Seaweed

In Argentina, where beef is a symbol of national pride, a government-led partnership has started certifying certain livestock as carbon neutral. It’s a big step that shouldn’t be underestimated, but getting the certification process right is crucial. The world’s livestock sector is a key driver of climate change, contributing around 12% of global greenhouse gas emissions. Two-thirds of agriculture’s annual greenhouse gas emissions come from livestock, with raising cattle for meat typically being the most emissions-intensive activity. While shifting diets to plant-based foods and alternative proteins can help reduce emissions, global meat consumption is growing with an expanding population and rising prosperity. There are ways that livestock producers can reduce those emissions. However, beyond social pressure, ranchers have few incentives to do so. Unless those steps to reduce emissions also increase productivity, they typically become costs with little...

An unwelcome visitor is headed for Florida and the Caribbean: huge floating mats of sargassum, or free-floating brown seaweed. Nearly every year since 2011, sargassum has inundated Caribbean, Gulf of Mexico and Florida coastlines in warm months, peaking in June and July. This brown tide rots on the beach, driving away tourists, harming local fishing industries and requiring costly cleanups. According to scientists who monitor the formation of sargassum in the Atlantic Ocean, 2023 could produce the largest bloom ever recorded. That’s bad news for destinations like Miami and Fort Lauderdale that will struggle to clean their shorelines. In 2022, Miami-Dade County spent US$6 million to clear sargassum from just four popular beaches. Satellite image of sargassum concentrations in the Atlantic during the month of March. USF/NOAA, CC BY-ND Sargassum isn’t new on South Florida beaches, but its r...

Deep below the ocean surface, the light fades into a twilight zone where whales and fish migrate and dead algae and zooplankton rain down from above. This is the heart of the ocean’s carbon pump, part of the natural ocean processes that capture about a third of all human-produced carbon dioxide and sink it into the deep sea, where it remains for hundreds of years. There may be ways to enhance these processes so the ocean pulls more carbon out of the atmosphere to help slow climate change. Yet little is known about the consequences. Peter de Menocal, a marine paleoclimatologist and director of Woods Hole Oceanographic Institution, discussed ocean carbon dioxide removal at a recent TEDxBoston: Planetary Stewardship event. In this interview, he dives deeper into the risks and benefits of human intervention and describes an ambitious plan to build a vast monitoring network of autonomous sensors in the ocean to help humanity understand the impact. First, what is ocean carbon...

The global aquaculture industry has tripled in size since the year 2000, with producers raising a mind-boggling diversity of species, from seaweeds and clams to carp, salmon and cuttlefish. Many of these creatures are undomesticated and lead complex and highly social lives in the wild. The rapid growth in aquaculture means that billions of individual aquatic animals are now being farmed without basic information that could help ensure even minimal welfare standards. Our newly published study shows that these welfare risks are not uniform: Aquaculture is likely to have severe effects on welfare for some species, but negligible impacts on others. Whenever humans manage animals on a large scale, welfare becomes a concern. As experts on aquatic animals and their welfare, we believe that taking proactive measures to shape the aquaculture industry’s growth will be critical for its long-term success. A cuttlefish tackles a challenge originally designe...