Revitalizing Kelp Forests: A Global Perspective on Biodiversity
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When we think of forests, we often envision those comprised of trees, which cover about 30% of the Earth's land area. These terrestrial forests are crucial for our planet, often referred to as its lungs, as they play a vital role in converting carbon dioxide (CO2) into oxygen (O2) for various organisms. The functions these ecosystems provide are essential for maintaining balance and supporting life on Earth.
However, beneath the waves lies another vital type of forest: marine kelp forests. Kelp, a rapidly growing brown seaweed, blankets one-third of the world's coastlines and similarly contributes numerous ecosystem functions, including:
- Transforming CO2 into oxygen and sequestering carbon for extended periods.
- Reducing water acidity, making it more alkaline.
- Serving as a habitat for over 1,500 species of plants and animals.
In this video, you can explore a kelp forest and encounter various species:
These forests also provide significant ecosystem services to around 750 million people living within 50 kilometers of them. Ecosystem services refer to the advantages that natural systems offer to human societies, including fisheries, cultural significance through folklore, artistic inspiration, and opportunities for recreation.
Sadly, kelp forests globally have experienced a 40–60% decline over the past five decades, with some areas disappearing entirely due to various biological, physical, and chemical threats.
The decline of these kelp forests poses a direct risk to local biodiversity and the associated ecosystem services. Thus, it is crucial to restore and protect these vital marine environments. Restoration can mean enabling existing forests to recover, often by controlling excessive predator populations, while afforestation involves introducing kelp to areas where it previously did not exist by planting spores or mature plants on artificial reefs. Safeguarding healthy kelp forests from pollution is equally important. Below are examples of kelp restoration efforts and their impacts on biodiversity across different regions:
Japan
Kelp restoration initiatives in Japan date back to the 1700s, with hundreds of projects being launched, particularly in the last decade. The commercial importance of species like Saccharina has driven these efforts, as fishers began harvesting it in the 1300s.
Japan's approach has included both restoration and afforestation. Early strategies involved placing stones in coral reefs and eliminating competing algae. They also targeted the removal of sea urchins and fish that consume kelp. Although some initial efforts failed, continuous improvement led to more effective strategies, such as utilizing concrete blocks for artificial reefs and employing underwater tools to manage competing algae. The removal of grazers was essential for the success of kelp restoration, especially when kelp was adequately protected. This has allowed for commercial sales of grazers, benefiting both local communities and biodiversity.
Based on these experiences, a significant restoration project commenced in 1999, which involved placing concrete blocks in flourishing kelp areas to facilitate spore settlement and expansion to other regions. This initiative has yielded such positive results that other marine species previously affected by overfishing have also started to recover.
However, ongoing efforts face challenges, including insufficient funding, urbanization along coastlines, rising sea temperatures, and more frequent severe weather events. Some projects have been initiated as offsetting measures to compensate for ecological damage, whether through carbon offsetting or biodiversity offsetting. However, these practices may not effectively replace lost biodiversity and can inadvertently perpetuate harmful activities. Rather than merely focusing on limiting losses, governments should implement regulations and funding mechanisms to promote kelp population growth.
California, USA
Kelp restoration in California began in 1958 due to declining populations caused by poor water quality and overharvesting. Since the early 1900s, kelp has been an essential resource for various products, including alginates, potash, and acetone. Some areas were further devastated by warm water discharges from a nuclear power plant.
Initial restoration efforts focused on transplanting Macrocystis, a type of brown kelp, while also managing grazing fish and urchins. While many of these projects succeeded, others faced setbacks from storms and invasive species. Afforestation initiatives also emerged, using materials like old trams initially before transitioning to sturdier rocky substrates.
Recent projects aim to restore habitats destroyed by industrial activities, including efforts to revive bull kelp along a 350 km stretch of coastline, following a dramatic 95% decline in kelp over a decade. These restorations will enhance the economic and social health of coastal communities while supporting marine ecosystems.
To ensure sustainability, monitoring is conducted, and additional measures are taken to secure ecosystem functions. These may involve developing regulations, managing urchin populations through diving, utilizing aerial imagery for tracking forest development, preserving genetic diversity, and raising public awareness. Such initiatives will help mitigate future kelp forest degradation and biodiversity loss while fostering climate-resilient solutions.
Australia
Kelp restoration in Australia is relatively recent, focusing on the removal of urchins from spiny kelp forests, reviving giant kelp, and restoring the locally extinct fucoid crayweed (Phyllospora comosa).
- Removing urchins: Collaborations with fishery organizations, traditionally focused on abalone and urchin fishing, have addressed the spread of urchins, including those typically unharvestable.
- Restoring giant kelp: Previous efforts from 1997 to 2001 had limited success due to extreme weather events and warmer waters. Current research focuses on cultivating giant kelp from resilient strains that can withstand rising temperatures for future planting.
- Restoring fucoid crayweed: Initiated in 2011, this effort includes genetic mixing among populations to enhance resilience against climate change.
Taking Action
Given the vital importance of kelp forests, it is encouraging to see global initiatives aimed at their restoration. We can also contribute! Here are practical steps you can take to support kelp:
- Join a beach cleanup to reduce pollution affecting kelp forests.
- Adopt sustainable fishing practices to protect marine ecosystems.
- Support conservation organizations.
- Donate to kelp restoration initiatives.
- Choose sustainably sourced seafood.
Which of these actions can you incorporate into your routine? Do you have additional ideas for supporting kelp ecosystems? Thank you for your commitment to these efforts and for sharing your suggestions to inspire others.
About the Author
Dr. Erlijn van Genuchten is a renowned expert in environmental sustainability. As a science communicator, she aids researchers in the fields of nature and sustainability to enhance the dissemination of their findings, helping us all apply scientific insights for a sustainable future. Dr. van Genuchten has inspired countless individuals worldwide through her contributions to the United Nations, her book *A Guide to A Healthier Planet published by Springer Nature, and her social media presence.*
- More about her book “A Guide to a Healthier Planet”
- Invite Dr. Erlijn van Genuchten as a speaker
- Apply for science communication support
- Erlijn’s website
Credit:
This article is based on three scientific publications:
- Eger, A. M., Aguirre, J. D., Altamirano, M., Arafeh-Dalmau, N., Arroyo, N. L., Bauer-Civiello, A. M., … & Vergès, A. (2023). The Kelp Forest Challenge: A collaborative global movement to protect and restore 4 million hectares of kelp forests. Journal of Applied Phycology, 1–14.
- Eger, A. M., Marzinelli, E. M., Christie, H., Fagerli, C. W., Fujita, D., Gonzalez, A. P., … & Vergès, A. (2022). Global kelp forest restoration: past lessons, present status, and future directions. Biological Reviews, 97(4), 1449–1475.
- Elliott Smith, E. A., & Fox, M. D. (2022). Characterizing energy flow in kelp forest food webs: a geochemical review and call for additional research. Ecography, 2022(6), e05566.