Luminescent bone-eating worms, giant squid and a sea cucumber commonly known as the headless chicken monster: some extraordinary creatures live at the bottom of the sea. For a long time almost everyone agreed the pressure was too intense for any life to exist. Now, it seems, the more we look the more new species we find. But, many fear, marine life would be threatened if plans to extract precious metals from the potato-sized metallic nodules that grow on the seabed are allowed to go ahead. Metals such as copper, manganese and cobalt are in high demand in the manufacture of mobile phones and renewable energy technologies, such as batteries for electric cars, wind turbines and solar panels. Deep sea mining companies argue that we will need these metals to create a carbon Net Zero economy. Meantime, the World Wildlife Fund is pushing for a moratorium on deep sea mining. And several companies agree: including Google, BMW, Volvo and Samsung. Do we need to choose between green and blue? Or is there a third way that protects both the planet and all the riches in our oceans?Marine biologist, Helen Scales talks to Jim Al-Khalili about her life and work: fish watching off an atoll in the South China Sea to assess the extinction risks to the Humphead Wrasse and a research expedition to explore the brilliant abyss. And she warns of the environmental devastation that could be caused if plans to mine the metals on the bottom of the ocean were to be allowed to go ahead. Producer: Anna Buckley