Search

Shipping is regarded as an important vector for aquatic non-indigenous species (ANIS) worldwide. Less attention has been paid to its role in relation to environmental and economic causes of introduction and establishment, the knowledge of which is necessary to assess effects of changes in regulations on shipping. The purpose of this study was to estimate the impact of shipping on the incidence of ANIS in the Baltic Sea compared with environmental and economic factors. To this end, a production function was estimated with count data on ANIS (response variable) and shipping, environmental and economic factors as explanatory variables. Regression results from different regression models showed that shipping has a significant impact on ANIS incidence and can account for up to 38% of the number of ANIS in the sea. Predictions of the impact of measures implementing the Convention for the Control and Management of Ships' Ballast Water and Sediment indicated a reduction by 17% in the number of ANIS, which was counteracted by an expected increase in shipping traffic., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Despite a large body of literature on the calculations of costs of air emissions from shipping, calculations of damages to the marine water are missing. This paper calculated the costs of NO x emissions from shipping entering an environmentally heterogeneous sea by applying the abatement cost approach. The total costs and unit shadow cost of NO x were then calculated by means of the marginal abatement cost for international agreements on targets of nitrogen loads to the sea. This conceptual model highlighted the need to distinguish between direct emissions of NO x on the sea and indirect emissions through deposition of emissions on land in the catchment with subsequent transportation into the sea. Calculated total cost amounted to 240 million euros, where indirect deposition accounted for 23% of the costs. The unit shadow costs ranged between 1.41 and 3.69 euros/kg NO x -N depending on location of the vessel., (Copyright © 2021. Published by Elsevier Ltd.)

There are several environmental and ecological effects of shipping. However, these are rarely assessed in total in the scientific literature. Thus, the aim of this study was to summarize the different impacts of water-based transport on aquatic and nearshore ecosystems and to identify knowledge gaps and areas for future research. The review identified several environmental and ecological consequences within the main impact categories of water discharges, physical impacts, and air emissions. However, although quantitative data on these consequences are generally scarce the shipping contribution to acidification by SO x - and NO x -emissions has been quantified to some extent. There are several knowledge gaps regarding the ecological consequences of, for example, the increasing amount of chemicals transported on water, the spread of non-indigenous species coupled with climate change, and physical impacts such as shipping noise and artificial light. The whole plethora of environmental consequences, as well as potential synergistic effects, should be seriously considered in transport planning., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Mussel farming has been recognised as a low cost option for mitigating damage caused by eutrophication in the Baltic Sea. However, uncertain nutrient removal owing to weather and environmental conditions at the mussel farm site has not been previously considered. The purpose of this study was to estimate whether mussel farming has cost advantages even in conditions of uncertainty. To this end, the replacement cost method was used for the valuation of ecosystem services and a numerical cost minimisation model was constructed based on the safety-first approach to account for uncertainty in nutrient removal. This study showed that the value of mussel farming depends on the cost at the farm, and the impact on the mean and variability of nutrient removal in relation to other abatement measures. The study also pointed out the need of data on the decision makers' risk attitudes and measurement of uncertainty. The application to the Baltic Sea showed that the total value of mussel farming increased from 0.34 billion Euro/year to 0.41 or 1.21 billion Euro when accounting for uncertainty depending on assumption of probability distribution. The increase was unevenly distributed between the Baltic Sea countries, with it found to be lower for countries equipped with highly productive mussel farms and long coastlines., Competing Interests: The authors have declared that no competing interests exist.

Macrofaunal activities in sediments modify nutrient fluxes in different ways including the expression of species-specific functional traits and density-dependent population processes. The invasive polychaete genus Marenzelleria was first observed in the Baltic Sea in the 1980s. It has caused changes in benthic processes and affected the functioning of ecosystem services such as nutrient regulation. The large-scale effects of these changes are not known. We estimated the current Marenzelleria spp. wet weight biomass in the Baltic Sea to be 60-87 kton (95% confidence interval). We assessed the potential impact of Marenzelleria spp. on phosphorus cycling using a spatially explicit model, comparing estimates of expected sediment to water phosphorus fluxes from a biophysical model to ecologically relevant experimental measurements of benthic phosphorus flux. The estimated yearly net increases (95% CI) in phosphorous flux due to Marenzelleria spp. were 4.2-6.1 kton based on the biophysical model and 6.3-9.1 kton based on experimental data. The current biomass densities of Marenzelleria spp. in the Baltic Sea enhance the phosphorus fluxes from sediment to water on a sea basin scale. Although high densities of Marenzelleria spp. can increase phosphorus retention locally, such biomass densities are uncommon. Thus, the major effect of Marenzelleria seems to be a large-scale net decrease in the self-cleaning capacity of the Baltic Sea that counteracts human efforts to mitigate eutrophication in the region.