Somali pirates who are demanding $7 million in ransom for a British sailing couple said Saturday that boats from other countries are plundering Somalia's fish-rich waters.

Ahmed Gadaf, who described himself as a spokesman for the pirates, said Western fishing vessels "harass" local fishermen and destroy their nets. Gadaf spoke to The Associated Press by satellite phone.

Gadaf says the British couple, Paul and Rachel Chandler, are safe and will not be harmed.

SLIDESHOW: British Couple Kidnapped by Pirates

The Chandlers were headed to Tanzania in their boat, the Lynn Rival, when a distress signal was sent Oct. 23. The British navy found their empty yacht on Thursday, and both have been in sporadic contact with the British media since.

Illegal fishing off the coast of Somalia stirs strong passions in the country. The country's prime minister, Omar Abdirashid Ali Sharmarke, said in a speech Wednesday that many countries are fishing illegally in Somali waters and have pushed formerly profitable Somali fishermen into the pirate trade.

He also said during Wednesday's appearance at London-based Chatham House think tank that many pirates are former fishermen "responding to the loss and disappearance of their livelihoods."

Helene Bours, an expert on fisheries in Africa who works as a consultant for non-governmental organizations in Africa and Europe, said she was skeptical that international overfishing in Somalia had a significant effect on the rise of piracy.

"The extent to which the piracy business has developed is way beyond a few fishermen turning (into) pirates," she said.

Bours most international ships operated far from the Somali coast in order to bring in deep-sea fish, and would not be competing with smaller Somali fishing boats working closer to shore. She cautioned however, that the lack of reliable information from the chaotic country made any assessment unreliable.

Sharmarke said he was aware of extensive foreign fishing off Somalia's coast.

"I shall not name names, but suffice to say many countries are fishing illegally in Somali waters," he said. "We estimate that the value of the fish being taken from our waters is perhaps hundreds of millions of dollars."

Pirate attacks have increased the last several weeks after the recent end of the monsoon season. An international armada is patrolling the region to try to stop the attacks.