Recommended Conferences

International Conference on Climate Change Global Warming

Berlin, Germany
Related Subjects
 

Harmful algal blooms and eutrophication: nutrient sources, composition, and consequences

Author(s): Anderson DM, Glibert PM, Burkholder JM

Abstract

Although algal blooms, including those considered toxic or harmful, can be natural phenomena, the nature of the global problem of harmful algal blooms (HABs) has expanded both in extent and its public perception over the last several decades. Of concern, especially for resource managers, is the potential relationship between HABs and the accelerated eutrophication of coastal waters from human activities. We address current insights into the relationships between HABs and eutrophication, focusing on sources of nutrients, known effects of nutrient loading and reduction, new understanding of pathways of nutrient acquisition among HAB species, and relationships between nutrients and toxic algae. Through specific, regional, and global examples of these various relationships, we offer both an assessment of the state of understanding, and the uncertainties that require future research efforts. The sources of nutrients potentially stimulating algal blooms include sewage, atmospheric deposition, groundwater flow, as well as agricultural and aquaculture runoff and discharge. On a global basis, strong correlations have been demonstrated between total phosphorus inputs and phytoplankton production in freshwaters, and between total nitrogen input and phytoplankton production in estuarine and marine waters. There are also numerous examples in geographic regions ranging from the largest and second largest U.S. mainland estuaries (Chesapeake Bay and the Albemarle-Pamlico Estuarine System), to the Inland Sea of Japan, the Black Sea, and Chinese coastal waters, where increases in nutrient loading have been linked with the development of large biomass blooms, leading to anoxia and even toxic or harmful impacts on fisheries resources, ecosystems, and human health or recreation. Many of these regions have witnessed reductions in phytoplankton biomass (as chlorophylla) or HAB incidence when nutrient controls were put in place. Shifts in species composition have often been attributed to changes in nutrient supply ratios, primarily N∶P or N∶Si. Recently this concept has been extended to include organic forms of nutrients, and an elevation in the ratio of dissolved organic carbon to dissolved organic nitrogen (DOC∶DON) has been observed during several recent blooms. The physiological strategies by which different groups of species acquire their nutrients have become better understood, and alternate modes of nutrition such as heterotrophy and mixotrophy are now recognized as common among HAB species. Despite our increased understanding of the pathways by which nutrients are delivered to ecosystems and the pathways by which they are assimilated differentially by different groups of species, the relationships between nutrient delivery and the development of blooms and their potential toxicity or harmfulness remain poorly understood. Many factors such as algal species presence/abundance, degree of flushing or water exchange, weather conditions, and presence and abundance of grazers contribute to the success of a given species at a given point in time. Similar nutrient loads do not have the same impact in different environments or in the same environment at different points in time. Eutrophication is one of several mechanisms by which harmful algae appear to be increasing in extent and duration in many locations. Although important, it is not the only explanation for blooms or toxic outbreaks. Nutrient enrichment has been strongly linked to stimulation of some harmful species, but for others it has not been an apparent contributing factor. The overall effect of nutrient over-enrichment on harmful algal species is clearly species specific.

Similar Articles

Dinoflagellates: a remarkable evolutionary experiment

Author(s): Hackett JD, Anderson DM, Erdner DL, Bhattacharya D

Dinoflagellate diversity and distribution

Author(s): Taylor FJ, Hoppenrath M, Saldarriaga JF

Gene expression in proliferating cells of the dinoflagellate Alexandrium catenella (Dinophyceae)

Author(s): Toulza E, Shin MS, Blanc G, Audic S, Laabir M, et al.

Review of the main ecological features affecting benthic dinoflagellate blooms

Author(s): Fraga S, Rodríguez F, Bravo I, Zapata M, Marañón E

Genome evolution of a tertiary dinoflagellate plastid

Author(s): Gabrielsen TM, Minge MA, Espelund M, Tooming-Klunderud A, Patil V, et al.

Cell biology of cnidarian-dinoflagellate symbiosis

Author(s): Davy SK, Allemand D, Weis VM

Interactions between corals and their symbiotic algae

Author(s): Muller-Parker G, D’Elia CF, Cook CB

Symbiodinium transcriptomes: genome insights into the dinoflagellate symbionts of reef-building corals

Author(s): Bayer T, Aranda M, Sunagawa S, Yum LK, DeSalvo MK, et al.

A review on the effects of environmental conditions on growth and toxin production of Ostreopsis ovata

Author(s): Pistocchi R, Pezzolesi L, Guerrini F, Vanucci S, Dell’Aversano C, et al.

Harmful algal blooms and eutrophication: examining linkages from selected coastal regions of the United States

Author(s): Anderson DM, Burkholder JM, Cochlan WP, Glibert PM, Gobler, et al.

Putting the N in dinoflagellates

Author(s): Dagenais-Bellefeuille S, Morse D

Dinoflagellate bloom of Karenia mikimotoi along the Southeast Arabian Sea, bordering western India

Author(s): Robin RS, Kanuri VV, Muduli PR, Mishra RK, Jaikumar M, et al.

The mesozoic radiation of eukaryotic algae: the portable plastid hypothesis

Author(s): Grzebyk D, Schofield O, Vetriani C, Falkowski PG

Problems associated with shellfish farming

Author(s): Chinabut S, Somsiri T, Limsuwan C, Lewis S

Ballast water: a review of the impact on the world public health

Author(s): Takahashi CK, Lourenco NGGS, Lopes TF, Rall VLM, Lopes CAM

The globally distributed genus Alexandrium: multifaceted roles in marine ecosystems and impacts on human health

Author(s): Anderson DM, Alpermann TJ, Cembella AD, Collos Y, Masseret E, et al.

Neurotoxic shellfish poisoning

Author(s): Watkins SM, Reich A, Fleming LE, Hammond R

Global distribution of ciguatera causing dinoflagellates in the genus Gambierdiscus

Author(s): Litaker RW, Vandersea MW, Faust MA, Kibler SR, Nau AW, et al.

Evolution of saxitoxin synthesis in cyanobacteria and dinoflagellates

Author(s): Hackett JD, Wisecaver JH, Brosnahan ML, Kulis DM, Anderson DM, et al.

Ecology and oceanography of harmful marine microalgae (Project-2)

Author(s): Fukuyo Y, Kodama M, Omura T, Furuya K, Furio EF, et al.

Marine toxins: Chemistry, toxicity, occurrence and detection, with special reference to the Dutch situation

Author(s): Gerssen A, Pol-Hofstad, IE, Poelman M, Mulder PP, Van den T, et al.