Red tide a concern as whooping cranes land at Aransas National Wildlife Refuge

Nov 10, 2011 | Corpus Christi Caller-Times by Mark Collette | Related Press

Red tide a concern as whooping cranes land at Aransas National Wildlife Refuge

By Mark Collette

CORPUS CHRISTI — As the first whooping cranes of the season arrive at the Aransas National Wildlife Refuge, biologists there are worried that ongoing red tide may affect the endangered birds, which are sensitive to any changes in their environment.

It’s unclear what effect red tide, a toxic algae bloom that causes respiratory symptoms in humans, will have on the flock, but red tide is known to be fatal to birds, said Dan Alonso, manager of the refuge.

The red tide toxin tends to accumulate in razor clams, one food source for the birds, Alonso said.

Even if there is a harmful effect on the flock, there’s little wildlife officials can do because red tide is a natural occurrence, he said.

The persistent red tide bloom has lingered for weeks in the Coastal Bend and proved resistant to the weekend’s cool front.

The toxic algae seems to have regrouped and settled in Corpus Christi Bay, said Meridith Byrd, a harmful algae biologist with Texas Parks & Wildlife. Red tide in high concentrations can kill and particles of the toxin spread through the air can cause eye and throat irritation and coughing.

On Monday the bloom discolored Corpus Christi Bay from Indian Point to the Lexington Museum on the Bay and again near Oleander Point in Cole Park and at Swantner Park at the intersection of Ocean Drive and Airline Road.

Since September, red tide has killed an estimated 4.2 million fish from Galveston to Brownsville.

Patches of the red tide and dead fish were spotted Monday at the Victoria Barge Canal, at the east side of the Aransas National Wildlife Refuge; at Goose Island State Park and in Corpus Christi Bay at La Quinta Channel and Joe Fulton Canal.

Two whooping cranes sightings have been confirmed inside the refuge, manager Dan Alonso said. The flock is spread out between there and its nesting grounds in Canada on its yearly migration.

It’s expected to set a record for the second straight year, reaching about 300 birds, Alonso said.

That would break the 2010 population of about 280 whooping cranes that made the 2,400-mile journey from Canada to the Coastal Bend. The cranes teetered on the brink of extinction in the 20th century, and the population has risen from 16 birds in the 1940s.

Known for their size and their trademark honking sounds, the cranes stand up to 5 feet tall with a wingspan of more than 7 feet. They are marked by black wingtips and red crowns.

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