What is the difference between cold seeps and hydrothermal vents?

Cold (or marine) seeps are locations where hydrocarbon-rich fluid seeps up from below the seafloor, often as methane or hydrogen sulfide.

• Relatively stable and long-lasting
• Fluid temperatures are similar to surrounding seawater
• Emit gases and fluids including methane, oil, and hydrogen sulfides
• Organisms here grow slowly and can be extremely long-lived
• Occur at tectonically active areas like the Cascadia Margin in the Eastern Pacific, and along passive (inactive) continental margins, like along the U.S. Atlantic coast and the Gulf of Mexico
• Organisms that thrive at seep sites include slow-growing tubeworms, Lamellibrachia luymesi; those found at a seep site in the Gulf of Mexico were over 200 years old and about 2 meters (6 feet) long

Hydrothermal vents are openings on the ocean floor from which magma-heated, mineral-rich water emerges, often forming large chimneys.

• Driven by volcanism; volatile and short-lived
• Highly acidic fluids are of extremely high temperatures (> 400°C/750°F)
• Emit gases comprised of hydrocarbons and hydrogen sulfide
• Rich in minerals that precipitate out forming “white and black smokers”
• Organisms here grow quickly
• Occur at tectonically active areas like the mid-ocean ridges and the Pacific Ring of Fire
• Organisms that thrive at vent sites include giant tube worms (Riftia pachyptila), the fastest growing marine invertebrates on Earth [a little less than 1 meter (~3 feet) in a year]