Commotion in The Ocean?

Hardly a day passes without media statements about the crisis facing our oceans because of plastic pollution and in particular the unseen microplastics. Although seabirds and mammals are killed and maimed in great numbers by larger plastic particles, the evidence is not strong that there is a crisis for our marine ecosystem. Nevertheless, there is the potential for serious damage to the marine environment, damage which may be subtle, widespread and extremely difficult to reverse. Let’s look at the issues and try and find a way forward.

Seafloor sediment avalanches transport vast volumes of sediment, nutrient and pollutants from land to the deep sea and pose significant hazards to seafloor infrastructure such as cables and pipelines. For the last century we have tried to unravel the characteristics of these avalanches by studying their deposits in the geological record, generating miniature flows in the laboratory and using numerical models. We are now entering an exciting period because we finally have the technology to measure these flows in action on the seafloor. In this talk I’ll show you what we’ve discovered so far.

Shallow water coral reefs thrive mostly in the clear tropical waters. They hold about a third of all marine biodiversity and are among the most productive ecosystems on earth. A key factor in the success of corals is their symbiotic relationship with unicellular algae that live in their tissue and enable them to acquire nutrients from multiple pathways. I will discuss how nutrient pollution can affect the symbiotic relationship between corals and their algae and render reefs more vulnerable to global warming.