Although the vent sites are short-lived -- an individual site may last only 10 years or so -- as an ecosystem they've been stable for millions -- well, billions -- of years.
尽管这些喷口的存在时间很短－－ 大概每个只能延续10年左右－－ 但作为一个生态系统，它们已经很稳定地存在了几百万，甚至几十亿年。