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An analysis of the effects of crude and fuel oil on the mortality of herring eggs using Bayesian meta-analysis techniques

Show simple item record 2020-12-09T11:08:26Z 2020-12-09T11:08:26Z 2020-12-09
dc.title An analysis of the effects of crude and fuel oil on the mortality of herring eggs using Bayesian meta-analysis techniques en
ethesis.discipline.URI none
ethesis.faculty Bio- ja ympäristötieteellinen tiedekunta fi
ethesis.faculty Faculty of Biological and Environmental Sciences en
ethesis.faculty Bio- och miljövetenskapliga fakulteten sv
ethesis.faculty.URI Helsingin yliopisto fi University of Helsinki en Helsingfors universitet sv
dct.creator Raubenheimer, Marie-Claire
dct.issued 2020
dct.language.ISO639-2 eng
dct.abstract Oil spillages represent a serious environmental hazard for flora and fauna of marine and coastal ecosystems. Though marine oil spills have decreased since the 1970s, the increasing production of petroleum goods remains a potential source of pollution due to its use and transportation. When aquatic organisms, including fish, are exposed to toxic oil compounds, this can cause sublethal morphological changes and increase mortality. In this context, herring have been frequently studied, and results suggest that particularly herrings eggs and larvae are highly susceptible to oil toxicity. In this thesis, a Bayesian meta-analysis was conducted to investigate the effects of crude and fuel oil on the mortality of herring eggs from the genus Clupea. Observations from laboratory studies, collected during a literature review, served as input for the statistical analysis. To this end, Bayesian inference modeling was applied to generate posterior probability distributions for additional mortality caused by exposure to oil mixtures. Also, oil concentration, oil type, exposure time, and temperature were analyzed to study possible correlations with mortality impacts. The results of this study suggest that acute mortality of exposed herring eggs is similar to mortality observed for individuals exposed to only small concentrations or none at all. Of all evaluated oil types, medium grade crude oil caused the most significant change in instantaneous mortality with increasing oil concentration. Generally, distinct oil types had a greater influence on mortality outcomes than temperatures at the given concentrations. For the lowest temperatures, some correlations for increased mortality were found. Overall, the unexplained variability between the reviewed studies has a relatively small influence on mortality outcomes. In conclusion, the mortality of exposed herrings eggs is most likely delayed due to sublethal effects, rather than immediate, at the modeled concentrations. Altogether, uncertainty amongst the posterior probability distributions is high, indicating a wide possibility range for the monitored parameters' actual values. The reasons for elevated uncertainty likely stem from diverse experimental setups, biological differences between tested species, relatively small sample sizes, and model-related issues. Thus, future research could consider additional variables, information from observational studies and other fish species to reduce uncertainty in mortality outcomes. en
dct.subject Bayesian en
dct.subject meta-analysis en
dct.subject oil en
dct.subject pollution en
dct.subject herring en
dct.subject mortality en
dct.subject petroleum en
dct.subject hydrocarbon en
dct.language en
ethesis.language englanti fi
ethesis.language English en
ethesis.language engelska sv
ethesis.supervisor Kuikka, Sakari
ethesis.supervisor Mäntyniemi, Samu
ethesis.thesistype pro gradu -tutkielmat fi
ethesis.thesistype master's thesis en
ethesis.thesistype pro gradu-avhandlingar sv
dct.identifier.ethesis E-thesisID:fec13bad-5986-4bc2-9673-974dacdb43c2
ethesis-internal.timestamp.reviewStep 2020-10-21 08:52:11:673
ethesis.principalprofessor Horppila, Jukka
dct.identifier.urn URN:NBN:fi:hulib-202012094849
dc.type.dcmitype Text
ethesis.facultystudyline Ympäristömuutos fi
ethesis.facultystudyline Environmental Change en
ethesis.facultystudyline Miljöförändring sv
ethesis.mastersdegreeprogram Ympäristömuutoksen ja globaalin kestävyyden maisteriohjelma fi
ethesis.mastersdegreeprogram Master's Programme in Environmental Change and Global Sustainability en
ethesis.mastersdegreeprogram Magisterprogrammet i miljöförändringar och global hållbarhet sv

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