Seagrass beds represent critical and threatened coastal habitats around the world, and a new University of Florida study shows how much sunlight seagrass needs to stay healthy.
Loss of seagrass means fish, crabs and other animals lose their homes and manatees and sea turtles lose a source of food. Nutrients, such as phosphorous, may prevent seagrass from getting the sunlight it needs to thrive. Nutrients may come from many sources, among them fertilizers used in agriculture, golf courses and suburban lawns, pet waste and septic tank waste.
Scientists often use seagrass to judge coastal ecosystems’ vitality, said Chuck Jacoby, a courtesy associate professor in the Department of Soil and Water Science and co-author of a new UF study that examines light and seagrass health.
“By protecting seagrass, we protect organisms that use seagrass and other photosynthetic organisms that need less light,” said Jacoby, a faculty member in UF’s Institute of Food and Agricultural Sciences.
When nutrient levels are too high, microorganisms in the water, called phytoplankton, use these nutrients and light to grow and reproduce until they become so abundant that they block sunlight seagrass needs to survive, said Zanethia Choice, a former UF graduate student who led the investigation.
“Seagrass can cope with short-term light reductions, but if those conditions last too long or occur too frequently, seagrass will deteriorate and ultimately die,” Choice said. “Good water clarity is vital for healthy coastal systems.”
Choice studied seagrass beds in a 700,000-acre swath off the coast of Florida’s Big Bend.
Choice, now a natural resource specialist with the U.S. Forest Service in Mississippi, conducted the study as part of her master’s thesis, under the supervision of Jacoby and Tom Frazer, a professor of aquatic ecology and director of the UF School of Natural Resources and Environment.
Choice combined 13 years of light and water quality data and two years of seagrass samples from habitats near the mouths of eight rivers that empty into the Gulf of Mexico.
Seagrass off the Steinhatchee, Suwannee, Waccasassa, Withlacoochee, Crystal, Homosassa, Chassahowitzka and Weeki Wachee rivers constitutes part of the second largest seagrass bed in Florida. The largest bed is in Florida Bay, between the Everglades and the Florida Keys, Jacoby said.
Choice wanted to see how much light was needed to keep the seagrass in this region healthy. She found different seagrass species needed varying amounts of light, ranging from 8 to 27 percent of the sunlight at the water’s surface.
The UF/IFAS study will give water resource managers, such as the state Department of Environmental Protection, water-clarity targets they can use to set proper nutrient levels for water bodies, Jacoby said.
Reducing nutrient levels can promote the health of seagrass and coastal waters. For example, concerted efforts to reduce nutrients flowing into Tampa Bay over the past 20-plus years resulted in a 50 percent reduction in nitrogen, a 50 percent increase in water clarity and a return of lost seagrass, according to a study conducted by the Tampa Bay Estuary Program.
Unlike Tampa Bay, there is no evidence that elevated nutrient levels in Choice’s study area have led to loss of seagrass. UF researchers are trying to make sure nutrients do not pollute the seagrass beds off the coast of the Big Bend, and they hope their results will guide managers as they strive to prevent any damage.
The study of seagrass light requirements is published in this month’s issue of the journal Marine Pollution Bulletin.
Zanethia Choice | newswise
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy