Scientists prepare for debate on ocean crisis 150 years after 'extraordinary' expedition

In a few days, several hundred researchers will gather in the UK to discuss the crises facing the oceans - and pay tribute to the expedition that first opened them to the world. scientific review.

Exactly 150 years ago, the Challenger Expedition began a transformation in our understanding of the seas. It revealed the existence of a myriad of life forms at all depths and showed that the ocean floor was not a featureless plain, as then thought, but was dotted with mountain ranges and deep trenches.

"We now know that the oceans play a fundamental role in driving Earth's chemical, physical and biological processes," said Nick Owens, Director of the Scottish Marine Science Association. “They are crucial to the health of the planet and today they suffer from multiple threats. Challenger began that understanding, and it's fitting that we mark the 150th anniversary of the expedition by comparing the state of the oceans then and now. little affected by global warming; acidification caused by absorption of carbon dioxide was not an issue; and the millions of tonnes of plastic that now pollute our seas remained a distant threat. “The picture of the oceans revealed by Challenger provides us with a perfect baseline to examine the state of our seas today,” said Owens, who will speak at the Challenger 150 conference which opens in London on September 6.

Challenger sailed from Sheerness in December 1872 with a company of 250 sailors, engineers and marines – plus six scientists led by Scottish naturalist Sir Charles Wyville Thomson. Over the next four years, the ship, equipped with a steam engine for dredging, sailed 68,890 nautical miles across the Pacific, Atlantic and Southern oceans; took 133 balls from the bottom of the ocean; made 492 deep sea soundings and made 263 serial observations of water temperature along its route.

In addition to measuring sea depths, temperatures and currents, the expedition has collected marine life from all parts of the ocean.More than 100,000 species were collected, preserved and returned to the expedition's headquarters in Edinburgh.It took another 20 years to study these specimens, of which more.. .