A U.S. Defense Department official said one reason there has been a sudden increase in the number of seizures is because the waters off of Africa's east coast have become calmer following an extended period of choppy waters.
But Middleton thought the sudden jump in pirate activity is due to a change in their strategy.
"The weather is definitely a factor, but I don't think the main one," Middleton said. "It seems the pirates would be operating from a mother ship far out at sea away from the military presence, further out in the Indian Ocean where there is a freer environment for them to operate in."
Somali pirates, armed with rocket propelled grenades and plying the seas in small, fast craft, have thrived in recent years in the chaos of a country with no working government and have collected tens of millions of dollars in ransom from shipping companies for the safe return of the their vessels and crews.
The pirate attacks have surged in recent months, however, and gained global attention after pirates grabbed a ship loaded with Russian tanks, rocket propelled grenades and other assault-type weapons.
That attack was followed by the seizure of a Saudi supertanker laden with millions of dollars worth of crude oil.
Both ships were eventually freed after lengthy negotiations and air drops of ransoms that contained millions of dollars in cash.
ABC News' Kirit Radia, Jason Ryan and Anne Marie Dorning contributed to this report.