IVL Swedish Environmental Research Institute

Coastal marine ecosystems all over the world are under threat due to human activities and climate change. The Maritime Spatial Planning Framework Directive (2014/89/EU) states that maritime spatial planning should support and facilitate the sustainable growth of offshore activities such as fishing, shipping, and aquaculture, while preserving, protecting, and enhancing our marine environments. To succeed, data, good knowledge and careful planning of our complex marine ecosystems are required. Models can be effective tools for coastal zone planning and management, as they enable scenario simulations and non-invasive experiments. Access to good quality data both as input to models and for model validation is essential to ensure high quality model results. However, it is often a challenge to find good data. 

The goal of this synthesis was to evaluate opportunities and shortcomings in how data, models and planning tools are used today and how they could be used in the future. As part of this, we have compiled, described, and evaluated different models, planning tools and data sources. We have also investigated whether there are new technologies that could help fill the gaps and shortcomings identified. For example, can data and models be combined and used to facilitate coastal zone planning and management? 

The results from this synthesis show that the current inventory and mapping of species and flora in the coastal zone is insufficient, to serve as a basis for reliable planning. There are many available models and planning tools adapted for the coastal zone, but in most cases basic input data are missing, such as spatial data on where different species and biotopes are located as well as bathymetry. If the underlying data for the models or planning tools is deficient, there is a high risk that the results will be misinterpreted or overinterpreted. 

In addition to traditional inventory, new techniques and methods should be explored. This may involve combining, for example, environmental DNA, machine learning techniques, modelling, and measurements with new low-cost sensors to acquire the data of spatial distribution of species and biotopes that are missing. 

Furthermore, the results from this study show that there are great opportunities in sharing and reusing data in coastal zone planning and management. There are today several data portals where data is shared, however, it can be difficult to find the right data due to insufficient metadata. A system for data management and sharing is needed. In particular, we want to highlight the value of working with linked data and persistent identifiers. In order to preserve our coastal ecosystems and enable sustainable growth of offshore activities, we must gather expertise on for example environment and digitization from both authorities, researchers and business practitioners. This will require an overarching long-term investment that includes the development of new methods and techniques as well as data management. 

This paper describes the new developments of the Ship Traffic Emission Assessment Model (STEAM) which enable the modelling of pollutant discharges to water from ships. These include nutrients from black/grey water discharges as well as from food waste. Further, the modelling of contaminants in ballast, black, grey and scrubber water, bilge discharges, and stern tube oil leaks are also described as well as releases of contaminants from antifouling paints.

Each of the discharges is regulated by different sections of the IMO MARPOL convention, and emission patterns of different pollution releases vary significantly. The discharge patterns and total amounts for the year 2012 in the Baltic Sea area are reported and open-loop SOx scrubbing effluent was found to be the second-largest pollutant stream by volume. The scrubber discharges have increased significantly in recent years, and their environmental impacts need to be investigated in detail.

The occurrence of abandoned, lost, and discarded fishing gear (ALDFG) in aquatic environments contributes both to environmental and socioeconomic impacts. In nature, discarded fishing gear can release both macro- and microplastics as well as harmful chemicals and thereby contribute to pollution of water bodies and the degradation of habitats. This study is a further development of the project Quantification and environmental pollution aspects of lost fishing gear in the Nordic countries (Unsbo et al., 2022).

The project intends to compile information from the HELCOM-countries on the quantity and composition of lost fishing gear, originating mainly from recreational fishing. The study also considers the occurrence of harmful chemicals associated with the lost fishing gear and the potential impact of these chemicals on the aquatic environment. Suggestions on how to prevent further losses and mitigate negative impact of lost fishing gear are also provided.

The HELCOM-countries included in this report are Denmark, Estonia, Finland & Åland, Germany, Latvia, Lithuania, Poland, and Sweden. This study is based on several methodological approaches to obtain and compare data from different sources. It includes a literature survey, a stakeholder dialogue, an analysis of sales statistics from retailers and producers of fishing gear and national import and export statistics. A web-based questionnaire specifically directed towards gaining information from recreational fishers was developed and disseminated. The data generated from the questionnaire was then compared with official national statistics. 

The quantity and composition of lost fishing gear are difficult to estimate mainly due to the general lack of data within this area. In this study, estimations of lost gear such as fishing line, baits and sinkers were calculated. It is, however, important to recognise that estimates of lost fishing gear in the HELCOM-countries are rough and based on many assumptions, combined with a low response rate on the questionnaire.Sweden, Finland, Denmark, and Estonia have national statistics on the number of recreational fishers available for the public. This group encompasses around 1.7 million persons in Sweden, 1.5 million in Finland, 0.3 million in Denmark as well as 68 000 in Estonia. The other countries do not have any national statistics on the number of recreational fishers.

The following number of fishers were estimated for the other countries:  174 000 in Germany, 41 000 in Latvia, 60 000 in Lithuania, and 84 000 in Poland. The number of fishers were multiplied by the average amount of gear lost per person and year obtained from the questionnaire results. The estimated number of lost fishing gear by the HELCOM-countries thus amounts to 21 million baits, 9 million sinkers and 96 million metres of fishing line per year. The questionnaire generated 145 replies of which 94 respondents were from Sweden, 32 from Lithuania and 19 from Estonia.

National statistics on imports, exports and industrial production do not specify the intended user of the specific fishing gear. However, due to the specificity in behaviours and equipment of the type of fisher, it can be assumed that some of the commodity codes are likely to correspond either to sport and recreational fishing or to commercial fishing. Based on this assumption, the project has estimated total annual losses in the Nordic countries of 337 tonnes fishhooks, 78 – 745 million meters fishing line. 

Because of the large amount of fishing gear lost at sea, their presence is likely to have negative effects on aquatic ecosystems. Plastic additives and associated chemicals constitute a plethora of harmful substances that can leach from plastic materials. Fishing plummets made of lead are also problematic since lead is toxic. The use of lead in sinkers and plummets is already banned in Denmark and similar restrictions are likely to be introduced in all HELCOM-countries due to the possible coming proposal from the EU Commission (ECHA, 2022). 

The most common types of plastic used in fishing gear are Polyethylene (PE), Polypropylene (PP) and Polyamide (PA or nylon). Some common additives in plastics are stabilizers, fillers, colorants, antioxidants, flame retardants and plasticizers. Even if harmful substances do exist in fishing gear it has not, within the framework of this study, been possible to quantify the annual amount released to the environment. The necessary information on additives and chemicals present in fishing gear has not been reported or has never been analysed.

Producers and resellers of fishing gear, contacted in this study could not or were unwilling to share information about the chemical contents of their products even though REACH stipulates that suppliers should provide information about SVHC (substances of high concern) present in their products in concentrations over 0.1 % (weight by weight) within 45 days.  

We suggest the following measures to reduce the occurrence and impacts of lost fishing gear; 1) municipalities and retailers should provide information on the topic to increase the awareness among fishers, 2) incitements to reuse, recycle or recover fishing gear should be improved, 3) better information on chemical substances present in fishing gear, 4) ban of harmful substances including lead in fishing gear and 5) conduct clean ups of hotspots which also will contribute to reduce new losses. Implementation of the EU Single-Use Plastics Directive and upcoming extended producer responsibility including fishing gear in the HELCOM-countries are important drivers supporting this positive development.

In conclusion, the estimates presented here should be considered indicative of potential losses of fishing gear in the HELCOM-countries. By using two different and independent methods to collect data for estimating losses of fishing gear, we have aimed to shed light on the uncertainty in our estimates. Furthermore, we provide all assumptions and calculations for transparency. Even though the methods to some extent give similar results, the figures are overestimated due to our conservative assumptions based on the precautionary principle and better data is needed to provide more reliable decision support.  

Fosfor är ett essentiellt ämne för alla fotosyntetiserande organismer. I sjöar är det framförallt växtplankton som utgör basen för näringsväven. När tillförseln av fosfor till sjöar blir förhöjd, exempelvis genom kommunala och industriella avlopp eller näringsämnesläckage från jordbruksmark, ökar produktionen av växtplankton, ett fenomen benämnt övergödning. Övergödning av sjöar började i slutet av 1960-talet uppmärksammas som ett tilltagande miljöproblem och olika samhälleliga åtgärder vidtogs för att reducera tillförseln av fosfor, exempelvis genom att introducera fosforfällning vid de kommunala avloppsreningsverken.

Åtgärderna har i många, men inte alla, fall varit effektiva. Ett skäl till att vissa sjöar fortsatt att uppvisa hög näringsrikedom, trots att den externa tillförseln av fosfor till sjön via tillrinnande vattendrag och direkta punktutsläpp reducerats, är så kallad internbelastning. Normalt sett sker en betydande fastläggning av fosfor i sjöars bottensediment i biologiskt otillgängliga former, men under vissa förhållanden blir denna process mindre effektiv och biotillgänglig fosfor fortsätter år efter år att cirkulera mellan vatten och sediment och stimulerar därmed algproduktionen. Under senare år har samhälleliga åtgärder mot denna internbelastning alltmer kommit att diskuteras och på sina håll har även konkreta åtgärder genomförts. 

Med livscykelanalyser (LCA) kan effektiviteten i miljöskyddsåtgärder utvärderas utifrån deras sammanvägda miljöpåverkan med hänsyn tagen inte bara till deras positiva verkan på miljön utan även deras potentiellt negativa miljöpåverkan. I den här rapporten har olika åtgärder mot internbelastning av fosfor i sjöar utvärderats och hur dessa åtgärder bidrar till klimatpåverkan.

Rapporten har finansierats med stöd av EU:s LIFE-program, inom ramen för LIFE IP Rich Waters

There is often very limited information available about uncertainty in discharge data as it is rarely communicated by data providers. However, ‘soft’ information about station characteristics, climate and flow regime, and catchment characteristics can be used to understand the likelihood that discharge data in a particular location are uncertain. For example, if high flows are of short duration (i.e., a few hours) it is practically quite difficult to manage to gauge high flows, leading to likely extrapolation of stage–discharge rating curves and large high flow uncertainty.

The aim of this commentary is to share – and to encourage sharing – of soft information about data uncertainty sources, to promote more informed decisions on data uncertainty in hydrological studies. We summarize the soft information about discharge data uncertainty as a perceptual model of uncertainty. We find that soft information can inform us about three main types of uncertainty sources: uncertainty related to the hydraulic control, uncertainty related to incomplete gauging of the full flow range, and uncertainty due to measurement error. We believe that a key benefit of the type of generalized perceptual model of uncertainty we present is to facilitate dialogue on, and understanding of, possible sources of observational uncertainties and their impacts.