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Illustration by Mark Garrison<\/p><\/div>\n
In June, part of one previously undiscovered clinker trail came to the surface when Australia\u2019s Commonwealth Scientific and Industrial Research Organisation surveyed the seafloor between Tasmania and Queensland. Biologists found a mind-boggling diversity of marine life, but they also found a lot of human garbage, from modern plastics to clinker that might have been pitched over the side of a passing steamer during Queen Victoria\u2019s reign. The rocky relics are part geological record of the Anthropocene and part tangible record of maritime history.<\/p>\n
Clinker has also become an important part of marine ecosystems in places like the northeast Atlantic abyssal plain and the northwestern Mediterranean. There, far from the continental shelf, the ocean bottom is soft and muddy, leaving organisms such as anemones and brachiopods, which need to anchor to something solid, few places to attach.<\/p>\n
Clinker can provide substrate for sessile fauna, often filter feeders, in the deep sea, providing habitat that may otherwise not be available, explains Ramirez-Llodra and her colleagues in a recent paper<\/a>. In the northeast Atlantic, for example, clinker forms about half the available hard material for the anemone Phelliactis robusta<\/em> to anchor to, and the Mediterranean brachiopod Gryphus vitreus<\/em> also sometimes takes advantage of clinker for habitat. Although clinker appears to be toxic to other species, its usefulness to some is a rare case of human litter actually increasing deep-sea biodiversity.<\/p>\n But it won\u2019t last forever. Some of the clinker is already buried under sediment, or is being dredged up in fishing or research trawls. Eventually, the sea will cover the last of the historical trails the steamships laid down. Without clinker, organisms like\u00a0G. vitreus <\/em>will move onto other deep-sea anchorages, perhaps glacial dropstones<\/a>. But beneath the muddy bottom of the deep ocean will lie a geological record of humanity\u2019s long relationship with the sea.<\/p>\n","protected":false},"excerpt":{"rendered":" A survey of marine life off the east coast of Australia pulled up several handfuls of history this summer, along with a distressing amount of modern litter. The historical artifacts don\u2019t look like much\u2014just some lumpy, ash-colored chunks of baseball-sized <\/p>\n