Map of Maerl-Building Algae Reveals Britain’s Underwater Diversity
A groundbreaking genetic survey of habitat-building coralline algae has brought attention to one of the United Kingdom’s most critical yet less comprehended blue-carbon ecosystems. Conducted by marine biologists from the University of Exeter, this research has, for the first time, crafted a genomic map of maerl-forming algae across the southwest of Britain. These findings offer valuable insights into the resilience, vulnerability, and unique characteristics of these essential seabed constructors.
Unveiling the Mysteries of Maerl
The comprehensive study employed Whole Genome Sequencing (WGS) to analyze calcareous red seaweeds collected from 12 locations, stretching from Cornwall to South Wales. Maerl, composed primarily of the species Phymatolithon calcareum and Lithothamnion corallioides, forms intricate beds that provide nursery grounds for juvenile fish and shellfish while crucially sequestering carbon for centuries. Despite their ecological importance, the genetics of these algae have remained enigmatic until now.
Now documented in the journal Evolutionary Applications, this study stands as the UK’s first extensive genomic analysis of these coralline algae. Among its notable discoveries is a variant dubbed ‘Godzilla maerl,’ an oversized and coarse form of Phymatolithon calcareum, found uniquely in St Mawes, Cornwall.
“This is the first research project to assemble reference genomes for two maerl-forming species and apply WGS along Britain’s southern and southwestern coasts,” Dr. Tom Jenkins, the project leader, commented. “We’ve been able to reveal how genetically diverse these populations are and identify which beds are dominated by clones—key factors that shape their vulnerability to climate and environmental change.”
Understanding Local Impact and Adaptation
Genetic patterns uncovered distinct regional differences, suggesting limited exchange between populations and possible adaptation to local conditions. For example, researchers identified unique genetic lineages in algae from Cornwall, Dorset, and Milford Haven. In St Mawes, they discovered the Godzilla variant of P. calcareum, which grows up to three times larger than typical specimens and contains an extra chromosome set. “We can find no evidence of P. calcareum growing this large anywhere else in Europe,” noted Dr. Jenkins.
Cornwall’s southern coast also hosts the highest levels of genetic diversity, indicating potential resilience against environmental changes. Conversely, the Godzilla variant’s low genetic diversity might make it particularly susceptible to shifting environmental conditions.
“High genetic diversity—or clonality—can help us estimate how likely a population is to withstand future change,” Jenkins explained. “More variation means a greater range of responses when conditions shift.”
Implications for Environmental Management
For environmental managers, this research offers a powerful tool for assessing the health and long-term prospects of maerl beds, which can persist for millennia and rival coral reefs in their ecological function. Jamie Stevens, co-author and marine geneticist at Exeter, highlighted the potential of maerl as a significant component of carbon capture and an essential habitat for species like lobsters and crabs. “These are phenomenal underwater structures,” Stevens remarked.
In response to these findings, Natural England and Natural Resources Wales have expressed interest in incorporating this genetic information into their conservation strategies. By understanding maerl’s genetic resilience, they aim to better protect these crucial ecosystems amid the challenges posed by climate change.
Local Community Interest and Ongoing Efforts
This research resonates not only with environmental scientists and policymakers but also with local residents. The maerl beds’ ecological importance extends beyond their carbon capture capability, serving as vital nursery habitats that support marine biodiversity and local fisheries. The ramifications of such research foster community interest in sustaining these underwater ecosystems.
Efforts to protect maerl beds align with past and ongoing campaigns by local conservation groups advocating against coastal activities that threaten these fragile structures, such as dredging and anchoring. Public awareness initiatives are essential, educating residents on the value of maerl and rallying support for protective measures. These endeavors echo the broader community’s engagement with environmental stewardship reflected in regional conservation campaigns.
Potential Future Implications
The implications of this study reach far beyond the boundaries of the scientific community. As this research contributes to a deeper understanding of marine biodiversity, it reinforces the momentum for global conservation efforts to preserve critical habitats and address climate change impacts proactively.
Looking forward, the University of Exeter and its research partners emphasize the need for ongoing monitoring and further studies to continually adapt conservation strategies. By fostering collaborations between scientists, governmental organizations, and local communities, the efforts to safeguard maerl beds could serve as a model for addressing similar ecological challenges worldwide.
Get Involved
Residents interested in learning more about the significance of maerl and ongoing efforts to protect these ecosystems can access resources through local conservation groups. Community workshops and forums are planned to discuss the latest research findings and outline actionable steps for local conservation initiatives. Engaged citizens are encouraged to participate and contribute their perspectives to these collaborative conservation efforts, ensuring a broader public understanding and support for sustaining underwater biodiversity.
As a foundational step towards furthering understanding and protection of these vital ecosystems, the landmark research on maerl-building algae continues to be a testament to the intersection of scientific discovery and community engagement in addressing global environmental challenges.
