A deep-sea isopod that consumes Sargassum sinking from the ocean's surface.

Most deep-ocean life relies on organic carbon from the surface ocean. While settling primary production rapidly attenuates in the water column, pulses of organic material can be quickly transported to depth in the form of food falls. One example of fresh material that can reach great depths across the tropical Atlantic Ocean and Caribbean Sea is the pelagic macroalgae Sargassum. However, little is known about the deep-ocean organisms able to use this food source. Here, we encountered the isopod Bathyopsurus nybelini at depths 5002-6288 m in the Puerto Rico Trench and Mid-Cayman Spreading Center using the Deep Submergence Vehicle Alvin. In most of the 32 observations, the isopods carried fronds of Sargassum. Through an integrative suite of morphological, DNA sequencing, and microbiological approaches, we show that this species is adapted to feed on Sargassum by using a specialized swimming stroke, having serrated and grinding mouthparts, and containing a gut microbiome that provides a dietary contribution through the degradation of macroalgal polysaccharides and fixing nitrogen. The isopod's physiological, morphological, and ecological adaptations demonstrate that vertical deposition of Sargassum is a direct trophic link between the surface and deep ocean and that some deep-sea organisms are poised to use this material.

Observations of trash in the deep tropical Atlantic and Caribbean Sea.

Evidence of anthropogenic impacts on deep-ocean systems is frequently observed, even upon the first explorations of these remote environments. One of these impacts comes from marine debris, trash that is dumped or transported into the deep ocean. Understanding the abundance and distribution of marine debris is critical to identifying holistic changes and feedbacks that influence the health and sustainability of ocean ecosystems. Here, we document widespread plastic, metal, and glass debris in deep waters of the tropical Atlantic and Caribbean Sea, observed by remotely operated and human occupied submersibles. Trash was observed from depths 250 to >6000 m. A total of 139 pieces of debris were found, including a ladder, clothing, cans, cutlery, single-use sauce packages, and a parachute. These findings further illustrate the extent of debris pollution in deep waters and the need to understand the impact of debris pollution on sustainability in Earth's largest habitat. Con frecuencia se observan evidencias de que los desechos antropógenos afectan a los sistemas oceánicos profundos, incluso en las primeras exploraciones de estos ambientes remotos. Uno de estos impactos viene de desechos marinos, basura que es tirada o transportada a los oceánicos profundos. Entendiendo la abundancia y la distribución de los desechos marinos es crítico para identificar cambios holísticos y comentarios que influencian la salud y la sostenibilidad de los ecosistemas oceánicos. En esta investigacion documentamos una extensa variedad de desechos como: plásticos, metal y vidrio en los ecosistemas oceánicos del Atlántico tropical y el Mar Caribe, observados por vehiculos robóticos controlados remotamente y ocupados por humanos. La basura fue observada desde las profundidades de 250 a más de 6000 m. Se encontraron un total de 139 piezas de desechos, incluyendo una escalera, ropa, latas, cubiertos, paquetes de salsa de un solo uso y un paracaídas. Estos descubrimientos ilustran la gran relevancia de la contaminación por los desechos en aguas profundas y la necesidad de comprender el impacto de dicha polución por desechos en la sostenibilidad en el hábitat más grande de la Tierra.