Food sources of benthic communities at the Caiwei Guyot and Yap Trench, northwestern Pacific Ocean: inferences from carbon and nitrogen isotopes

To investigate nutritional resources for benthic communities at two sites in the northwestern Pacific Ocean (the Caiwei Guyot and the Yap Trench), stable isotopes of carbon and nitrogen (δ13C and δ15N) were measured in the tissues of megabenthic consumers (Porifera, Asteroidea, Crinoidea, Holothuroidea, Ophiuroidea, Gammaridea, and Actiniaria) as well as four potential food sources (suspended particles, sinking particles, zooplankton, and sedimentary organic matter, SOM). Fast-sinking particles are generally thought to be the primary food source for benthic consumers, but that paradigm does not seem to apply at these abyssal sites. Here, the δ13C and δ15N signatures of fast-sinking particles (as collected by sediment traps; δ13C = −24.1 to −22.6‰, δ15N = 1.4 to 5.4‰) were significantly lower than those of the megabenthos (δ13C = −20.1 to −16.1‰, δ15N = 10.2 to 17.9‰), indicating that these particles are not likely a direct food source for the animals. Buoyant particles (and slow-sinking...

为探究西北太平洋两处站点（采薇海山（Caiwei Guyot）和雅浦海沟（Yap Trench））的底栖群落（benthic communities）营养资源，本研究测定了大型底栖消费者（megabenthic consumers）（包括多孔动物门（Porifera）、海星纲（Asteroidea）、海百合纲（Crinoidea）、海参纲（Holothuroidea）、蛇尾纲（Ophiuroidea）、钩虾亚目（Gammaridea）和海葵目（Actiniaria））组织以及四种潜在食物来源（悬浮颗粒物（suspended particles）、沉降颗粒物（sinking particles）、浮游动物（zooplankton）和沉积有机质（sedimentary organic matter, SOM））中的碳氮稳定同位素（stable isotopes of carbon and nitrogen）（δ¹³C和δ¹⁵N）。通常认为快速沉降颗粒物（fast-sinking particles）是底栖消费者的主要食物来源，但这一范式（paradigm）似乎并不适用于这些深渊站点（abyssal sites）。本研究中，快速沉降颗粒物（由沉积物捕获器（sediment traps）采集；δ¹³C为−24.1至−22.6‰，δ¹⁵N为1.4至5.4‰）的δ¹³C和δ¹⁵N特征（signatures）显著低于大型底栖生物（megabenthos）（δ¹³C为−20.1至−16.1‰，δ¹⁵N为10.2至17.9‰），表明这些颗粒物不太可能是该类动物的直接食物来源。浮力颗粒物（buoyant particles）（以及慢速沉降...