Spotlight on Science

Each month, an expert from the Marine Institute will shine a light on their area of work, sharing insights on our ocean knowledge. As the national agency responsible for supporting the sustainable development of our marine resources, the Marine Institute delivers scientific knowledge, expert advice and services to government, industry and a wide range of stakeholders.

This month, Dave Clarke, Section Manager, Marine Environment and Food Safety Services, writes about the Marine Institute’s involvement in research on toxic algal blooms in the Arctic and why it matters for Ireland’s fisheries. 

From Ireland to Greenland: The Marine Institute joins expedition to learn more about toxic algal blooms in the Arctic

When it comes to the Arctic, vast, pristine landscapes of white and blue ice and clean, clear seas come to mind. However, these marine ecosystems are already being re-shaped by environmental changes and drivers. 

Plankton - tiny primary producers which form the base of the marine food web are especially sensitive to these changes. They are considered an Essential Ocean Variable because shifts in their abundance or behaviour can signal wider environmental impacts. 
Under certain environmental conditions, some phytoplankton species give rise to harmful algal blooms (HABs). Although HABs are usually associated with temperate and warm coastal regions, scientists are concerned that HAB events may become increasingly common in the Arctic soon, with far-reaching consequences and impacts for biodiversity, food safety, fisheries, and the people who depend on them as a source of food and economy.   

To investigate the current HAB species occurring off the West coast waters of Greenland, and how plankton community diversity, structure and abundance may change in the future, this summer, an international team of scientists, including Dave Clarke from the Marine Institute, participated in the GreenHAB project survey expedition (MSM139), aboard the research vessel RV MARIA S. MERIAN, led by Alfred Wegener Institute (AWI), Germany.

This survey combined oceanography, molecular biology, ecology, and paleontology to paint a comprehensive picture of phytoplankton behaviour on the backdrop of melting glaciers and changing water chemistry. Using state-of-the-art equipment and experimental setups, the team collected samples from 33 sites on the West coast of Greenland, ranging from fjords to open ocean. They sampled 28,900 metres of the water column, isolated hundreds of plankton species, and even drilled 82 sediment cores, gaining a glimpse into centuries of ocean history.

Participating in HAB surveys is critical for understanding how harmful algal bloom species and events are changing in response to climate change and how these changes affect marine ecosystems. This knowledge is particularly important for fisheries and aquaculture, their sustainability, food safety, and economic value. 

Irish seafood products are internationally renowned and highly regarded for their taste, sustainability, quality and food safety, while the seafood aquaculture industry is an important economic resource in many rural communities around the coastline. Aquaculture areas are regularly impacted by HAB events, particularly those giving rise to food safety concerns due to toxins produced by some phytoplankton accumulating in shellfish.

In Ireland, it is critical that we continually enhance our knowledge and learning of new methodologies in detecting known and emerging HAB species and their toxin profiles. Building technical capacity helps us stay ahead of the emerging threats. This survey and working with international experts in the areas of taxonomy, molecular biology and genetics, gives us the opportunity to assess new detection methods and their potential implementation. These advances strengthen Ireland’s existing monitoring programmes and current national research projects on marine biotoxins and surveillance of toxin-producing phytoplankton species.

The findings from the GreenHAB project not only deepen our understanding of Arctic ecosystems under climate stress but also serve as an indication of what may occur in other marine ecosystems in the North Atlantic.