Journal of Marine Science: Research & Development
Open Access

Seaweed ecosystems; Biodiversity; Marine conservation; Coastal protection; Carbon sequestration; Ocean acidification; Seaweed farming; Ecosystem services; Marine pollution; Climate change

Introduction

The vast and diverse ecosystems of the world’s oceans are home to many forms of life, from the microscopic plankton that fuel the marine food web to the enormous whales that roam the seas. Among the most important, yet often overlooked, marine habitats are those dominated by seaweeds. These simple, photosynthetic organisms, which include red, green, and brown algae, form some of the most productive ecosystems in the world. Seaweed forests, often compared to terrestrial forests due to their complexity and the services they provide, are critical to the health of coastal ecosystems and the broader marine environment. Seaweeds play a fundamental role in marine food webs and are essential for maintaining biodiversity in coastal regions. They provide food, shelter, and breeding grounds for a wide array of marine organisms, from small invertebrates to large fish and mammals. In addition to their ecological importance, seaweed ecosystems also offer numerous benefits to humans, including carbon sequestration, coastal protection, and the potential for sustainable resource use. However, these vital habitats are increasingly threatened by human activities, including pollution, coastal development, and climate change [1-3].

Description

Seaweed ecosystems are made up of various species of marine algae, which are classified into three primary groups: red algae (Rhodophyta), green algae (Chlorophyta), and brown algae (Phaeophyta). These algae, which can vary in size from microscopic phytoplankton to massive kelp forests that can grow up to 60 meters in length, thrive in coastal areas where sunlight penetrates the water. Seaweed ecosystems can be found in shallow waters along rocky shores, estuaries, and lagoons, and are most commonly associated with kelp forests, seagrass meadows, and coral reefs [4].

Kelp forests: Kelp forests, primarily dominated by brown algae, are some of the most productive and biodiverse marine ecosystems in the world. These towering underwater forests provide habitat for thousands of species, including fish, invertebrates, sea otters, and marine mammals. Kelp can grow at astonishing rates, reaching up to half a meter per day under optimal conditions. The dense canopy formed by kelp fronds creates a complex three-dimensional environment that supports a wide variety of marine life.

Seaweed meadows: In addition to kelp forests, seaweed meadows are another type of seaweed ecosystem. These meadows are often dominated by smaller species of red and green algae, which form extensive underwater mats in shallow coastal areas. These meadows serve as vital habitats for juvenile fish, crustaceans, and mollusks, providing shelter and food in the early stages of their life cycles [5].

Biodiversity in seaweed ecosystems

Seaweed ecosystems are incredibly diverse, supporting a wide variety of marine life. The complex structure of seaweed beds provides niches for numerous species, from microscopic plankton to large marine mammals. The high levels of biodiversity found in these ecosystems can be categorized into several important groups:

Fish and invertebrates: Seaweed ecosystems provide essential food and shelter for numerous fish and invertebrate species. Small fish, such as gobies and damselfish, use the kelp canopy to hide from predators and seek food. Invertebrates, such as sea urchins, snails, and crabs, feed on the seaweed itself or on the smaller organisms that live within the algae.

Marine mammals: Larger marine mammals, such as sea otters and manatees, are closely linked to seaweed ecosystems. Sea otters, for example, rely on kelp forests for shelter and as a hunting ground. They feed on sea urchins and other invertebrates, helping to regulate the populations of these organisms and prevent overgrazing of kelp.

Birds: Birds, particularly seabirds, also benefit from seaweed ecosystems. Many seabirds forage in the shallow waters of kelp forests and seaweed meadows, feeding on fish and invertebrates. In addition, seaweed ecosystems serve as nesting grounds for some bird species, which build their nests in the protection of dense seaweed beds [6].

Endangered species: Some species that depend on seaweed ecosystems are endangered or vulnerable. For example, the green sea turtle relies on seagrass meadows and seaweed beds for food, and the dugong, a large marine herbivore, feeds primarily on seagrass and algae. Protecting these ecosystems is crucial for the conservation of these and other vulnerable species.

Discussion

Challenges facing seaweed ecosystems

Despite their many benefits, seaweed ecosystems are under increasing threat from both natural and anthropogenic factors. Some of the most significant threats to seaweed habitats include.

Climate change: Climate change poses a significant threat to seaweed ecosystems, particularly through rising sea temperatures and ocean acidification. Many seaweed species are highly sensitive to temperature changes, and prolonged periods of warming can lead to shifts in the distribution of seaweed species or even the loss of entire ecosystems. Ocean acidification, caused by increased CO2 levels, can affect the ability of seaweeds to grow and reproduce, threatening their survival.

Pollution: Pollution from agricultural runoff, sewage, and industrial waste is another major threat to seaweed ecosystems. Excess nutrients from fertilizers can lead to eutrophication, causing harmful algal blooms that smother seaweed beds and disrupt the ecological balance of coastal ecosystems. Additionally, chemical pollutants, such as pesticides and heavy metals, can contaminate seaweed habitats, harming marine life and compromising the health of the ecosystem [7-10].

Overharvesting: Seaweed harvesting, particularly for commercial purposes, can lead to the depletion of seaweed resources and the degradation of seaweed ecosystems. Overharvesting can disrupt the balance of these ecosystems, reduce biodiversity, and harm the species that depend on seaweed for food and shelter.

Coastal development: Coastal development, including the construction of ports, resorts, and industrial infrastructure, often leads to the destruction or degradation of seaweed habitats. Dredging, sedimentation, and physical damage from construction activities can smother seaweed beds and reduce the availability of suitable habitat for marine species.

Conclusion

Seaweed ecosystems are vital for the health and sustainability of coastal environments. They provide essential ecosystem services, support a diverse array of marine life, and offer numerous benefits to human communities, including carbon sequestration, coastal protection, and water quality improvement. However, these important habitats are facing a range of threats, including climate change, pollution, and overharvesting. Protecting and restoring seaweed ecosystems is critical for maintaining biodiversity, mitigating climate change, and ensuring the long-term health of our oceans. Through targeted conservation efforts, sustainable resource management, and increased public awareness, we can safeguard the future of seaweed ecosystems and the many benefits they provide to both marine life and humans.

Acknowledgement

None

Conflict of Interest

None

References

1. Adavanne S, Politis A, Virtanen T, Adavanne S (2018) Direction of arrival estimation for multiple sound sources using convolutional recurrent neural network. 2018 26th European Signal Processing Conference (EUSIPCO) Piscataway IEEE 1462-1466.

Google Scholar

2. Adi, Adi K, Johnson MT, Osiejuk TS (2010) Acoustic censusing using automatic vocalization classification and identity recognition. Journal of the Acoustical Society of America 127: 874-883.

Indexed at, Google Scholar, Crossref

3. Allen, Allen AN, Harvey M, Harrell L, Jansen A, et al. (2021) A convolutional neural network for automated detection of humpback whale song in a diverse, long-term passive acoustic dataset. Frontiers in Marine Science 8: 165.

Google Scholar, Crossref

4. Arteta, Arteta C, Lempitsky V, Zisserman A, Lempitsky, et al. (2016) Counting in the wild. European Conference on Computer Vision Berlin Springer 483-498.

Google Scholar

5. Baevski, Baevski A, Zhou Y, Mohamed A, Auli M (2020) wav2vec 2.0: a framework for self-supervised learning of speech representations. Advances in Neural Information Processing Systems (NeurIPS) 33: 12449-12460.

Google Scholar

6. Mariotti A, Pan Y, Zeng N, Alessandri A (2015) Long-Term Climate Change in the Mediterranean Region in the Midst of Decadal Variability. Clim Dyn 44: 1437-1456.

Google Scholar, Crossref

7. Zeroual A, Assani A, Meddi M (2017) Combined Analysis of Temperature and Rainfall Variability as They Relate to Climate Indices in Northern Algeria over the 1972-2013 Period. Hydrol Res 48: 584-595.

Google Scholar, Crossref

8. Stocker TF, Qin D, Plattner GK, Tignor M, Allen SK, et al. (2013) AR5 Climate Change 2013: The Physical Science Basis. IPCC Cambridge UK.

Google Scholar

9. Sahnoune F, Belhamel M, Zelmat M, Kerbachi R (2013) Climate Change in Algeria: Vulnerability and Strategy of Mitigation and Adaptation. Energy Procedia 36: 1286-1294.

Google Scholar, Crossref

10. Boudalia S, Gueroui Y, Zebsa R, Arbia T, Chiheb AE, et al. (2023) Camel Livestock in the Algerian Sahara under the Context of Climate Change: Milk Properties and Livestock Production Practices. J Agric Food Res 11: 100528.

Google Scholar, Crossref