April 2007

Baby Bird Island

One of Galveston Bay’s few remaining natural islands, North Deer Island, is a 144-acre bird maternity ward.

By Henry Chappell

North Deer Island’s inhospitableness makes it the perfect place for a rookery. The 144-acre island sits in Galveston Bay, about three miles west of the Galveston landing of the I-45 causeway — too far for coyotes to swim. There’s little fresh water, so smaller mammalian predators such as raccoons are scarce. Diamondback rattlesnakes, however, thrive there.

As do birds. Eighteen species of colonial waterbirds and shorebirds nest on the island, including great blue herons, great egrets, roseate spoonbills, royal terns, black-crowned night-herons, white ibis, neotropic cormorants, the federally endangered brown pelican, and the state-endangered reddish egret and white-faced ibis. As many as 30,000 nesting pairs have been documented there during peak breeding season.

Since the 1950s, erosion and subsidence, due mostly to human activity in the Galveston Bay area, have claimed an average of 5 feet of the island’s shoreline per year, and up to 20 feet during tropical storm years.

North Deer is one of the bay’s few remaining natural islands. Several islands that once provided habitat for colonial birds have disappeared or have been rendered uninhabitable by sand dumping from dredging operations. South Deer Island has eroded to the point where it’s no longer viable rookery habitat. Down Deer Island, sometimes called Middle Deer, disappeared decades ago.

Galveston Bay is a working estuary, the largest on the Texas coast. Through the 1990s, commercial shrimp harvest averaged over 5 million pounds per year. The bay produces more oysters than any single body of water in the country.

About 30 percent of the nation’s petroleum industry is located there. In terms of foreign tonnage, the Port of Houston is the largest port in the U.S. These are the realities. Side effects of commerce, abetted by indifference and economic inertia, destroyed most of Galveston Bay’s islands. Another human enterprise, engineering, may save the bay’s most important island rookery.

I smelled the birds before I saw them.

From behind the steering wheel of our 21-foot Bay Runner, TPWD biologist Jamie Schubert said, “This is it.” For a few seconds, I couldn’t resolve the mass of bills and feathers in front of me. Then one of the birds spread its wings, and what had looked like a tangle of hackberry and dead limbs became a clump of a dozen juvenile brown pelicans lounging in the late-morning sun.

We had come upon the island suddenly after heading south from Tiki Island Marina through steady rain. One instant I was bent against the downpour, peering beneath the wet bill of my cap; the next instant I was squinting at pelicans and groping suddenly for my sunglasses.

To me, a Kentuckian transplanted in North Texas, the bay felt ominous, foreign. Tides and hazards, boat roads, volatile weather that only baymen seem to understand. The rain, wind and sudden appearance of the island added to the effect.

I can’t call North Deer Island picturesque, but it has a familiar, rough, scrubby, wild quality, like a productive piece of West Texas rangeland — diverse, harsh, teeming. For every wild thing you see, thousands more slither, scuttle, squirm and flap back to hide in the island’s ever-present brush.

Pelicans seem to be taking over the island, or at least expanding their territory, but no one’s complaining. The brown pelican is the only federally listed endangered species known to nest on the island. In 2003, 31 percent of all breeding brown pelicans in Texas — 1,500 to 2,000 pairs — nested on North Deer Island.

The brown pelican population dropped to a low of about 100 birds in the late ’60s and early ’70s, mostly because of DDT poisoning. The birds’ numbers have steadily risen since the Environmental Protection Agency banned the pesticide in 1972.

“When I moved here in 1988, you didn’t see pelicans,” Schubert said. “Now you see them every day.”

Like most colonial water birds, pelicans nest primarily in brush and trees on coastal islands. On North Deer, they use the uplands along the northern and northeastern shoreline and forage in the surrounding marshes.

Lime prickly ash, mesquite, paloverde, mulberry, hackberry and woolybucket bumelia dominate the higher ground. Lantana is the predominant shrub. Prickly pear is also commonly found in the uplands.

Dredge material that was dumped over 60 percent of the island actually increased the upland rookery. “One of the reasons this island is so important is that the dredge spoil raised more of it above the tidal range, so that we have greater diversity of trees,” Schubert said.

Those trees seemed to be growing pelicans. The young birds lazed, at once dignified, grotesque and comical, occasionally lifting into stately flight.

Although North Deer’s importance increased as other bay islands disappeared, Winnie Burkett, Audubon Texas’ colonial waterbird steward, says she doesn’t believe that the island gets a disproportionate number of birds. “I don’t think there’s a bigger concentration on North Deer than in the days when islands were abundant,” she said. “I suspect we had a lot more birds when there were more islands.”

Erosion loss on the steep northeastern shoreline is exacerbated by the longshore currents (currents running parallel to the shore) caused by the proximity of the Gulf Intracoastal Waterway (GIWW), which runs just 30-100 feet to the north. Galveston Bay’s natural depth typically ranges between 3 and 10 feet, so it’s not surprising that the dredging of the GIWW has drastically altered underwater currents.

We cruised west, along the northern shoreline where the uplands slope more gently to merge with salt marsh. TPWD biologist Shannon Torrance and I passed binoculars back and forth. Torrance had just joined the team at the Dickinson office after completing her doctoral studies at Texas Tech University. This was her first look at North Deer.

Though pelicans were still much in evidence, we began to see ibises (both white and white-faced) and great egrets foraging in the smooth cordgrass, salt wort and grass wort for shrimp and other crustaceans. A juvenile great blue heron, his head just visible above the grass, croaked and flapped toward the island’s interior. Willets and ruddy turnstones hunted along the edge, where marsh meets uplands. Laughing gulls wheeled overhead. Mullet jumped in patches of open water. We’d caught the tail-end of breeding season in early August. Had we arrived in peak breeding season — May and June — bird numbers would have been even higher.

In addition to providing forage for wading birds, these island marshes are important nurseries for shrimp, crab, menhaden, sea trout, flounder, red drum, Atlantic croaker, and other fin and shellfish.

Longshore currents are eating away at this 4,600-foot stretch of northern shoreline. Schubert eased the boat around to the southwestern shore. Twice he had to lift the prop and pole us into deeper water. Scores of ibis foraged in the marsh. Schubert pointed out a juvenile yellow-crowned night-heron. Through binoculars, I got a good look at the subdued juvenile plumage, the tan streaking on the breast, the thin neck and dark bill.

This shoreline is much less susceptible to wave erosion than it was only a few years ago. About 100 feet from shore, what looks like a long oyster bar is actually an artificial 900-foot breakwater constructed of stiff clay dredged from the bottom and armored with limestone. Like a natural reef, the break-water lessens erosion by tripping up incoming waves. A similar breakwater runs along the southern shoreline.

Schubert pulled up alongside the structure, climbed out and walked along the top to inspect a small washout. Appropriately, an oystercatcher picked its way through the limestone rip-rap — another addition to my life list and an interesting departure from my usual grassland and woodland birds.

The breakwater was constructed in spring 2003 under Phase I of the North Deer Island Protection and Restoration Project. Phase II of the project, currently funded by TPWD, U.S. Fish & Wildlife Service, Texas General Land Office, NRG Energy, Houston Audubon Society, Galveston Bay Estuary Program, National Fish & Wildlife Foundation, Environmental Protection Agency/Gulf of Mexico Program, Texas GenCo EcoCenter, Shell Marine Habitat Program and the Harris and Eliza Kempner Fund, will stabilize 5,750 feet of shoreline, benefiting 89 acres of coastal habitat, including 57 acres of marsh.

Schubert, the project leader, plans to put the bid out early this summer. Construction should start around September 1.

The project will address erosion loss and marsh restoration only. Bay island subsidence, caused in part by withdrawal of groundwater during development of the Texas City industrial complex, has declined significantly now that the area relies on water from impoundments.

Erosion along the steep northwestern shoreline will be stanched by a rock revetment built directly on the bank. Along the northern shoreline, seven rock “groins,” jetties protruding perpendicular to the shore, will lessen erosion by disrupting parallel longshore currents.

The southern and southwestern shorelines will be protected by continuation of the breakwaters constructed during Phase I, totaling 4,600 and 3,600 feet of protection, respectively.

In addition to erosion mitigation, these rock structures also provide substrate for oyster spats and other encrusting organisms, leading to further reef development.

Along the southwestern shoreline, sediments leftover from dredging of the breakwater channel will be deposited between the breakwater and the island shoreline and graded to an elevation suitable for marsh development.

Phase II improvements should protect 49 acres of marsh and 25 acres of upland habitat. About 8 acres of marsh will be restored through distribution and grading of sediment dredged from barge access channels, along with the planting of cordgrass and other native marsh plants donated by the Texas GenCo EcoCenter.

Even after Phase II completion, Galveston Bay’s colonial birds will remain vulnerable. “When we have all of our birds on one island, and there’s a problem, we can lose an entire nesting season,” Winnie Burkett said. “We need to spread things out; we don’t want all our eggs in one basket. The more healthy islands we have in the bay, the better.”

Artificial islands constructed of dredge material from the widening of Houston Ship Channel should eventually provide bird habitat. “Those islands are still pretty raw, but they’re beginning to grow vegetation,” Burkett said. They should start being more attractive to a variety of birds.”

Heading for the marina, we rode back into rain. Torrance and I sat up front, heads down, tugging our cap bills — an appropriate spot for the new kid and the pesky writer.

To the northwest, a barge lumbered along the Intracoastal Waterway. Massive, ugly, threatening and much like the vessel that will house the engineering crews who’ll build the breakwaters, groins and revetments at North Deer Island.

Irony and hope abound throughout Galveston Bay.

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