The Scientist November 2019

11.2019 | THE SCIENTIST 33

BOB GRANT

toward the panhandle. When the storm

passed, upwelling resumed, and strong

currents swung the red tide around the

Keys and into coastal waters of the Atlan-

tic along the state’s eastern shore.^6

Climate change and its effects on

patterns of environmental conditions—

rising sea surface temperatures increas-

ing the frequency of intense hurricanes;

changes in marine ecosystem func-

tion—add another layer of complexity.

“In the 20th century, it was a ques-

tion of looking at how are these local

changes affecting red tide,” Heil says.

In the 21st century, she continues, the

focus has shifted to how climate change

might be altering the longstanding eco-

logical cycling represented by Florida

red tides. “There are all these different,

changing dynamics.”

“Just like anything,” Hubbard adds,

“it’s not necessarily entirely predictable.”

Mitigating the eff ects of red tides

Although plenty of discoveries lie in

wait for the scientists studying the basic

biology and ecology of K. brevis and the

nature and evolution of red tide events,

funding these days is usually earmarked

for monitoring and mitigation. Heil was

the recipient of some of that episodic

funding last October, when the Andrew

and Judith Economos Charitable Foun-

dation donated $1 million to establish

the Red Tide Institute at Mote, as the

protracted K. brevis bloom churned in

the Gulf and made its way around the

state’s southern tip.

On a rainy July day at the facility this

year, Heil’s head lab technician, Amanda

Muni-Morgan, swirled several beakers

filled with greenish water—it was chock-

full of K. brevis cells. She added gramine,

an extract from the giant cane plant

(Arundo donax) that may help lyse the

phytoplankton cells, but may also help

mitigate the aftereffects. “Killing K. bre-

vis cells is not difficult,” explains Heil.

“The problem is, you release the toxin

when you kill the cells.”

Heil says she and her colleagues plan

on testing a variety of other compounds

as potential treatments to mitigate the

toxicity and longevity of red tides. Cur-

rently, researchers and public health offi-

cials have no options at their disposal for

effectively controlling blooms. Heil adds

that she’s focusing on naturally derived

compounds such as gramine, as they are

less likely than harsher, synthetic chem-

icals such as herbicides to perturb the

environment when added to seawater in

the field. This work is in its early stages,

notes FWRI’s Hubbard. “Right now, com-

ing up with solid, robust strategies for

testing those compounds is important.”

Unfortunately, funding for phyto-

plankton biologists seeking to untangle

that complexity is patchy, says Kirk-

patrick. Large and widespread blooms

like the 2017–2019 red tide attract a

lot of media and public attention, but

only happen periodically, and “episodic

events get episodic funding.”

The result, she says, is slowed sci-

entific progress on the basic biological

front. “Over the years, I’ve had people say

to my face, ‘Why don’t you know more?’”

she recalls. “It’s not for lack of wanting to

know more. It’s for lack of the funding to

do the studies to know more.” g

Bob Grant is editor in chief ofThe Scientist.

Email him at [email protected]

References

1. P.A. Tester, K.A. Steidinger, “Gymnodinium
   breve red tide blooms: Initiation, transport, and
   consequences of surface circulation,” Limnol
   Oceanogr, 42:1039–51, 1997.


2. I. Bravo, R.I. Figueroa, “Towards an ecological
   understanding of dinoflagellate cyst functions,”
   Microorganisms, 2:11–32, 2014.


3. D.M. Anderson et al., “Alexandrium fundyense
   cysts in the Gulf of Maine: long-term time series
   of abundance and distribution, and linkages to
   past and future blooms,” Deep Sea Res Part 2 Top
   Stud Oceanogr, 103:6–26, 2014.


4. C.A. Heil et al., “Blooms of Karenia brevis
   (Davis) G. Hansen & Ø. Moestrup on the West
   Florida Shelf: Nutrient sources and potential
   management strategies based on a multi-year
   regional study,” Harmful Algae, 38:127–40, 2014.


5. J.M. Lenes et al., “Iron fertilization and the
   Trichodesmium response on the West Florida
   shelf,” Limnol Oceanogr, 46:1261–77, 2001.


6. R.H. Weisberg et al., “The coastal ocean
   circulation influence on the 2018 west Florida
   shelf K. brevis red tide bloom,” JGR Oceans,
   124:2501–12, 2019.

IN SEARCH OF SOLUTIONS: Amanda Muni-

Morgan, a technician in Cynthia Heil’s Mote lab-

oratory, tests the eff ectiveness of compounds in

killing K. brevis cells and neutralizing brevetoxins.