“It’s no exaggeration to say that Japan faces a critical situation when describing the rapid decline of marine supply in its domestic waters that is linked to seaweed loss. Tengusa (seaweed) provides food for marine species.”
— Tomohiro Takase, head of the fisheries department at the Hachijojima municipality
Seagrass, though small, is very important to marine ecosystems. It acts as a nursery and homes for fish who need a place to grow up and hide. The energy it provides to marine life helps maintain biodiversity and the way humans fish and experience the marine world. However, due to rising temperatures of our oceans, seagrasses have become extremely vulnerable, as have small animals that impact the rest of the food web. In Japan, where seaweed and marine resources play an important role in culture and diet, it was linked that the drastic depletion of its fish stocks back in 2006 was caused by the loss of these seaweed colonies. On Hachijojima island located 300 miles south of Tokyo, the drastic decline of abalone, an expensive product providing lucrative income, from 20 tons per year to less than one ton left fishermen to face a gloomy future.
While in 2006, there was much doubt about the exact cause of these seagrass losses, in 2020, the scientific community understands the role of warming waters on these habitats. Also, boating in shallow waters and coastal developments have only caused even further damage to seagrasses. According to the Japan Times, a Hokkaido University research group found that if global warming advances at the current pace, the seawater temperature around Hokkaido will rise by as much as 10 degrees celsius by the 2090s and at least four principal breeds of edible kelp will cease to exist by the 2040s – only twenty years from today.