Periodic Reporting for period 1 - STORAGE (Predicting the fate of plaSTic On beaches by theiR 3D-distribution and weAtherinG procEsses)
Reporting period: 2022-08-18 to 2024-08-17
Context
Plastic pollution has emerged as one of the most significant environmental challenges worldwide. Since the 1950s, the mass production of synthetic polymers has led to an unprecedented accumulation of plastic in the oceans. Current models estimate that approximately two-thirds of the plastic released into the ocean has either stranded or settled along shorelines across the globe. Plastic debris, carried by ocean currents and winds, can travel vast distances, often converging in one of the five subtropical gyres, where it persists as "legacy plastics." These areas of concentrated plastic accumulation, known as "Garbage Patches," pose a significant threat to marine environments. Shorelines near these gyres, such as those of Hawai'i, are particularly vulnerable to accumulating large amounts of plastic debris.
While these large-scale models are valuable in identifying high accumulation areas, they often lack the resolution needed to fully describe the temporal and spatial variations in plastic accumulation as well as the state of plastics (e.g. size, shape, degradation degree) in these regions. For instance, field-studies have revealed that there may be between 10 to 70 times more debris buried below the surface of beaches than is visible. However, due to the challenging nature of sampling buried plastics, only a limited number of studies have explored this issue, and even fewer have examined deeper than 10 cm into the sand.
Plastic debris undergoes significant transformations once it enters the environment. Exposure to moisture, heat, sunlight, and mechanical forces leads to changes in the chemical structure and physical properties of plastics, affecting their buoyancy, travel pathways, and accumulation patterns. Notably, plastic fragmentation occurs much faster onshore due to higher temperatures, oxygen levels, solar radiation, and mechanical forces from waves and sand movements. This rapid fragmentation can transform beached macroplastics into microplastics in a short period, further complicating efforts to track and manage plastic pollution.
There is a need to refine our understanding of plastic pollution fate in these high-accumulation zones of plastics to improve our abilities to develop effective mitigation strategies tailored to the specific challenges these areas face.
Objectives and Pathway to Impact
STORAGE aims to address these critical knowledge gaps by investigating the fate of marine plastic debris (MPD), particularly its transformation and transportation within coastal environments. By focusing on high-priority zones, such as the beaches of Hawai'i, which are heavily impacted by the North Pacific Garbage Patch, STORAGE will provide valuable insights into the distribution and transformation of MPD.
Through repeated field surveys and investigating the fragmentation behaviors of beach plastics, STORAGE seeks to create a comprehensive understanding of how MPD is transported, buried, and transformed over time. This includes sampling and measuring the plastic abundance and distribution in the sand column of Hawaiian beaches and investigate how the distribution and concentrations of these plastics change with beach morphology, polymer type, and environmental conditions, such as seasonal wind, wave and tide characteristics. This information is envisioned to guide evidence-based policies and targeted cleanup efforts, enabling more effective management and reduction of plastic pollution in coastal environments. By analyzing the rates and mechanisms of plastic fragmentation, STORAGE will provide essential data that can inform global plastic pollution models and contribute to more effective intervention strategies. For instance, by identifying areas where plastic fragmentation is rapid, targeted clean-up efforts can be implemented to remove debris before it fragments into microplastics or is buried deeper in the sand.
Expected impacts
STORAGE is expected to have scientific, economic, and societal impacts.
Scientifically, data and and knowledge from STORAGE is expected to enhance our understanding of plastic pollution's fate in coastal environments and contribute to global efforts to monitor and mitigate this issue. The data generated by STORAGE will support the development of more accurate models for predicting the fate of MPD.
Economically, STORAGE is envisioned to guide more effective and targeted clean-up strategies, with the potential to reduce the financial burden associated with marine pollution. The project’s findings will be directly applicable to stakeholders such as The Ocean Cleanup, who are working on large-scale efforts to remove plastic from the ocean.
From a societal perspective, STORAGE is envisioned information that can guide policy development and public awareness campaigns by addressing current knowledge gaps.
Plastic pollution has emerged as one of the most significant environmental challenges worldwide. Since the 1950s, the mass production of synthetic polymers has led to an unprecedented accumulation of plastic in the oceans. Current models estimate that approximately two-thirds of the plastic released into the ocean has either stranded or settled along shorelines across the globe. Plastic debris, carried by ocean currents and winds, can travel vast distances, often converging in one of the five subtropical gyres, where it persists as "legacy plastics." These areas of concentrated plastic accumulation, known as "Garbage Patches," pose a significant threat to marine environments. Shorelines near these gyres, such as those of Hawai'i, are particularly vulnerable to accumulating large amounts of plastic debris.
While these large-scale models are valuable in identifying high accumulation areas, they often lack the resolution needed to fully describe the temporal and spatial variations in plastic accumulation as well as the state of plastics (e.g. size, shape, degradation degree) in these regions. For instance, field-studies have revealed that there may be between 10 to 70 times more debris buried below the surface of beaches than is visible. However, due to the challenging nature of sampling buried plastics, only a limited number of studies have explored this issue, and even fewer have examined deeper than 10 cm into the sand.
Plastic debris undergoes significant transformations once it enters the environment. Exposure to moisture, heat, sunlight, and mechanical forces leads to changes in the chemical structure and physical properties of plastics, affecting their buoyancy, travel pathways, and accumulation patterns. Notably, plastic fragmentation occurs much faster onshore due to higher temperatures, oxygen levels, solar radiation, and mechanical forces from waves and sand movements. This rapid fragmentation can transform beached macroplastics into microplastics in a short period, further complicating efforts to track and manage plastic pollution.
There is a need to refine our understanding of plastic pollution fate in these high-accumulation zones of plastics to improve our abilities to develop effective mitigation strategies tailored to the specific challenges these areas face.
Objectives and Pathway to Impact
STORAGE aims to address these critical knowledge gaps by investigating the fate of marine plastic debris (MPD), particularly its transformation and transportation within coastal environments. By focusing on high-priority zones, such as the beaches of Hawai'i, which are heavily impacted by the North Pacific Garbage Patch, STORAGE will provide valuable insights into the distribution and transformation of MPD.
Through repeated field surveys and investigating the fragmentation behaviors of beach plastics, STORAGE seeks to create a comprehensive understanding of how MPD is transported, buried, and transformed over time. This includes sampling and measuring the plastic abundance and distribution in the sand column of Hawaiian beaches and investigate how the distribution and concentrations of these plastics change with beach morphology, polymer type, and environmental conditions, such as seasonal wind, wave and tide characteristics. This information is envisioned to guide evidence-based policies and targeted cleanup efforts, enabling more effective management and reduction of plastic pollution in coastal environments. By analyzing the rates and mechanisms of plastic fragmentation, STORAGE will provide essential data that can inform global plastic pollution models and contribute to more effective intervention strategies. For instance, by identifying areas where plastic fragmentation is rapid, targeted clean-up efforts can be implemented to remove debris before it fragments into microplastics or is buried deeper in the sand.
Expected impacts
STORAGE is expected to have scientific, economic, and societal impacts.
Scientifically, data and and knowledge from STORAGE is expected to enhance our understanding of plastic pollution's fate in coastal environments and contribute to global efforts to monitor and mitigate this issue. The data generated by STORAGE will support the development of more accurate models for predicting the fate of MPD.
Economically, STORAGE is envisioned to guide more effective and targeted clean-up strategies, with the potential to reduce the financial burden associated with marine pollution. The project’s findings will be directly applicable to stakeholders such as The Ocean Cleanup, who are working on large-scale efforts to remove plastic from the ocean.
From a societal perspective, STORAGE is envisioned information that can guide policy development and public awareness campaigns by addressing current knowledge gaps.
STORAGE is structured around three key objectives, each involving specific tasks and methodologies. During the first two years of STORAGE, the progress that has been made towards its scientific and technical objectives are summarized below:
Objective 1: Comparing Distribution and Concentration of MPD on Hawaiian Beaches
> Field Sampling of Surface and Buried MPD:
o Activities:
- Plastic sampling was conducted on the island of Oʻahu, part of the Hawaiian archipelago in the North Pacific Ocean. The study focused on three beach sites located on Oʻahu's east side: James Campbell, Kokololio (Laie), and Waimānalo. Quarterly surveys were conducted from November 2022 to February 2024, targeting plastic debris (>0.5 mm) within each 10 cm layer of sand down to 1 m depth, using 60 x 60 cm quadrats.
- In collaboration with the International Pacific Research Center (IPRC) at the University of Hawaiʻi, we extended the study to Hawaiʻi Island (Big Island), where we repeated an earlier study (currently un-reported data) on the depth distribution of plastics on a rocky beach, offering a decade-long comparison.
o Progress and Achievements:
- The surveys on Oʻahu have provided a first insight into the 3D distribution of MPD on sandy Hawaiian beaches, revealing trends in plastic concentration across different depths and over time. This data significantly enhances our understanding of plastic abundance and distribution both on the surface and buried within the sand column.
- The additional study on a rocky beach provides valuable comparative data on how plastic distribution has changed over a decade and also addresses a notable gap in rocky beach plastic monitoring (in contrast to sandy beach monitoring). The inclusion of rocky beach environments, which are less commonly studied compared to sandy beaches, broadens the scope of coastal MPD monitoring and adds depth to our understanding of plastic pollution across diverse coastal landscapes.
Objective 2: Assessing Polymer Transformation Upon Weathering
> Setting Up Weathering Studies:
o Activities:
- We initiated weathering studies on plastic films and reference nurdles (polypropylene, PP, and polyethylene, PE) at the Centre for Marine Debris Research in Waimanalo, Hawai’i, beginning in February 2024. Samples were collected across three sets of aging experiments, each lasting three months. Environmental factors such as temperature and humidity were measured, and solar radiation exposure was continuously monitored using UVA and UVB sensors.
- In collaboration with Ecole Centrale Nantes and Ifremer, a student intern co-developed a fragmentation simulator for swash zone experiments, aimed at studying plastic fragmentation behavior in the dynamic coastal environment.
- Through another collaboration with the International Pacific Research Center (IPRC) at the University of Hawaii, we collected various plastic items from a container spill that occurred outside Hawaii in 2020. The collection involved both opportunistic visits to Hawaiian beaches and community contributions. We documented the debris in a comprehensive database, recording the location, visual state, and date of discovery. Samples of these plastic materials were collected for degradation state analysis at Ifremer.
o Progress and Achievements:
- Initial data collection on the natural weathering processes of marine plastic debris (MPD) is ongoing. Samples are periodically analyzed for changes in chemical structure using Fourier Transform Infrared (FT-IR) spectroscopy, molecular composition via Gel Permeation Chromatography (GPC), and mechanical properties. This work will enable us to understand how various environmental conditions influence the degradation pathways of polymers, providing crucial insights into MPD transformation within coastal environments.
- The initial tests and results from the fragmentation simulator have set the foundation for more efficient studies on plastic fragmentation behavior in the swash zone during the next phase of the project (incoming phase at Ifremer).
- The collection and analysis of samples from the container spill will allow us to investigate the extent of degradation with precise temporal data. Knowing the time of the spill and the varied collection times of the debris will help us better understand the rates and pathways of plastic degradation under real-world conditions.
bjective 3: Modeling MPD Capture & Release on Hawaiian Beaches
> 3D Mapping and Modeling:
o Activities:
- We collected and conducted initial analyses on the data from Objective 1, generating an overview of the 3D distribution of plastic particles on both sandy and rocky beaches in Hawai'i.
- During field surveys, we set up cameras to monitor beach accretion and erosion, enabling us to evaluate correlations between beach dynamics and the burial and release of plastics from the sand column.
- We initiated a collaboration with the School of Ocean and Earth Science and Technology (SOEST) at the University of Hawai'i to leverage their expertise in beach dynamics. This collaboration also involved collecting GPS points for evaluating beach erosion and accretion, using SOEST's equipment. Additionally, we are utilizing their satellite data and analysis on beach dynamics, including wave, wind, and tide determinants.
- Collaboration with the International Pacific Research Center (IPRC) on the container spill incident provided valuable data on plastic transportation from the ocean to Hawaiian shores.
- Through analysis of data we are investigating important factors to consider such as beach morphology, sand accretion/erosion, and environmental conditions like wind and wave action.
o Progress and Achievements:
- Initial data analysis from field surveys is offering valuable insights into the distribution and concentration of plastics within the sand column.
- Collaborations with SOEST and IPRC are enhancing our understanding of the environmental factors—such as wind, waves, currents, tides, and beach dynamics—that are crucial for modeling plastic concentration flux within the sand column.
- A three-month secondment at The Ocean Cleanup office in Rotterdam facilitated collaboration with their team, particularly in understanding the modeling requirements for plastic capture and release. This included discussions on the importance of modeling sand sediment movement, introduced through connections the potential application of the XBeach model.
Summary:
The STORAGE project has successfully laid initial groundwork for understanding the complex interactions between MPD distribution, weathering, and beach dynamics. By systematically collecting and analyzing data, we are advancing towards a comprehensive model that will inform effective management strategies for marine plastic pollution.
Objective 1: Comparing Distribution and Concentration of MPD on Hawaiian Beaches
> Field Sampling of Surface and Buried MPD:
o Activities:
- Plastic sampling was conducted on the island of Oʻahu, part of the Hawaiian archipelago in the North Pacific Ocean. The study focused on three beach sites located on Oʻahu's east side: James Campbell, Kokololio (Laie), and Waimānalo. Quarterly surveys were conducted from November 2022 to February 2024, targeting plastic debris (>0.5 mm) within each 10 cm layer of sand down to 1 m depth, using 60 x 60 cm quadrats.
- In collaboration with the International Pacific Research Center (IPRC) at the University of Hawaiʻi, we extended the study to Hawaiʻi Island (Big Island), where we repeated an earlier study (currently un-reported data) on the depth distribution of plastics on a rocky beach, offering a decade-long comparison.
o Progress and Achievements:
- The surveys on Oʻahu have provided a first insight into the 3D distribution of MPD on sandy Hawaiian beaches, revealing trends in plastic concentration across different depths and over time. This data significantly enhances our understanding of plastic abundance and distribution both on the surface and buried within the sand column.
- The additional study on a rocky beach provides valuable comparative data on how plastic distribution has changed over a decade and also addresses a notable gap in rocky beach plastic monitoring (in contrast to sandy beach monitoring). The inclusion of rocky beach environments, which are less commonly studied compared to sandy beaches, broadens the scope of coastal MPD monitoring and adds depth to our understanding of plastic pollution across diverse coastal landscapes.
Objective 2: Assessing Polymer Transformation Upon Weathering
> Setting Up Weathering Studies:
o Activities:
- We initiated weathering studies on plastic films and reference nurdles (polypropylene, PP, and polyethylene, PE) at the Centre for Marine Debris Research in Waimanalo, Hawai’i, beginning in February 2024. Samples were collected across three sets of aging experiments, each lasting three months. Environmental factors such as temperature and humidity were measured, and solar radiation exposure was continuously monitored using UVA and UVB sensors.
- In collaboration with Ecole Centrale Nantes and Ifremer, a student intern co-developed a fragmentation simulator for swash zone experiments, aimed at studying plastic fragmentation behavior in the dynamic coastal environment.
- Through another collaboration with the International Pacific Research Center (IPRC) at the University of Hawaii, we collected various plastic items from a container spill that occurred outside Hawaii in 2020. The collection involved both opportunistic visits to Hawaiian beaches and community contributions. We documented the debris in a comprehensive database, recording the location, visual state, and date of discovery. Samples of these plastic materials were collected for degradation state analysis at Ifremer.
o Progress and Achievements:
- Initial data collection on the natural weathering processes of marine plastic debris (MPD) is ongoing. Samples are periodically analyzed for changes in chemical structure using Fourier Transform Infrared (FT-IR) spectroscopy, molecular composition via Gel Permeation Chromatography (GPC), and mechanical properties. This work will enable us to understand how various environmental conditions influence the degradation pathways of polymers, providing crucial insights into MPD transformation within coastal environments.
- The initial tests and results from the fragmentation simulator have set the foundation for more efficient studies on plastic fragmentation behavior in the swash zone during the next phase of the project (incoming phase at Ifremer).
- The collection and analysis of samples from the container spill will allow us to investigate the extent of degradation with precise temporal data. Knowing the time of the spill and the varied collection times of the debris will help us better understand the rates and pathways of plastic degradation under real-world conditions.
bjective 3: Modeling MPD Capture & Release on Hawaiian Beaches
> 3D Mapping and Modeling:
o Activities:
- We collected and conducted initial analyses on the data from Objective 1, generating an overview of the 3D distribution of plastic particles on both sandy and rocky beaches in Hawai'i.
- During field surveys, we set up cameras to monitor beach accretion and erosion, enabling us to evaluate correlations between beach dynamics and the burial and release of plastics from the sand column.
- We initiated a collaboration with the School of Ocean and Earth Science and Technology (SOEST) at the University of Hawai'i to leverage their expertise in beach dynamics. This collaboration also involved collecting GPS points for evaluating beach erosion and accretion, using SOEST's equipment. Additionally, we are utilizing their satellite data and analysis on beach dynamics, including wave, wind, and tide determinants.
- Collaboration with the International Pacific Research Center (IPRC) on the container spill incident provided valuable data on plastic transportation from the ocean to Hawaiian shores.
- Through analysis of data we are investigating important factors to consider such as beach morphology, sand accretion/erosion, and environmental conditions like wind and wave action.
o Progress and Achievements:
- Initial data analysis from field surveys is offering valuable insights into the distribution and concentration of plastics within the sand column.
- Collaborations with SOEST and IPRC are enhancing our understanding of the environmental factors—such as wind, waves, currents, tides, and beach dynamics—that are crucial for modeling plastic concentration flux within the sand column.
- A three-month secondment at The Ocean Cleanup office in Rotterdam facilitated collaboration with their team, particularly in understanding the modeling requirements for plastic capture and release. This included discussions on the importance of modeling sand sediment movement, introduced through connections the potential application of the XBeach model.
Summary:
The STORAGE project has successfully laid initial groundwork for understanding the complex interactions between MPD distribution, weathering, and beach dynamics. By systematically collecting and analyzing data, we are advancing towards a comprehensive model that will inform effective management strategies for marine plastic pollution.
Results and Impacts from the Project at the current stage
1. Insights into Subsurface Plastic Pollution: The field surveys conducted on the sandy beaches of Hawaii, reaching depths beyond 10 cm, have provided a first insight into the concentration and distribution of buried plastics. Given Hawaii's proximity to the North Pacific Garbage Patch, these findings offer a more comprehensive understanding of the volume of plastics that strand on Hawaiian shores by revealing what lies beneath the surface.
2. Temporal Analysis of Buried Plastics: The quarterly surveys conducted from November 2022 to February 2024 have yielded significant data on the vertical distribution of plastics, gives a first insight into how buried plastic concentrations change over time, and at various depths (up to 1 meter detph) within the sandolumn.
3. Foundation for Future Modeling: Although the modeling of plastic capture and release on Hawaiian beaches is still in its early stages, the data collected thus far lays a solid foundation. The insights gained are envisioned to further research aimed at predicting the movement and accumulation of plastics in coastal environments.
Key Needs for Further Uptake and Success
1. Ongoing Research: Continued research is necessary to complete the analysis of the collected data and to begin the modeling phase. A deeper understanding of the environmental factors influencing plastic distribution is essential for improving the accuracy and effectiveness of the models.
2. Continued Collaborations: Ongoing collaboration with institutions such as SOEST, IPRC, and The Ocean Cleanup will be important for accessing the expertise, data, and technologies needed for the project's success. These partnerships will also play a key role in validating and applying the hypothesis and models once they are developed.
1. Insights into Subsurface Plastic Pollution: The field surveys conducted on the sandy beaches of Hawaii, reaching depths beyond 10 cm, have provided a first insight into the concentration and distribution of buried plastics. Given Hawaii's proximity to the North Pacific Garbage Patch, these findings offer a more comprehensive understanding of the volume of plastics that strand on Hawaiian shores by revealing what lies beneath the surface.
2. Temporal Analysis of Buried Plastics: The quarterly surveys conducted from November 2022 to February 2024 have yielded significant data on the vertical distribution of plastics, gives a first insight into how buried plastic concentrations change over time, and at various depths (up to 1 meter detph) within the sandolumn.
3. Foundation for Future Modeling: Although the modeling of plastic capture and release on Hawaiian beaches is still in its early stages, the data collected thus far lays a solid foundation. The insights gained are envisioned to further research aimed at predicting the movement and accumulation of plastics in coastal environments.
Key Needs for Further Uptake and Success
1. Ongoing Research: Continued research is necessary to complete the analysis of the collected data and to begin the modeling phase. A deeper understanding of the environmental factors influencing plastic distribution is essential for improving the accuracy and effectiveness of the models.
2. Continued Collaborations: Ongoing collaboration with institutions such as SOEST, IPRC, and The Ocean Cleanup will be important for accessing the expertise, data, and technologies needed for the project's success. These partnerships will also play a key role in validating and applying the hypothesis and models once they are developed.