Whale Sharks

Mote Marine tracks Whale Sharks

In mid-June, Sarasota’s Mote Marine Laboratory got word that boaters were watching whale sharks on the surface just 20 miles west of Manatee and Sarasota Counties. That’s fairly close to the Gulf shoreline for this species, the largest of all sharks with some as large as 40 feet. The polka-dotted whale shark doesn’t eat other fish (or humans). It’s a wide-mouth filter feeder that survives mostly on plankton and fish eggs.

Mote researchers grabbed their gear and sped off in a 42-foot Yellowfin powered by three 400-horsepower Mercury Verado outboards. The team located five whale sharks from 20 to 40 miles offshore and took underwater and above-surface photos and videos to record each sighting. Furthermore, they were able to get close enough to tag two of the sharks with real-time tracking devices. In about six months, the implants will self-release and float to the surface. Mote specialists then will be able to remotely download timelines of water depths and temperatures.

One of the tagged whale sharks was about 25-feet in length and nicknamed Minnie. Yes, as in Minnie Mouse. This was a salute to the Walt Disney Company for its financial support of the implant project. Another, about 16 feet, is nicknamed Colt for Colt Nagler who assisted the team. His father, Captain Wylie Nagler, owner of Yellowfin Yachts, supplied and captained the fast, spacious vessel that helped make the expedition successful.

By Bill AuCoin Southern Boating August 2018

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Hurricane Lessons Learned

The 2017 hurricane season brought larger and more frequent storms that caused significantly more damage than anyone thought possible. It also brought some hurricane lessons.

The latter days of summer still bring warm temperatures and typically good weather to enjoy being near, on or in the water. But they can also bring great storms in the form of hurricanes. In fact, although the official hurricane season is from June 1st to November 30th, the peak of the season is from mid-August to mid-September, when ocean temperatures are at their highest—fuel for hurricane development. What can we learn from the hurricane lessons of 2017?

What’s in a name?

A hurricane is a type of tropical cyclone, i.e., a low-pressure area that only forms over warm water. It contains bands of showers and thunderstorms that rotate counterclockwise around a center (the eye) and extend outward for as much as several hundred miles.

Actually, the term “hurricane” indicates the strength of the storm. Hurricanes have sustained winds greater than 73 mph. Systems with winds between 39 and 73 mph are classified as tropical storms, and those with winds less than 39 mph are called tropical depressions. Hurricanes themselves are also ranked in terms of strength according to the Saffir-Simpson Scale—categories of one at the low end to five at the high end with sustained winds exceeding 156 mph. (Gusts can approach 200 mph.)

The greatest threat to ships at sea comes from the strong winds and the high waves they can generate. Stronger and larger storms will produce the highest waves. In fact, measured waves have exceeded 50 feet and, theoretically, a rogue wave in that environment could exceed 100 feet. In those conditions, a boat can easily capsize and sink, and keep in mind that rescue efforts are nearly impossible.

Skip the beach

For beachgoers, even if the storm is far off, swells can make for dangerous surf conditions. As the storm nears, waves become higher and more frequent, and strong rip currents can be expected. Along the coast, the greatest threat comes from the strong winds and, especially, storm-induced high tides. “Storm surge” is an inland rush of water caused by strong onshore winds. High waves on top of this surge can literally smash structures. Storm surge is highest with stronger and larger storms and maximum where the center crosses the coast. Hurricane Katrina produced a storm surge of nearly 28 feet at Pass Christian on the Mississippi Gulf coast, and the surge pushed inland at least six miles.

Even boats at a dock face risks. The risk magnifies with the strength of the storm and the proximity of the eye. Strong winds and high waves can batter a boat against the dock itself, and restraining ropes can break under great stress. A significant storm surge can drive a vessel far inland and as the storm moves by, the wind direction will change by as much as 180 degrees. A more sheltered, inland port is a better alternative.

As you move away from the immediate coast, wind can still do damage. In particular, trees are broken or uprooted, which can take out power lines. That was the case in Puerto Rico with Hurricane Maria. In addition, there is also a significant concern with the heavy rain that can produce inland flooding. Hurricane Harvey, for example, dumped over 60 inches of rain in the Houston, Texas, area last September causing the catastrophic flooding there. If this wasn’t enough, tropical cyclones, when they start affecting land, can generate tornadoes and are most likely to occur in the right front quadrant of the storm. Hurricane Harvey produced 57 tornadoes.

Be in the Know

There is only one official source of hurricane information: The National Hurricane Center (NHC) in Miami, Florida. Media outlets and even private weather companies get their information from the NHC. The Center will send out storm bulletins every six hours or every three hours if the storm is endangering land. The Tropical Cyclone Public Advisory gives a plain language account of the storm, including current strength and location and forecasts for future strength and movement out to five days. This information is also provided in map form. The Forecast Advisory adds marine information for areas predicted to be in the path of 64-, 50-, and 34-knot winds and 12-foot seas.

The NHC will issue specific watches or warnings as needed. Watches mean dangerous conditions are possible within 48 hours and to take necessary precautions. Warnings mean a more definite and immediate threat (within 36 hours); seek shelter or evacuate if ordered. Besides tropical storm or hurricane watches and warnings, a storm surge watch or warning is for “life-threatening inundation from rising water,” and an extreme wind warning is for winds in excess of 114 mph. All of this information is also provided by local National Weather Service (NWS) offices. For marine interests, consult the marine forecasts issued by the NWS.

Flagged as Dangerous

There is a more traditional warning system used at select small boat stations along the coast: the U.S. Coast Guard’s warning display flags. Tropical storm warnings are indicated by a single red flag with a black rectangle in the middle. Hurricane warnings are represented by two of those flags. For more information on Marine Safety during hurricane season, go to nhc.noaa.gov/prepare/marine.php

By Ed Brotak Southern Boating August 2018

Waterspouts: spectacular but dangerous

What do you know about waterspouts?

A mesmerizing vortex that spins down from a cloud to the surface of the ocean is one description of a waterspout. A starker definition is that it’s a tornado over water. Waterspouts may beguile you with their ephemeral beauty, but they pose a serious hazard for boats and a threat to anyone in their path if they come ashore. From a scientific viewpoint, there are differences between tornadoes and waterspouts. Waterspouts can be broken down into two categories: the weaker and more common fair weather waterspouts, and the much stronger, but far less common, tornadic waterspouts.

Fair weather waterspouts

Fair weather waterspouts can occur without a “parent” thunderstorm. They can develop underneath tall cumulus clouds that are very common in the warmer months. Usually, they are relatively small, typically a few hundred feet across or less with average wind speeds near 50 miles per hour. They may only last a few minutes, but the largest ones can go on for an hour. They also often move slowly or are stationary for a time.

The first indication of a circulation is a dark spot on the water surface. This is a low-level circulation that will develop vertically under the updraft of a growing cumulus cloud. The upper part of the funnel will become visible when water droplets condense as the vortex further develops (it isn’t water droplets being sucked up from below). This visible funnel may or may not reach all the way down to the ocean surface and even if it doesn’t, one should assume a surface circulation exists.

Waterspouts can occur virtually anywhere. They are not uncommon over the Great Lakes. They even occur over the offshore waters of Alaska. Spouts can occur anywhere along the Atlantic and Gulf coasts, especially in the summer. A number of research projects have indicated that the area surrounding the Florida Keys has the highest concentration of waterspouts in the world. During the southern rainy season, typically from late May into September, hundreds can occur. Even though these waterspouts are weaker, they can certainly damage a boat and, if they come ashore, can cause damage to property and injuries to beachgoers. Fortunately, fair weather waterspouts almost always dissipate quickly over land.

Tornadic waterspouts

Like tornadoes, tornadic waterspouts are produced by severe thunderstorms. These can be vortices that form over land and then move over water, or they can develop from strong thunderstorms over water, typically near the coast. They tend to be more common in the spring, but can occur at other times. These waterspouts are much more akin to their overland counterparts. Very strong winds with speeds of more than 100 miles per hour are certainly possible, and the waves they can generate could capsize even larger vessels.

If they move over land, damage can be extreme and even fatalities can occur. A recent example occurred this past April when a tornadic waterspout moved over Okaloosa Island, across Santa Rosa Sound and into Fort Walton Beach, Florida. With estimated winds between 100-105 miles per hour, the storm tore the roof off a home on Okaloosa Island injuring two people and damaged parts of Fort Walton Beach.

The conditions that form the two different types vary considerably. Tornadic waterspouts (and tornadic thunderstorms in general) develop in a very unstable atmosphere with significant temperature changes through its height. Ambient winds tend to be strong and change with height (causing wind shear). Often synoptic scale systems, such as fronts or low-pressure areas, are involved. Fair weather spouts develop in a more benign atmospheric environment with weaker winds and a consistently warm and moist atmosphere. Typically, there are no larger scale weather systems associated with their occurrence; however, smaller scale features or boundaries where winds change direction (land breeze fronts, outflow boundaries from previous convection) are often involved. Typically, a line of developing cumulus clouds rather than single clouds is noted. If conditions are ripe for fair weather waterspout development, they will often occur on successive days.

What to Do

Before you head out, check the latest National Weather Service (NWS) forecasts for the beach and offshore waters. If waterspout occurrence is possible, it will be highlighted. Tornadic waterspouts are somewhat easier to forecast because the atmospheric situation is more pronounced. Fair weather waterspouts are more difficult to anticipate, although meteorologists in places like Key West have developed forecasting schemes that help. When you are out on the water, continue to monitor weather sources for changes in the forecast. If a waterspout is seen or detected by Doppler radar (and many can’t be detected by radar), the NWS will issue a Special Marine Warning.

The same is true when severe thunderstorms are over water. Then the warning would read “Severe thunderstorms capable of producing waterspouts.” Frequently check sky conditions for cumulus cloud development. If you see a waterspout, head at a 90-degree angle away from its apparent motion. Never try to navigate through a waterspout. If caught in one, make sure that all on board are in secure locations and wearing life jackets. Additionally, if a waterspout comes ashore (and officially becomes a tornado), the NWS will issue a Severe Weather Statement. A Tornado Warning will be issued if a waterspout comes ashore.

WATERSPOUT RESOURCES

NOAA Waterspout Video: oceantoday.noaa.gov/waterspouts

NWS Miami’s “About Waterspouts”: weather.gov/mfl/waterspouts

NWS Miami’s “South Florida Waterspout Forecasting”: weather.gov/mfl/waterspout_fcsting

By Ed Brotak, Southern Boating July 2018

Photos: SHUTTERSTOCK © ELLEPISTOCK,© NOAA/MELODY OVARD, NOAA/TIM OSBORN

Want more? Check out our Sea Watch archive.

Lionfish: Eat ’em to Beat ’em

Lionfish don’t belong here.

Their natural domain is in the South Pacific and Indian Oceans. There, they are a normal and healthy part of reef ecosystems. Here in the US? Not the case.

Learn more about the 2019 Lionfish Challenge.

About 30 years ago, the (admittedly beautiful) red-and-white striped lionfish began appearing off the coast of Florida. They’ve expanded quickly since, demolishing native fish populations in the Caribbean and up the Eastern Seaboard.

The pesky species can and will eat anything: their appetites are voracious and unending. Unfortunately, native species of small reef fish like baby snapper and grouper don’t recognize them as predators. That makes bad things happen to the ecosystem.

In the Bahamas, the bait fish (or prey fish) biomass fell between 65 to 95 percent after the initial invasion. That’s according to Stephanie Green, a marine scientist at Stanford’s Center for Ocean Solutions.

And the big predators, like sharks, don’t see the fish as a meal. Their venomous spines have allowed them to spread rampantly. So, it’s the perfect storm: lionfish spread, unchecked, devastating reef ecosystems and fisheries.

Unchecked may even be an understatement. The fish are prolific breeders, putting even rabbits to shame. A single female can release upward of 6 million eggs a year. Those millions of eggs are capable of floating for more than a month, dispersing for thousands of miles, spreading into new areas. They’re everywhere: lionfish can be found in shallow mangroves or 1000 feet deep, which is why populations are hard to wipe out once established.

Eat ’em to Beat ’em

That’s not to say that efforts are not underway. With nets and spears, divers and scientists are taking to the water to turn the hunters into the hunted. There are lionfish hunts from North Carolina to the Caribbean and beyond. Organizations like REEF and agencies like Florida Fish and Wildlife provide resources and information on hunts, biology and more.

There is some good news though. Lionfish are delicious. There’s even a “Eat ’em to beat ’em” campaign among conservationists, biologists, hunters, and chefs. Comparable to any other flaky white fish, the species can be baked, fried, ceviche-d, and more. Whole Foods is developing its own product lines, too, like smoked lionfish. There are a million ways to prepare it.

Here’s one way we like:

Lionfish Nachos

from The Lionfish Cookbook by Tricia Ferguson and Lad Akins

Ingredients:

8 wonton wrappers
1/2 cup oil
8 lionfish fillets
3 tablespoons soy sauce
2 tablespoons Thai chili sauce
1 cup seaweed salad*
1/4 cup wasabi mayonnaise

*Items can be found at Asian markets.

Directions:

Place oil in a small frying pan and heat oil until hot. Place one wonton wrapper in at a time. Cook briefly until it starts to bubble (approximately 10 seconds). Turn and cook another 10 seconds. Remove and drain on kitchen towel.

Put wasabi mayonnaise into a squeeze bottle and set aside. Combine sweet soy sauce, sweet chili sauce together in a bowl and set aside. Spray skillet with non-stick cooking spray.

Cook lionfish fillets in a skillet over medium-high heat for 2 to 3 minutes, until flaky and tender. Cut or flake lionfish so it is in small pieces. Toss lionfish in soy sauce mixture.

Place lionfish on wonton wrappers, top with seaweed salad and drizzle with wasabi mayonnaise.

By Erin Brennan

Rip Currents

Rip Currents: Life or Death

If you’ve heard warnings of possible rip currents, take them seriously!

Last year in the United States, 62 people perished due to rip currents. That’s more deaths than caused by hurricanes, tornadoes or lightning. Furthermore, tens of thousands of people require rescue by lifeguards from these extremely dangerous situations each year. In fact, 80 percent of rescues performed by lifeguards are in rip current events according to the U.S. Lifesaving Association.

What causes a rip current?

When waves continuously come ashore along a beach, circulations are created in the water. Some of the water will move parallel to the coastline, and some of it will move back out to sea in a return flow. In calmer conditions, this return flow is fairly weak and inconsequential, but if waves are higher and the period between waves decreases (typically, but not always, related to a stronger onshore wind), this return flow can become concentrated like a jet stream in the atmosphere and produce a rip current.

Why they’re dangerous

Rip currents are more common where there is an obstruction to the water flow along the shore such as a pier, jetty, groin, or reef. One of the worst situations occurs when there is a sandbar just off and parallel to the shoreline, which will block the return flow of water. If a breach or break occurs in the sandbar, returning water channels through it, accelerating as it goes.

Rip current speeds are typically in the 1 to 2 feet-per-second range (.7 to 1.4 mph) but have been measured as fast as 8 feet per second (5.5 mph)—faster than Olympic swimmers. Rip currents vary in width from as narrow as 10 to 20 feet to several hundred feet across. They will extend out from the beach past where the waves are breaking, anywhere from a few hundred to a few thousand feet where they will dissipate. Rip currents can and do occur on any beach where there are breaking waves, even along the shores of the Great Lakes.

The summer months see the most rip current incidents because of increased beach usage and the significant majority of victims are young men. With miles of inviting beaches and temperatures that promote outdoor activities much of the year, Florida leads the country in rip current fatalities with an average of nearly 20 drownings per year. The states of North Carolina and Texas follow. Puerto Rico also had 11 victims in 2017, according to statistics from the National Weather Service (NWS). The NWS acknowledges that rip current fatalities may be underestimated.

Check before diving in

If you’re cruising in the U.S., check the rip current status in your area via the NWS, which includes a beach forecast on weather.gov as well as surf forecasts on ripcurrents.noaa.gov/forecasts.shtml. Local media outlets also typically carry beach forecasts and include the rip current risk forecast. Rip current forecasts are shown as Low (unlikely), Moderate (possible), or High (Life-threatening rip currents likely). Going to a beach area with lifeguards present offers the most protection; check with them to learn if rip currents are occurring or expected.

When visiting beaches without lifeguards, take extra time to assess for rip currents. For example, anything floating, such as seaweed or debris is moving quickly out to sea. That is an indicator that rip currents may be present. Another indicator is an area where the water color is decidedly different from its surroundings, such as a break in a sandbar, a break in the incoming waves or a noticeable channel where the water is churning or choppy. Unfortunately, these indicators may not be readily apparent from the beach or water level. Dangerous rip currents can go undetected by a swimmer, especially when they’re not looking for them.

What to do

If you are caught in a rip current, don’t panic. The danger of rip currents is not that they will pull you under, which is what undertow does. Rip currents will pull non-swimmers and weak swimmers out to sea and into deeper water where they will tire quickly. Even strong swimmers will be in danger if they try to swim against the flow. The key is to swim parallel to the shoreline. Rip currents aren’t that wide, and even if you are swept out beyond the breakers, rip currents don’t extend much further. A caught swimmer will eventually break free as long as they remain calm and just float or tread water while calling for help. (This is one reason to swim where a lifeguard is on duty.)

If you see someone in trouble, get help from a lifeguard. When possible, get a flotation device to the person. If nothing else, try talking to them to calm them down while giving instructions for reaching safety. Never attempt to rescue someone unless properly trained. Numerous people have drowned while attempting to save someone else. Most of all, remain calm and swim on.

By Ed Brotak, Southern Boating June 2018

The Delicacy Dilemma: Stone Crabs and Ocean Acidification

Stone crabs may face challenges from ocean acidification.

The first study on Florida stone crabs and ocean acidification was published this month by a Mote Marine Laboratory scientist and offers clues for relieving environmental stress on these tasty and economically valuable crabs. The study in the peer-reviewed Journal of Marine Biology ad Ecology provides the first evidence the stone crab embryos develop more slowly and fewer eggs hatch to larvae (babies) in controlled laboratory systems mimicking ocean acidification.

Ocean Acidification (OA) is a chemically induced decrease in ocean water pH at global to local levels that is being driven by increased levels of carbon dioxide in the atmosphere. The impact of OA on marine and estuarine species and habitats is worsened when combined with the impacts of nutrient-rich coastal runoff, sewage water inputs and loss of wetlands due to coastal development. Some coastal habitats in Florida are experiencing seasonal declines in pH three times faster than the rate of OA anticipated for global oceans by the end of the century.

Stone Crabs

Most stone crab fishing occurs in coastal habitats susceptible to Ocean Acidification along with other potential stressors, including reduced oxygen levels and harmful algal blooms. The stone crab industry centered along West Florida was valued in 2015 at $36.7 million, but since 2000, the average annual commercial harvest has declined by about 25 percent.

Mote scientists are studying stone crabs under various environmental conditions, starting with acidified water, to help resource managers sustain this critical fishery. “By identifying stone crabs’ susceptibility to ocean acidification throughout their embryonic and larval development, we can better understand whether the species will be able to tolerate and eventually adapt to the levels of ocean acidification projected for our coastal oceans in the future,” says Mote Postdoctoral Research Fellow Dr. Philip Gravinese, who authored the new paper to disseminate his doctoral research, which was conducted through the Florida Institute of Technology in 2012 at Mote’s campus on Summerland Key, Florida.

Tracking the Crabs

“Stone crabs brood their eggs in coastal habitats [where] their larvae hatch and develop into juvenile crabs—essential steps toward producing the next generation of adult crabs whose claws will be harvested. These early life stages are sometimes more sensitive to changing environmental conditions.”

Gravinese conducted the first-ever laboratory study on Ocean Acidification and stone crabs with funding support from the Protect Our Reefs license plate grant program administered by Mote ND the Department of Biological Sciences at Florida Institute of Technology.

With assistance from the Florida Fish and Wildlife Conservation Commission, Gravinese obtained 16 egg-bearing stone crabs from commercial traps within 10.5 miles of Florida’s coast. He used only females carrying orange eggs—rich in yolk not yet consumed by the early-stage embryo. He placed eight crabs into tanks with acidified seawater mimicking pH conditions forecasted by some models for the ocean’s future and eight into tanks with present-day pH seawater.

What happened?

Each day, Gravinese sampled 20 eggs from each female’s brood which contain hundreds of thousands of eggs. He determined each embryo’s stage of development by examining the eggs’ yolk content, eyespot size, and egg volume. Gravinese also examined about 100 larvae from each brood to document how many hatched successfully, and he sampled 20 hatched larvae per brood to document any deformities using digital photos magnified 25 times.

Throughout the experiment, Mote scientists monitored and tested the water temperature and chemistry features to maintain stable, controlled conditions in the Ocean Acidification Flow-Thru Experimental Raceway Units at Mote’s Summerland Key campus.

The results revealed that young stone crabs may struggle as the oceans acidify. “The stone crabs’ embryonic development slowed by 24 percent and hatching success decreased by 28 percent with exposure to lower pH in this study,” says Gravinese. “This could represent a reduction in the supply of larvae (baby stone crabs) and a potential bottleneck for new recruits into the fishery.”

Larvae from both study groups appeared normal in size and shape, but it remains to be seen whether longer exposure to low pH water would cause changes over time.

While broods in acidified water had fewer eggs hatch on average, their hatch success varied more widely than that of broods in the present-day pH water.

“The fact that some individual females’ broods showed variability could suggest that there’s a genetic component that may help some crabs be more tolerant than others of ocean acidification,” suggests Gravinese.

The question remains, could OA relate to Florida’s long-term decline in stone crab catches?

“It’s hard to say because no one has correlated pH in larval habitats with their abundance,” says Gravinese, noting an option for future research. “We do know coastal areas are changing, some with pH dropping significantly, but there are also other environmental changes that may be playing a role, including hypoxia, or low oxygen levels, elevated seawater temperature, and Florida red tide.”

This year, Gravinese expects to publish the first-ever research investigating how Florida red tide algae (Karenia brevis) affects sub-legal-size stone crabs, which represent the next generation of individuals to enter the fishery. He also expects to publish expanded doctoral research on how acidification and increased water temperature jointly and independently affect stone crab larvae.

At Mote’s City Island research campus in Sarasota, Florida, Gravinese’s recent lab studies have involved monitoring female crabs throughout their entire process of producing and fertilizing eggs in acidified water to check for “generational carry-over effects” (from mother to larvae) on larval development, hatching success and larval survival. This study could identify a potentially greater resilience to future acidification. Gravinese and colleagues have also been examining juvenile crabs’ ability to forage for food under low oxygen and elevated temperature scenarios.

In late 2017 to early 2018, a number of Florida’s commercial fishers anecdotally reported fewer stone crabs in their traps. The specific reasons remain unclear, as stone crabs not only face mounting threats, but harvests naturally vary from year to year, and it’s challenging to gauge the impacts of storms, cold fronts, octopus predation and other environmental variables. “The fishery has good and bad years, in what appears to be a repeating pattern, but the overall trend in the annual harvest seems to be negative,” Gravinese says.

However, he notes that research on different life-history stages may allow for better strategies to reduce pressure on stone crabs. For example, communities can strengthen efforts to reduce nutrient-rich runoff and sewage water inputs that will likely exacerbate ocean acidification.

Tips to Reduce Runoff:

In your landscape, use native and Florida-friendly plants and porous surfaces: mulch, shell, brick pavers and others that allow water to sink into soil, reducing runoff.

Pick up pet waste and dispose of it with your trash. Dispose of hazardous substances at County-approved sites and do not pour pollutants down storm drains.

Follow laws and ordinances on fertilizer use in your area.

For more information on Ocean Acidification? See our article on OA and coral disease.

By Hayley Rutger, Mote Marine Laboratory & Aquarium

Photo courtesy of Hayley Rutger, Mote Marine Laboratory & Aquarium

Beware of Thunderstorms

Thunderstorms can be dangerous. Here’s what you need to know to reduce your risk.

Although thunderstorms can occur any time of the year, as the weather gets warmer and more humid, they peak in activity. The South is a hotbed for thunderstorms, and while most locations record more than 50 storms a year, some areas of Southwest Florida get over 100.

As one of nature’s most potent hazards, the threats from thunderstorms are multiple. A lightning strike, even an indirect hit, can kill or seriously injure a person, destroy the
electronics on a boat or, even worse, start a fire. Winds can shift 180 degrees in seconds, and wind speeds can top 50 knots. The combination of strong winds and the waves they
generate can capsize large vessels.

Thunderstorm types

There are a number of thunderstorm types, but for our purposes here, we’ll touch on forced and non-forced convection storms. Forced convection storms occur particularly in the fall and spring and are associated with pronounced weather systems, such as cold fronts or low-pressure areas. They can even happen during winter in more southern locations. The storms themselves tend to be stronger especially in terms of wind and often evolve into squall lines that make them difficult to navigate. They can form any time of day and move very quickly over the ground, sometimes more than 50 knots. Squall
lines are groups of storms and are often accompanied by high wind and heavy rain.

The non-forced, typical “pop-up” thunderstorms of summer (also known as air-mass thunderstorms) develop over land during the heat of the afternoon and early evening. They often form along the sea breeze front as it pushes inland during the day. Although not typically strong, summer thunderstorms in the south tend to be prodigious lightning producers. Only moderately gusty winds are expected with a pop-up storm, but when severe, known as a pulse storm, winds can develop in excess of 50 knots.

At night, the land cools off and storms over land tend to dissipate, but the water remains warm, and an offshore flowing land breeze can develop. Storms that have moved over the water can maintain themselves, and even new storms can develop over the warm waters into the morning. Generally speaking, thunderstorms over water are weaker than those
over land, but that doesn’t mean they can’t produce hazardous conditions. Storms moving off the land over the water would pose the greatest risk to mariners.

Prepare and beware

This may seem like common sense to experienced boaters, but before you head out on your boat, check the forecast. Be sure to also check the most current weather radar image. This is the best way to tell if thunderstorms have already developed and may be a
threat. Tracking the storms for a time will indicate the direction and speed of
movement.

Newer displays even depict individual lightning strikes utilizing either land or satellite-based sensors. If there is a significant thunderstorm threat, cancel your trip or at least postpone it until conditions improve.

Once you’re on your way, continue to monitor the weather as you go. As mentioned, thunderstorms can develop and move quickly. If you have onboard radar, check it, and as the saying goes, “Keep an eye on the sky.”

Cumulus clouds developing vertically can quickly build into thunderstorms. In any case, you should always have an escape route planned in case the conditions deteriorate.
If you are caught in a storm, stay inside your cabin if you have one. If not, stay as low as you can in the boat. Keep away from metal objects and electronics (unless you unplugged
them). Keep in mind that threats from a thunderstorm aren’t limited to just under the main cloud and rain area.

Watch the water surface. Microbursts are blasts of strong winds that can propagate outward from the parent storm. Wind speeds can exceed 80 knots and may be responsible for the infamous “white squalls.”

Lightning from the top of the cloud, known as “positive giants,” can strike miles from the cloud itself. Consider having a lightning protection system for your boat.

Official National Weather Service Thunderstorm Warnings

Severe Thunderstorm: A storm that produces a tornado, winds of at least 50 knots or hail at least one-inch in diameter.
Severe Thunderstorm Watch: Conditions are favorable for severe thunderstorm occurrence within a 2 to 8-hour period as given.
Severe Thunderstorm Warning: An event is occurring or imminent.
Special Marine Warning (SMW): Thunderstorms are detected over water or will be shortly moving over water. Winds greater than 33 knots could be expected with the storms.
An SMW could also be issued for 3/4-inch hail or waterspouts which may not accompany full-blown thunderstorms. Such warnings would activate the Tone Alert feature on NOAA Weather Radio and would also be issued by the Coast Guard and appropriate commercial radio stations.
There are no specific NWS warnings for lightning. If thunderstorms are mentioned in a forecast or actual report, the potential for cloud-to-ground lightning is always inferred.

nws.noaa.gov/om/marine/home.htm

By Ed Brotak, Southern Boating April 2018

PHOTO: © ANEESE; ADOBE STOCK, ILLUSTRATION: © ADOBE STOCK/PATTARAWIT

Underwater Sound

Humans can’t hear underwater sound in the same way that whales or other creatures can.

Sound is an integral part of the undersea world. In fact, sound travels very well through water and much faster than through air. Furthermore, due to the thermal structure of the ocean, there are sound channels, or zones, where sound waves can propagate for long distances—hundreds and even thousands of miles—without losing much amplitude.

Humans can hear underwater sound but not very well because our ears and hearing system were designed to detect sound traveling through the air, whereas fish have inner ears and are better for detecting sound transmission through water. Fish also have the lateral line system on the outside of their bodies that can detect sound vibrations.

Cetaceans—aquatic mammals including whales, dolphins, and porpoises—also have evolved to hear underwater sound well, and they’ve developed the ability to make sounds to communicate with each other. Humpback whales, especially, are famous for their “songs.” Some toothed whales even have developed their own form of sonar, which they use to bounce sound waves off objects to determine the nature of the object and its distance. Scientists believe that echolocation—the biologically correct term—is critical for these ocean residents to perceive their 3D environment and travel through it.

Why is sound so critical to marine creatures? Because light and visibility issues often hamper sight, and olfactory signals are diluted and dispersed by water, sound is important to locate food, avoid predators, navigate the undersea world, and is the primary means of communication with their species.

Since the oceans formed and life flourished in them, marine creatures evolved to utilize sound. Marine life does not recognize the “foreign” sounds that man makes underwater
and often shies away from them if possible, including sounds as seemingly harmless as the bubbles that come out of scuba air tanks. Of much greater concern are the louder and more omnipresent man-made sounds that contribute to underwater noise pollution.

There are a number of major sources of man-made noise in the oceans, including the use of sonar. The Navy uses very powerful audio signals, and the sound can travel for hundreds of miles. Another major source of noise is the sound from ships, whose turning propellers, engines and ship systems emanate through and from the hull. In recent years, geological surveying to discover underwater oil and gas deposits has led to another significant source of noise. Prospecting operations use sound waves generated by blasts from seismic airguns to reveal geologic features underneath. These blasts can come out every 10 seconds, and the whole process can continue for weeks or months. The sound is estimated to be orders of magnitude greater than ship noise. The initial boom will morph into a more continuous roar as it traverses the ocean, and the sound can travel hundreds of miles.

Underwater sound can drive the ocean’s inhabitants away from natural locations and affect feeding and reproduction. It can interfere with communications between individuals
or individuals with a group, and it has been speculated that sonar signals have caused some whale beaching incidents.

To address the issue of noise pollution in the ocean, the National Oceanic and Atmospheric Agency (NOAA) started a two-phase program in 2010 concentrating on cetaceans. Phase One involved defining the problem. One component consisted of mapping marine mammal locations, including variations over time. Of primary concern were “Biologically Important Areas,” where cetaceans reproduce, feed and migrate on a regular basis. The other component involved mapping of sonic danger zones. In 2014, NOAA deployed 10 undersea listening stations to measure ambient noise levels and to determine trends. Man-made sound levels were categorized by location, time, intensity, and source— commercial and passenger ships (chronic noise) and seismic surveys (noise events).

Phase Two of the program addresses mitigation of the noise problem over the next decade. For example, voluntary guidelines for commercial shipping to reduce underwater noise have been laid out, and now ships are being built that are 1,000 times quieter. Also, seismic vibrators like the ones used on land are being developed for underwater use to send out low-frequency vibrations rather than explosive shock waves resulting in a less obtrusive sound.

A variety of environmental groups, such as the Natural Resources Defense Council and Ocean Conservation Research in the U.S. and the International Ocean Noise Coalition, a
group of more than 150 non-government organizations from around the world, have taken legal actions against noise polluters. In fact, in 2013 the Marine Mammal Protection Act was successfully used to combat the U.S. Navy’s use of sonar in the Pacific.

By Ed Brotak, March 2018

photos from Wikipedia and Adobe

The Tsunami Threat

Due to its sheer magnitude and velocity, the tsunami is one of the most destructive forces in nature. From the Japanese words for “harbor wave”, tsunamis are actually a series of waves whose crests can be tens or even hundreds of miles apart. When this huge mass of water hits a coast, it can plow inland for miles like a raging river that can be over 100 feet high, and it can destroy everything in its path.

Unlike wind-driven waves or astronomically driven tides, tsunamis are the result of geological activity under the ocean floor, some movement that will cause a displacement
of a large amount of water, such as underwater landslides or volcanic eruptions. But the most significant tsunamis are caused by sudden movements of the sea floor associated
with earthquakes.

In the deep open ocean, a surface tsunami wave may only be a few inches high. But unlike other ocean waves, a tsunami wave extends downward to the ocean floor. This is
a tremendous mass of water, and the wave can be traveling at remarkable speeds of up to 500 mph. As it approaches a coastline and the water gets shallower, the wave slows to 20 or 30 mph; the water piles up, causing a significant rise in ocean level. When it reaches the coast, a tsunami seldom appears as a towering wave but rather like a fast-rising flood.

On average, locally damaging tsunamis occur twice a year, but major tsunami events that can affect areas hundreds or even thousands of miles away from the origin point only
occur about twice per decade. Since 1900, the seismically active Pacific basin has seen nearly three-quarters of all tsunami events. Less than 10 percent occurred in the Atlantic
and Caribbean.

In this millennium, there have been two historic tsunami events. In December 2004, a 9.1-magnitude earthquake off the Indonesia coast initiated tsunamis that killed 250,000 people some as far away as the east coast of Africa. Japan suffered devastating tsunamis that killed 18,000 people after a 9.0 earthquake hit in March 2011. The water traveled as much as six miles inland.

The US Tsunami Warning System run by the National Weather Service protects the citizens of the United States and its territories. There are two Tsunami Warning Centers. The one in Palmer, Alaska, serves the continental U.S., Alaska and Canada. The other in Honolulu, Hawaii, serves not only the Hawaiian Islands and U.S.-owned territories in the Pacific but also on the Atlantic side, Puerto Rico and the Virgin Islands.

To detect actual tsunamis as they are moving through the ocean, NOAA developed the Deep-ocean Assessment and Reporting of Tsunami (DART®) station which consists of a bottom pressure recorder anchored to the sea floor and a moored surface buoy with a transmitter to send information via satellite back to the Centers. The pressure sensor can convert a measured reading to the height of the ocean surface above, and if the system detects an unusual height, it will start sending readings every 15 seconds.

With the greatest tsunami risk in the Pacific region, the DART network of stations runs the length of the Aleutian Islands and southern Alaska as well as along the West Coast and Hawaii. Although the Atlantic is much less prone to tsunamis, there are stations off the East Coast, in the Gulf and off Puerto Rico where meteotsunamis tend to occur. With accelerated development along many coastlines and rising sea levels, future tsunami events could be catastrophic.

When seismic data indicate that a significant earthquake has occurred somewhere around the world, an Information Statement is issued immediately by the appropriate Warning
Center. Next, the nearest sea level gauges are closely monitored to see if a tsunami has been generated and its magnitude. The DART network will activate if a tsunami is approaching. If a tsunami has the potential to affect a covered area, there are three levels of alerts that can be issued by the appropriate Center:

Tsunami Watch: an event has occurred but the threat is yet to be determined. The public is advised to stay tuned for more information and be prepared to act.
Tsunami Advisory: implies strong currents and dangerous waves near the water and that people should vacate the beaches.
Tsunami Warning: dangerous coastal flooding and powerful currents exist. People are urged to seek higher ground and/or move inland. Warnings are typically issued within five minutes of the initiating earthquake. The official tsunami alerts are disseminated by local NWS offices.

Tsunami warnings are just one part of the National Tsunami Hazard Mitigation Program which includes agencies of the Federal government and 28 U.S. states and territories. Another component, Mapping and Modeling, uses computer analysis of possible tsunami events in conjunction with local topography to forecast the magnitude of potential flooding. The Mitigation and Education component is the public outreach to inform citizens of the tsunami risk in their area and what actions should be taken in response to the various advisories. To lessen property damage, land use policy and planning are also advocated.

By Ed Brotak, Southern Boating February 2018

ALL PHOTOS: COURTESY OF NOAA

The Dead Zones

“The Dead Zone” may sound like the title to an old horror movie, but these barren ocean wastelands are very real. Officially referred to as “hypoxia”, dead zones are areas of the ocean that are devoid, or nearly devoid, of aquatic life. Creatures that could move away have done so, while others have died. The problem is a reduced level of life-sustaining oxygen in the water. Some dead zones occur naturally. However, the worst of them today are the result of man’s activities.

The main cause of man-made dead zones is nutrient pollution called “eutrophication” by scientists. Nutrients such as nitrogen and phosphorous are vital to plants and are major ingredients in many fertilizers. If excessive amounts of these elements find their way into bodies of water—fresh or salt water—they will spur the overgrowth of algae and phytoplankton (microalgae). The initial algal bloom can block sunlight from reaching the
waters below. Plant life at lower levels can’t produce oxygen thus beginning the hypoxia process. When the algae die and sink it will decompose, using up more oxygen in the lower reaches. There is not enough oxygen left to support normal aquatic life and the result is a dead zone.

Eutrophication has steadily increased in recent years due to industrial activities, the effluent from wastewater treatment and, in particular, intensive agricultural practices. It is estimated that human activities produce twice as much nitrogen and phosphorous as natural sources. The extensive use of animal manure and commercial fertilizers to
increase agricultural production is a major source of nutrient contamination in water that has drained off farmlands.

Dead zones typically develop during the summer months. Obviously, during the growing
season, more fertilizer, etc. is being applied to crops. Also, we get temperature stratification in bodies of water. Upper layers are heated by the intense sunlight. The
warmer water is less dense, lighter and there is little vertical mixing with the colder, denser water below. If decomposing algae uses up oxygen in the bottom waters, it can’t be replenished from above. Dead zones normally last several months until fall weather systems promote mixing.

It’s important to note that although dead zones and the red tide can be linked to a similar cause—nutrient pollution— they are not the same. The red tide is also an excessive algae
bloom, but in this case, an actual toxin is released into the water by the algae. This can kill fish, make shellfish dangerous to eat and even make people sick.

Dead zones exist around the world; more than 100 of them have been documented. In the U.S. alone, the Great Lakes, the East Coast and, particularly, the Gulf of Mexico all have dead zones. The northern Gulf, the region of the Louisiana/ Texas continental shelf, has an enormous dead zone in the summer. This is critical since the northern Gulf encompasses almost half of the nation’s coastal wetlands. Commercial and recreational fishing in the region, including the shrimp industry, generate $3 billion annually.

The Gulf of Mexico Dead Zone was first discovered in August 1972. Scientists found oxygen-depleted bottom waters off the Louisiana coast at depths ranging from 30 to 70 feet. Normally, oxygen levels identify about 7 parts per million (ppm), but they had dropped to 2 ppm or less. It is believed that even though there was some oxygen depletion noted before this, conditions became much worse starting in the 1970s. Since
1985, the dead zone has been measured and mapped to show its size, and the actual size of the dead zone varies from one year to the next. This past summer, the Gulf of Mexico dead zone grew to 8,776 square miles, the size of New Jersey. Not only was this the largest it’s ever been since measurements began, but the Gulf of Mexico now had the largest dead zone in the world.

Why is this occurring here? The Mississippi River flows into the Gulf of Mexico along the Louisiana coast. The Mississippi River watershed encompasses 1.2 million square miles or 41 percent of the continental U.S., and it even extends into Canada. Much of this land is devoted to agriculture.

There is no way to remotely detect dead zones. Satellite imagery can show massive algal and phytoplankton blooms near the ocean surface, which are the precursor of hypoxic areas. But to check what’s going on underneath the surface, samples of water must be taken. One of the main groups dealing with this problem is the Louisiana Universities Marine Consortium (LUMCON). They have a Hypoxia Research Team that monitors conditions in the northern Gulf utilizing a marine laboratory (the DeFelice Marine Center) and a fleet of research vessels.

On the Federal side, the National Centers for Coastal Ocean Science not only provide money for research but also produce an annual forecast in June of the expected maximum size of the Gulf dead zone. Computer models use runoff projections for the Mississippi River based on antecedent precipitation. To help alleviate this problem, the EPA-formed Mississippi River/ Gulf of Mexico Hypoxia Task Force has set a goal size of under 2,000 square miles for the dead zone by 2035. And though some reduction in nutrient pollution
has been accomplished, it is estimated that a further reduction of 60 percent would be necessary to achieve the set goal.

By Ed Brotak, Southern Boating January 2017

Eddies in the Ocean

Put a Spin on It! Eddies in the Ocean effect more than just the water.

For many years, oceanic circulations were considered to be fairly simple with a huge spinning gyre in the middle of each ocean that was surrounded by swift-moving
currents along the periphery. With advances in observational capability in the 1960s, the complexity of oceanic circulations became apparent. There were numerous vortices or eddies much smaller than the massive gyres but still significant. With a diameter ranging from 50 to 200 miles or more, they are officially called “mesoscale eddies” or sometimes “rings”. They also can extend downward into the ocean for thousands of feet. These eddies can last from weeks to months or even more than a year. They travel hundreds or even thousands of miles albeit at a slow forward speed of perhaps a half a knot.

Strong western boundary currents like the Gulf Stream are prolific producers of eddies. The Gulf Stream doesn’t flow in a straight line; it has meanders or bends. These meanders can form oxbow-like flows similar to the way that rivers do. These oxbows can become cut off, forming eddies in a process that can take a month or more. The Gulf Stream separates warmer waters to its south and east from cooler waters to the north
and west. Depending on which side they form, these eddies contain either relatively warm or cold water compared to their surroundings. Warm eddies are found to the north and west of the Gulf Stream. They rotate clockwise (anti-cyclonic eddies) and sea level is slightly (6 inches or more) higher within them. Cold eddies are to the south and east of the Gulf Stream. They rotate counterclockwise (cyclonic eddies) and sea level is
slightly lower in them.

These eddies are a critical component of the oceanic environment. On the largest scale, they help move heat or energy. They are part of the ocean-atmosphere system that
transports excess heat from the tropics toward the energy deficient poles. Thus, oceanic eddies affect worldwide ocean temperatures and the atmospheric climate above the water.

With varying concentrations of saltiness (cold eddies are less salty, warm ones more so),
they help transport and balance salinity. Warm-core eddies can actually trap and transport a wide variety of aquatic life within them. But it’s the cold-core eddies that tend to have the greater amount of biological activity. Nutrient-rich bottom waters are pulled up in cold eddies and nourish aquatic ecosystems. The nutrients are then transported by the moving vortex.

There are also smaller eddies in the ocean. These measure 50 miles across or less but can still last for weeks or months. And, recently discovered are even smaller eddies, or “submesoscale vortices”; they measure less than a mile across and are primarily surface features. The idea of having progressively smaller vortices in the ocean is consistent with fluid dynamics theory. It’s these small-scale systems that actually transport energy, etc. which achieves the balance nature is always seeking.

How are eddies detected and tracked? Specialized drifting buoys can be deployed and tracked by satellite GPS technology. Their motion over time will indicate any persistent circulations. Satellites themselves have been constantly monitoring the ocean surface since the 1960s. Infrared thermal imagery will show hot or cold eddies clearly. Sensitive satellite altimeters can also detect small changes in sea level, characteristic of these eddies. Some cold eddies will show up on visible images as green vortices if significant amounts of phytoplankton are present.

Besides the broad-scale effects described above, oceanic eddies can have a direct impact on man’s activities. Certainly, nutrient-rich eddies teaming with aquatic life will attract fishing interests. The effects of eddies on current flow and sea level height can impact the operations of offshore energy production sites. The Gulf of Mexico is a prime example of its numerous offshore oil rigs (and soon, wind farms). The Loop Current is the clockwise flow of warm water that dominates the Gulf. It spawns a multitude of eddies, some of which can produce exceptionally strong currents of 3 to 4 knots. Drilling operations would have to be halted if these conditions are encountered. Horizon Marine, an oceanographic services company whose main clients are from the offshore energy industry, keeps track of these eddies. This includes detection, forecasting, and cataloging. They even name the eddies!

And, of course, the impact of eddies on current direction and speed can affect navigation. Forward speed can be hastened or slowed by a few knots. This will affect the timing of operations and fuel usage. Knowledge of eddy circulations that may be encountered can help in planning the most efficient route. Yacht racers even use this information in planning their strategy.

There is also a theory that ties warm-core eddies and hurricane intensification. Tropical cyclones get their energy from warm water. It makes sense then, that if a tropical
cyclone moves over a warm eddy, it would intensify. And keep in mind that eddies have considerable vertical depth; they are deep pools of warm water or “high ocean heat content” as it is known. It appears that Hurricane Harvey moved over such an eddy on Friday, August 26th. It intensified into a major Category 4 hurricane before moving
ashore and devastating sections of the Texas coast before bringing the unprecedented flooding to Houston.

By Ed Brotak, Southern Boating Magazine December 2017

PHOTO: U.S. ARMY/ 1ST LT. ZACHARY WEST

Artificial Reef: Nature’s Best Friend?

Time will tell whether artificial reefs can replace some of the millions of acres of reefs that have already been lost.

Reefs, especially coral reefs, are an integral part of the undersea world. They are the most biodiverse regions of the ocean. Many species of fish utilize reefs for food, protection and even breeding sites, so they are crucial to the fishing industry. Today, unfortunately, they are facing a challenging environment. Overfishing and destructive fishing procedures have depleted fish populations in many locations and in others, pollution has destroyed the reefs that serve as their habitat. Climate change has also played a part in damaging our planet’s reefs. All told, millions of acres of natural reefs have been lost.

Yet man has been inadvertently establishing reefs for as long as he has traversed the oceans. Over a period of time, shipwrecks—the remains of sunken ships—attract marine
life and become their own form of reefs. It was just a matter of time before the thought of doing this deliberately came about. The idea was simple enough. Where the ocean floor was featureless, just put something down there with surfaces that algae, barnacles and, especially, coral polyps can attach to. In time, an artificial reef forms.

The first “official” artificial reef (AR) was established in the U.S. off the coast of South Carolina in the 1830s, when log huts were sunk to the ocean floor in order to attract marine life. It wasn’t until the 1950s that the idea of making ARs took off. Initially, there was no science involved. People just started dumping things into the ocean: old ships, railroad cars, rocks, cinder blocks, old tires, and various debris. They believed they were achieving two goals: forming new reefs and also getting rid of things that had outlived their usefulness. But without scientific observations, the success of such endeavors was questionable. In fact, damage to the undersea environment was sometimes the result.

One of the worst cases occurred with the Osborne Reef, an artificial reef made up of 700,000 old tires off the coast of Fort Lauderdale, Florida. Initially tied together, the tires soon broke loose due to the shifting tides. As a result, they proceeded to destroy the marine habitat, including the natural reefs they were trying to protect and enhance. The project to retrieve these tires has cost taxpayers millions of dollars.

In 1984, the National Fishing Enhancement Act brought science into the artificial reef business by way of the National Oceanic and Atmospheric Administration. A year later, the National Artificial Reef Plan was developed. The goal was to enhance fishery resources but minimize environmental risks. State and local program managers were provided guidelines on siting, construction, development, and assessment of ARs. Officially, the Office of National Marine Sanctuaries (ONMS) must issue a permit for an AR to be established on their grounds. States have similar procedures for offshore areas they control.

In fact, every state from North Carolina through Florida and around the Gulf Coast to Texas has an AR program. With more than a thousand miles of coastline, Florida leads the way in AR establishment with over 3,000 manmade reefs. In the Gulf of Mexico, hundreds of oil and gas platforms have been converted into ARs. Apparently, the bases of marine wind turbines will also suffice. Probably the best-known ARs have been made from sinking now-obsolete ships. The largest of these was the U.S.S. Oriskany, a 44,000-ton aircraft carrier sunk in 200 feet of water some 24 miles off the coast of Pensacola, Florida, in 2006.

In addition to “pre-existing objects,” ARs can now be made of materials specifically designed for that purpose. One of the most successful material categories has been “reef balls.” Made from concrete specially formulated to resist disintegration for many years but still be ecologically safe, the “balls” are the most effective way to create a sustainable reef habitat. They come in a variety of shapes and sizes; many look like igloos and can range in size from 1½ feet and 30 pounds to 6 feet and 6,000 pounds. The Reef Ball Foundation has deployed more than half a million balls in 60-plus countries around the world making them the most widely used AR component. There are also economic benefits to ARs since successful ones are prime fishing grounds and attract fishermen both amateur and professional. Snorkelers and divers will come to view the reef and its marine life. Tourism will increase, and overall, ARs can have a positive effect on local economies.

On the downside, there are risks associated with ARs. Since fish are attracted to ARs, illegal dumping to produce fishing “hot spots” has become a problem. According to Kathy Broughton, marine ecologist with the ONMS, there is also potential contamination of the underwater environment by toxic chemicals. This means any pre-existing object to be used must be carefully inspected with any potential contaminants removed.

For the U.S.S. Oriskany, $20 million was spent to make the ship environmentally safe before sinking. For new materials such as reef balls, their initial composition must be carefully selected. Broughton also says, “They (ARs) may facilitate invasive species introductions and increase disease frequency in fish and invertebrates. ”Noting these concerns, the ONMS emphasizes protecting and, where appropriate, restoring and enhancing natural habitats, populations, and ecological process as opposed to constructing human-made habitats.

FOR ADDITIONAL INFO:
National Ocean Service Artificial Reef: oceanservice.noaa.gov/facts/artificial-reef.html
Scientific Review of Artificial Reefs:nmssanctuaries.blob.core.windows.net/sanctuaries-prod/media/archive/science/conservation/pdfs/artificial_reef.pdf
Reef Ball Foundation: reefball.org

By Ed Brotak, Southern Boating December 2017

Photos: Courtesy of NOAA and Reefball.org

Wind Power

Harvesting the Wind: Offshore wind power farms come to America.

Man has been utilizing wind power for thousands of years. Sailboats date back to the Roman Empire. Windmills of some type go back almost as far. Wind turbines, windmills that generate electricity, were developed in the late 1800s. They were used locally to provide power in places outside of urban electric grids. But it was the oil shortages of the 1970s that prompted a re-examination of alternative, renewable energy sources, including wind. The first wind farm in the U.S. (and, in fact, the world) was installed in southern New Hampshire in late 1980. It consisted of 20 turbines at 30 kilowatts each with blades less than 50 feet long.

Although oil became more plentiful and less expensive in the 1980s, some countries—especially in Western Europe— pursued wind energy vigorously. In the U.S., interest waned except in California, where environmental regulations made reduced fossil fuel usage a goal. As oil prices escalated in recent years, wind energy became economically viable. Wind farms began springing up in the U.S., typically over sparsely inhabited land areas. The idea of offshore wind farms had taken hold in other parts of the world, especially the North Sea. The first offshore wind facility was built in Denmark in 1991. For numerous reasons—political and otherwise—the U.S. once again lagged behind in wind power. It wasn’t until December 2016 that the first offshore wind farm in the U.S. became operational. The Block Island Wind Farm (BIWF) is about three miles southeast of Block Island, Rhode Island. It consists of five turbines at six megawatts each and submarine cables that connect the turbines and link the facility to a distribution network on Block Island.

What are the advantages of building wind farms off shore? A major factor is the wind itself—it tends to be stronger and more consistent over water. The relatively smooth surface reduces frictional slowing of the wind, and there are no obstacles to induce turbulence or block the wind. Also, the power of the wind increases exponentially with its speed.

Even a small boost in velocity can mean much more electricity generated. Another obvious benefit is that it doesn’t take up excessive land space. In addition, many coastal areas have high population densities and a greater demand for electricity. Other renewable sources of energy may be lacking. There are, however, disadvantages for marine sites.

Constructing and maintaining equipment in the ocean is difficult and often expensive. Depending on the occurrence of oceanic storms, the equipment may have to contend
with winds over 100 mph and waves of 50 feet or greater. Getting the generated electricity back to shore can also be challenging and costly. If the wind farm is within view
of the shore, aesthetics may be a concern, especially for tourist destinations.

One of the limiting factors for offshore wind energy is the need to have the turbines secured to the ocean floor. This has relegated wind farms to near offshore areas where
the coastal shelf is at a depth of 200 feet or less. One way around this is to have floating turbines. Although prototypes have been experimented with for some years, the world’s first floating wind farm off the coast of Scotland has just become operational. In theory, such floating structures could function in water as deep as 3,000 feet or more. Although not economically practical now without government subsidies, it is believed that advances in floating turbine technology will allow profitable operations in the future.

The wind turbines themselves can be massive. With a central tower that may be 300 feet high and rotating blades of 250 feet in length, the entire structure might rise more than 600 feet above the water level. And beneath that, the supporting foundation can extend from the ocean surface down to several hundred feet below the ocean floor. Their sheer size brings about other concerns.

For example, mariners risk colliding with one of the wind turbines, especially when visibility is diminished. Either a boat could strike the tower or the windmill blade could
hit a mast, etc. Deepwater Wind, the parent company of the BIWF, has a page on its website solely dedicated to “Information For Mariners.” The Mariners Fact Sheet gives
the latitude and longitude of all equipment and includes a map. Briefing For Mariners describes all current and planned operations.

Another concern about offshore wind farms is the effect on marine life. Government biologists will scout out potential sites to ensure the least amount of disturbance to the
environment. There is particular uncertainty over sensitive fish habitats. Some preliminary studies from other countries have actually shown that the supporting foundation of the wind turbines can act as an artificial reef that enhances marine life. As for fishing, the BIWF has a Fishery Liaison, who facilitates communications from the commercial fishing industry to the BIWF and the various government agencies involved. They are there to help resolve any conflicts that may arise.

Although much of the proposed wind farm development is off the Northeast Coast, locations farther south are being studied. Generally, winds are stronger in the higher latitudes. But the area off the Outer Banks of North Carolina is deemed prime grounds due to consistent winds and shallow water. Even in the Gulf of Mexico, sites off the Texas and Louisiana coasts are also being considered. dwwind.com

By Ed Brotak, Southern Boating October 2017
Photos courtesy of Brooke Carney/ NOAA Sea Grant

Wounded Veterans help with Coral Restoration

On a Mission: Heroes plant 500 corals in a single day assist in coral restoration.

Stellar scientists, hero veterans and future leaders recently planted 500 corals near Looe Key in the Florida Keys, marking the sixth year of a unique partnership involving science, conservation and coral restoration.

Members of the Combat Wounded Veteran Challenge (CWVC) and SCUBAnauts International joined forces with scientists from Mote Marine Laboratory on June 27th for the record-breaking mission on the reef. The number of corals planted marked the most-ever the groups have planted in a single day since they began working together in 2012.
In total, they have planted more than 1,600 corals in an area unofﬁcially named “Hero’s Reef” honoring all current and former members of the U.S. Armed Forces.

CWVC improves the lives of wounded and injured veterans through rehabilitative, high-adventure and therapeutic outdoor challenges while furthering the physiological, biomedical and pathological sciences associated with their injuries. The veterans who participate in the outdoor challenges have suffered from traumatic brain injuries, Post-Traumatic Stress Disorder (PTSD) or have lost limbs.

SCUBAnauts International involves teens in the marine sciences with intensive dive and science training. Through its partnerships with universities and research organizations, SCUBAnauts learn to take charge as they work on innovative projects that positively impact our oceans, such as this coral restoration.

Combined efforts from Mote, Combat Wounded Veteran Challenge, and the SCUBAnauts, planted 500 Stagorn Coral on Hope Reef on Tuesday, June 27th, 2017.

Ten years ago, Mote established an underwater coral nursery where scientists grow colonies of the threatened staghorn coral (Acropora cervicornis) for replanting and coral restoration on decimated or damaged sections of reef within the Florida Keys National Marine Sanctuary.

When the colonies reach a suitable size, small fragments (nearly 2 inches long) are snipped off and used to create a new colony—similar to the way new plants are grown from cuttings of existing plants. These cuttings are then mounted on the reef so they can grow and develop into new colonies.

Mote has more than 10,000 colonies of staghorn coral in its underwater nursery, including more than 85 genotypes, allowing researchers to determine which corals have the heartiest genetic makeup and the best chances of survival. To date, Mote has planted more than 40,000 reef-building coral fragments to help restore Florida’s reef. Mote is also working on a new coral micro-fragmenting technology that is enabling the organization to regenerate larger reef-building boulder corals on the reefs. Mote’s goal is to continue working in partnership with these and other groups to plant more than a million corals.

“This is really a wonderful annual event,” said Dr. Michael P. Crosby, Mote president and CEO. “I don’t know of any other partnership like this involving really innovative science, young citizen scientists and veterans who are sharing their leadership skills. But this event has broader impacts beyond just doing great science. Coral reefs are on the way toward extinction because of decades of human impacts. They were already stressed, and now we have increasing temperatures, increasing acidity and more diseases that are pushing them past their tipping point. If we lose coral reefs, we’ll lose the oceans and if we lose our oceans, we’ll lose the very oxygen we need to survive.”

By Hayley Rutger, Mote Marine Laboratory for Southern Boating September 2017

PHOTOS: CONOR GOULDING/MOTE MARINE LABORATORY

Liked this story? You can find more environmentally friendly Sea Watch Stories here.

Are Acidifying Oceans Slowing Coral Disease?

Blackout Black Band

Could acidifying oceans actually slow down coral disease?

Coral reefs face intensifying struggles as greenhouse gases warm and acidify the ocean, but new research suggests a potential silver lining: Some coral diseases might also dwindle amid environmental change. A controlled lab study led by Mote Marine Laboratory and published in the journal

A controlled lab study led by Mote Marine Laboratory and published in the journal PLOS ONE revealed that black band disease was less deadly to mountainous star coral (Orbicella faveolata) as water acidiﬁed, or decreased in pH. Scientists from Mote and the University of South Carolina, and students from the University of Rhode Island, University of New Hampshire, University of Hawaii, and Unity College in Maine conducted the research with funding from the Dart Foundation and the Protect Our Reefs grants program supported by sales of the Protect Our Reefs specialty license plate. Student contributions were backed by the National Science Foundation (NSF) Research Experiences for Undergraduates program and Mote College Internship Scholarships.

Scientists from Mote and the University of South Carolina, and students from the University of Rhode Island, University of New Hampshire, University of Hawaii, and Unity College in Maine conducted the research with funding from the Dart Foundation and the Protect Our Reefs grants program supported by sales of the Protect Our Reefs specialty license plate. Student contributions were backed by the National Science Foundation (NSF) Research Experiences for Undergraduates program and Mote College Internship Scholarships.

The ocean’s pH is decreasing through the process of ocean acidiﬁ cation (OA) driven by excess carbon dioxide, the same greenhouse gas that’s triggering temperature increases worldwide. OA may weaken or dissolve corals’ hard skeletons and bring on other changes in multiple marine species. Warming water stresses corals, causing them to lose the vital algae in their tissues. Coral diseases, another major threat, may worsen in stressed corals, but few studies have examined how these conditions could change amid low pH levels expected with OA.

The new study is the ﬁrst to examine how low pH water affects black band—a fast-progressing, often deadly, worldwide coral disease affecting at least 42 coral species in the Caribbean. Black band, a variable group of multiple bacteria species, forms a dark circle that spreads across a coral and kills it. Under attack is mountainous star coral, a major contributor to the reef system of the Florida Keys and listed as threatened under the U.S. Endangered Species Act.

“Mountainous star coral only grows a couple of millimeters a year, and black band can kill a 100-year-old coral within weeks,” said Dr. Erinn Muller, lead author and manager of Mote’s Coral Health and Disease Research Program.

At a very small scale, black band produces a lower pH environment than its surroundings—localized acidiﬁ cation. “In the lab, we thought that exposing an infected coral to acidiﬁ ed water would accelerate the virulence of this disease, but to our surprise, the opposite happened,” Muller said.

During 2013 lab work at Mote’s Summerland Key campus, the researchers inoculated 32 mountainous star coral fragments with black band disease. Some were placed in tanks with temperature and pH similar to present-day ocean water, while others were put into tanks with elevated temperature, lowered pH or both. They used year-2100 projections from the Intergovernmental Panel on Climate Change’s Fifth Assessment Report.

“These experimental studies in the lab are extremely important; they give us a glimpse into the potential future for our reefs,” said Mote’s Ocean Acidiﬁ cation Research Program manager Dr. Emily Hall, who oversees research in Mote’s Ocean Acidiﬁcation Flow-through Experimental Raceway Unit on Summerland Key, which was established due to an NSF grant. “With ocean acidiﬁcation, not every organism is affected the same way. It’s important for managers of marine protected areas to know how the impacts might vary.”

The researchers carefully monitored the water conditions and photographed and measured the coverage of black band for 16 days. By then, some coral fragments had perished completely from the disease. The team sampled black band bacteria and the corals’ natural resident bacteria—some of which contribute to the coral immune system—and sequenced their 16S rRNA gene, which helps classify bacteria into scientiﬁc categories. Their analysis revealed a surprise.

“Though warmer temperatures didn’t signiﬁcantly affect the progression of black band disease in this time period, the low pH treatment did—it slowed the progression rate of the disease by 25 percent,” Muller said. “It took us awhile to believe it.” Skeptical, Muller and her colleagues ran similar tests with other coral species apart from the mountainous star coral in the current study. The mountainous star coral showed the clearest trend, but data from other species suggested similar patterns.

How might acidiﬁcation slow down black band disease?
“Black band disease has a very distinct consortium of microbes, and it seems that lowered pH affected different microbes in different ways,” said study partner Dr. Kim Ritchie, associate professor at the University of South Carolina at Beaufort. “The abundance of one signiﬁ cant member of the consortium went down.” Speciﬁcally, acidiﬁed water reduced the abundance of Oscillatoriophycidae, a class of cyanobacteria that often dominates black band disease. These bacteria carry pigments that give the disease its distinct color. Though these bacteria live in the already-acidiﬁed environment of black band, past studies by others suggest that cyanobacteria can decline if the water becomes acidiﬁed beyond their tolerance limits.

“There were also shifts in the corals’ own microbial community, but none that explained the change in the disease. What happened in the black band itself, a reduction in the main contributor to the disease consortium was likely a better explanation,” Muller said. “One of our next steps is to study how low pH inﬂuences the very small scale conditions in the microenvironment of black band disease as the outside environment changes.”

By Hayley Rutger, Mote Marine Laboratory for Southern Boating August 2017