Hypersub@Cosyna – pilot deployment

May 2014, Arjun Chennu

Hypersub is a novel observatory system developed at the Max Planck Institute for Marine  Microbiology in Bremen (Fig 1). The flagship instrument of Hypersub is a hyperspectral imager which can be used to capture high-resolution (~1mm) spectral images of the seafloor over an area of 1 m2. Using a recently developed method, these spectral images can be used to generate detailed maps (Fig 2) of photosynthesis pigments (chlorophyll a) at the sediment surface.

Hypersub

Complimentary to the benthic scanner on hypersub is a fast repetition rate fluorometer (FRRf) for measuring the photosynthetic activity of phytoplankton. The FRRf integration, a part of the EU FP7 project SenseOCEAN, is a specialized instrument for probing various aspects of the photosynthetic machinery of phytoplankton. Additionally, hypersub includes a topography scanner, and sensors for oxygen, light and temperature. 

 

chlorophyll map

Hypersub is designed to be deployed underwater and remotely-operated with the only external dependencies being power supply and a network connection. The COSYNA infrastructure is able to supply just this through its near-shore underwater nodes in Helgoland, Germany and Ny Ålesund, Norway. This provides a unique opportunity to monitor the seasonal changes of the benthic microbial phototrophs in the Arctic with extended over-winter measurements through remote operation. In order to prepare for a deployment in Ny-Ålesund in Sep 2014, a pilot deployment of hypersub@cosyna was made at Helgoland.  Issues assessed were connectivity, remote operation through the COSYNA network, sea-worthiness and practicality of deployment. The deployment was a success as well as a learning experience, such as about the need for strengthening the frame for an over-winter deployment. Overall, it was decided to green-flag the over-winter deployment in the Arctic later this year.

The project is a collaborative initiative between the MPI Bremen (Dr. Arjun Chennu) and the Scientific Diving Team, AWI Helgoland (Prof. Philipp Fischer).

Chennu et al., 2013