Deep Sea Water Column: A Significant, Underestimated Reservoir of Marine Microplastics
Category: Resource Management · Effect: Strong effect · Year: 2019
Microplastic concentrations are highest in the mesopelagic zone (200-600m), indicating this vast deep-sea environment is a critical, yet often overlooked, sink for plastic pollution.
Design Takeaway
Designers must broaden their scope beyond surface-level pollution to account for the deep-sea as a major accumulation zone for microplastics, influencing material choices and product lifecycles.
Why It Matters
Understanding the distribution and accumulation of microplastics in the deep ocean is crucial for developing effective global strategies to mitigate plastic pollution. This research highlights the need to consider the entire water column, not just surface waters, in environmental assessments and policy development.
Key Finding
The study found that the deep ocean's water column, particularly the mesopelagic zone, holds significant amounts of microplastics, which are also being consumed by marine life.
Key Findings
- Highest concentrations of microplastics were found at depths between 200 and 600 meters.
- Microplastics are readily ingested by pelagic organisms, indicating their integration into marine food webs.
- The deep pelagic water column represents a substantial reservoir of marine microplastics.
Research Evidence
Aim: To determine the vertical distribution and biological transport of microplastics within the epipelagic and mesopelagic water column of a marine ecosystem.
Method: Field research and laboratory analysis
Procedure: Microplastic samples were collected from the water column at depths ranging from 5 to 1000 meters using remotely operated vehicles and specialized samplers. Microplastics were identified using Laser Raman spectroscopy. The presence of microplastics in key marine organisms (pelagic red crabs and giant larvaceans) was also examined.
Context: Marine ecosystems, specifically the Monterey Bay pelagic ecosystem.
Design Principle
Consider the full lifecycle and environmental fate of materials, especially in vast and less-studied ecosystems.
How to Apply
When designing products or systems that may enter marine environments, conduct thorough risk assessments that include potential impacts on deep-sea ecosystems and food webs.
Limitations
The study was conducted in a specific bay, and findings may vary in different oceanic regions. The exact pathways of microplastic transport and degradation in the deep sea require further investigation.
Student Guide (IB Design Technology)
Simple Explanation: This study shows that a lot of tiny plastic pieces end up in the deep ocean, not just floating on the surface, and that sea creatures are eating them.
Why This Matters: It's important for design projects to understand the complete environmental impact of materials and products, including how they affect less visible but critical ecosystems like the deep sea.
Critical Thinking: If the deep sea is a major sink for microplastics, what are the implications for designing products that are intended to degrade or be recycled, and how can we ensure these processes don't inadvertently contribute to deep-sea pollution?
IA-Ready Paragraph: Research indicates that the deep pelagic water column, particularly the mesopelagic zone (200-600m), acts as a significant reservoir for microplastics, with concentrations exceeding those found in surface waters. Furthermore, these microplastics are readily incorporated into marine food webs through the ingestion by pelagic organisms. This highlights the critical need for design considerations to extend beyond immediate surface pollution and encompass the full environmental fate of materials within the entire ocean column.
Project Tips
- When researching environmental impacts, consider the full depth of the environment, not just the most visible parts.
- Think about how materials can be transported through ecosystems, even to remote locations.
How to Use in IA
- Use this research to justify the importance of studying the environmental impact of your chosen materials or product in a wider context.
- Cite this study when discussing the potential for pollution to travel to and accumulate in deep-sea environments.
Examiner Tips
- Demonstrate an understanding of the full environmental scope of a design problem, including less obvious areas of impact.
- Show how your design choices consider the long-term fate of materials in complex ecosystems.
Independent Variable: Depth of water column
Dependent Variable: Concentration of microplastics
Controlled Variables: Location (Monterey Bay), sampling methods, identification techniques
Strengths
- Utilized advanced sampling technology (ROVs).
- Employed rigorous identification methods (Laser Raman spectroscopy).
Critical Questions
- What are the long-term ecological consequences of microplastic accumulation in the deep sea?
- How do different types of plastics behave and distribute vertically in the water column?
Extended Essay Application
- Investigate the potential for bioaccumulation of microplastics from deep-sea organisms up the food chain.
- Develop novel materials or filtration systems designed to capture microplastics at various depths.
Source
The vertical distribution and biological transport of marine microplastics across the epipelagic and mesopelagic water column · Scientific Reports · 2019 · 10.1038/s41598-019-44117-2