Deep Sea News

Although the earliest interest and sampling in the deep sea occurred in the late 1800's, a majority of deep-sea exploration did not occur until after the 1960's. The current amount of sampling and exploration of this great environment is without precedent. Despite this, new species and new habitats are constantly being found (e.g. Roxanne...You Don't Have to Put on the Red Light!). Hydrothermal vents were not discovered until 1976. So how much of the deep sea has actually been explored or sampled? This is indeed a tough question to answer. To derive an exact answer we would have to know of every single sample of every deep-sea expedition taken plus all the submersible and ROV dives and how much area they have covered. Of course this is extremely unreasonable, but an exercise in estimation...

ROVS and Submersibles
Total Number of ROVS and Submersibles 20
Total Number of Operational Years 30
Total Number of Dives Per Day 1
Total Number of Lifetime Dives 153600
Total Distance Covered in Each Dive (km) 1
Effective Viewing Distance (m) 10
Area Covered Per Dive (km2) 0.01
Total Area Covered by ROV and Submersibles (km2) 1536

Trawls and Sledges
Average Trawl Distance (km) 1
Average Trawl Opening (m) 5
Total Area Sampled Per Trawl (km2) 0.005
Number of Total Trawls 20000
Total Area Covered by Trawls and Sledges 100

Cores
Core Size (m2) 1
Total Number of Cores 20000
Total Area Covered by Cores (km2) 0.02

Benthic Landers
Total Number of Benthic Landers 20
Total Visual Field (km2) 1
Total Area Covered by Landers (km2) 20

Total Area of Deep Sea Sampled (km2) 1656.02
Earths Surface Area (km2) 150000000
Percentage of Surface Covered by Deep Sea 70.8%
Area of Deep Sea (km2) 106200000
Percentage of Deep Sea Area Covered 0.0016%

The above estimate is likely to be unreasonably high for several reasons. The assumption that all the ROV's/submersibles dive every day is unreasonable and does not take into account downtime for travel to sampling sites or maintenance. Likewise, although the total number of ROV's/submersibles is near the current total estimate not all of these have been in operation since 1975, although the Alvin was commissioned in 1964. I also feel that the total distance covered per dive is high, especially when dives visit specific features such as hydrothermal vents or methane seeps. Perhaps more importantly, the assumption that each of the above samples/dives were taken in a unique location is unlikely has ROV's/submersibles dives frequently return to specific sites. I can adjust these parameters (reduce the operational years to 20, dives occur every other day, and limit travel distance to 0.75km) the estimate falls to 504.03 km2 or 0.0005% of the deep-sea floor. In addition, the trawl distance, average trawl opening, total number of trawls and cores, and field of few for the benthic landers are likely to be high as well.

Because these are rough calculations, I encourage any comments or revisions to these estimates.