A study published in the scientific journal Science in 2008 listed 17 big human influences in ocean ecosystems and listed different ecoregions with their mean influence. The Ross Sea was listed with a mean human influence of 0.1, which was the lowest of all ecoregions (the study qualified 4.95 – 8.47 as ‘medium impact’, ‘very high’ was >15.52).

The Ross Sea is one of the largest marine ecosystems that are still structured by natural forces without too much human influence. Yes, there is some fishing going on and historically there has been some whaling and sealing, but this all has, so far, not had a major impact on the ecosystem. Most populations have recovered from the historic hunting and with the new MPA fishing has been banned from important parts of the area.
There are few scientific stations in the area, with McMurdo being the largest station on the continent with in summertime around 2000 scientists. These scientist will have an impact, even though there are regulations in the Antarctic Treaty system that regulate their influence. The new MPA has a large no take zone where no fishing is allowed at all, also for scientists. There is a zone where no commercial fishing is allowed, but scientists are allowed to catch for scientific reasons.
The last group of humans that have a direct influence are tourists. We sail around there and go ashore to see things. Our behaviour ashore is strictly regulated by IAATO regulations. We have strict biosecurity measures (vacuuming our clothes to avoid bringing seeds, we disinfect our boots each time before we go ashore) and regulations how to behave ashore to avoid disturbance.
All of this to keep the world’s most pristine marine ecosystem pristine! I think we’re on the right track for that (if we forget about global influences like climate change…).