Plankton are dying primarily due to ocean deoxygenation caused by factors like plastic pollution and its impact on sunlight penetration, which inhibits their ability to photosynthesize.
Here's a breakdown of the key factors:
Ocean Deoxygenation: A Primary Threat
- Reduced Sunlight: Plastic pollution, along with increased sediment and algae blooms, blocks sunlight from reaching plankton.
- Photosynthesis Inhibition: Plankton rely on photosynthesis to produce energy and oxygen. When sunlight is limited, photosynthesis decreases significantly.
- Oxygen Depletion: As photosynthesis declines, the ocean's oxygen levels decrease, leading to deoxygenation.
- Suffocation: Plankton, like all living organisms, need oxygen to survive. Deoxygenation essentially suffocates them.
The Role of Plastic Pollution
Plastic pollution exacerbates the problem of deoxygenation through:
- Blocking Sunlight: Large concentrations of plastic waste floating on the ocean's surface act as barriers, preventing sunlight from penetrating the water column.
- Altering Ecosystems: Plastics can disrupt the natural balance of the marine ecosystem, impacting plankton populations indirectly.
Other Contributing Factors:
While deoxygenation is a major factor, other issues also contribute to plankton mortality:
- Climate Change: Rising ocean temperatures and increased ocean acidity affect plankton physiology and reproduction.
- Pollution (Beyond Plastics): Chemical runoff from land-based sources (pesticides, fertilizers, industrial waste) can poison plankton.
- Ocean Acidification: Increased carbon dioxide (CO2) in the atmosphere leads to ocean acidification, which can hinder plankton's ability to build shells and skeletons.
In summary, the death of plankton is a complex issue primarily driven by ocean deoxygenation, which is worsened by plastic pollution blocking sunlight and inhibiting photosynthesis, along with contributions from climate change, general pollution, and ocean acidification.
