Understanding, Preparing for, and Managing Harmful Algal Blooms

This semester, the SE CASC Global Change Fellows have worked to create science expert videos that communicate the state of the science of various landscape conservation challenges related to global change in the southeastern United States. Students chose a topic of interest, interviewed an expert in the field, and created an informative video and blog post to share what they learned. The following video and summary were created by SE CASC Global Change Fellow, Ámbar Torres Molinari.

The State of Harmful Algal Blooms (HABs)

Photo: Ámbar Torres Molinari

Written by: Ámbar Torres Molinari
Interviewee: Dr. Astrid Schnetzer (Associate Professor, Department of Marine, Earth and Atmospheric Sciences, NCSU)

The Plankton Ecology Lab is led by Dr. Astrid Schnetzer. Dr. Schnetzer and her students conduct research on plankton food webs including primary producers in freshwater and marine environments. The Plankton Ecology Lab has conducted research and monitoring in several regions including across North Carolina, the Gulf of Mexico, and the Arctic regions. Understanding how biological, environmental, or anthropogenic factors cause shifts in species composition and diversity of plankton is important to mitigate and predict how ecosystem productivity and resources are impacted. For instance, shifts in favor of harmful bloom-forming algae can lead to excess biomass being accumulated, and as the biomass degrades can cause oxygen depletion and fish kills. These Harmful Algal Blooms (HABs) may also be linked to the production of algal toxins which are transferred through the food chain and, when contaminated fish or shellfish are consumed, cause sickness or even death in mammals, birds, and humans. Increased nutrient discharge in coastal waterways is one of the major factors that contribute to an increase of toxic blooms in varying regions across the globe. Different HAB species also prefer their own set of growth conditions (e.g. nutrient regime, temperature) which makes their study a challenging task. Different monitoring tools have been developed from satellite imagery to locate algal blooms from space to novel on-site sampling and testing which allows researchers to determine species composition and if blooms are toxic. Long-term observations (time-series studies) and the integration of novel molecular techniques as well as collaborations with stakeholders are tools that the Plankton Ecology Lab employs to understand the ecological impacts of HABs. Currently, this includes research funded by NC Sea Grant to examine algal toxin accumulation in fish and blue crab in the Chowan River and Albemarle Sound and a grant through NC State’s Center for Human Health and the Environment (CHHE) Pilot Program. For the latter project Dr. Schnetzer and Dr. Tal Ben-Horin investigate the potential risks from the bioaccumulation of algal toxins in oysters across NC coastal waters in relationship to environmental conditions. More collaborations like these are needed to generate more multidisciplinary data that allows diverse stakeholders to better understand, prepare, and manage HABs. Generating this information by region and comparing across varying environments will be crucial to understand how natural and anthropogenic drivers (climate change) will impact aquatic ecosystem health and the ecosystem resources that coastal communities depend on.

Main Points

  • Are Harmful Algal Blooms increasing? Studies indicate HABs are increasing in intensity and magnitude in several regions across the globe.
  • There has been an increase and improvement in harmful algal bloom monitoring and testing.
  • To better predict, mitigate, and manage harmful algal blooms a variety of approaches are needed from satellite imagery to molecular tools.
  • Collaboration between stakeholders such as water quality monitoring agencies, researchers, and communities are key to the better understanding and management of harmful algal blooms.

Relevant Resources:

My gratitude goes to Dr. Astrid Schnetzer and The Plankton Ecology Lab for their continued support, as well as Dr. Tal Ben-Horin.