- Breeding Season: Invertebrates, sea turtles, and birds will be facing the brunt of the spill just as they are laying eggs or caring for them in important wildlife areas.
- Trans-Gulf Migration Season: "We're near the peak of the trans-gulf migration," said David Viker, the U.S. Minerals Management Service's southeast regional chief for migratory birds. "Tens of millions of tiny feathered birds that could fit in your hand are making the jump from South America to North America and are exhausted upon arrival."
- Hurricane Season: A big storm could complicate recovery and cleanup efforts and spread oil throughout the gulf. NOAA and others are predicting a particularly rough year for Atlantic storms, with Colorado State University's respected Bill Gray forecasting 15 named storms and four major hurricanes.
The first of June is the official start of hurricane season, but the storms may come sooner. No hurricanes have hit the United States in May, but 18 tropical storms have formed in the Pacific this month. "We get a hurricane in here in the next month and that completely complicates the paradigm," said environmental toxicologist Ronald Kendall of Texas Tech University in Lubbock. One drop of oil on an egg can kill young invertebrates, he says.
- La Niña: Moderate El Niño conditions are expected to dissipate by June. That phenomenon, which means warmer Pacific waters, creates so-called wind shear in the Atlantic that helps break up hurricanes as they form. So without El Niño, June storms might be more likely to form. In its place, say several climate models, is a La Niña period, which means warmer temperatures in the southern areas of the United States and generally more powerful storms.
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