The birds are mainly juveniles who have likely been unable to feed themselves after fledging from their nests.
Whakatane senior biodiversity ranger Jessyca Bernard said DOC has sent four for necropsy to rule out other causes of death.
"It is concerning that our records of little blue penguin 'die off' events seem to indicate it's happening more frequently," Jessyca Bernard says.
"Like humans all over the world, other animals are also finding that changes in our global climate can have negative effects on their ability to survive.
"Fluctuations in the average annual sea water temperature around northern Aotearoa seem to be having a knock-on effect for seabirds, especially penguins"
When northeast winds and warmer subtropical seas head towards Aotearoa, it changes the prey species distribution and foraging conditions are more challenging for seabirds.
Penguins being flightless are unable to go a long way from the colony to try and reach cooler waters and therefore are more affected in years with warmer water.
If the adults are forced to spend longer finding scarce food, the cost is borne by their chicks not getting fed as much and losing body condition such as vital fat reserves needed to keep them warm at sea.
Adult kororā usually know where to find reliable food supplies but inexperienced younger birds are less fortunate and haven't figured out the best areas yet.
DOC expects these warming events to become more frequent in the years ahead due to increasing carbon dioxide levels in the atmosphere.
The oceans cover 70% of the world's surface but absorb 90% of the excess heat generated by greenhouse gas emissions.
Principal science advisor Graeme Taylor says the La Nina weather pattern is continuing this summer in a rare 'triple dip' event (3 years in a row).
"When this climate sequence last happened in 1998-2000, it caused the third highest die-off of penguins reported washed up on New Zealand beaches.
"It is expected that the warmer sub-tropical seas brought south in these La Nina conditions will affect food availability for penguins and inexperienced chicks will be the group most affected."
Sadly, sick penguins are difficult to rehabilitate but if you come across an injured penguin with cuts or being harassed by dogs, call 0800 DOC HOT.
