Summary
Algal blooms are part of our oceans and coastal ecosystems’ dynamics, however in recent years reports of increase in frequency and magnitude of these blooms have caused alarm. Macroalgal blooms are also increasing and becoming harmful to ecosystems and humans. Finding causes, consequences and ability to forecast and manage these blooms are challenging scientists, managers and policy makers. Macroalgal blooms are from species of green, red and brown divisions; some are from introduced species, others are native, or from large displacements of pelagic species. Increases in nutrient availability from continental fertilizers, industrial and residential wastes, discharged at local scale and accumulated in the oceans; as well as climate change are suggested as major causes that facilitate these massive growths. While we have strong correlations, in some cases we need experimental proofs linking nutrients to some macroalgal blooms. Our studies from South Florida and the Caribbean demonstrate that losses of seagrass beds are the immediate impact of massive influxes of macroalgae on shores and beaches; and increase in frequency and magnitude of these events results in ecosystem shifts to benthic macroalgae dominated systems. In addition, lack of basic biological knowledge of blooming species needs to be addressed. The problem is dire, and needs coordinated efforts of scientists, managers and policy makers. However, macroalgal blooms are fixing carbon and incorporating nutrients, a wise use of those blooms can become an opportunity for stakeholders and for cleaning the oceans.
Brief biography
Dra. Ligia Collado-Vides is a marine botanist working at Florida International University; her research is on tropical marine macroalgae on seagrass and reef ecosystems in South Florida and the Caribbean. Among other projects, her group is conducting a monitoring program estimating the influx and measuring metals and nutrient on of the pelagic Sargassum in Florida. Her group has developed a Citizen Science program for Sargassum landings in South Florida and the Caribbean. She is the founder and coordinator of the international discussion list-serve for Sargassum SagNet that brings together experts, managers, policy makers and public at large, she is a supporter of Sargassum Podcast. Dr. Collado-Vides is actively involved in the Sargassum development at local and regional levels. Dr. Collado-Vides got her PhD from the Universidad Nacional Autónoma de México, where she became Associated Professor; in Florida, her position is Associate Chair of the Department of Biological Sciences at FIU. She is a member of the Association of Marine Laboratories of the Caribbean, the Latin-American and Caribbean Association of Phycology, and member of the American and the International Phycological Societies. She has more than 58 scientific publication, large amount of scientific meetings participation, she devotes strong efforts to improve scientific and environmental literacy through national and international education.
References
- Rodríguez-Martínez RE, Priyadarsi DR, Torrescano-Valle N, Cabanillas-Terán N, Carrillo-Domínguez S, Collado-Vides L, García-Sánchez M, van Tussenbroek BI. 2020. Element concentrations in pelagic Sargassum along the Mexican Caribbean coast in 2018-2019. PeerJ 8:e8667
- van Tussenbroek BI, Hernández Arana HA, Rodríguez-Martínez RE, Espinoza-Avalos J, Canizales-Flores HM, González-Godoy CE, Barba-Santos MG, Vega-Zepeda A, Collado-Vides L. 2017. Severe impacts of brown tides caused by Sargassum spp. on near-shore Caribbean seagrass communities. Marine Pollution Bulletin 122: 272-281.
- Santos R, Varona G, Avila C, Lirman D, Collado-Vides L. 2019. Competition between seagrass and macroalgae determines the spatial structure of submerged aquatic vegetation seascapes: The case of the Anadyomene spp bloom in Biscayne Bay, Florida. Marine Pollution Bulletin 150:110742.
- Lapointe et al 2021 Nutrient content and stoichiometry of pelagic Sargassum reflects increasing nitrogen availability in the Atlantic Basin. Nature Comm 12:3060