An oceanographic cruise should be planned down to the smallest detail months in advance. Everything must be carefully chosen: the objectives of the mission, the period, the sampling plan and the various needs of each research group. The costs of the ship are not to be underestimated, not to mention those related to the preparation and shipping of materials and the movement of people. That’s why, when the day before leaving, the mission you have been planning for months is canceled for the lockdown measures imposed to counter the spread of the coronavirus, you cannot help but be embittered even if aware that it was the right choice.

Dreaming about PERLE 3

The PERLE (Pelagic Ecosystem Response in the Levant Experiment) project aims at describing the formation and dispersion of Levantine Intermediate Water (LIW) and its role in marine ecosystems. La!DOM participated in the PERLE 2 cruise in March 2019, during wich our PhD student Giancarlo Bachi collaborated with Marianne Acker of the Woods Hole Oceanographic Institution (WHOI). During 30 days aboard, samples were collected for the analisys of chromophoric dissolved organic matter (CDOM), C-P lyasis, methane concentration, methane isotopes and particulate organic matter (POM). Furthermore, incubation experiments were carried out using surface water enriched with High Molecular Weight DOM (HMWDOM). In the PERLE 3 campaign, the goal was to replicate part of the activities carried out during PERLE 2 and integrate the data collected the year before with new samples (DNA, enzymatic activity) and new on-board incubation experiments. We also setup an ultrafiltration system to concentrate the HMWDOM and to be used directly on board and subsequently in the laboratory.

Aids from Massachussets

Here comes into play the collaboration with Daniel J. Repeta, senior scientist at the Woods Hole Oceanographic Institution (WHOI). He kindly provided us the ultrafiltration membrane and, during a visit in our laboratories, gave us the indications for the construction of the ultrafiltration system. Given the promising results of PERLE 2, the Repeta team provided us also, with bottles, reagents and everything that is needed to treat samples for C-P lyasis measurements to be used during PERLE 3.

A never born “pearl” !

The PERLE 3 was scheduled from March 11th to April 12th. Unfortunately, the day before departure the Italian government declared the entire national territory a “red” zone, preventing international and inter-regional travels. Despite the great regret, the cancellation of the mission was the only way forward and without doubts the right choice. In fact, after six days of sailing the R/V Pourquoi Pas? was forced by the French authority to go back and the PERLE 3 mission was definitively canceled. This mission was a unique opportunity for our research group, it would have allowed us to increase our knowledge on the dynamics of the DOM in the Mediterranean Sea. The incubation experiments and the samples for enzymatic activity and CP lyase would have provided us with important information on the biological lability of DOM.