Life in the islands fringing the Antarctic Peninsula is abundant, a place of seemingly endless variety. The whole region is richly biodiverse, a living example of how things can be, when free from the influence of man.

We made a landing on the small cobble beach at Hannah Point, named after the British sealing vessel Hannah that was wrecked here in 1820 while operating in the South Shetland Islands.

Vertical cliff edges soar up to 50 metres above sea level where several prehistoric-looking giant southern petrel raise enormous young, fluffed up in self-grown downy duvets.

On the beach a welcoming colony of hundreds of Gentoo penguins stumble about across the stones, sometimes falling flat on their fronts. Others are swimming in the shallows, dipping and gliding underwater.

Elephants seals, colossal and snorting, are packed side by side on the edge of the beach, every now and then one will raise a vast jowly head and give a fearsome steamy roar. It's mesmerising.

Megacolony

The Arctic Sunrise, our Greenpeace host vessel, stopped at known landing points. But while we were at sea we heard of the discovery of a so-called megacolony of up to a million penguins on the Danger Islands in the northern part of the Weddell Sea.

"This discovery more than ever emphasises the need for protection of these waters," said Will McCallum, the campaign leader of the bid to turn a large part of the Weddell Sea into an ocean sanctuary. "It's fantastic to think that colonies of this size still exist but we must protect them."

To the west of the Antarctic Peninsula, it's a different story. Numbers of Adelie penguins are dropping. And last year in the east of the continent there was a mass penguin die-off on Petrels Island. From a colony of about 18,000 breeding penguin pairs, just two chicks survived.

French scientists found thousands of starved chicks and unhatched eggs. It's thought the adults could not reach their feeding grounds because of too much sea-ice, possibly created by an excess of fresh meltwater in the system. It could be just part of the natural order but a similar event happened in 2013, when no chicks survived.

On the whole Antarctic waters harbour a bountiful ecosystem but it is incredibly fragile and the pressures are growing in all directions, from climate change to krill fishing to accessibility.

Another species

Another landing dropped us on the volcanic Penguin Island, where amid all wondrous fecundity, another species stalked the shores - tourists. Just offshore a cruise ship was anchored. Greenpeace expedition guide Tom Foreman told me the numbers of tourists had grown significantly in recent years.

"In the early part of the 2000s, the numbers were around four to five thousand. Now it's more like 30,000 a year," he said.

This is something that has to be closely controlled and it's true to say most cruise operators are heavily self-regulated. Passengers must disinfect their boots and gear, coming on and offshore to prevent the spread of disease between different landing sites. But sometimes, it's impossible to control numbers.

We saw at least two stray tourists wandering dangerously close to some fur seals, whose bacteria-filed bite is so infectious it means a hospital evacuation immediately. So if that's allowed to happen, who knows the dangers the building tourist numbers will present to the animals themselves?

The bottom line is Antarctica is still in pretty good shape. But it's apparent this unique landscape needs to be very carefully managed as multiple threats loom on the horizon.