Marine Debris Flashcards
What is the definition of Marine Debris?
Marine debris encompasses all materials present in the marine environment that should not be there. This includes plastics, derelict fishing gear, glass, metal, and rubber.
What are the sources of marine debris?
- Land-based sources account for the majority (80-90%) of marine debris, originating from rivers, wind-blown litter from landfills, tourism/beach activities, and atmospheric transport of particles.
- Other sources include fishing activities, waste from boats, and offshore platforms.
What is the brief history of Marine Litter?
Early reports date back to the 1950s, with increasing awareness in the 1960s and 1970s.
Notable studies, like Kenyon and Kridler’s 1969 paper on albatross ingesting plastics, highlighted the severity of the issue.
What are the direct effects of marine debris?
- Ingestion and entanglement are common direct effects, leading to false satiation, digestive tract blockages, reduction of fat stores, and release of toxins.
- Plastic ingestion is particularly concerning, affecting various marine species and potentially causing death.
What are microplastics?
Microplastics are plastics with a size less than 5 mm, originating from small beads, plastic fibers, or the breakdown of larger plastics.
What are the impacts on marine species?
Seabirds, marine mammals, turtles, and fish are all affected by marine debris through ingestion and entanglement.
Entanglement can lead to drowning, reduced feeding ability, injuries, and death.
What are the extent of these issues?
Marine debris affects a wide range of species, with reports of ingestion and entanglement documented across many regions.
The problem extends to the deep sea, with debris found even in remote areas.
Estimation of the debris in the oceans?
Difficult to estimate total debris in the oceans. Approximately 50% of plastics float, but monitoring only captures floating debris, underestimating deeper ocean and shoreline presence.
What is the estimated plastic waste input into oceans?
An estimated 5-12 million tons of plastics enter the marine system annually, a significant portion of global plastic production.
What is the distribution of debris?
Debris density varies globally, with higher concentrations observed in certain regions due to ocean currents and human activity.
Missing plastic
Significant amounts of plastic seem to be missing from surface observations, potentially accumulating in shorelines, interacting with biology, sinking, or forming nanoplastics.
What are the research gaps and improvements?
Research should focus on realistic concentrations and ecological impacts, with better monitoring of debris sources, pathways, and distributions. Degradation processes and vertical fluxes require further study.
What are the conclusions of marine debris?
Mismanaged waste is a primary source of debris. The discrepancy between plastic entering oceans and observed surface debris highlights the need for improved monitoring and understanding of plastic cycling.
