Squelching across the ooze in orange Wellington boots, Christian Kpandei cuts a lonely figure as he resumes digging a new home for his precious periwinkles.

Like many here in Kozo Creek, he says an oil slick that washed up late last year painted his dugout canoe black, stained mangroves with a waist-high sheen of sludge and smothered thousands of his spiral shellfish.