导论：深海研究的范式演变与本书框架

> Deep-sea science, as one of the youngest frontiers in geosciences, has witnessed paradigm shifts driven by both technological breakthroughs and the expansion of cognitive boundaries. Over the past 150 years, human understanding of the deep ocean has evolved from the perception of a “lifeless dark abyss” to a dynamic sphere teeming with biological activity and tightly coupled to the global Earth system. This chapter first traces the historical evolution of deep-sea research paradigms, from the first systematic sampling voyages in the 19th century to the development of in situ observation systems in the 21st century, analyzing key technological innovations and core discoveries at each stage. It then clarifies the logical connections among the three core research areas of this book—deep-sea hydrothermal vents, seamounts, and deep-sea organisms—and explains the interdisciplinary research value across these fields. Finally, it introduces the bilingual reading guide, the use of supporting digital resources, and a bilingual glossary of core deep-sea research terms, laying the foundation for in-depth learning in subsequent chapters.

1.1 深海研究的范式演变历程：从采样时代到原位观测时代

The evolution of deep-sea research paradigms can be roughly divided into four stages, each marked by breakthrough technologies that expanded the depth and breadth of human exploration.

1.1.1 19世纪：采样时代的开启

The starting point of systematic deep-sea research is widely recognized as the 1872–1876 Challenger expedition, the first global oceanographic voyage funded by the British Royal Society. The converted naval survey ship HMS Challenger sailed 129,000 kilometers across the Atlantic, Pacific, and Indian Oceans, measuring depth at 492 deep-water stations using a weighted hemp rope with a depth measurement error of less than 1% for depths below 2000 meters. The expedition collected 4,000+ previously unrecorded species, including deep-sea isopods, radiolarians, and foraminifera, and confirmed the existence of deep-sea sediments including calcareous ooze, siliceous ooze, and red clay. The deepest measurement recorded during the voyage was 10,862 meters in the Mariana Trench, later named the Challenger Deep, marking the first confirmation of the existence of hadal zones (depth >6000 meters) ^[1].

Before the Challenger expedition, the mainstream scientific view held that the deep sea was a lifeless, cold, high-pressure, lightless environment incapable of supporting complex life, as all known ecosystems relied on photosynthesis for energy. The discovery of deep-sea organisms during the expedition broke this cognitive bias for the first time, but the scientific community at the time still believed that deep-sea ecosystems relied entirely on the input of particulate organic carbon (POC) sinking from the upper ocean, known as “marine snow”. The sampling methods of this era were extremely limited, with samples only obtained from single stations, unable to reflect the spatial distribution and dynamic changes of deep-sea ecosystems.

<!-- 纸书注：此处可配图1-1 挑战者号航迹与深海采样点分布示意图 --> ^[1] Data source: British Oceanographic Data Centre, 2023 updated Challenger expedition dataset.

1.1.2 20世纪上半叶：探测技术的初步突破

The 1920s saw the widespread application of echo sounders, which replaced weighted rope depth measurement and improved depth measurement efficiency by nearly 100 times. A single voyage could map thousands of kilometers of seafloor topography, leading to the discovery of abyssal plains (flat seafloor areas at 3000–6000 meters depth) and seamounts (isolated underwater mountains with heights ranging from hundreds to thousands of meters). Although the global distribution of seamounts was not fully mapped at this time, later multibeam sonar surveys confirmed that there are more than 100,000 seamounts worldwide, over 90% of which are located in the high seas and have not been fully explored ^[2].

In the 1930s, the Carnegie Institution of Washington’s research vessel Carnegie conducted the first large-scale measurements of deep-sea geochemical parameters, including dissolved oxygen, nutrients, and pH. The results showed that deep-sea dissolved oxygen levels were extremely

low, with values often below 0.5 ml/L in the North Pacific Deep Water, while nutrient concentrations (nitrate, phosphate) were 10–100 times higher than surface waters, confirming that deep-sea water masses are isolated from atmospheric exchange for long periods. These early geochemical measurements laid the foundation for the later discovery of deep-sea chemosynthetic ecosystems.

1.1.3 20世纪下半叶：范式转折与热泉革命

The second half of the 20th century witnessed two technological breakthroughs that fundamentally overturned the long-standing “heterotrophic dependency” paradigm of deep-sea ecosystems: the development of crewed deep-submergence vehicles (DSVs) and the first in situ observation of hydrothermal vent communities. In 1960, the Swiss-designed, Italian-crewed bathyscaphe *Trieste* successfully dived to the bottom of the Challenger Deep in the Mariana Trench, reaching a depth of 10,916 meters, piloted by U.S. Navy Lieutenant Don Walsh and Swiss oceanographer Jacques Piccard. The 20-minute stay on the hadal seafloor observed a flatfish (later identified as a hadal snailfish, *Pseudoliparis swirei*) swimming slowly over the silty bottom, providing the first direct visual evidence of multicellular life at full ocean depth. Although the *Trieste* had no sampling capability, this dive shattered the prevailing scientific belief that no complex life could exist at pressures exceeding 1,000 atmospheres, opening the door for systematic deep-submergence exploration. The paradigm-shifting discovery came in 1977, when the Woods Hole Oceanographic Institution’s (WHOI) crewed submersible *Alvin* conducted a dive along the Galápagos Rift at a depth of 2,500 meters. Instead of the expected barren basalt seafloor, the dive team observed dense communities of giant tube worms (*Riftia pachyptila*, up to 2 meters in length), giant clams (*Calyptogena magnifica*), and red-shelled shrimp (*Rimicaris exoculata*) clustered around cracks in the seafloor spewing dark, mineral-rich fluid at temperatures up to 350°C. Subsequent geochemical analysis confirmed that these fluids were hydrothermal vent fluids, rich