Den globala produktionen och konsumtionen av vegetabiliska oljor och andra biobaserade oljor och bränslen har ökat under de senaste decennierna. En orsak till ökningen är strävan att ersätta petroleumbaserade oljor och produkter med jämförbara förnybara oljor och produkter. Eftersom de globala och regionala transporterna innefattar mycket stora volymer sker transporter ofta med kemikalietankfartyg. De flesta vegetabiliska och andra biobaserade oljor som fraktas med fartyg kan ha skadliga effekter på marin miljö, marina arter och habitat, om de vid olyckor eller tankrengöringar släpps ut i havet. För att minska risken för förorening av den marina miljön har IMO, International Maritime Organization, skapat ett globalt regelverk för sjötransporter av kemikalier i bulk. De viktigaste regleringarna finns i MARPOL konventionen Annex II och i IBC-koden. Regleringarna är även införda i svensk lag. 

Lagliga och olagliga utsläpp av lastrester av vegetabiliska oljor och andra biobaserade oljor sker frekvent från fartyg i Östersjön och Västerhavet i samband med tankrengöringar. Mellan 2020 och 2023 registrerade Kustbevakningens övervakningsflyg 233 utsläpp av flytande kemikalier som inte var mineralolja i svenskt territorialvatten och i svensk ekonomisk zon. Cirka 15 procent av utsläppen skedde i marina skyddade områden och utsläppen har i många fall varit stora och täckt flera kvadratkilometer havsyta. Utöver de registrerade utsläppen finns även ett mörkertal. I de fall de utsläppta substanserna har kunnat bestämmas har de ofta utgjorts av råtallolja, tallbecksolja, vegetabiliska oljor som palmolja, rapsolja, sojaolja, raffinerade fraktioner av vegetabiliska oljor, eller av fettsyrametylestrar (FAME) och blandade fettsyror (MFA). 

I stort sett alla vegetabiliska oljor, fettsyror och fettsyrametylestrar (FAME) har en densitet betydligt under 1 g/cm3 vilket medför att ett utsläpp åtminstone inledningsvis kommer att flyta på, eller sträva upp mot, vattenytan. Råtallolja och tallbecksolja har däremot en densitet nära 1 g/cm3 vilket innebär att de under vissa förhållanden flyter och under andra sjunker. Mekanisk påverkan via vågrörelser, partiell nedbrytning av bakterier, eller att substanserna binder till partiklar i vattnet kan leda till att utsläppen sönderdelas, sprids i fria vattenmassan eller sjunker till botten. Att ett utsläpp efter några dagar eller veckor inte längre syns på vattenytan innebär inte att det helt har brutits ner av bakterier. 

De vegetabiliska oljor och andra biobaserade oljor som vanligen transporteras med fartyg i Östersjön och Västerhavet är nedbrytbara av bakterier, vilket innebär att de efter en tillräckligt lång tid inte utgör någon risk för miljön. Nedbrytningshastigheten kan dock variera stort. 

Nedbrytning sker snabbare i syrerika och näringsrika miljöer och kan gå mycket långsamt i syrefria sediment. Vegetabiliska oljor kan polymerisera efter ett utsläpp vilket medför att bakteriernas nedbrytning går långsammare eller avstannar. Intermediära nedbrytningsprodukter, till exempel vissa fria fettsyror, kan vara toxiska för mikroorganismer och för vissa andra marina organismer. Den toxiska effekten är övergående eftersom även de intermediära nedbrytningsprodukterna efter en tid kommer att brytas ner av bakterier. 

Under optimala laboratorieförhållanden kan cirka 80 procent av en given mängd råtallolja brytas ner av bakterier på 28 dagar. Vid verkliga utsläpp i naturliga miljöer ska man förvänta sig en långsammare nedbrytningshastighet. Till exempel har klumpar av råtallolja påträffats på bottnar och på skyddade platser på land flera år efter registrerade utsläpp. Under optimala förhållanden har vegetabiliska oljor och FAME liknande nedbrytningshastigheter som råtallolja. Rester av polymeriserade vegetabiliska oljor kan dock finnas kvar i sediment under lång tid, ibland i flera år. Utsläpp av vegetabiliska oljor och FAME avdunstar endast i försumbar grad. 

Även om utsläpp av vegetabiliska oljor och andra biobaserade oljor efter en kortare eller längre tid helt bryts ner av bakterier kan utsläpp ha stor påverkan på djur och växter i marin miljö. När och var utsläpp sker har stor betydelse. 

Ett stort antal studier i olika delar av världen har visat att utsläpp av vegetabiliska oljor och andra biobaserade oljor är lika farliga för sjöfåglar som petroleumbaserade oljor. De flytande oljornas förmåga att förorena fåglars fjäderdräkt är i detta sammanhang viktigare än oljornas ursprung. Även intag av biobaserade oljor när fåglar försöker putsa fjädrarna rena är skadliga. Utsläpp av vegetabiliska och andra biobaserade oljor i havsområden där ett stort antal individer eller hotade arter sjöfåglar uppehåller sig utgör ett betydande hot mot artbevarande och biologisk mångfald. 

Utsläpp av vegetabiliska och andra biobaserade oljor kan påverka marina djur och växter via flera olika direkta och indirekta mekanismer. Toxiska effekter av intermediära nedbrytningsprodukter, till exempel långkedjade fria fettsyror, har observerats på kräftdjur, fisk och mikroorganismer. Även effekter på musslors tillväxt och överlevad har beskrivits. Utsläpp kan även påverka växter och djur genom kvävningseffekter, det vill säga att olja lägger sig som ett täcke över växter och djur på stränder eller bottnar, eller att oljan fysiskt påverkar djurs andningsorgan. 

När utsläpp av vegetabiliska och andra biobaserade oljor bryts ner av bakterier konsumeras syre. Syrefria områden kan då bildas vilket kan påverka en rad olika organismer. Hur stora syrefria områden som kan bildas är bland annat beroende av utsläppets storlek och områdets vattenomsättning. Syrefria områden kan även bildas då polymeriserade vegetabiliska oljor bildar en hinna på vattenytan eller över sediment och därmed hindrar fri diffusion av syre. 

Sverige och övriga medlemsländer i EU har en skyldighet att utse marina skyddade Natura 2000-områden, i såväl territorialvattnet som i ekonomisk zon, enligt art- och habitatdirektivet och fågeldirektivet. Regelverken är införda i den svenska miljöbalken. Syftet är att skydda arter och habitat. Enligt miljöbalken 28 a § krävs tillstånd för att bedriva verksamheter eller vidta åtgärder som på ett betydande sätt kan påverka miljön i ett Natura 2000-område. Vidare anges i 28 a § att tillstånd får lämnas endast om verksamheten eller åtgärden ensam eller tillsammans med andra pågående eller planerade verksamheter eller åtgärder inte: (1.) kan skada den livsmiljö eller de livsmiljöer i området som avses att skyddas, (2.) medför att den art eller de arter som avses att skyddas utsätts för en störning som på ett betydande sätt kan försvåra bevarandet i området av arten eller arterna.

Givet det starka skydd EU och Sverige har infört i Natura 2000-områden, bör alla utsläpp av vegetabiliska och andra biobaserade oljor från kemikalietankfartyg i Natura 2000-områden, givet de betydande skador sådana utsläpp kan ha på sjöfåglar och bottenfauna, alltid betraktas som särskilt skadliga och bedömas som att de allvarligt skadar svenska intressen och tillgångar. 

Utsläpp i havsområden som inte är Natura 2000-områden, men i känsliga områden som hyser en rik bottenfauna och flora, eller koncentrationer av häckande eller övervintrande fåglar, bör även bedömas som att de på ett betydande sätt skadar svenska intressen och tillgångar. 

Alla större utsläpp som täcker flera kvadratkilometer havsyta har en potential att påtagligt skada bestånd av marina och kustbundna djur och växter och bör, oavsett utsläppsplats, bedömas som att de på ett betydande sätt skadar svenska intressen och tillgångar. 

I denna rapport beskrivs effekter av utsläpp av råtallolja, inklusive raffinerade fraktioner av tallolja, vegetabiliska oljor, fettsyrametylestrar (FAME) och blandade fria fettsyror (MFA), på marint liv. I rapporten ges även en bakgrundsinformation om hur kemikalierna vanligen produceras, används, namnges och transporteras.

The breeding grounds of the North Atlantic population of Sandwich Tern Thalasseus sandvicensis range along the coasts of western Europe and in the Baltic Sea: predominantly in the Netherlands, UK, France, Germany, and Denmark, with a smaller fraction of the population breeding in southern Sweden. This population has fluctuated strongly in size in recent decades due to human activities, pollution, changing availability of food, and outbreaks of highly pathogenic avian influenza. To evaluate whether management actions to further protect the species are needed in Sweden, better knowledge about the recent development of the breeding population is required. We found that the total number of breeding pairs in Sweden between 2007 and 2014 fluctuated between ca 390 and ca 570 pairs. Later, the number increased markedly from ca 630 pairs in 2015 to ca 1,830 pairs in 2021. In 2022 and 2023, the number decreased partly due to avian influenza outbreaks and ca 1,540 pairs bred in 2023. Most pairs bred in the provinces of Blekinge, Gotland, and Skåne. The four largest colonies hosted ca 55% of the cumulative number of breeding pairs between 2007 and 2023. This aggregated distribution makes the species vulnerable to various threats.

The transport of non-petroleum substances such as vegetable oils, other bio-based oils and their refined products by chemical tankers is increasing worldwide. The majority of the non-petroleum substances carried by chemical tankers will have detrimental effects on the marine environment if accidentally spilled or discharged during tank washing procedures. Swedish Coast Guard aircrafts detected 233 discharges of floating non-petroleum substances in the Swedish territorial sea and Swedish Exclusive Economic Zone (EEZ) between 2020 and 2023. The majority of the discharges, 84%, were detected in the EEZ. About 14% of the discharges were detected within protected marine Natura 2000 sites. Together, the detected discharges covered 1071 km2 of sea surface. Discharges in marine Natura 2000 sites covered 228 km2. We conclude that the regulations in the IMO MARPOL Annex II convention are not strict enough to meet the objectives of EU nature legislation regarding protection of sensitive seas areas.

In 2022, highly pathogenic avian influenza (HPAI) A(H5N1) virus clade 2.3.4.4b became enzootic and caused mass mortality in Sandwich TernThalasseus sandvicensis and other seabird species across north-western Europe. We present data on the characteristics of the spread of the virus between and within breeding colonies and the number of dead adult Sandwich Terns recorded at breeding sites throughout north-western Europe. Within two months of the first reported mortalities, 20,531 adult Sandwich Terns were found dead, which is >17% of the total north-western European breeding population. This is probably an under-representation of total mortality, as many carcasses are likely to have gone unnoticed and unreported. Within affected colonies, almost all chicks died. After the peak of the outbreak, in a colony established by late breeders, 25.7% of tested adults showed immunity to HPAI subtype H5. Removal of carcasses was associated with lower levels of mortality at affected colonies. More research on the sources and modes of transmission, incubation times, effective containment, and immunity is urgently needed to combat this major threat for colonial seabirds.

The West Siberian / North European population of Long-tailed Duck Clangula hyemalis that breeds in Fennoscandia and Northwestern Russia, and winters in the Baltic Sea, has declined by at least 65 % since the 1990s and is classified as globally vulnerable. To propose effective management actions to stop the decline, knowledge about demographic parameters is required. A photo survey method by which it is possible, in winter, to collect data on sex ratios and production of first-winter birds is presented here. The plumage traits and bill patterns, which are detectable in photos taken at a distance, are described. The traits can be used to discriminate between three categories of birds: adult males, first-winter males, and females. To extrapolate results from several photo surveys and obtain population-wide estimates of demographic parameters, knowledge about non-random distributions of different bird categories is needed. It was found that different age and sex categories were distributed differently across flocks of different sizes. The required sample sizes and the possible constraints and biases related to the photo survey method are discussed.

Underwater radiated noise (URN) from commercial ships is a significant source of elevated noise levels in the oceans and can have a negative impact on marine wildlife. Noise from commercial shipping places additional stress on the oceans, but is one of the least studied environmental pollutants, and there is an urgent need to reduce the aggregate stress levels. 

Until recently, reduction of underwater noise has not been prioritised by ship designers, shipowners, or crews. Even within the field of marine management, noise has received limited interest. However, the International Maritime organization (IMO) has adopted global guidelines on URN reduction, which are currently being updated. Within the EU, the Marine Strategy Framework Directive (MSFD 2008/56/EC) Descriptor 11 criteria 11.2, now provides a framework for marine administrators to manage noise by establishing threshold values. 

Marine management focuses on the total noise load on the marine environment. Management entails several considerations before recommendations can be made. As a first step, interdisciplinary teams need to assess the aggregated noise levels and determine acceptable thresholds based on the local ecosystem, then assess which existing mandates and management tools can be used, and finally assess how effective these mandates have been in improving the environment. These activities must also be managed in a way that is acceptable to various relevant stakeholders, who would need to follow the decisions. The URN from a ship can be affected by the vessel’s design, either during its construction or during upgrades, and balances a trade-off against fuel efficiency. However, the URN can also depend on how the ship is operated. Regulating ship speed is one potential management tool, and its effectiveness needs to be assessed. Other management measures include how shipping lanes are drawn, areas to avoid, financial support, information, etc. 

This report focuses on possible policy measures that the Swedish authorities could adopt to lower URN by regulating the speed of ships. The report presents an interdisciplinary analysis, using a case study of an area in the southern Kattegat that covered several maritime zones, different national jurisdictions, intensive traffic, and high natural values. An important part of the work was to assess whether existing source models for ship noise could be used for the type of ships that are common in waters around Sweden. In this study, the JOMOPANS-ECHO (J-E) model was used.

The J-E model was validated by comparing measurement data from a hydrophone station at Vinga on the Swedish coast that collected data from ships (254 passages) that used the port of Gothenburg. The analysis showed some deviation between the J-E model and measurement data, which could be due to differences in the length and speed of ships in waters around Sweden compared to the ships used in the development of the J-E model. However, this was likely to have negligible impact on the outcome of the case study.

Analyses of ship traffic in 2021 showed that 4,511 unique vessels visited the study area at least once. Most ships followed the main routes, but no part of the study area was completely free from ship traffic. About 68% of the ships visited the study area for 1-4 days, while about 32% visited the area more regularly. The most common ship types were General Cargo Ships, Dry Bulk Ships, and Tankers. The ships that on average travelled at highest speeds were RoPax Ships, RoRo Ships, Vehicle Carriers, and Container Ships. The ships were registered in 64 countries. About two percent of the ships were registered in Sweden and about four percent in Denmark.

Legal analysis showed that Sweden has the right and the responsibility to take measures to reduce underwater noise from ships to the extent that the noise can be deemed to pollute the marine environment. However, this mainly applies to Sweden’s territorial seas, which cover roughly half the area being studied for this report. In the portion that constitutes Danish territorial sea, Denmark has comparable opportunities for managing URN. In areas that are Swedish or Danish exclusive economic zones (EEZs), the ability to introduce mandatory speed limits is significantly limited. There, the most realistic option would be to request the IMO to establish speed limits, or alternatively to issue a recommendation to navigate at lower speeds, although such guidance could not be enforced on ships that do not voluntarily reduce their speed.

It was estimated that lowering the ships' speeds to a hypothetical limit of 11 kn would reduce the average URN levels by 4.4 ± 2 dB, as registered by local receivers in the study area. This speed limit would affect approximately 44% of the ships in the area. A maximum speed of 13 kn would instead reduce the level by 1.9 ± 0.5 dB and would affect 11% of the ships on average. The reduction in noise levels may temporarily be much higher in the immediate vicinity of individual fast ships, and there might be a high degree of variation between different ships.

The study and report make it clear that it is a complex task to assess the feasibility and benefit of introducing a specific marine management tool, in this case an enforceable local speed limit. But it is also clear that there are reliable methods to make the preliminary assessments, and that it requires interdisciplinary analyses and competence.

The West Siberian/North European population of Long-tailed Duck (Clangula hyemalis), which breeds in the Russian Arctic and northern Fennoscandia and winters in the Baltic Sea, has declined rapidly since the 1990s. To identify the causes of the decline and initiate effective conservation measures information on basic demographic parameters is needed. A photo survey method was used to estimate female age ratios and the proportion of males among adults in wintering Long-tailed Ducks at coastal and off-shore areas in the Baltic Sea. Female age ratios were defined as the number of first winter males, assumed equal to the number of first winter females, per adult female. Several thousand individuals were sampled each winter from 2008 to 2021. Female age ratios fluctuated between years and were consistently lower in the southern than in the central Baltic Sea. The proportion of males among wintering adults birds was male-biased, more so in the southern Baltic Sea than in other regions. A population model was used to analyse if low female age ratios between 2008 and 2021 has constrained population growth. Given that the estimated weighted mean female age ratio of 0.153 was representative at the population scale, an extremely high adult female mean annual survival rate of 0.872 would have been needed to maintain a stable population. Considering known sources of anthropogenic mortality in the Baltic Sea, and instead assuming a more realistic survival rate of ca. 0.80, a population decline of ca. 7.7% per year should have occurred during the study period.

1. The postnatal growth period is a crucial life stage, with potential lifelong effects on an animal's fitness. How fast animals grow depends on their life-history strategy and rearing environment, and interspecific comparisons generally show higher growth rates at higher latitudes. However, to elucidate the mechanisms behind this gradient in growth rate, intraspecific comparisons are needed. 

2. Recently, barnacle geese expanded their Arctic breeding range from the Russian Barents Sea coast southwards, and now also breed along the Baltic and North Sea coasts. Baltic breeders shortened their migration, while barnacle geese breeding along the North Sea stopped migrating entirely.

3. We collected cross-sectional data on gosling tarsus length, head length and body mass, and constructed population-specific growth curves to compare growth rates among three populations (Barents Sea, Baltic Sea and North Sea) spanning 17° in latitude.

4. Growth rate was faster at higher latitudes, and the gradient resembled the latitudinal gradient previously observed in an interspecific comparison of precocial species. Differences in day length among the three breeding regions could largely explain the observed differences in growth rate. In the Baltic, and especially in the Arctic population, growth rate was slower later in the season, most likely because of the stronger seasonal decline in food quality.

5. Our results suggest that differences in postnatal growth rate between the Arctic and temperate populations are mainly a plastic response to local environmental conditions. This plasticity can increase the individuals' ability to cope with annual variation in local conditions, but can also increase the potential to re-distribute and adapt to new breeding environments.

Several million tons of chemicals, in addition to crude oil and mineral oil products, are transported by tankers each year in the Baltic Sea. The transportation of chemicals by specialised chemical tankers or combined chemical/oil product tankers is growing worldwide, both in respect to the number of substances and the total volume transported. A diversity of chemicals are carried by chemical tankers in the Baltic Sea, including acids, bases, alcohols, ammonia, vegetable oils, biofuels, fuel additives and a large number of different hydrocarbons including benzene, styrene, xylenes, acetone, phenols etc.

To reduce the legal and illegal discharges of noxious chemicals from chemical tankers, and the associated negative effects on the marine environment, the chemical industries in the Baltic region must take full responsibility for the transport of their chemical raw material and products. It is now also the time for authorities to strengthen the regulations regarding discharges of noxious chemicals from chemical tankers. A first step should be to make it mandatory to perform a prewash procedure at the port of unloading when the tanks have contained any of the Y-categorised chemicals. A total ban to discharge residues of noxious chemicals from chemical tankers in marine protected areas should be uncontroversial and could be adopted immediately by the countries around the Baltic Sea.

In this report we analyse the relation between the Port State Control (PSC) system, as implemented by Paris Memorandum of Understanding (Paris MoU), and the Marine Strategy Framework Directive (MSFD), which obligates EU member States to achieve a Good Environmental Status of their marine waters. The deficiency codes in the Paris MoU PSC THETIS list were reviewed to explore how the codes relate to, i.e. directly or indirectly affect, the marine environment. We further sorted these identified deficiency codes into different, partly overlapping, categories based on their relation to MSFD descriptors. The number of deficiencies in the different categories were thereafter used as indices to infer pressures on the marine environment from different classes of ships. The approach was applied on a PSC inspection data set of ships that operated in the Baltic Sea or Skagerrak in 2018 to investigate if the number of deficiencies in four deficiency categories differed among ship types, ships of different ages and ships from different flag states. We also analysed how deficiencies related to five different MSFD descriptors were distributed among ship classes.

General cargo, container and dry bulk ships had on average more deficiencies per ship than other ship types. The youngest ships had on average fewer deficiencies per ship than older ships and ships from black and grey listed flag states had on average more deficiencies per ship than ships from white listed flag states. Ships registered in Sweden had on average fewer deficiencies per ship than average ships from white-listed flag states. The number of all deficiencies per ship was generally correlated with the number of deficiencies related to the marine environment. Thus, on a general level, the total number of registered deficiencies also reflected the relative environmental performance of different ship classes. However, on a more detailed level, when deficiencies related to specific MSFD descriptors were analysed, some deviances from this general pattern were observed.

The number of ships, as well as the total travelled distance, differed greatly among the different classes of ships. The total pressure on the Baltic marine environment, will, therefore, be larger from the more common middle-aged ships than from older ships, even though older ships on average performed worse than young and middle-aged ships. Similarly, because ships from white listed flag states are much more common, the total number of deficiencies of ships registered in white listed flag states, and hence, the total pressure on the marine environment, is much higher than the total number of deficiencies of, and total pressures from, ships from black and grey listed flag states.

The insight that the total pressure of a class of ships is affected not only by the average performance of the ships in that class, but also by the number of ships and the total travelled distance, does not in any way reduce the need to stop the operation of the worst performing individual ships, and by various means to improve the average performance of ships in the low performing general cargo and dry bulk ship classes. From a marine environment management perspective, it is also important to recognize that also continuous smaller improvements of the performance of the more numerous middle-aged ships and of ships registered in white listed flag states will increase the possibility to achieve Good Environmental Status of the marine environments in Europe.

We conclude that although the Paris MoU scheme for Port State Controls is an important measure to prevent pollution from ships, there is no harmonization between the work of Paris MoU and the marine environmental management in the EU including the implementation of MSFD. At least eight of the eleven descriptors of the MSFD are influenced by shipping but at least three of them cannot be evaluated by the present scheme for PSC. It is possible, according to our view, to develop the present PSC system to also include control measures that focus on these three descriptors, that is, on the effect on biodiversity, sea-floor integrity and on the production of underwater noise. It is also important to investigate ways to add or modify deficiency codes that would capture the chemical composition of waste streams and remnant chemicals after tank cleanings. An additional development of the PSC system could be to also investigate the behaviour of ships during the period between PSC inspections, e.g. through the use of logged AIS-data. The proposed system development would likely require both new financial resources and competencies.