Yesterday we completed the third successful deployment of the HyBIS system (Hydraulic Benthic Interactive Sampler). HyBIS is one of several underwater vehicles operated by the National Oceanography Centre to study deep-ocean seabed environments. It consists of a stain-less steel frame that carries several underwater cameras designed to observe the environment and to monitor the vehicle’s operating systems, which include a steering unit with two propellers and a complex array of telemetry, hydraulic, and electrical systems. This includes a special ultra-Short baseLine (USBL) beacon that helps map the HyBIS position as we survey. Additional ocean bottom sensors and sampling devices can be attached to the frame, depending on the aims of the mission.
During this year’s PAP cruise, HyBIS is deployed to collect seafloor images from the abyssal plain and, if possible, from abyssal hills. We use the image data to study the larger invertebrates that live on the seafloor such as sponges, anemones, worms and echinoderms. We call this group of organisms benthic megafauna. Back ashore, we will be counting the number and types of the organisms on the photographs to describe the diversity and the composition of the species assemblages.
We will also be measuring the body size of the organisms to estimate the mass of the living megafauna (biomass). We will be using the biomass data together with the physical and chemical data that we collect at PAP to assess the links between surface carbon production, sinking carbon fluxes (marine snow) to the seabed (food supply) and deep-ocean biomass distributions (food demand). We will also be comparing this year’s observations with image data collected in previous years to assess how the megafaunal communities at PAP are changing over time and to help answering questions about impacts of climate change on ocean carbon budgets and deep-ocean food webs.
Written by Simone Pfeifer