Researchers with the pollution control outfit Ocean Cleanup recently completed the first aerial survey of the Great Pacific Garbage Patch, and the results are rather grim. The accumulation of garbage in the middle of the Pacific Ocean is even bigger than expected.

"While the flight plan took us along the Northern boundary of the patch, more debris was recorded than what is expected to be found in the heart of the accumulation zone," researchers wrote in a blog post.

Using their eyes as well plastic scanning equipment, researchers tallied pieces of debris larger than 0.5 micrometers -- 1.5 inches and up. Over the span of just 2.5 hours, the crew aboard the C-130 Hercules aircraft visually counted more than 1,000 pieces of debris.

Additional survey flybys will be conducted this week. Once completed, the data will be combined with observations made during a boat-based survey of the garbage patch conducted in 2015. Ocean Cleanup's Mega Expedition featured 30 research vessels and produced the first complete map of the garbage patch.

The combined data from the sky and sea surveys will be presented in a scientific paper to be published in 2017. The exploratory work is all in preparation for an ambitious cleanup attempt, which is scheduled to begin before the end of the decade.

"The Aerial Expedition -- our final reconnaissance mission -- brings us another step closer to the cleanup of the Great Pacific Garbage Patch," said Boyan Slat, CEO and founder of The Ocean Cleanup. "The initial findings of the expeditions again underline the urgency to tackle the growing accumulation of plastic in the world's oceans."