July – August 2007
Volume 49 – 3
Local Research Institutions
Working to Restore Florida Keys Coral Reefs
Coral might be the slowest-growing crop ever farmed, but researchers say damaged reefs
could be repaired faster if they perfect methods to cultivate the marine organisms. The
Florida Aquarium, working with researchers from the University of Florida’s Tropical
Aquaculture Laboratory in Ruskin and Mote Marine Laboratory’s Summerland Key
station, is helping to make that happen.
“With the loss of naturally growing coral, it is imperative we determine the causes of its
destruction and then methods to supplement the loss with new growth, like seeding native
waters with healthy coral fragments,” said Ilze Berzins, vice president of biological
operations for the Florida Aquarium. Seven coral species were harvested from an
underwater sea wall at the U.S. naval base in Key West Harbor. Planned sea wall
construction threatened to encase or destroy existing corals. Last year, almost 160
cookie-sized coral fragments were placed at a reef near Key West where a freighter ran
aground in 1993. Fragments placed at the Key West site had been managed in one of
three ways. One set was raised in a Ruskin greenhouse, held in tanks of artificial
seawater. Another was cultured at the Mote Marine Laboratory facility at Summerland
Keys, using an outdoor system with seawater pumped from offshore. A third was placed
on the damaged reef almost immediately after harvest. Each fragment is numbered so it
can be tracked.
“If you grow coral in a greenhouse in a land-based system and put it in the wild, will it
survive?” asks Craig Watson, director of the Tropical Aquaculture Laboratory. “There
are those who say no, because it will be acclimated to those conditions where it grew and
it can’t survive elsewhere. We don’t believe that, and we are setting out to prove that
wrong.”
Source: Bay Soundings, Spring 2007.
Bay Scallops in Sarasota Bay
Earlier this spring, there were some interesting reports from local fishing guides that were
finding dime sized bay scallops in their cast nets. Just recently, a local school group
found some adult size scallops off of Emerson Point (bay scallops grow extremely
rapidly in April-June). This might prove to be the best year for scallops in local waters in
the past 30 years, since they essentially disappeared in the early 1970’s. Occasionally,
small numbers of scallops have been found in Sarasota Bay (several years ago I found
enough to provide brood stock and to conduct genetic studies). So, I am not convinced
that we are seeing anything like complete recovery of bay scallops (their abundance
widely varies from year to year), but lets hope this is a positive sign. More to come in the
next newsletter!
Drying the American Southwest
The large human population and widespread industrial and agricultural economies of the
southwestern United States and northern Mexico depend on the cheap and ready
availability of water that may be affected by changes in precipitation, evaporation,
groundwater storage, and river flow as climate warms. A broad array of climate models
agree that this region will dry substantially during the next century and that conditions as
dry as those of the Dust Bowl will become the normal ones in the region. These changes
would be caused by atmospheric circulation patterns that create a pole ward expansion of
the subtropical dry zones. This aridification should be unlike any climate state that exists
in the instrumental record.
Source: Science Magazine Vol. 316, May 2007.
Ladies Angle for Fishing Skills at “Ladies, Let’s Go Fishing!”® St. Petersburg
Seminar, Oct. 12-14, 2007
Women of all angling abilities can acquire and fine-tune fishing skills at the award
winning Ladies, Let’s Go Fishing!”® seminar! Hosted by Florida’s Fish and Wildlife
Conservation Commission (FWC) and presented by Mercury Outboards, the program
offers a full weekend of educational fishing activities on Oct. 12-14 at the Holiday Inn
Harborside, Indian Rocks Beach.
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Contact: LLGF, P.O. Box 550429, Fort Lauderdale, FL 33355, phone 954-475-9068, fax
954-474-7299, toll free information 1-888-321-LLGF (5543), email:
[email protected], website: www.ladiesletsgofishing.com.
The Upside-Down Jellyfish in Sarasota Bay
Has Anyone Seen This Organism in Tampa Bay and to the North?
Keen observers of Sarasota Bay shallow waters may have noticed that there appears to
have been a rather large increase in abundance in recent years of the Upside-Down
Jellyfish (Cassiopeia xamachana). Most folks familiar with this creature commonly
associate it with shallow, protected areas in the Florida Keys. If you have seen this
organism in Tampa Bay or to the north, please let me know.
The Upside Down jellyfish is a “weird” looking creature. Many of us are most familiar
with the medusae jellyfish form of jellyfish – nearly transparent “bell shaped” organism
gently pulsating in a weak swimming motion, often with trailing tentacles. The common
name Upside-Down Jellyfish is very descriptive. It is simply a jellyfish which has mostly
lost its swimming habit and lies upside-down on the bay bottom, exposing greenish frilly
membranes directly to sunlight. In a manner of speaking, the Upside-Down jellyfish has
become a “farmer,” the coloration in the frilly membranes is caused by the presence of
symbiotic algae within the jellyfish tissue. The algae help provide nutrition and some
think that oxygen generated by the algae helps the jellyfish survive in waters with low
levels of dissolved oxygen.
Figure 1
Biologists classify jellyfish as belonging to a major group of
animals called Cnidarians which also includes corals and sea
anemones. One of the defining characteristics of this group
of animals is that they have stinging cells called nematocysts
(Figure 1). These stinging cells can fire harpoon – like
projectiles that can contain poison to capture small prey
items for food. In most jellyfish, these stinging cells are so
small they can’t penetrate human skin. The Upside-Down
jellyfish has fairly harmless stinging cells, but if you handle
them you will most probably experience some stinging
sensation. However, some jellyfish can have a potent toxin that can cause severe pain or
even death. Although rarely seen in local waters, you definitely want to avoid the
jellyfish called the “Portuguese man-of-war” (trust me on this). If stung, splash with
water to cleanse. If you rub the wound, you could trigger more stinging cells. Pouring
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something acid on the wound will help, some soft drinks (Pepsi or Coke) red wine (I
would probably drink the wine instead) or even urine will work (source: Scientific
America). Note: using urine is not recommended or endorsed by the University of
Florida.
Jellyfish reproduction is one of those “facts can be stranger than fiction” type of stories.
Reproduction involves both sexual and asexual stages (biologists refer to this as
“alternation of generations”).
The “adult” medusa form (free swimming bell shaped form) reproduces sexually
releasing eggs and sperm into the water (Figure 2). The fertilized egg develops into a
planula larvae that hooks on to the bottom and grows into another form called the polyp.
The polyp resembles a miniature sea anemone. This stage can last a long time, perhaps
as long as years in some cases. During this stage, the polyps can reproduce asexually –
cloning or budding themselves to eventually produce yet another stage of jellyfish life,
called the ephyra. It is this form that grows into the adult medusa jellyfish.
Figure 2
Rain Sensor Rebate Available to Manatee County Customers
Residents using potable water from Manatee County Utilities who do not have a working
rain sensor on a system installed before September 1998 may be eligible for a $50 rebate
if they install an approved rain sensor. Sensors cost $30 or $100 to $125 if professionally
installed.
The rebate is funded through a new Southwest Florida Water Management District grant
administered by the Manatee County Extension Service. For an application, go to
http://manatee.ifas.ufl.edu/water.htm or call 941-722-4524.
Source: Bay Soundings, Spring 2007
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Tampa Bay Gains Seagrasses
Tampa Bay has gained nearly 1,300 acres of seagrass since 2004, and now supports more
seagrass than at any time measured since the 1950’s, according to newly released data
presented to the Tampa Bay Estuary Program (TBEP). Additionally, water clarity in the
bay is also the best it has been since record-keeping began, with all major bay segments
meeting targets.
Overall, the amount of seagrasses in Tampa Bay increased by 4.7% from 2004-2006,
according to surveys conducted by scientists with the Southwest Florida Water
Management District’s Surface Water Improvement and Management (SWIM) Program.
Seagrasses – which generally grow in waters less than six feet deep – are an important
barometer of the bay’s health because they require relatively clean water to flourish. The
results indicate that Tampa Bay has about 28,299 acres of seagrass – far less than the
Estuary Program’s goal of 38,000 acres, but the highest recorded total since the
benchmark 1950’s period adopted by the program. Water clarity also is meeting goals
for all bay segments for the first time since scientists began tracking water quality in the
1970’s.
Although the overall “report card” on the bay’s health is positive, not all bay segments
experienced seagrass expansion. Significant declines were noted in Middle Tampa Bay –
which lost 1,180 acres of seagrass from 2004-2006 – and in Hillsborough Bay, with a
loss of 151 acres of seagrass during that time frame.
Conversely, the area generally north of the Gandy Bridge, known as Old Tampa Bay,
experienced a 16% increase in seagrasses from 2004-2006 – good news for an area that
had been steadily losing seagrasses for a decade.
Source: Bay Soundings, Spring 2007.
The National Estuary Program Celebrates 20th Birthday
The National Estuary Program celebrates 20 years of community-based watershed
management in 2007.
Created by Congress through amendments to the federal Clean Water Act, the
program designated 28 “estuaries of national significance” – including Tampa Bay – and
provides annual funding to help develop and implement comprehensive management
plans to improve those waterways. The Tampa Bay Estuary Program was nominated to
the national program in 1987 and designated in 1990.
Source: Bay Soundings, Spring 2007.
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Melting Faster
Observations of the extent of Arctic sea ice in September – at the end of the melt season, when ice
coverage is at its annual minimum – have shown a large decline over the past several decades, consistent
with current qualitative understanding of natural variability and the effects of a warming climate.
Nearly all climate models predict that September Artic Sea ice extent will continue to decline through
the 21st century, largely in response to rising concentrations of atmospheric greenhouse gases. How well
do observations and models agree, though? To answer that question, Stroeve et al. compared the output
of the more than a dozen models participating in the Intergovernmental Panel on Climate Change Fourth
Assessment Report that calculated sea ice. They found that nearly all of the models overestimated
annual minimum Arctic sea ice area, in many cases by large amounts. These findings have two
important implications: first, that the effect of rising greenhouse gases may have been more important
than has been believed; and second, that future loss of Arctic sea ice may be more rapid and extensive
than predicted.
Source: Science Magazine Vol. 316, May 2007.
Sincerely,
John Stevely
Sea Grant Extension Agent
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