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Laguna Madre - Saltier than the Ocean

A cache by Jarihend Send Message to Owner Message this owner
Hidden : 3/29/2009
1 out of 5
1.5 out of 5

Size: Size: not chosen (not chosen)

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Geocache Description:

The Laguna Madre (Spanish for "Mother Lagoon") is one of the most overlooked natural wonders in North America and is usually much saltier than the ocean, due to being nearly landlocked in a semiarid environment. It is one of only six hypersaline lagoons in the world. Its salinity generally increases from south to north, with distance from its major inlet near Port Isabel. It is a long, shallow bay-130 miles the length of Padre Island in the United States and Mexico.

Its biological corridor, though, extends well into Mexico, to the mouth of the Río Soto la Marina in the state of Tamaulipas. In the United States, Laguna Madre is separated from the Gulf of Mexico on the east by Padre Island, and bounded on the west by mainland Texas, and extends from Corpus Christi in the north to Port Isabel in the south. The Gulf Intracoastal Waterway runs through the length of the Laguna Madre in the United States. It covers 609 square miles of estuarine and coastal marine systems. The submerged land, marshes, spoil islands, variable salinity and depths, including the variety of seagrass, make the Laguna Madre a unique natural community. It is one of the most important wildlife refuges on the U.S. coast, as home to many species of fish, migratory birds, sea turtles, and even wildcats. It accounts for almost 80% of Texas seagrass beds which provide the main winter food and feeding grounds for the winter duck populations and the summer nursery area for young brown shrimp. Skipjacks, pinfish, broad killifish and striped mullet forage in the shoalgrass areas. Mollusks and crustaceans, generally associated with the areas of underwater vegetation, are important as waterfowl food.

Little and Big Shell Beaches are located near the (27 degree N. latitude) convergence point. This convergence point is where long shore currents moving north to south and currents moving south to north meet. Because the currents converge at this point, a good number of large, as well as small shells are deposited on the beach. Winds blow away the sand, leaving the exposed shells behind. The sand is then accumulated in dunes which may become stabilized by vegetation or are driven into the Laguna Madre.

On North Padre Island, Gulf waves break on the upper shore especially during fall and winter. They agitate the water and suspend sand so that they erode and destroy, or deposit and construct as applicable. Flat waves and smooth, round, symmetrical waves transport sand to the beach. Steeper waves remove sand. Swash bars and berms are beach deposits formed as a result of this wave action. The Gulf beach is a complex environment where water and air interact and compete for sediments. These sediments are deposited high on the beach are dried and transported landward by persistent onshore winds. This migrating sand is trapped along the back edge of the beach by salt-tolerant grasses and flowering plants.

The park has a Grasslands Nature Trail, a 3/4-mile loop trail, which winds through a grasslands-and-dunes area. Please stay on the path as hiking across the dunes is discouraged. Beach hiking can be slow going but rewarding, especially if you like bird watching or beachcombing. Low tide and after a storm are the best beachcombing times. Plants stabilize the sand with roots and spreading vines, forming a relatively continuous dune ridge. The fore-island dune ridge traps additional sand and prevents it from migrating back to the sea. Storms and high tides cut into these dunes, abruptly changing the contours of the island.

Kemp’s Ridley turtle nests have been found on North Padre Island National Seashore. Wildlife officials released 10,594 Ridley hatchlings along the Texas coast in 2008. The turtles are endangered due to shrimpers' nets. The National Seashore is also one of the few places the public can go to see sea turtle hatchlings being released into the wild. Today, the National Park Service locates, studies, and protects nesting Kemp’s Ridley turtles and their eggs. The National Park Service maintains the records of the sea turtle nests found in Texas and collaborates with and provides technical assistance to other entities leading nest detection programs elsewhere in Texas. Eggs found on North Padre Island and northward along the Texas coast are transported to the National Seashore's incubation facility for protected care. Left unprotected on the beach the eggs and hatchlings can fall victim to a variety of human-related and natural threats. When patrollers locate a track site where a nesting female emerged on the beach, but biologist are unsuccessful at finding the nest after hours of searching, a trained Kemp's Ridley nest collector dog is often brought to the site.

If the orange and black sign is flying be sure to watch for any signs of the kemp turtles while walking along the beach. Please mark any sightings with your GPS and report it to the Visitor Center. Please post any sightings in your logs for an extra smiley. We have been asked to help with this by marking and reporting any sites we might find while at the beach and to notify a park ranger where it is located. Please get a GPS reading of its location and give this information to a park ranger if one is nearby or take this information to the Visitor’s Center so they can protect the turtles. Please try and mark the area if possible to aid in their locating the nests and to prevent others from harming them. For further information, please check out the following website:

There are two locations within the National Park for the general public to access the Laguna Madre: at Bird Island Basin and at Yarborough Pass. Camping along the Laguna Shore outside of these areas is not allowed and hiking along the Laguna Shore outside of them is strongly discouraged because of the shoreline’s environmental sensitivity. Because there is little flow of sediments along the Laguna shore, damage to the mudflats can last a long time. Tire tracks and footprints left over twenty years ago can still be seen in some parts.

The Bird Island Basin area on the Laguna Madre is one of the top spots in the nation for windsurfing because of its steady wind, warm water, and shallow depths. They were having windsurfing races the day we were there. It is located on the Laguna Madre approximately four miles from the visitor’s center. Usage fee for Bird Island Basin is $5/day if used for windsurfing or camping but there should be no additional charge for just completing the requirements for the earthcache. This is covered in your entrance fee.

For more information on the park, check out the Padre Island National Seashore Home Pge. :// .

Fees- Padre Island National Seashore entrance station $10 – go to the Visitor Center where you can tour the exhibits and learn more about the area from informative deck talks given by the rangers as well as have access to the Gulf of Mexico beaches.

The Visitor Center has two wheelchairs designed for use on loose sand available for loan at no charge. Users must leave a driver's license or their personal wheelchair at the information desk while the beach wheelchairs are on loan.

We would like to give our appreciation to the Park Rangers at Padre Island National Seashore for their help with this earthcache and for permit # IMR-SO-PAIS 2501-08-016. Please remember to report to the rangers or visitor center any turtle nests or hatchlings that you may see and to protect and mark their locations with your GPS .

Another helpful suggestion is for you to carry gloves and a trash bag with you on your visit and to help pick up any debris cluttering the island. Leave nothing behind but wonderful memories of your trip here. This truly is one of our national treasures!!! We hope you have enjoyed your trip to the National Seashore and have learned more about this rare water and beach area.

To receive credit for this earthcache, please complete the following requirements and respond to me by email and please do not post the answers:

1. What makes the Laguna Madre so unique? .
2. Go to the posted coordinates for the informative sign located at the access to Laguna Madre and Bird Island Basin. What are the four species indicated on the informative sign that can be found in the Laguna Madre?
3. Post picture of you near the Laguna Madre shore (N27 27.984 W097 18.835) with Bird Island in the background along with your GPS.
4. What was the wind speed on the day you visited the Visitors Center? This is posted at the Center on their deck area where the informative talks are given and also inside the museum area. There is also sand located in a box on the deck that is for handling and showing items that were found on their beaches? What did you find or see in this exhibit?
5. Were you able to participate in any turtle sightings or releases? If so please report what you found and post pictures to share with others.
This is not a requirement but would like to know if you used it while there. An audio tour is now available at Padre Island National Seashore where you can access information about designated sites from your cell phone. There is a number listed on the tall information sign located at Bird Island Basin (N 27 27.981 W097 18.786) near the smaller sign that you were given the listed coordinates to answer question #2. This is also location #2 on their audio cell phone tour. There is no cell phone usage fee for this but your charge would depend on your calling plan. What is this number posted and did you use it or find it helpful during your self-guided tour of the National Seashore Park?

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