Hurricanes

This week marks 13 years since Hurricane Katrina, an event some citizens of Louisiana are still recovering from. We may have all heard the name, but do we know what a hurricane is, how wetlands are affected, and how coastal landforms can decrease hurricane impacts?

“Hurricanes” are low-pressure tropical storm systems that differ from other storms in severity as well as location. A hurricane is a storm with winds above 64mph accompanied by heavy rain that originates in either the NE Pacific or the N Atlantic Ocean (the oceans that touch the USA). Due to a phenomenon called the Coriolis Effect, hurricanes rotate counter-clockwise, whereas a southern hemisphere storm would rotate clockwise. Hurricanes develop a characteristic “eye of the storm” in the center, which is an area of low pressure and low wind. Just outside of the eye is the most severe weather, the eyewall, with winds reaching up to 210mph in the strongest storms! Hurricane “category” ratings are as follows:

  • Category 1: 74-93mph
  • Category 2: 96-109mph
  • Category 3: 110-129mph
  • Category 4: 130-157mph
  • Category 5: >158mph

Hurricanes develop over areas with warmer waters, typically nearer the equator, and move away from the equator. [1] Coastal Louisiana is hit by hurricanes on an increasingly regular basis, and those hurricanes all develop in the North Atlantic Ocean in late summer and fall. Our “Hurricane Season” occurs from June through November each year. [2] Several aspects of hurricanes pose major threats to our wetlands statewide. High winds can topple trees, rip up shrubs and grasses, and move sediments around. High rainfall can cause flooding in areas that are not well-adapted to high-water conditions. Storm surge can push saline seawater into brackish and freshwater systems. Hurricanes cause massive disturbance in coastal wetlands, but wetlands are a crucial barrier that protects major cities from taking as much damage. CWPPRA works to combat land loss and protect the future of coastal Louisiana.

Some CWPPRA projects restore barrier islands, which are natural defenses that develop in the Deltaic Cycle. Barrier islands lessen storm surge during hurricanes, bearing the brunt of the waves. Sadly, they cannot provide perfect protection because they are degrading, but they are not the last line of defense. We still have coastal marshes that are great at storing water and acting like a speed bump to storm surge. It is estimated that each mile of coastal marsh decreases storm surge by about a foot. Unfortunately, many coastal marshes are decaying into open water and are no longer protective barriers. CWPPRA will continue to restore wetlands and nourish barrier islands to #ProtectOurCoast!

 

[1] https://en.wikipedia.org/wiki/Tropical_cyclone

[2] https://www.ready.gov/hurricanes

Featured image from [1]

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National Honey Bee Day – August 18th

August 18th was National Honey Bee day in the USA, but what’s all the buzz about? Pollinators play vital roles in plant communities, including carrying pollen from plant to plant. How does that work? How do honey bees know which flowers need their help? How do they communicate with other bees? All of that and more to come on this special #WetlandWednesday!

There are many kinds of pollinators, from birds to bugs to bats! A mutualistic relationship between pollinators and flowering plants allows the pollinators to collect food and allows the plant to spread its pollen to other individuals. Different animals have different strategies of carrying pollen. Honey bees use some very complex methods of finding, harvesting, and spreading pollen within plant communities. There are almost 20,000 described species of bees; some live in colonies and some do not, some pollinate only one plant species and some pollinate multiple species. The most cultivated of the honey bees (genus: Apis), the Eastern Honey Bee (A. mellifera), is a colonial bee species that does not specialize on one plant. In flight, bees build up an electrostatic charge on their fine, branched hairs. When bees climb into flowers looking for sugary nectar, their charged hairs attract pollen even from a couple of millimeters away! The charge and the branches in their hairs help to keep the pollen attached when the bee leaves in search of its next bounty of sugar.

How do honey bees find flowers? Using a combination of visual, chemical, and communicated clues, bees are highly specialized to find the flowers that are just right for them. Compound eyes do not have the high definition visuals that human eyes have, but they can see ultraviolet light. Some flowers have ultraviolet patterns on their petals called “nectar guides”. [1] When in flight, bees will not always see color, but they can still see shapes and can recognize nectar guide shapes, as well as smell aromas from the flowers. Bees can also communicate instructions or coordinates for finding flowers through “waggle dancing”! [2]

Honey bees pollinate throughout wetlands across the world and have major positive impacts on ecosystem health. Native trees and shrubs of Louisiana that are dependent on pollinators like the European honey bee include Wax Myrtle (Morella cerifera), Southern Magnolia (Magnolia grandiflora, our Louisiana state flower), and Dwarf Palmetto (Sabal minor). Some smaller flowers that need bee pollinators include Wooly Rosemallow (Hibiscus lasiocarpus), Coneflower (Rudbeckia triloba), and Trumpet Creeper (Campsis radicans). [3] Honey bees are also vital in pollinating about 90% of agricultural crops nationwide! Without pollinators, our Louisiana wetlands would not be as productive and vibrant as they are, and we need the help of pollinators to #ProtectOurCoast!

 

[1] https://www.bumblebee.org/bodyEyehtm.htm

[2] https://en.wikipedia.org/wiki/Waggle_dance

[3] http://pollinator.org/guides

Featured image from https://www.louisianabeesanctuary.org/

The Louisiana Artificial Reef Program

Established in 1986, the Louisiana Artificial Reef Program takes advantage of obsolete oil and gas platforms which were recognized as providing habitat important to many of Louisiana’s coastal fishes [1]. Participating companies donate materials, and 1/2 of their savings into the Louisiana Artificial Reef Trust Fund.

In 1999, the Louisiana Artificial Reef Program created the World’s largest artificial reef  from the Freeport sulfur mine off Grand Isle, Louisiana.

lareefprogram.png

The Louisiana Artificial Reef Program Has:

  • Converted over 400 obsolete platforms into permanent artificial reefs Gulf-wide
  • Developed 30 inshore reefs in Louisiana state waters
  • Supported 71 oil and gas companies to participate and donate

One of the (5) main objectives of the Coastal Master Plan, includes the restoration of  coastal habitats. Programs such as the Louisiana Artificial Reef Program, provide fisheries habitat in the form of converted rigs, provide support to CWPPRA and other partners funding coastal restoration projects.

Source:

[1] McDonough, Mike. The Louisiana Artificial Reef Program. Available: http://www.wlf.louisiana.gov/fishing/artificial-reef-program [July 10, 2018].

Levee Systems in Louisiana

As flooding events continue to increase in frequency and intensity, it is essential for the State of Louisiana to continue moving forward in technology and ingenuity for the construction of levee systems.

Since 1718 natural and man-made levee systems in Louisiana have been crucial in attempt to control the “Mighty Mississippi”. The Mississippi River drains 41% of the continental U.S. and more than half of Louisiana’s land is in a flood plain [1]. Therefore, careful planning, construction and maintenance of levee systems in Louisiana must continue to improve.

What is a levee?

According to the Federal Emergency and Management Authority (FEMA) a levee is a “man-made design and construction in accordance with sound engineering practices to contain, control, or divert the flow of water to provide protection from temporary flooding [2].

Some History on levees:

Before European control, natural processes occurred along the Mississippi River in which sediment deposits created natural levees reaching up to a meter or two in height. [3]. Initially, state government required that farmers and land owners build their own levees with ~10-12 cubic yards per day and reaching 75 feet long in some areas [4].

Today, with multiple Acts by the United States Congress, levee systems are professionally implemented by multiple entities to promote control and prevent flooding.

Who is Involved:

There is no one entity solely responsible for levee construction and maintenance in Louisiana [2].  Some entities that share the responsibility include but are not limited to the following:

levee districts

Current Programs including Levee Development and Planning:

Necessary Plans for the Future:

The Louisiana Master Plan for a Sustainable Coast 2017 calls for project  “construction of a levee to an elevation of 15-35 feet around the Greater New Orleans area from Verret to the Bonnet Carre spillway” [5].

La_pic

Incremental Improvements recommended by David Muth (A Director of National Wildlife and Fisheries) include [5]:

  • Levee resilience
  • Increased water storage capacity inside levees
  • Public incentive to participate in building raising or relocation programs
  • Restoring the wetland buffers outside levee

A Plan in the year 2009 from Netherland Engineers to CPRA recommended the following [5]:

  • Raising levees to protect from a 500 year event or greater around central New Orleans
  • Raising levees to 1,000-year levels east of the Industrial Canal and on the West Bank.
  • Recommended a new levee and gates along the New Orleans land bridge, into St. Tammany Parish.

netherlands_rec

As flooding events continue to increase in frequency and intensity, it is essential for the State of Louisiana to continue moving forward in ingenuity for flood prevention, policy, planning, funding, and coastal restoration efforts.

Additional Links regarding Levees:

 

Work Cited:

[1] ALBL. “Association of Levee Boards of Louisiana”. 24 April 2018, http://albl.org/

[2] FEMA, “Levees – Frequently Asked Questions”.  24 April 2018, https://www.fema.gov/media-library-data/20130726-1803-25045-4819/st_broomelv.pdf

[3] Kemp, Katherine “The Louisiana Environment: The Mississippi Levee System and the Old River Control Structure”. 24 April 2018, http://www.tulane.edu/~bfleury/envirobio/enviroweb/FloodControl.htm

[4] Rogers, David. “Evolution of the Levee System Along the Lower Mississippi River”. 24 April 2018, http://web.mst.edu/~rogersda/levees/Evolution%20of%20the%20Levee%20System%20Along%20the%20Mississippi.pdf

[5] Schleifstein, Mark. “New Orleans area’s upgraded levees not enough for next “Katrina” engineers say”. 24 April 2018, http://www.nola.com/futureofneworleans/2015/08/new_levees_inadequate_for_next.html