December 12, 2010

Sabine National Wildlife Refuge, Southwest Louisiana

The Sabine National Wildlife Refuge is a 124,000 acre area of coastal freshwater and brackish wetlands located in Southwestern Louisiana. It is a great to place to go to get a sense of what all of coastal Lousiana looked like before the advent of levees, oil/gas drilling, and development that resulted in the loss of half of these lands in the last 75 years.

Much of the Sabine NWR are wet prairies

You can access the Sabine NWR on the Creole Nature Trail, which is a National Scenic By-way leaving from Sulphur, LA off I-10 and heading south to the coast. It is a rich area for birds, being a major stop-over location for neotropical migrants preparing for their trip across the Gulf of Mexico in the fall or arriving from that arduous jouney in the spring. It contains a combination of open wet prairies, marshy freshwater wetlands, and brackish salt marshes and tide flats.

Snow Geese in a marshy pond

It is also a major wintering area for arctic species such as snow geese and summer breeding grounds for a variety of subtropic wetland birds such as roseate spoonbills, ibises, herons, and egrets. While most of the birds were located pretty far away, I was able to put my little Cannon digital camera into my binoculars (thanks John) and lay it again the railing of the watch tower to get these decent close up shots of the birds. It was almost like having a scope!

A couple of moorhens wading in the marsh

But, of course, it isn't as if the Sabine National Wildlife Refuge is a pristine wilderness. It too is experiencing many of the same problems that the rest of coastal Louisiana is. Canals have been dug, oil wells drilled, subsidence is happening, and the sea is encroaching.

The Intercoastal Waterway is a dredged channel that circumnavigates the refuge.

The Intercoastal Waterway is a 3000+ mile transportation corridor that runs from New Jersey to Brownsville, TX. It follows natural inlets and sounds where barrier islands provide protection from hazards of the open ocean. Where such features are not available, it has been dredged into a channel through coastal wetland marshes and swamps. The effects of this dredging can be devasting in some areas, by adding additional influxes of salt water and increasing erosion. But, it is an important economic corridor. You cross it several times as you visit several parts of the Creole Nature Trail. It is heavily used for barge traffic and the petroleum industry, but is also popular with recreational boaters and yachters. It is the primary route for people doing the Great Loop from New York to New Orleans to Chicago and back to New York.

A brackish canal in the middle of the refuge

Lake Calcasieu is a brackish lake that runs from the Gulf Coast all the way up to Lake Charles some 40 miles inland. Sabine National Wildlife Refuge borders its western edge. But, much of the lake has been dramatically altered by shipping, dredging, and the oil industry. What was once a large shallow tide flat and salt marsh is now a large open lake.

Tide flats on the edge of Lake Calcasieu

The natural outlet to the sea has been widened and channelized to allow shipping traffic all the way to the refineries in Lake Charles. We crossed it on the little free ferry that is there for industrial trucks.

The little shuttle ferry crossing the channel

Atlantic bottlenose dolphins frequent Lake Calcasieu (see middle right)

The U.S. Fish and Wildlife Service is doing things to try and mitigate the effects of industry on the refuge and the wildlife. One thing they have done, which I was unable to take a photo of, is that they have installed wave berms in the open water areas that form due to subsidence or hurricane damage. These berms slow down the wave action on open ponds, causing less erosion on the edges. They also encourage the deposition of silt in the middle of the ponds and allow marsh plants to grow and reclaim the open water from the inside-out.

Recovery of marsh grasses after a prescribed burn

You wouldn't think that fire would be a common or important part of a wetland ecosystem, but it is. Typically, when the marsh grasses died, the tops of them would dry out, despite being in standing water. Fires started by frequent lightning strikes would burn away the old stuff and encourage new growth. That new growth was very important for a variety of wildlife. The U.S. Fish and Wildlife Service is now conducting prescribed burns on the prairies and wetlands to restore the natural processes that had stopped due to 100 years of fire suppression.

Hilina checking out the blowing fluff of a cattail catkin

We did two of the nature trails in the refuge. One to the brackish mudflats of Lake Calcasieu and the other the 1.5 mile boardwalked Wetlands Walkway loop. Amazingly, despite temperatures in the low 50's and a stiff breeze, there were still a few mosquitoes buzzing us. I can only imagine what this place is like in summer.

View of the marsh with snow geese without binoculars

We did see a flock of roseate spoonbills in the marsh and three flew directly overhead, but I was unable to take a picture of those really cool birds. They are Hilina's favorite because they are pink. Look them up on wikipedia to see what they look like if you have never seen one before! We also saw three white-faced ibis fly over.

Young live oaks recovering from the effects of Hurricanes Rita (2005) and Ike (2008)

One special "ecosystem" of the Sabine area are the live oak stands called "chenins". These chenins formed on deltaic crescents that were deposited when the Mississippi River flowed through this area some 5,000+ years ago. These slivers of high land are only a few feet above the surrounding marshes, but high enough to allow enough drainage through the sand for live oaks to grow. Some oaks are said to be up to 2,000 years old. But, subsidence, erosion, and the effects of numerous hurricanes are taking their toll on these little islands of forest in a sea of marsh.

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