Biological Oceanography
in a Changing Ocean
Monitoring system for particle fluxes and carbon sequestration into the deep ocean
About
The observation of particle fluxes and various marine meteorological and oceanographic variables has been conducted at the European Station for Time Series in the Canary Islands (ESTOC), located 60 miles north of Gran Canaria (29º 10' N, 15º 30' W), for approximately 30 years. The ESTOC program began in February 1994 through a Spanish-German agreement involving four partners (IEO and ICCM in the Canary Islands, and Univ. Bremen, and IfMk Kiel in Germany). Since 2013, it has been operated by PLOCAN.
For nearly two decades (1991-2009), a mooring equipped with sediment traps placed at depths of 600 and 3100 meters was deployed at ESTOC. Starting from 2009, the sediment traps were relocated to other locations, resulting in the discontinuation of the time series data generated up to that point. In 2018, a new sediment trap was deployed at a depth of 1600 meters, along with continuous measurements of various physical and biochemical parameters at the surface. However, a minimum of two sediment traps are required to comprehensively understand particle fluxes in the water column.
The FLUCARO project aims to reinstate the sediment traps at ESTOC, continuing the objective of maintaining long-term time series data, which is crucial for making future projections regarding carbon sequestration in the Canary Islands and validating climate models. In addition to employing conventional techniques for studying particle fluxes, FLUCARO also intends to utilize state-of-the-art sensors such as Underwater Video Profilers (UVP) and explore innovative approaches such as the use of gliders.
Approach
Sediment traps are the most widely used devices to study particle fluxes in the ocean. Its universality allows for the comparison among data from all around the globe.
Three sediment traps will be placed at FLUCARO mooring at three different depths corresponding one with the base of the epipelagic layer (200 m), and the other two with the top and the base of the mesopelagic layer (500 and 1000 m, respectively).
Sediment traps
The Underwater Vision Profiler or UVP is designed to study large (>100 µm) particles and zooplankton simultaneously and to quantify them in a known volume of water. The UVP system makes use of computerized optical technology with custom lighting to acquire digital images of zooplankton in situ.
A UVP6 will be attached to the FLUCARO mooring at the base of the epipelagic layer, right above the shallower sediment trap (~200 m) allowing for comparison of particle fluxes with the traps and to study zooplankton abundances and variability.
UVP6
The SeaExplorer underwater glider is a powerful autonomous sensing platform designed to collect water column data profiles with very wide spatio-temporal coverage (thousands of km and weeks to months of endurance).
A second UVP6 will be attached to a SeaExplorer glider which will carry out 4 cruises per year in the frame of the PLOCAN seasonal ocean-observing program of ESTOC, complementing the data generated by the mooring.