The devastating impact of oil spills on marine wildlife:

The ecological impact of oil spills form ships and oil platforms on our oceans cannot be overlooked. As a major contributor to pollution, ships and oil platforms release a dangerous cocktail of contaminants, including oil spills, toxic chemicals, micro-plastics, and noise pollution. The consequences of chronic oil pollution are often downplayed, undetected, and unreported, with routine spills posing threats to marine wildlife.

In the North Sea, this concerning scenario is playing out, as oil platforms and ships encroach upon vital marine habitats causing irreversible habitat loss with potentially long recovery periods, if any recovery is possible at all. These habitats play a crucial role in nutrient cycling within the ocean, and their degradation poses a serious threat to this essential function. Adding to the distress, oil and gas activities are impacting the very foundation of marine food webs - plankton – through oil pollution.

Oil spills have devastating effects on marine mammals, impacting them in various ways. Direct contact with oil during swimming, ingestion of oil-contaminated prey, and inhalation of toxic vapors at the surface pose significant threats. These spills can lead to immediate deaths among marine mammals. These harmful consequences not only affect individual animals but also disrupt populations and entire ecosystems, underscoring the grave impact of oil spills on marine mammal species (Matkin et al., 2008). The oil spilled during these incidents possesses the capacity to be equally lethal to seabirds (Camphuysen et al., 2010).

I investigate the effects oil spills from offshore oil platforms and ships have on the North Sea’s wildlife, shedding light on the urgent need for more responsible and sustainable practices to safeguard our marine ecosystems.

Vital Data Used

Two data sources were used for this analysis. Oil slick locations and species distribution maps.

Oil slicks were provided by SkyTruth. SkyTruth’s project Cerulean is an innovative algorithm designed to detect oil slicks using Synthetic Aperture Radar (SAR) imagery. The algorithm scans Sentinel-1 SAR imagery with a focus on vertical polarization emitted and received (VV) for dark, smooth areas that indicate oil slicks. SAR imagery is useful for this purpose because of its ability to penetrate clouds and its 6-day temporal resolution, allowing for timely and frequent acquisition of images. Additionally, the contrast between the surface scattering of radar pulses off the small wavelets in clean water versus the smoother, darker appearance of oil slicks on radar images makes SAR imagery a useful tool for detecting oil spills (SkyTruth, 2023). I used oil slicks from 2020 in the North Sea. I filtered the oil slick by category to only included "Infrastructure", "Vessel Old", "Recent", and "Adjacent.

Species distribution maps used in this analysis are from Waggitt et al. 2019. Waggit et al. 2019 generated monthly distribution models of cetaceans and seabirds. A comprehensive survey of the North-East Atlantic was conducted between 1980 and 2018, collecting 2.68 million km of data. The data was collated, standardized and used to create distribution maps for 12 cetacean and 12 seabird species. These models are at a resolution of 10 km2 and are at a monthly temporal scale.

Species distribution models were preprocessed and filtered to the study areas spatial and temporal resolution. After data cleaning, zonal statistics were generated from each oil spill resulting in an average animal per km2 value for each oil spill.

• SkyTruth, 2023, https://skytruth.org
• Waggitt, J. J., Evans, P. G., Andrade, J., Banks, A. N., Boisseau, O., Bolton, M., ... & Hiddink, J. G. (2020). Distribution maps of cetacean and seabird populations in the North‐East Atlantic. Journal of Applied Ecology, 57(2), 253-269.

Study Area

The study area is the North Sea. In this analysis the countries exclusive economic zones (EEZ) were used. I included Germany, Sweden, United Kingdom, and Norway (shown in grey). The oil spills in 2020 are visible in red.

The findings shed light on the intricate relationship between anthropogenic activities and their ecological repercussions.

The pronounced vulnerability of species such as the Black Legged Kittiwake, Harbour Porpoise, and Northern Fulmar – all listed as 'Vulnerable' by the IUCN – to oil spills underscores the compounding threats that already at-risk species face in modern marine ecosystems. The fact that such a significant proportion of the most affected species are on the IUCN Vulnerable list suggests that oil spills from platforms and ships over the years might be exacerbating the decline of certain species, pushing them closer to the brink of extinction.

Moreover, the regional concentration of oil spills in areas like Germany and the United Kingdom indicates potential policy or regulatory gaps in these regions. These discoveries are crucial as they can inform conservation strategies, prompting more targeted interventions, and inspire a re-evaluation of maritime activities and oil spill mitigation efforts in the affected regions.

Successful demonstration of incorporating SkyTruth's Oil Spill SAR detection algorithm to understand the impacts on wildlife in the North Sea.

In this exploratory analysis, I have successfully demonstrated the potential of incorporating SkyTruth's Oil Spill SAR detection algorithm into a workflow for assessing the impact of oil spills originating from platforms and ships on the surrounding marine wildlife. In 2020, a total of 475 oil spills were detected from vessels and offshore infrastructure in the North Sea. While these incidents are not considered major oil spills, their cumulative effect on the environment is often underestimated, leading to significant harm to wildlife and ecosystems over time.

A comparative analysis of the number of oil spills by area in the United Kingdom, Norway, Sweden and Germany revealed that the United Kingdom and Germany experienced the highest number of oil spills by countries EEZ. However, when considering the impact on the number of individuals of a specific species, such as the IUCN Vulnerbale listed species Black Legged Kittiwake, Harbour Porpoise, and the Northern Fulmar, the United Kingdom, covering a much larger area, was the most destructive.

This key finding highlights the importance of considering not only the number and extent of oil spills but also their location in relation to specific species' habitats. In the case of the Common Guillemot and the Northern Fulmar, over my results show that over 1000 individuals were were potentially affected. Over 600 marine mammals, including dolphins and whales were also potentially affected by these oil spills in 2020.

Smaller oil spills can have considerable consequences on their health and well-being.

The integration of SkyTruth's Oil Spill SAR detection algorithm into the workflow allows for a more comprehensive understanding of the effects of oil spills on marine wildlife, enabling more effective conservation and management strategies.

Further Research

This workflow and methodology can easily be adapted to create an interactive tool and app, whereas, an oil spill location can be inputed and the outputs would be figures and graph highlighting the number of individual marine species most likely affected by the spills and also importantly shine a spot light on the country and individual platform, company, or ship responsible for the spill.

Future research could also explore the integration of additional data sources, such as oceanographic and meteorological parameters, to better account for environmental conditions that may influence the dispersal and impact of oil spills. Moreover, expanding the geographical scope of the study and applying the developed methodology to other regions would enhance the generalizability and applicability of my findings, ultimately contributing to the global efforts in protecting marine wildlife from the detrimental effects of oil spills.

Learn More

GitHub: https://github.com/ryanboarman/oil-slick-analysis

SkyTruth: www.skytruth.org

Waggit et al. 2019: Waggitt, James J., et al. "Distribution maps of cetacean and seabird populations in the North‐East Atlantic." Journal of Applied Ecology 57.2 (2020): 253-269.

Citations

Camphuysen, K. C. J. Declines in oil-rates of stranded birds in the North Sea highlight spatial patterns in reductions of chronic oil pollution. Marine Pollution Bulletin 60, 1299–1306 (2010).

Matkin, C. O., Saulitis, E. L., Ellis, G. M., Olesiuk, P. & Rice, S. D. Ongoing population-level impacts on killer whales Orcinus orca following the ‘Exxon Valdez’ oil spill in Prince William Sound, Alaska. Marine Ecology Progress Series 356, 269–281 (2008).