05 Marine Debris, Sedimentation & Dredging.pptx

A slide presentation on Marine debris, sedimentation and dredging with notes embedded. Examples from Queensland, Australia.

1. This Photo by Unknown Author is licensed under CC BY-SA Marine Debris, S edimentation & Dredging

2. MARINE DEBRIS This Photo by Unknown Author is licensed under CC BY Marine debris Any solid material that is manufactured or processed and directly or indirectly, intentionally or unintentionally, disposed of or abandoned in the marine environment Marine debris examples include plastics, fishing gear, and abandoned vessels Marine debris injures and kills marine life, interferes with navigation safety, and poses a threat to human health

3. PLASTICS Plastics are one of the most extensive types of marine debris Plastics can take hundreds to thousands of years to decompose Plastics are now known to break down into smaller components, called microplastics Plastics such as bottle caps, balloons and lighters are mistaken for food and eaten by sea turtles, seabirds and marine mammals

4. This Photo by Unknown Author is licensed under CC BY-SA MICROPLASTICS Microplastics and their associated toxic chemical components contribute to human and wildlife health risks as the toxic microplastics are ingested and move through the marine food web.

5. This Photo by Unknown Author is licensed under CC BY-SA-NC

6. MARINE SNOW Marine snow contains flecks from plant and animal carcasses, faeces, mucus, dust, and viruses – however, now, microplastics are infiltrating this marine snow

7. This Photo by Unknown Author is licensed under CC BY-SA-NC

8. Sunken/abandoned fishing gear has numerous impacts on the environment, including damaging marine habitats, entangling marine species, creating hazards to navigation, and ghost fishing of commercially important species resulting in lost catch opportunities and economic losses for fishermen Derelict nets, ropes, lines, or other fishing fear can wrap around marine life Entanglement leads to injury, illness, suffocation, starvation and death FISHING GEAR

9. ABANDONED VESSELS Abandon vessels threaten oceans, coasts, and waterways by obstructing navigational channels, causing harm to the environment, and diminishing commercial and recreational activities They may pose an immediate or future threat to wildlife and habitats, as they can release hazardous substances to surrounding areas Abandoned vessels may occur in large numbers, following a natural disaster In Australia, there are more than 8000 vessels shipwrecked – only 2000 of these have been found

10. SEDIMENTATION Any deposit of insoluble material, primarily rock and soil particles, transported from land areas to the ocean by wind, ice, and rivers, as well as the remains of marine organisms This Photo by Unknown Author is licensed under CC BY

11. DREDGING – the act of removing silt and other material from the bottom of bodies of water It is a routine necessity in waterways around the world because sedimentation (the natural process of sand and silt washing downstream) gradually fills channels and harbours

12. ENVIRONMENTAL DREDGING Dredging is also performed to reduce the exposure of fish, wildlife, and people to contaminants and to prevent the spread of contaminants to other areas of the water body This is environmental dredging and is often necessary because sediments in and around cities and industrial areas are frequently contaminated with a variety of pollutants

13. DREDGING - CARDWELL

14. DREDGING - TOWNSVILLE The $232 million Channel Upgrade project will see the Platypus channel (Port end) widened to 180m and accommodate vessels up to 300m long when completed in 2024.

15. DREDGING – THE NEGATIVES However, dredging can also hurt the environment. Research the negative effects of dredging and write down a list.