Species such as Alaria esculenta, which currently thrive in north Atlantic waters, could struggle to cope with a warming ocean over the coming decades.
Scottish Association for Marine Science (SAMS).
With seaweed farming gaining momentum in Europe, scientists are warning that climate change could pose a major threat to the sector over the next fifty years.
Research by the Scottish Association for Marine Science (SAMS), published in Frontiers in Marine Science, highlights that cold-water seaweed species, which currently thrive in the northern Atlantic, may start to disappear by 2070 due to rising ocean temperatures, increased storm frequency, and unpredictable salinity levels caused by heightened rainfall.
The study, led by SAMS marine ecologist Reina Veenhof, modelled the viability of five common farmed seaweed species, including Alaria esculenta and Laminaria digitata, under future climate projections. Findings suggest that these species, which are found in the cool waters of the UK, northern France, and parts of North America, may struggle to survive as waters warm.
"These seaweeds are growing outside of their ideal temperature range, leading to reduced yield and even potential stock loss,” Veenhof explained in a SAMS press release.
While colder northern regions, like Scotland, might experience minimal temperature effects on seaweed by 2070, they will likely face more frequent storms and higher rainfall, challenging existing farming conditions. Seaweed farms are particularly vulnerable to storm damage, which could hinder growth and increase production costs, the researchers explain.
To address these challenges, the study emphasizes the importance of new farming techniques. One promising approach, “priming” during the early gametophyte stage, involves exposing young seaweed to mild stress, building resilience to future temperature and salinity fluctuations. Widely used in agriculture, this technique could enhance the hardiness of seaweed crops amid changing ocean conditions.
Seaweed farming, viewed as a sustainable industry due to its carbon-absorbing properties and lack of additive needs, holds significant potential in Europe. However, scientists warn that the sector lags significantly behind Asia in both scale and technological advancement.
Veenhof notes that robust research investment could bring European seaweed farming up to par with global leaders, stating, “It will take a big effort, but with sufficient resources, we can safeguard a European seaweed industry for the long term."
The study concludes that without increased funding in research and development, Europe’s seaweed industry could face significant hurdles in adapting to climate change. However, with the right resources, seaweed farming could continue to play a role in sustainable aquaculture for decades to come.
The full study, "Sustainable seaweed aquaculture and climate change in the North Atlantic: challenges and opportunities", can be viewed here.
