Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nutrients that feed red tide 'under the microscope' in major study

07.11.2014

Florida red tide organism has more flexible biology than previously known -- new knowledge for mitigation and management

The "food" sources that support Florida red tides are more diverse and complex than previously realized, according to five years' worth of research on red tide and nutrients published recently as an entire special edition of the scientific journal Harmful Algae.


The rosette of Niskin bottles is submerged to collect water samples.

Credit: Mote Marine Laboratory

The multi-partner project was funded by the National Oceanic and Atmospheric Administration's ECOHAB program* (described below) and included 14 research papers from seven institutions.

The research team studied four red tide blooms caused by the harmful algae species Karenia brevis in 2001, '07, '08 and '09, plus the non-bloom year 2010. Their goal was to understand which nutrients supported these red tides and the extent to which coastal pollution might contribute, helping reveal what drives red tide in southwest Florida.

Study partners documented 12 sources of nutrients in southwest Florida waters -- including some never before associated with K. brevis. Results supported the consensus that blooms start 10-40 miles offshore, away from the direct influence of land-based nutrient pollution, but once moved inshore blooms can use both human-contributed and natural nutrients for growth.

The project documented the microbiology, physiology, ecology and physical oceanography factors affecting red tides in new detail, provided a synthesis of results and offered suggestions for resource managers addressing red tide in the coastal waters of southwest Florida.

Florida red tide blooms -- which occur naturally in the Gulf of Mexico and most frequently off southwest Florida -- are higher-than-normal concentrations of the microscopic algae species K. brevis, a plant-like organism whose toxins can kill fish and other marine species, make shellfish toxic to eat and cause respiratory irritation in humans. These blooms occurred centuries before the mid-to-late twentieth century population boom along Florida's coast. Now, with large numbers of coastal residents and visitors in Florida, blooms can significantly affect public health and the economy.

Public information and short-term forecasts help mitigate red tide impacts, but ongoing research is critical to inform resource managers working to understand and potentially reduce nutrients available to blooms.

"Data go a long way toward increasing our understanding," said Dr. Cynthia Heil, Senior Research Scientist at Bigelow Laboratory for Ocean Sciences in Maine, who co-edited the special issue of Harmful Algae and was formerly with FWC's Fish and Wildlife Research Institute. "This report, which includes data from four different red tides and numerous laboratory studies and modeling efforts by biological, chemical and physical oceanographers, shows the collaborative efforts needed to understand why Florida red tides are so frequent and harmful in this region."

Co-editor Dr. Judith O'Neil, Research Associate Professor at the University of Maryland Center for Environmental Science, added, "We learned that K. brevis is an adaptable and flexible organism. We identified 12 different sources of nutrients that it can take up and use. One of the most interesting things that hadn't previously been taken into account is this organism's ability to not just use sunlight, like plants, but to also consume other single-celled organisms as a nutrient source. Additionally, its migratory behavior and directed swimming allows K. brevis access to nutrient sources everywhere it finds them -- at the surface, bottom and throughout the water column."

According to the study, K. brevis can get the nutrients nitrogen and/or phosphorus from the following sources (bold sources were newly linked to K. brevis blooms through the ECOHAB project):

  • Undersea sediments
  • Decaying fish
  • Water flowing out of estuaries
  • Deposits from the atmosphere
  • Nitrogen from the air transformed, or "fixed," into a more useable form by the naturally occurring bacteria Trichodesmium. (They are a type of cyanobacteria, which use energy from sun to make food, like plants. They can multiply and form blooms.)
  • Waste from zooplankton -- small aquatic animals visible to the naked eye
  • The "grazing" of smaller zooplankton, dubbed "microzooplankton" because they can only be seen under a microscope. (Grazing includes their "sloppy eating" of other tiny life forms, along with the their waste.)
  • Picoplankton -- tiny life forms that K. brevis consumes
  • Bacteria transforming nitrogen in the water into more useful forms
  • Light creating available nutrients from natural, dissolved compounds like tannins in the water
  • Decay of Trichodesmium blooms (newly documented as a long-term nutrient source for K. brevis blooms)
  • Nitrogen from the air "fixed" by other cyanobacteria that are NOT Trichodesmium


The researchers concluded that many of these nutrient sources are individually more than enough to support observed blooms, but no single nutrient source is solely responsible.

Naturally occurring Trichodesmium (defined above) provided the most nitrogen, but not all, for K. brevis blooms developing offshore. Nearer to shore and within estuaries, major nitrogen sources believed to support blooms included estuary water carrying land-based nutrients to sea, underwater sediments and dead fish decomposing, in addition to other sources.

A few coastal sources -- estuary water, deposits from the atmosphere and underwater sediments -- are known to carry natural nutrients as well as some enhanced levels due to human activity. With other nutrient sources -- such as microscopic life forms -- connections with human activities are less direct, so it is harder to predict how they might be influencing red tides.

"Nature is messy, but this project has put several new pieces in place," said Dr. Kellie Dixon, Senior Scientist at Mote Marine Laboratory and Co-Principal Investigator for the ECOHAB project. "Until now we had not looked at this many of the 12 sources and their specific quantities simultaneously. Some of the sources, like nutrients released from the sediments, had never been measured in southwest Florida's coastal waters until we studied them for ECOHAB."

The project blended nutrient studies with physical oceanography, shedding new light on how blooms are brought to shore.

"Until now, effective management of harmful algal blooms caused by K. brevis was complicated because we didn't know enough about how different nutrient sources and forms taken up by K. brevis interacted with the physical environment," said Matt Garrett of the Fish and Wildlife Research Institute, who managed the ECOHAB project. "This project provides data that can help inform management recommendations on how to control nutrient sources and possibly improve forecasting models."

The special issue of Harmful Algae includes the following management recommendations:

  • Maximize efforts to reduce potentially controllable nutrient inputs and sources that contribute to K. brevis blooms.
  • Monitor for known physical conditions that favor/disfavor the initiation, transport and export of K. brevis blooms in the southwest Florida region.
  • Identify and provide necessary funding at state and federal levels to maintain the southwest Florida coastal observing system infrastructure on an operational basis.

See abstracts for all the papers at: http://www.sciencedirect.com/science/journal/15689883/38

For full text of individual papers, please ask the media contacts listed above.

This research was funded by NOAA's NCCOS Ecology and Oceanography of Harmful Algal Blooms Program (ECOHAB): Karenia program -- a five-year collaborative research project funded by NOAA's Coastal Ocean Program. The effort was led by the FWC's Fish and Wildlife Research Institute in St. Petersburg, Fla., and involved Co-Principal Investigators from the College of William and Mary's Virginia Institute of Marine Science (VIMS); Mote Marine Laboratory; University of Miami; Old Dominion University; University of Maryland Center for Environmental Science; Horn Point Laboratory; and the University of South Florida.

Darlene Crist | EurekAlert!

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>