability of spawning grounds limits the size of the stocks. In the Baltic Sea, the food supply is rarely restricted, and the size as well as growth of the schools is usually unrelated to competition and predation (within the species and with other species), which is almost always the case in lakes.

Salmon – the Formula 1 of fishes

The Atlantic salmon (Salmo salar) were previously found in most of the larger waterways that flow into the Baltic Sea. During the 20th century, their numbers dropped significantly as a result of constructions of hydropower installations. However, the number of salmons has increased during the last decade, partly due to reduced commercial fishing for the species. Concurrently, trolling for the species has become more and more popular, and today top class salmon trolling is offered in large parts of the sea.

Salmon spawn in large waterways with rapidly flowing water, with the bottom consisting of gravel and stones. Spawning is the finale of the species’ annual migration, called salmon run, which occurs during the autumn. The fry, having hatched the following spring, remain in the waterway for 1-4 years, during which they will develop into juvenile fish called parr, to then migrate out into the sea as smolt. This journey takes place in the spring, around the time the next generation of fry hatches. Smolts remain in the sea for 1-8 years. Once they reach maturity, they begin their migration back to the spawning ground where they once hatched. Many of the salmon die shortly after spawning.

The presence of salmon in the rivers used for hydroelectric power generation is entirely dependent on compensatory releases. Since they began at the end of the 19th century, about 113 million salmon have been brought back to the Baltic Sea ecosystem.

Zander – the hunter with an exceptional vision

The zander (Sander lucioperca), also called pikeperch, is a challenging game fish but can be caught using many different methods. The most common pikeperch fishing method is trolling with a wobbler. Yet, when it comes to catching large specimens, a minor revolution was brought by the technological development of sonar, which allowed for the so-called ‘sniping’ for large pelagic fish. Over the past few years, several specimens over 10 kg have been caught using this method, examples that were previously very rarely caught by sport fishermen.

The very existence of zander requires specific environmental conditions. Above all, they need warm, cloudy and fish-rich water. In other words, zander thrive best in large, nutrient-rich plain lakes and in the inner bays of the Baltic Sea archipelagos, where they have benefited from the pronounced eutrophication that occurred in the latter part of the 20th century. Among other things, this is because the zander sneaks up on its prey, which thanks to its well-developed vision, it can see despite poor visibility. However, it is also because the zander requires a long warm period in order to propagate successfully. Ideally, zander fry must reach 10 centimetres in size before the autumn and the beginning of the cold season, otherwise mortality rises to very high rates during the winter months. Thus, not only is a warm spring necessary for spawning, but the growth of the fry also depends on a warm summer and good weather conditions during autumn.

Spawning occurs in pairs, and afterwards the roe is guarded by the parent zander, primarily the males. This is to prevent it from being eaten by other fish such as predatory ruffe (Gymnocephalus cernua). This is one of the reasons why it can be effective to spin fish for zander during the spawning period. The parent zander guards the roe warily, and instinctively attack anything that moves in the vicinity of the nest.

Garfish – the beaked projectile

The garfish (Belone belone), otherwise known as garpike or sea needle, is a marine species that has become more common in the Baltic Sea over the last thirty years, and the northernmost border of its territory has gradually shifted north. When salmon trolling took off in the early 1990s, occasional specimens of garfish were caught as bycatch, but by the 2000s, it could be caught in large quantities. Today, garpike fishing is possible from April to June along large parts of the Baltic coast and all the way up to Stockholm. This had previously been completely unthinkable.

In the Baltic Sea, adult individuals of the species are found only during the spawning migration that occurs from the late winter until the beginning of June. The sea needle fish appear in shoals close to the beach, and during the spawning itself they swim around at high speed, causing the water to appear as ‘boiling’. After the spawning migration, they return to their foraging areas, which are primarily located out in the open Atlantic.

Garfish has a very distinctive appearance with a beak-like mouth, and is reminiscent of a small swordfish. It is greenish silver in colour, and oddly enough, its bones are green. They can be found along Sweden’s West Coast throughout the summer period. The garpike is a predominantly pelagic schooling fish that can be found in shallow waters, where it hunts prey fish, such as tobis (Ammodytes tobianus) and sprat (Sprattus sprattus).

European flounder – the curious chameleon of the sandflats

The European flounder (Platichthys flesus) is an attractive game fish, great for angling from the beach and bottom fishing using worms or shrimp as bait. The Swedish record for the largest catch is 56 cm and 2.23 kilo, performed in Öresund by Per Isacsson in 1987. Swedes call this species skrubbskädda, which is inspired by the rough and grating skin along the sides of the fish on which one can ‘scrub’ (skrubb) one’s hands if one fails to handle the fish with care.

The European flounder, also known as white fluke, is by far the most common flatfish in the Baltic Sea, where it thrives in brackish water. It is therefore found throughout the coastal area, but is rare in the northernmost parts of the Bay of Bothnia. Sometimes it also makes its way up the mouths of waterways in order to forage, and can be found in freshwater, even though it is a marine species. A salinity exceeding approximately 6 per mil is a prerequisite for its reproduction.

On the West Coast the European flounder spawns during the winter and spring in the Baltic Sea. A female usually produces about 2 million pelagic eggs, which require regional adaptation to cope with the salinity gradient of the Baltic Sea. However, the water in the northern part of the Baltic Sea, is not sufficiently salty. As a result, the eggs fall to the seafloor. In recent years, the possibility that these flounder may constitute a separate species has been a subject of debates.

Cod – the main predator sadly in distress

In the 20th century, the Baltic Sea underwent a major environmental change. The Atlantic cod (Gadus morhua) is probably the species that has been most affected by this development. Because it is the most common predatory fish in the Baltic Sea, this has also resulted in significant changes to the entire ecosystem. Cod has pelagic liquid roe, which in the Baltic Sea require a salinity of about 11 per mil to float. This is an adaptation to the brackish water, and the roe of cod native to Västerhavet (the Kattegatt and Skagerrak straits) require a significantly higher salinity. In the Baltic Sea, they sink to the seafloor like a stone.

As a result of eutrophication, the stocks of Baltic herring increased in the second half of the 20th century. For a few years at the end of the 1970s, large saltwater inflows from Västerhavet created good conditions for cod spawning. There was also an abundance of prey fish, and as a result the stock of cod absolutely exploded.

Between 1970 and 1980, the spawning stock increased from 200,000 tonnes to 700,000 tonnes, becoming one of the largest in the world. Fishing was relatively unregulated at the time, and between 1980 and 1985, an unimaginable 300,000-400,000 tonnes of Baltic cod were annually. This can be compared to the total global cod catch, which during the same period was around 2 million tonnes per year. This means that approximately 20 per cent of the world’s cod catch originated in the small, inland Baltic Sea. However, this was a period of rapid transition, and by the early 1990s the spawning biomass had sunk to less than 100,000 tonnes, while catch had decreased to under 50,000 tonnes.

In 1994, Peter Arvidsson caught the largest Swedish cod ever recorded, near a shipwreck south of Abbekås in the southern Baltic sea. The fish was 122 cm long and weighed a total of 32.42 kg.

Vimba – a fighter of the streams

The body shape of the vimba (Vimba vimba) is similar to that of the ide (Leuciscus idus), on the other hand it lacks the high back of fish such as carp bream (Abramis brama) and white bream (Blicca bjoerkna). The head has a distinctive appearance; the mouth is located beneath an elongated nose. During spawning, males adapt a spectacular appearance with dark sides and an orange belly. Its life in lakes and along the coast remains a relative mystery, but vimba is a schooling fish that is primarily bottom-feeding.

Vimba fish have a limited distribution in the Baltic Sea and are mostly found in the central-southern parts of the basin. They spawn exclusively in running water, which is why dams and other water exploitation have had a negative impact on both their distribution and the stock status. Vimba are also found in southern Finland, the Baltic countries: Lithuania, Latvia and Estonia, Poland, but do not occur in Danish waters. The distribution area also extends from Central and Eastern Europe eastwards to the Ural Mountains and the Caspian Sea.