My Google news feed regularly serves up heartbreaking images of negative human impact on the natural world, like the 620,000-square-mile island of trash floating in the Pacific Ocean, and birds and sea turtles with plastic six-pack rings stuck around their beaks. But, very occasionally, I come across a story about the detritus of human existence becoming the scaffolding for nature to heal itself.
In 2018, Arizona State University ecologist and scuba diver Greg Asner travelled to Bikini Atoll, the site of US nuclear tests that began in 1946 and continued through 1958. These tests were designed to answer the question of what would happen if a nuclear bomb with the equivalent of 23 kilotons of TNT was detonated in the water near a fleet of obsolete steel warships—which sounds like a question an eight-year-old might ask, but in this case grown men asked and then spent billions of government dollars doing it. News flash: many ships sank, and the whole region was contaminated with radiation. More than 70 years later, however, these sunken ships now rank among the top scuba diving destinations in the world. Asner, however, wasn’t interested in the sunken relic warships of World War II so much as the abundance and diversity of coral that had made those ships their home.
Estimates indicate that living coral has declined by half since the 1950s, primarily due to warming oceans. Ocean ecologists postulate that the best way to save the many threatened species of coral is to move them to cooler, deeper water. Because coral can’t move long distances (no fins, no feet), it needs some help with migration. Like stepping stones.
In Asner’s 2022 Diversity paper, he says that nearly 2,000 of the world’s largest artificial reefs are generated on shipwrecks. And, at least on the ships of Bikini Atoll, the diversity of coral is two thirds that of neighboring natural reefs—a number that is seen as a resounding endorsement for the success of artificial reef structures. Steel, it turns out, is an excellent substrate for coral.
Despite the success story of artificial reefs and their potential to help coral species survive warming oceans, examples of nature depending on human-made structures are few. However, the reverse is quite common: Humans are often inspired by nature’s engineering feats, and we frequently try to replicate them. From the cockleburs that inspired Velcro, to Japan’s Shinkansen bullet train, designed in imitation of the Kingfisher’s beak, human invention is full of biomimicry. The field of optics is no exception.
This issue of Photonics Focus explores biomimetics at the interface of photonics. One feature article explores the unique optical properties of marine and avian animals, and the technologists working to replicate those properties for camouflage, communication, and even photovoltaics. Another story delves into the complex visual system of the mantis shrimp and scientists’ efforts to replicate it with sophisticated sensors. Our third feature highlights neuromorphic computing, a technology that mimics the neurons and synapses found in highly efficient mammalian brains.
Nature has had millennia to develop its strategies for efficiency, energy generation, and survival, whereas the problems facing humans demand a compressed R&D timeline. A warming planet and its related symptoms are problems for which scientists and engineers urgently seek answers—and if we look closely, we might find some solutions have already been designed by nature.
Gwen Weerts, Editor-in-chief
