The HMS Challenger Expedition (1872-1876)

The HMS Challenger expedition, sailing from Portsmouth, England in late December, 1872 and returning late May, 1876, remains today one of the most relevant oceanographic expeditions in history. It sailed almost 70,000 miles, making port stops on every continent except Antarctica and gathering enough oceanographic data to fill 50 volumes “each the length of a bible” states Judith Wolf, a scientist at the National Oceanography Centre Liverpool. The total amount of published data totaled 29,500 pages and took 23 years to complete. Almost 5000 new species were discovered, as well as hundreds of depth soundings, water samples, bottom temperature measurements, and temperature profiles. The discoveries made, samples collected, and measurements taken during the three year voyage are still relevant to scientists today and provide and important baseline for what a pre-industrial ocean looked like, something that is invaluable in the time of climate change and ocean acidification.

In 1843, a naturalist named Edward Forbes proposed the theory that the number of animal individuals and species diminishes with depth and dwindles down to virtually zero below 1,800 feet. Samples collected by later voyages of the HMS Lightning and HMS Porcupine found evidence refuting this theory; clams, scallops, and corals below the theoretical depth limit proposed by Forbes. Charles Wyville Thompson, an Edinburgh University professor and marine zoologist who would later become the chief scientist of the HMS Challenger expedition, believed in the likelihood of life in the deep sea and persuaded the Royal Society of London and, subsequently, the Royal Navy, to support a detailed and lengthy voyage with the sole intention of learning more about the biological, physical, chemical, and geological components of the global ocean. There was also an economic motivation to explore the ocean: with the invention of the telegraph, seafloor topography became much more important because the seafloor was the only way to connect Europe and North America by telegraph. According to the Birch Aquarium at UC San Diego, the primary motivations for the voyage were:

• To investigate the physical conditions of the deep sea in the great ocean basins (as far as the neighborhood of the Great Southern Ice Barrier) in regard to depth, temperature, circulation, specific gravity and penetration of light.
• To determine the chemical composition of seawater at various depths from the surface to the bottom, the organic matter in solution and the particles in suspension.
• To ascertain the physical and chemical character of deep-sea deposits and the sources of these deposits.
• To investigate the distribution of organic life at different depths and on the deep seafloor.

With these goals in mind, the HMS Challenger set out from Portsmouth, England on 21 December, 1872 with a crew of 243. Among those were only 5 scientists, 21 officers, a prosector (one who cut up bodies for dissection), a scientific illustrator, and 216 crew members. Only 144 would remain at the end of the voyage.

The HMS Challenger began her career as a Royal Navy ship in 1858 and was the flagship of the British naval command responsible for the waters around the Australian continent between 1866 and 1870. She was a 200 foot long, square-rigged corvette with 17 guns and a 1200 horsepower steam engine. To prepare for the voyage, all but two of her 17 guns were removed to make space for laboratories, workrooms, and storage space for samples. The steam engine was primarily to be used when deploying heavy gear and conducting scientific operations, otherwise she was to be under sail. The Challenger was filled to the brim with everything the scientists and crew would need for the voyage, including specimen and sampling jars, alcohol for preserving samples, and various scientific tools and instruments including 180 miles of Italian hemp rope for making depth soundings, barometers to measure pressure, dredging and towing equipment, thermometers, and equipment used to take various types of sediment, water, and biological samples.

As crucial as the voyage and discoveries made by the Challenger were, daily life aboard the HMS Challenger during the expedition was intense and often grueling. The days were long, the rations minimal, and the work often tiresome. Most records of the voyage come from the officers and scientists, typically the more educated members of the voyage, so accounts from the crew are rather minimal compared to the scientific and official records. However, a 19-year-old steward's assistant named Joseph Matkin sent many letters to his cousin throughout the voyage, which provide an account of the day-to-day happenings onboard. Matkin was highly literate, and his point of view has helped historians understand the perspective of a crew member who had minimal scientific affiliation, but was curious about the scientific happenings onboard. His point of view often shares the point of view that historians can assume was popular with the rest of the crew: they were tired of many things about life at sea, and the tendencies of the "scientifics," as the scientists were frequently referred to. Over 50 crew members are assumed to have deserted throughout the voyage, mainly in the ports of Australia. As important as the expedition was for oceanography, life for those onboard was certainly hard.

Shortly after embarking, Matkin described the scene onboard the ship, saying, “All the Scientific Chaps are on board, and have been busy during the week stowing their gear away. There are some thousands of small air tight Bottles, and little boxes… packed in Iron Tanks for keeping specimens in, insects, butterflies, mosses, plants, etc. There is a photographic room on the main deck, also a dissecting room.”

“When the dredge is hauled up [the scientists] stand round in their shirt sleeves, and commence overhauling the mud for fish etc., and as soon as they get any, down they all go to dissect and pickle them in glass jars."

On the food, Matkin wrote, “I have never been so hungry. I will tell you what the routine for meals is now: at 6AM Breakfast of Cocoa & hard Biscuit… at 11.30, dinner; one day it is salt pork & pea soup – the next salt Beef & Plum duff, the next salt Pork again & the 4th – Preserved potatoes & Australian Beef in tins… if any one can get fat on that in 4 years they must eat more than their allowance.”

He also describes the religious services onboard: "We had a short service in the morning, the Captain officiates for we are not allowed a Chaplain, only Ships carrying 295 men & upwards are allowed a Chaplain and we have only 242 on board."

From his letters, we know that he was frustrated with the communication of the officers and scientists down to the crew: “You will read better accounts of these islands—and of the 2 men whom we are bringing away [recent rescues]—in the newspapers, for the scientifics have nothing else to do but go on shore & gather their information for the papers.”

To read a detailed account of the voyage from Matkins, click here:

The discoveries made by the HMS Challenger were groundbreaking in the field of oceanography, and proved that there was indeed a wealth of life in the ocean deeps. The depth soundings taken throughout the voyage helped provide a more complete picture of the seafloor and further proved the the ocean basins were far from flat. Furthermore, in March 1875, scientists were taking a standard depth sounding off the coast of Guam and stumbled across the Mariana Trench, measuring a depth of 4,475 fathoms, or 26,850 ft. To honor this discovery, the deepest point in the Mariana Trench was named the Challenger Deep. Over 4,700 new species were discovered and catalogued throughout the expedition, with samples remaining in museums all over the world that are still studied today. Many of these samples are being used to study the effects of climate change and acidification on the oceans because they provide insight into what our oceans looked like before the industrial revolution began to significantly alter our oceans through massive releases of carbon dioxide.

The temperature and chemical measurements taken throughout the voyage are some of the most crucial takeaways from the voyage. They also provide a baseline for what a pre-industrial ocean looked like and a reference point for how much we've truly altered the oceans since the dawn of the industrial revolution. This data is crucial to scientists studying climate change's impacts on the ocean today, and they can help give us an idea of what the oceans will look like in the future if we remain on this track.

The HMS Challenger expedition was the first major expedition in modern history funded solely for the purpose of scientific discovery. Its findings were momentous and changed the foundation of the study of oceanography from something studied on a small scale by regional scientists to a global study, something to be approached as a single, integrative system rather than just a local concern. The specimen collected and samples and readings taken throughout the voyage are still relevant to scientists today, and have become especially important as we try to understand how anthropogenic climate change and related issues are affecting the ocean today. According to Rachel Mills, the dean of environmental life sciences at the University of Southampton, UK, "If you're studying a certain shellfish, and you know that the shells are becoming thinner because of the rising acidity of the oceans, we have that record of what they were like 150 years ago thanks to Challenger." The legacy and spirit of the Challenger has inspired many namesakes, including Challenger Deep, the deepest known point in the ocean, and the NASA shuttle Challenger, and inspires many ocean explorers today.