The accumulation of marine litter in the world’s oceans over the past decades has risen. Plastic is ubiquitous, cheap to produce and extremely durable. Every piece of plastic ever produced still exists, therefore much of it has ended up, in the oceans.
Worryingly, plastic breaks up over time into smaller and smaller pieces known as microplastics, which end up in wastewater, freshwater, and marine environments and are ingested by marine life such as plankton and shellfish, which are in turn consumed by ever larger predators and have been shown to make it all the way to our dinnerplates, with unknown consequences. Larger marine wildlife has also suffered from ingestion of and entanglement in marine debris, with growing numbers of whales, turtles, and seabirds found dead with stomachs full of plastic.
While public awareness for this issue has grown rapidly in recent years, in part thanks to documentary series such as the BBC’s Blue Planet II and to public outreach campaigns such as UN Environment’s Clean Seas Campaign, much work remains to be done to understand and mitigate the impacts of marine litter and microplastics on marine ecosystems.
While some data exist at local and regional levels, consolidated global databases and source inventories based on standardised methodologies will be needed to better understand the flows of litter into the marine environment.
Managing and conserving marine areas is essential for achieving the SDGs. Marine spatial planning, Inter-Coastal Zone Management, Protected Areas, Ecosystem-Based Adaption Plans and other forms of marine management all play a part in managing oceans. Information on different management types could be used to measure this target; however, additional research on how to combine information on different types of management is needed.
As of the close of 2018, marine protected areas cover 7.4% of the global ocean at almost 27 million km2. About 90% of this area lie within the territorial sea or Exclusive Economic Zones of coastal nations, and only 10% is located in the high seas. While the total marine protected area appears on track to meet the Aichi target in two more years, a recent analysis indicates that only 41% of 232 marine ecoregions, less than half, have met the 10% target, with 10 ecoregions still without protection to date.
It is important to conserve at least 10% of each ecoregion to ensure ecological representation among protected areas for measuring progress in effective marine area protection.