Genetic characterization of Atlantic sturgeon stocking material used in Lithuania to restore the Baltic sea population

Abstract. Satellite-based data are very important for air quality applications in the Baltic Sea area, because they provide information on air pollution over sea and there where ground-based network and aircraft measurements are not available. Both the emissions from urban sites over land and ships over sea, contribute to the tropospheric NO2 levels. The tropospheric NO2 monitoring at high latitudes using satellite data is challenging because of the reduced light hours in winter and the snow-covered surface, which make the retrieval complex, and because of the reduced signal due to low Sun. This work presents a detailed characterization of the tropospheric NO2 columns focused on part of the Baltic Sea region using the Ozone Monitoring Instrument (OMI) tropospheric NO2 standard product. Previous works have focused on larger seas and lower latitudes. The results showed that, despite the regional area of interest, it is possible to distinguish the signal from the main coastal cities and from the ships by averaging the data over a seasonal time range. The summertime NO2 emission and lifetime values (E = (1.0 ± 0.1) × 1028 molec. and τ = (3.0 ± 0.5) h, respectively) in Helsinki were estimated from the decay of the signal with distance from the city center. The method developed for megacities was successfully applied to a smaller scale source, in both size and intensity (i.e., the city of Helsinki), which is located at high latitudes (∼60° N). The same methodology could be applied to similar scale cities elsewhere, as far as they are relatively isolated from other sources. The transport by the wind plays an important role in the Baltic Sea area. The NO2 spatial distribution is mainly determined by the contribution of strong westerly winds, which dominate the wind patterns during summer. The comparison between the emissions from model calculations and OMI NO2 tropospheric columns confirmed the applicability of satellite data for ship emission monitoring. In particular, both the emission data and the OMI observations showed similar year-to-year variability, with a drop in year 2009, corresponding to the effect of the economical crisis.

Download Full-text

Anadromous Sturgeons: Habitats, Threats, and Management

Anadromous Sturgeons: Habitats, Threats, and Management ◽

10.47886/9781888569919.ch17 ◽

2007 ◽

Keyword(s):

Baltic Sea ◽

North Sea ◽

Atlantic Sturgeon ◽

The Baltic Sea ◽

Genetic Analyses ◽

Inland Fisheries ◽

The North ◽

Oder River ◽

European Sturgeon ◽

The Baltic

Abstract.â€”A century ago, sea sturgeon (Atlantic sturgeon Acipenser oxyrinchus and European sturgeon A. sturio) were prevalent in the fish communities of all major German rivers, both in the North and the Baltic Sea drainages. Since then, population sizes have decreased rapidly due to overfishing, pollution, and hydropower construction. The last catches in the Baltic drainage occurred in the late 1960s. Only individual captures of sturgeon have been reported in the last 30 years, the most recent being in Lake Ladoga (Russia) in 1984 and off the coast of Estonia in 1996, approximately 25 years after the disappearance of the species from the fishery. Today, sturgeon are considered extinct in German waters. In 1996, the Federal Agency for Nature Conservation, in cooperation with the Society to Save the Sturgeon, started the pilot phase of a remediation program involving assessment of the prerequisites for remediation. The first juvenile European sturgeon were transferred to the Leibniz-Institute of Freshwater Ecology and Inland Fisheries under a scientific cooperation agreement with the Centre dâ€™Ã‰tude du Machinisme Agricole, du Rural, des Eaux et ForÃªts in May 1996. With these specimens, an ex situ measure was initiated. In addition, phylogenetic and population genetic analyses of the species were carried out using mitochondrial DNA and microsatellites. These genetic analyses of recent and historical material have proven the existence of two different species in what was previously considered the Baltic or common sturgeon. The Atlantic sturgeon has been identified as endemic in the Baltic Sea and the European sturgeon in the North Sea. According to morphological evidence based on archaeological samples, the Atlantic sturgeon invaded the Baltic Sea approximately 2,000 years ago and has been the only sturgeon species there for the last few centuries. These results led to the separation of the remediation activities in North Sea and Baltic Sea tributaries. Broodstock development using the northernmost populations of the Atlantic sturgeon is currently being carried out. Subsequent reproduction for restocking requires a sufficiently large broodstock and a genetic breeding plan based on pedigree analysis. As a further prerequisite, an evaluation of the status of critical habitat for the early life stages of Atlantic sturgeon in the Oder River has been performed in collaboration with the Institute for Inland Fisheries of Poland. Alternative fisheries techniques, based on data for the bycatch of exotic sturgeon, are being developed to reduce the fishing pressure on juvenile sturgeon upon release.

Download Full-text