Erkki Leppäkoski

• PhD
• Professor Emeritus at Åbo Akademi University, Turku, Finland

The risk assessment (RA) developed according to the BWM Convention is the most recently agreed global RA for bioinvasions. It was developed to enable a selective ballast water management (BWM) approach according to the BWM Convention and the G7 Guidelines. It describes three different BWM RA methods, “environmental matching”, “species’ biogeographi...

A good understanding of the mechanisms and magnitude of the impact of invasive alien species on ecosystem services and biodiversity is a prerequisite for the efficient prioritisation of actions to prevent new invasions or for developing mitigation measures. In this review, we identified alien marine species that have a high impact on ecosystem serv...

A good understanding of the mechanisms and magnitude of the impact of invasive alien species on ecosystem services and biodiversity is a prerequisite for the efficient prioritisation of actions to prevent new invasions or for developing mitigation measures. In this review, we identified alien marine species that have a high impact on ecosystem serv...

The International Convention for the Control and Management of Ship's Ballast Water and Sediments sets requirements to prevent organism transfers. Vessels on certain routes can be exempted from such requirements based on risk assessment (RA). As the convention nears its entry into force, the interest in exemptions increases. Such RA should be condu...

Öljyvahinkojen seurauksena mereen päässyt öljy aiheuttaa eliöissä ja elottomassa ympäristössä välittömiä ja pitkäaikaisia muutoksia. Tämä julkaisu on ensimmäinen kansallinen, yhtenäinen toimintasuunnitelma laajamittaisia öljyvahinkotilanteita varten. Raportissa tutkijoista, asiantuntijoista ja viranomaisista koostuva työryhmä on koonnut yhteen olen...

This risk assessment study focuses on intra Baltic Sea shipping. The HELCOM Guidance to distinguish between unacceptable high risk scenarios and acceptable low risk scenarios – a risk of spreading of alien species by ships on Intra-Baltic voyages (HELCOM Risk Assessment (RA) Guidance) was taken as a starting point to develop the RA concept. In addi...

Quantitative field studies (density, wet weight biomass, Shannon diversity, species richness, evenness of distribution) on benthic sublittoral macrofauna were made in the vicinity of an oil refinery in southwest Finland before and after the installation of a new wastewater treatment plant that reduced the amount of oil and liquid effluents by ca. 9...

The brackish-water seas of Europe, i.e. the Black (including the Sea of Azov), Caspian and Baltic Seas, can be regarded as “brackish-water islands”, locked in by land masses and isolated from other major brackish-water bodies by physical (ocean and land) barriers. During the last two centuries, more than 300 alien species have been recorded in the...

This risk assessment study follows the environmental match of donor and recipient regions of ballast water and the voyage duration as risk quantifiers. The ports considered were Gothenburg (Sweden), Copenhagen (Denmark), Kiel (Germany), Klaipeda (Lithuania), Kemi, Tornio and Raahe as one port region (Finland), and Sköldvik/Kilpilahti (Finland). All...

Recommendations to HELCOM The Baltic Sea countries have international obligations to address invasive alien species, principally according to the Convention on Biological Diversity (1992) and, concerning marine areas, the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (IMO 2004). At the meeting of the...

The introduction of invasive marine species into new environments through ships’ ballast water, attached to ships’ hulls and via other vectors has been identified as one of the four greatest threats to the world’s oceans. Different treatment methods have been proposed for onboard ballast water treatment options to reduce this effect, among those al...

European brackish water seas (Baltic Sea, Black Sea and Sea of Azov, Caspian Sea) are subject to intense invasion of non-indigenous species (NIS). In these seas, salinity is the most important range limiting factor and native species seem to reach a minimum species richness at intermediate salinities. This trend, revealed by Remane in 1934 and late...

The history of research into nonindigenous species and invasion biology in the Baltic Sea is briefly reviewed from faunistic notes made by the early naturalists of the early 1800s to more sophisticated and diversified studies that began in the last decade of the 20th century. In the 1990s, biologists working in the Baltic Sea area increasingly cont...

Non-native aquatic species dispersed via ships' ballast water create a threat for local marine ecosystems throughout the world. Increasing maritime traffic and faster ships have increased the risk for species introductions during the last decades and effort has been made to develop reliable methods for ballast water management. While various techno...

In a literature-based study, 29 non-indigenous species present in northeastern European waters were assessed for their potential for introduction and establishment in Finnish inland lakes. Their physiological and ecological demands were compared to abiotic and biotic lake conditions. The availability of adequate vectors was surveyed from shipping s...

The brackish Baltic Sea is known to function as a bridgehead for the spread of non-indigenous species (NIS) between the Eastern and Western Hemispheres and, in an ecological sense, between freshwater and the sea. The recent basin-wide invasion of the predatory fishhook water flea Cercopagis pengoi and the North American bristle worm Marenzelleria v...

A new alien species for Finland, the amphipod Gammarus tigrinus Sexton, 1939 (Fig. 1), was recorded in summer 2003 in both Hamina (NE Gulf of Finland) and Turku (SW Fin-land). G. tigrinus is native to North America and differs from native Baltic Sea gammarids by coloration and the dense curly setae (males). Before this, G. tigrinus is established i...

There are about 100 nonindigenous species recorded in the Baltic Sea. Invasive species have resulted in major changes in nearshore ecosystems, especially in coastal lagoons and inlets that can be identified as "centres of xenodiversity". Fewer than 70 of these species have established reproducing populations. Dominant invasion vectors include unint...

The global scale of alien species invasions is becoming more and more evident in the beginning of the new millennium. Though the problem of biological invasions became a rapidly growing research area, there are large gaps still, both geographically and thematically, to be filled in the near future. This book is the first attempt to provide an overa...

We review the ecological impacts of Ponto-Caspian invaders in the Baltic Sea, selected lakes and rivers in inland Europe, and the North American Great Lakes. Each of these regions has been invaded multiple times in recent decades by Ponto-Caspian invertebrates and fishes. In attempt to identify predictable patterns, we compared the magnitude and di...

An Internet Database on aquatic alien species in the Baltic Sea area was developed as an initiative of the Baltic Marine Biologistsorking Group on Nonindigenous Estuarine and Marine Organ-isms in 1997; in 2000 a new concept of the online Database appeared with support received from the Baltic Marine Environment Protection Commission (HELCOM). This...

A total of 100 nonindigenous species (NIS) have been recorded in the Baltic Sea (including the Kattegat). Some 70 of these species have been able to establish reproducing populations. The Atlantic coast of North America and the Ponto-Caspian realm have been the most important source areas. Among the most successful and invasive species are the barn...

Since the early 1800s, about 103 NIS have been recorded in the Baltic Sea. In this brackish sea (salinity range from less than 2 to approximately 20 PSU) horizontal and vertical gradients provide the nonindigenous species of different origin an extended repertoire of hospitable conditions. Several ecological functions of the non-native animals are...

It is evident that the history of introduction of nonindigenous aquatic species into Europe dates back to pre-historic times. In this paper, we review from a historical perspective some of the human activities that have facilitated the potential of alien species from all continents but Antarctica to become established in coastal and inland waters o...

The biogeographical peculiarities of the Baltic Sea have developed since the last glacial period. The characteristic mixture of marine, brackish water, and freshwater species, and relicts from previous periods in the Baltic, is threatened by ongoing environmental changes. This review focuses on the recent impacts of nonindigenous species, eutrophic...

Long-term changes in sediment macrofauna communities at two sites affected by fish farming in the Archipelago Sea, south-west Finland have been investigated. Sampling stations in the Särkänsalmi Strait and Kaukolanlahti Bay, previously investigated 1982-1991, were revisited in 1994, 1995 and 1998 to detect signs of recovery following a decrease in...

A major vector for unintentional species introductions is international shipping. A wide range of organisms have been transported over long distances in ships' ballast tanks and as hull fouling. Although many desk studies and ship sampling programmes have been carried out, little information is available on changing numbers of individuals in ballas...

The Baltic Sea, a semi-enclosed brackish water region, has been inoculated by non-indigenous species for centuries. Today, much of its biological diversity is of foreign origin (i.e. xenodiversity), intentionally or unintentionally moved by humans over ecological and geographical barriers. As many as 98 introduced species have been recorded in the...

The biological diversity of the European brackish water seas, either enclosed (Baltic and Black) or iso-lated from the world ocean (Caspian and Aral), is by far lower than that of the fully marine water bodies. The ecosystem may consist of only a few components, so that only one or two species represent a functional group. Any new species added qui...

With contributions from: A. Godhe, D. Daunys, H. Botnen, H. Hagen, I. Olenina, I.V. Telesh, M Östman, P.I. Krylov, S. Olenin, V. Skjævestad, V.E. Panov and Z. Gasiunaite

Semi-enclosed coastal inlets are particularly interesting areas for studies on non-native species since they show steep gradients in physical environment, biological communities, pollution and intensity of human activities. Due to the ecotone effect their biota is constituted of a mixture of marine, brackish and freshwater indigenous and non-indige...

The Archipelago Sea in the northern Baltic has been subjected to large-scale cultural, economic and ecological changes, especially during the last three decades. Environmental threats originate from both basin-wide sources, affecting the whole Baltic Sea, and from local sources, such as nutrient loading from nearby river outflows, intense agricultu...

This review is the first attempt to compare the Baltic Sea and the Black Sea, from an environmental viewpoint. These two seas are subjected to man-induced change and seriously threatened by increasing eutrophication and environmental deterioration. Both sea basins are isolated from the ocean by physical and ecological barriers. Following the glacia...

Environmental problems of the Baltic Sea have been among the major concerns of its coastal states during the past 25 years. Practically all the threats to the Baltic environment discussed during the First UN Conference on the Human Environment in Stockholm in 1972 are still actual topics in the environmental debate and objects of environmental rese...

In Boudouresque CF, Briand F, Nolan C (Eds) Introduced species in European coastal waters

Examples are given from two enclosed brackish-water seas of man-introduced species in man-modified habitats, their origin and routes of dispersal, and relations with other species, including man, and their economic importance to mariculture and tourism and as fouling organisms.

In aquatic hazard assessment used for extrapolations over entire ecosystems or water bodies, the environmental gradients which greatly modify the fate and effects of chemical substances in aquatic communities (marine, estuarine, brackish-water, as well as limnic) must be known. The Baltic Sea, in spite of being a geographically very limited water b...

The Baltic Sea environment : history - eutrophication - recruitment - ecotoxicology : proceedings of the 10th Symposium of the Baltic Marine Biologists, Kiel, September 29 - October 3, 1987: eds. H. Theede, W. Schramm, Kieler Meeresforschungen ; Sonderheft 6, 7-17 Symposium of the Baltic Marine Biologist. 10 Kiel 1987

Publ. Water Res. Inst. National Board of Waters, Finland, nr. 68, 117-121

Baltic Sea Monitoring Symposium, Tallinn, USSR, 10-15 March 1986, Baltic Sea environment proceedings ; 19, 521-530 Baltic Sea Monitoring Symposium Tallinn 1986

Ophelia, suppl., nr. 3, 123-135

Finnish marine research, nr. 250, 3-18

The location of the Baltic Sea in the northern high latitudes affects the structure and function of the Baltic ecosystem. There are also large regional differences in surface salinity and chemical properties. The salinity conditions in the Baltic Sea are very stable. No marked tide-induced currents occur in the area. During different marine and fre...

The Baltic Sea: ed. by A. Voipio, Elsevier oceanography series ; 30, 219-274

The drainage from about 250 river systems and the municipal and industrial wastes of some 17 million people sooner or later end up in the Baltic, which has been described as one of the most severely polluted sea areas in the world. Human activities have caused excessive eutrophication and resulted in damaging oil spills, and the chronic discharge o...

Soft-bottom macrofauna were sampled in Saltkällefjord (west coast of Sweden), polluted by sulphite pulp and paper mill wastes, and in certain SW-Finland coastal inlets into which both domestic and industrial wastes are discharged The parameters studied were: species composition, abundance, wet weight biomass, distribution of species, size class dis...

The history of brackish-water biology in the Finnish coastal waters from the Linnaean period to the 1990s is briefly reviewed. The first notes on benthic animals date back to 1769. Two "insects", Idotea entomon (Oniscus) and Gammarus pulex, were mentioned as causing damage to fishing. Sporadic studies of benthic organisms were started in the middle...

Water Protection Measures in Fish Industry : reports of an international seminar, Tallinn, Estonia, SSR, May 25-28, 1982, 15-28 Water Protection Measures in Fish Industry Tallinn 1982 Publishing place: [s.l.]

Andra svensk-finska seminariet om Bottniska viken, Luleå, Sverige, 16-17 juni 1981 = Second Swedish-Finnish Seminar on the Gulf of Bothnia, Luleå, Sweden, June 16-17, 1981: ed.: Hans Cedervall, SNV PM 1618, 140-144 Svensk-finska seminariet om Bottniska viken. 2 Luleå 1981

Proceedings of the 14th Conference of the Baltic Oceanographers, Gdynia, 1984, 631-636 Conference of the Baltic Oceanographers. 14 Gdynia 1984

10th annual Symposium of the Finnish Society of Toxicology, Turku, 19.-20.5.1989 : abstracts = Suomen Toksikologiyhdistyksen vuosikokous, Turku, 19.-20.5.1989: eds. P. Rantamäki, K. Pyykkö, M. Ahotupa, 62 Symposium of the Finnish Society of Toxicology. 10 Turku 1989

1. In the Gullmarsfjord (west coast of Sweden), an area affected by paper- and pulp-mill wastes was studied. 2. In the interstitial water separated by centrifuging, a relatively high salinity was found. In the studied topmost 8 cm of the sediment, the salinity increased distinctly downward. 3. The polluted sediments, containing wood fibre, had high...