Browsing by master's degree program "Magisterprogrammet i miljöförändringar och global hållbarhet"

Both microplastics (MPs, size 0.1 to 5 mm) and pharmaceuticals and personal care products (PPCPs) are ubiquitous in aquatic environments globally. Polystyrene microplastic (PS-MP) and diclofenac (DCF) are among the most widespread and commonly occurring MPs and PPCPs in the environment. Exposure to these chemicals in single has been reported to cause oxidative stress, immobilization, changes in growth and reproduction and even mortality in Daphnia magna. Moreover, MPs have the ability to act as a vector for PPCPs, and several laboratory studies have reported that PS-MP is able to absorb DCF. However, the combined toxicity of MPs and PPCPs remains largely unknown, especially as is the case for the combined toxicity of PS-MP and DCF in D. magna. In this study, D. magna was exposed to PS-MP and DCF, both in single and combined, at a concentration of 0.5 mg/L each. The aim was to assess the combined toxicity of the two, and determine whether they had a synergistic, additive, or antagonistic effect in D. magna. Whole organism endpoints monitored included mortality, immobilization, and moulting. Physiological endpoints monitored focused on oxidative stress and antioxidant defence, including reactive oxygen species (ROS), superoxidase dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST). The results indicated that both PS-MP and DCF in single were able to significantly alter D. magna antioxidant and biotransformation enzyme activities by inhibition of SOD and GST, while there were no observed impacts on the monitored whole organism endpoints or ROS and CAT. However, similar significant inhibition of SOD and GST was not observed in the combined exposure, which indicates that the combined toxicity of PS-MP and DCF in D. magna was most likely antagonistic. These results highlight that the combined toxicity of MPs and PPCPs is a complex topic that still needs further investigation to fully understand the complex interactions between MPs and PPCPs.

Light is crucial for aquatic ecosystems, as photosynthesis supports the higher trophic levels. Light attenuates in water due to absorption and scattering by optically active substances (OAS), the main ones in coastal environments being chlorophyll-a (chl-a), particulate matter and coloured dissolved organic matter (CDOM). Light attenuation measurements are also important indicators of many environmental changes. Traditionally, Secchi depth has been used to monitor changes in light attenuation. However, Secchi depth (ZS) is a not an accurate estimate of light attenuation, and conversion to light attenuation coefficient (Kd) is needed to study light conditions as aquatic organisms observe them. Therefore, calibration between methods is important. In this study, light attenuation was estimated with Secchi disc, a light meter and light loggers to scrutinize the possibilities of autonomous measurements in this context. The aims of the study were 1) to compare three methods for estimating light attenuation and 2) to identify the environmental drivers affecting the relationships and accuracy of these methods, and 3) to assess the possibility of using conductivity as a proxy for light attenuation. The main hypotheses were that the differences in conversion between ZS and the two sensor-based methods in different concentrations of optically active substances can be explained by contribution of scattering to light attenuation, and that variation in different Kd-estimates is due to the different measurement spectra. The effect of three OASs (chl-a, particulate matter, CDOM) on differences among light attenuation estimates were quantified in Pohjanpitäjänlahti bay. Light attenuation was mainly controlled by CDOM, followed by particulate matter and chl-a. Conductivity was found to be a good proxy for light attenuation. However, there was a mixed signal if the differences among methods could be explained by OAS concentrations or conductivity, as the hypotheses were supported with one device pair but not with the other. Therefore, the differences among light measurement methods might stem from the characteristics of the devices or measurement errors. However, all the methods were found suitable for tracking changes in light attenuation and a summary table of the advantages and disadvantages of each method is presented to help choose a suitable method to estimate light attenuation e.g., in future studies or environmental monitoring.

Knowledge co-production has become more widespread in sustainability research as it possesses the potential as a tool to provide policymakers with usable knowledge in collaboration with researchers to increase the impact of scientific knowledge. This thesis complements the current literature by providing empirical insights of the perception of Finnish national-level policymakers who have participated in Strategic Research Councils (SRC) projects. SRC is a funding instrument with the aim to produce high-quality research with societal impact in collaboration with relevant stakeholders. The perception of Finnish researchers is already somewhat covered in literature and therefore the material for this thesis was collected by interviewing non-researcher participants in SRC projects. The analysis of the material was conducted as a theory-bound qualitative content analysis. The first coding was conducted with a material-based approach to allow the perception of the interviewees to prevail. The final analysis is conducted with three different modes of interaction obtained from the literature: science-push, policy demand, and iterative modes used as main categories. The analysis provides a standpoint on the research question: How do policymakers perceive the interaction in the co-production process? Methods to include policymakers and their participation in national-level co-production processes are versatile in Finland. The knowledge co-production between researchers and national-level policymakers results in usable knowledge and furthers policy uptake especially when collaboration and participation are genuine and profound. This study concludes that the inclusion of policymakers in the early stage of research, two-way communication, iterative interaction, and trust building are factors related to successful interaction, as the policymakers perceive success. The success factors could also help to overcome barriers of co-production presented in earlier literature.

The aim of this thesis is to understand how restrictions and recommendations to limit the spread of Covid-19 pandemic affected air quality in Helsinki from January to September 2020 and examine the health benefits coming from the decreased pollutant levels. During that time many restrictions to people’s movements took place. This caused a decrease in traffic rates which in turn affected air quality. The air pollutants included in this study are nitrogen oxide (NOx), tropospheric ozone (O3) and particulate matter (PM2.5 and PM10). The data was uploaded from SMEAR III -station in Kumpula neighborhood and the results were obtained by comparing concentrations from 2020 to those of 2018-2019. The data were divided into three periods, which were studied separately. The first period was the time before the lockdown (1.1.-17.3.), 2nd period was during the lockdown (18.3.-15.6.), and the 3rd period was after the lockdown (16.6.-30.9.). In addition, the health effects caused by the changes in pollutant concentration were studied with a calculator for financial benefits of emission reductions made by Finnish Environment Institute. The change in NOx concentrations during 2020 compared to 2018-2019 were -36.4 % in 1st period, -26.5 % in 2nd period and +34.1 % in 3rd period. The changes for O3 were +4.8 % (1st period), -8.6 % (2nd period) and -11.6 % (3rd period). PM2.5 concentrations changed -39.4 % (2nd period) and 0.0 % (3rd period) and PM10 concentrations -46.9 % (2nd period) and -14.7 % (3rd period) during 2020 compared to 2018-2019. Decrease of NOx in 1st period caused 2 600 t€/y savings in costs of air pollution related health effects. The changes in PM2.5 and NOx generated savings of 38 000 t€/y during 2nd period and -2 400 t€/y during 3rd period. Even though the pollutant concentrations decreased in most periods, the decrease can’t be explained only by changes in traffic rates and human activities. Other factors contribute air pollutant levels as well, including atypical weather during 2020. The study could be continued by separating the effects of weather, traffic and other contributing factors in changes in air pollutant concentrations.

Cyanobacteria are an important part of the phytoplankton community and aquatic ecosystems. Cyanobacteria can form large mass occurrences, i.e. blooms, which can be toxic or cause other harm. Research and monitoring of cyanobacteria has been based on microscopy analysis. However, molecular-based methods, such as 16S rRNA sequencing are replacing microscopy analyses in the near future. The Finnish Environment Institute has stated that molecular methods are part of environmental monitoring before 2030. In this Master’s thesis the aim was to determine whether conventional microscopy analyses and 16S rRNA sequencing differ when comparing nano- and micro-sized cyanobacteria. The material was collected from a laboratory experiment of the Finnish Environment Institute’s (SYKE) MiDAS project, which was conducted in the summer of 2020. The results of the microscopy and 16S rRNA analyses differed from each other. The relative abundances of the cyanobacteria genera differed between sample types. Microscopy analyses estimated that the alpha diversity was higher compared to the results of the sequencing analyses. The main reason for the difference between the types of analyses was due to the differences in cyanobacteria belonging to the order of Synechococcales. Some of the Synechococcales species were observed only by the sequencing analyses, e.g. Snowella and some of the Synechococcales species were only observed by the microscopy analyses, e.g. Romeria and Woronichinia. It was observed that both methods are prone to identification errors. The differences between the 16S rRNA sequencing and the microscopy analyses are vastly different. It may affect on the review of long-term data of the phytoplankton community. Therefore, it is important to examine the differences between the types of analyses. Studying the dissimilarities between the types of analyses should be focused on the research of the small cell-sized colonial cyanobacteria, i.e. the species of Chroococcales and Synechococcales.

Tämä opinnäytetyö käsittelee uuden ympäristöseurantamenetelmän kehitystyötä. Hauruja (Fucus spp.) on seurattu Suomen rannikolla jo pitkään, mutta nykyisiin kartoitus- ja seurantamenetelmiin liittyy haasteita ja epätarkkuutta. Hauruvaltaiset elinympäristöt ovat uudessa uhanalaisuusarvioinnissa määritelty erittäin uhanalaisiksi. Tarvetta uusille seurantamenetelmille siis on. Drone-teknologia on kehittynyt ja halventunut viime vuosina, mikä on avannut uusia mahdollisuuksia hyödyntää kaukokartoitusta. Edulliset valokuvaamiseen tarkoitetut dronet mahdollistavat sekä ajallisesti että paikallisesti erittäin tarkkojen ilmakuvien tuottamisen. Näitä on maailmalla käytetty menestyksellisesti myös rannikon kartoituksessa ja seurannassa. Suomessa drone-kuvia ei kirjallisuuden perusteella ole käytetty makrolevien kartoitukseen tai seurantaan. Tämän tutkimuksen tarkoitus on selvittää, sopivatko tällaiset drone-kuvat hauruyhteisöjen kartoitukseen ja monitorointiin itäisellä Suomenlahdella sekä tuottaa tietoa menetelmän jatkokehitystä ajatellen. Kuvasin 22 merenranta-alueen reunaympäristön alkukesällä 2020. Kuvatuista alueista valitsin kahdeksan jatkotutkimuksiin, jotka kuvattiin uudelleen syksyllä 2020. Tällöin niiden alueelta kerättiin kuvatulkinnan tueksi 263 tukipistettä, joilta mitattiin veden syvyys ja arvioitiin haurujen esiintyvyys Drop-kuvausmenetelmällä. Rajasin ilmakuvilta näkyvät haurualueet ja vertasin niitä tukipisteaineistoon. Havaitsin, että 80 % havainnoista tieto luokittui oikein. Cohenin kappa -testin perusteella kohteiden välillä sekä eri syvyyksillä olevilla kasvustoilla oli suuria eroja havaintojen luotettavuudessa. Syvemmällä kuin 2,5 metrissä olevien haurukasvustojen erottaminen onnistui huomattavasti huonommin. Myös matalimman kasvuston (0 – 0,5 m) erottaminen oli hankalaa. Tulokset ovat lupaavat, mutta niiden perusteella menetelmää ei kuitenkaan vielä voi todeta toimivaksi, vaan lisätutkimuksia tarvitaan. Tämän tutkimuksen perusteella kehitystyötä kannattaa jatkaa käyttämällä tarkkaa paikkatietoa ilmakuvien ja tukipisteaineiston tuottamiseen sekä uusia kuvantamismenetelmiä, jotka kykenevät tuottamaan tavanomaista RGB-kameraa paremman erottelukyvyn. Drone- ja meritöiden turvallisuuden parantamiseksi tehtiin riskienhallintaprosessi, jossa tunnistin, analysoin sekä raportoin töihin liittyvät merkittävimmät riskit.

Climate change is one of the biggest challenges our planet and humanity are experiencing. The time window for finding ways to miti-gate carbon emissions is getting smaller and there is an urgent need to find solutions that aim not only to reduce greenhouse gas (GHG) emissions, but to address the complex problems of land use change, deforestation, loss of biodiversity, and inequality. REDD+ is a multi-objective initiative under UNFCCC designed to reduce GHG emissions through deforestation and forest degradation togeth-er with non-carbon co-benefits of livelihoods, poverty, biodiversity, and local peoples and indigenous peoples rights. By applying a Qualitative comparative analysis (QCA) this thesis compares 12 various REDD+ countries national political contexts and particularly REDD+ policies and measures over time in order to identify conditions that enable or hinder the countries from achieving results in reversing forest cover trajectories. All the countries analyzed here are tropical, developing, or emerging countries with a political commitment to REDD+ with characteristics that hinder carbon-effective, cost-efficient, and equitable (3E) implementation of REDD+. The thesis builds on three previous REDD+ qualitative comparative analyses of various REDD+ countries' progress in developing and implementing national REDD+ policies and measures. The analysis follows an underlining theoretical assumption that both insti-tutions and agencies affect the REDD+ policy outcome. The longitudinal data used in the analysis is based on expert assessments conducted in three various data collection rounds in 2012, 2014, and 2016. The results show a set of enabling conditions under which countries can achieve a positive outcome. The findings from the previous studies have highlighted the importance of already initiated policy change and effective forest legislation from the institutional context, and from the actor-centered policy arena, the presence of powerful coalitions and the availability of performance-based payments. Here, two enabling remote conditions are identified (1) pressure from the forest resources and (2) the presence of effective forest legislation. The pressure from the forest resources leads to a positive outcome together with (3) strong national ownership and politi-cal will combined with (4) performance-based payments or (5) REDD+ policies and measures. The effective forest legislation.leads away from business-as-usual practices towards a broader transformational change when combined with (6) powerful transformation-al coalitions and (7) inclusive policy processes. Policy relevance: Well over a decade has passed since REDD+ was launched in 2007 but the progress has been much slower than it was initially expected. The evidence on what works and what does not is essential to achieve the GHG reductions needed to keep the global warming below 2C. The findings from this study can guide towards more effective, efficient, and equitable REDD+ policy design formulation and implementation.

Peatlands play an important role in the carbon cycle. Natural peatlands are in general sinks of carbon dioxide (CO2) and sources of methane (CH4), whereas drained peatland forests are CH4 sinks but their CO2 emissions increase compared to natural peatlands. Rotational even-aged forestry followed by ditch network maintenance (DNM) affect the water dynamics of the soil by increasing the water table level (WTL) first during clear-cut after which the WTL is lowered by DNM. Rising of WTL causes more anaerobic conditions and risk that CH4 sink turns into CH4 emissions. Lowering the WTL causes more aerobic conditions and strengthens the CH4 sink function but also increases CO2 emissions. In continuous cover forestry (CCF) where only part of the trees are removed, WTL would be naturally maintained. This could maintain CH4 sinks while lowering CO2 emissions by keeping the WTL at an adequate depth. Net emissions of CO2 and CH4 could be expected to follow the changes in CO2 and CH4 concentrations in soil. To understand the processes isotopic values can be used to interpret the production pathways of CO2 and CH4 since different pathways produce different isotope values. In this master’s thesis the aim was to study how the concentration of CO2 and CH4 as well as CO2 isotope values change in a peat soil and how partial harvest affects them. Gas samples were collected from the peat profile (5 – 65cm) at two different drained peatland forests, Lettosuo and Paroninkorpi, from control plots and partial harvested plots during 2019 and 2020. Samples were also collected from the moss layer. In addition, WTL, temperature of peat and O2 concentrations were measured. Concentrations and isotope values were analysed the laboratory with gas chromatography and isotope analyser (Picarro G2201-i). Water table level and temperature were generally higher in partial harvested areas than in control. Highest concentrations of both CO2 and CH4 were found in the deeper layers of the soil. Partial harvest had higher CO2 and CH4 concentrations in the deep layers (50 – 65cm) than control. The differences between partial harvest and control areas could be explained with the higher WTL in partial harvest. The measured isotopic values of CO2 indicated that most of the CO2 in the soil was derived from atmosphere or heterotrophic respiration and only <<20 % of CO2 was derived from CH4 oxidation. Even though both in control and in partial harvest the CH4 concentrations in the deep soil layers were high, the oxidation processes decrease the concentrations under the atmospheric CH4 concentration maintaining the CH4 sinks in both treatments. In partial harvest the CH4 sink is not in risk due to oxidation even though the WTL is higher. This should be verified with gas flux measurements.

Salt-induced flocculation is a process in which dissolved salts in seawater modify dissolved organic matter (DOM) surface charges and enable its transformation into larger fractions. These larger particles can settle to the benthos removing organic matter from the water column. Flocs formed in the flocculation process are often referred to as suspended particulate material (SPM). SPM is an important part of the biogeochemical cycles. SPM is a vector for pollutants, a food source for organisms and a habitat for microbes. Flocculation is part of the estuarine “coastal filter” -system controlling the material fluxes from land to sea. Climate change is causing water temperatures to increase in both inland and coastal waters affecting the biogeochemistry of aquatic ecosystems. Flocculation is a physicochemical process potentially impacted by temperature but the effects of temperature on flocculation are not well known. In my master’s thesis, I studied the effects of water temperature on the salt-induced flocculation of humic-rich river water. The flocculation experiments were conducted in spring 2023 using humic-rich water sampled from Vantaanjoki, Helsinki, Finland. The effects of temperature were studied in two separate experiments at temperatures ranging from 3 ºC to 20 ºC. The studied variables included quantitative suspended particulate matter as well as the optical properties of DOM including colored DOM and fluorescent DOM. Results of the experiments show that temperature did not have a significant effect on the salt-induced flocculation of DOM in humic-rich river water. However, the optical properties of DOM shifted with increasing temperatures and changing flocculation dynamics. Results show that molecular size increased as temperature increased but also when temperature was lower than 3 ºC. Explanation for the observed trends is discussed but more research is needed for more firm conclusions. DOM concentrations are expected to increase in the Arctic and sub-Arctic rivers transporting more organic matter to estuaries. Results of this thesis suggest that rising temperatures will not increase the amount of particulate matter through salt-induced flocculation meaning that a larger portion of the transported material remains in dissolved fraction. Increases in DOM concentrations may shift marine food webs by changing the food and light availability as well as biogeochemistry in estuaries.

Mercury is a toxic heavy metal that ends up in aquatic ecosystems both as atmospheric deposition as well as from the catchment area surrounding the water body. Under the right circumstances, inorganic mercury can be methylated into methylmercury, which accumulates in organisms and food webs and is harmful to humans and animals. Humans are exposed to methylmercury mainly through consumed fish as almost all the total mercury content in fish muscle consist of methylmercury. Mercury content of fish is affected by numerous different factors, such as the food consumed by the fish, the characteristics of the fish species and fish individual, level of lake eutrophication, mercury concentration in water and catchment area. Thesis studies total mercury content and mercury bioaccumulation in cyprinid fish. The species included in the study are roach (Rutilus rutilus), bream (Abramis brama), bleak (Alburnus alburnus), white bream (Blicca bjoerkna), blue bream (Ballerus ballerus), ide (Leuciscus idus), tench (Tinca tinca), rudd (Scardinius erythrophthalmus) and crucian carp (Carassius carassius). Three main research questions were: (1) Can diet of different cyprinid fish explain the mercury content? (2) Is mercury content consistent between fish species in different lake types, or does lake type affect mercury content? (3) Is mercury bioaccumulation consistently similar between fish species between lake types? The fish samples for this study were gathered prior to MSc during July-August in 2020 and 2021 from Kukkia, Hauhonselkä and Pääjärvi, which are classified as mesotrophic lakes, and from eutrophic Vesijärvi, Tuusulanjärvi and Hulausjärvi. Total length, weight, sex, sexual maturity, condition factor (K), fish diet and muscle total mercury content were determined from each fish. The diet of the fish and the differences in the total mercury content were tested with analysis of variance. Mercury bioaccumulation was tested with using linear regression analysis and the slope coefficient obtained from the regression equation was tested for bleak and roach with t-test. From the abundant species of the study the highest length corrected (to length 16.6 cm) mercury contents were measured in bleak and roach, while the contents were lower in white bream and bream. The mercury content differed most clearly in species whose feeding behaviour was very specialized. For example, the differences in mercury contents between bleak, which mainly consumes surface insects and zooplankton, and bream, which prefers benthic food, were clear in every lake studied. Mercury contents were mainly higher in mesotrophic lakes compared to eutrophic lakes, but results varied by species. In addition to fish diet and lake type, fish’s metabolism, growth rate and life cycle length probably influenced the species-specific mercury contents. When comparing the abundant species, the bioaccumulation of mercury was steepest in bleak and roach. Compared to these species’ bioaccumulation was slower in white bream and bream. When comparing mercury bioaccumulation within species between different lake types, the differences were species-specific. For example, the bioaccumulation of bleak was consistently steeper in mesotrophic lakes compared to eutrophic lakes, but the bioaccumulation of white bream was steeper in eutrophic lakes. Based on this study, it can be concluded that mercury content and bioaccumulation in cyprinid fish were influenced by e.g., species-specific characteristics, fish diet and level of the lake productivity. In addition to these factors, mercury content and bioaccumulation of fish may have been affected by the land use of the lake catchment area, as well as the anoxic areas of the lakes, which are propitious places for methylation. This study provided valid information on which factors may be relevant for cyprinid fish when observing their mercury content and bioaccumulation.