Over the last two decades, the Observatory has carried out around 350 fieldtrips, providing a huge amount of information on the abundance, diversity and function of marine microorganisms.
On March 2001, 20 years ago, the Blanes Bay Microbial Observatory (BBMO) began an uninterrupted monthly sampling. This is an initiative of a group of scientists from the Institut de Ciències del Mar (ICM) that began in 2001. During these years, the researchers involved have made about 350 trips to obtain water samples and analyse the abundance, diversity and activity of the marine microorganisms in the bay.
This is a very valuable record, especially because of its temporal extension. In the NW Mediterranean, it is only surpassed by Josep Pascual's oceanographic data series, with almost 50 years of history, and in the world there are only a few time series as complete as the one in Blanes. The only time the BBMO missed the monthly sampling was during the beginning of the total confinement decreed by the government to stop the expansion of Covid-19 last year.
The main fact that makes the Blanes record highly valuable is the amount of information on the microbial community it includes. Marine microorganisms are considered the largest reservoir of diversity in the biosphere. Apart from being relevant because of their abundance, they are important because of the number of biochemical reactions in which they are involved.
"It is a great success to have been able to maintain the sampling and the analyses at the bay for so long, given that most research projects are funded for only three years", states the ICM researcher and sampling coordinator Josep M Gasol, who warns of the need for longer-term funding for projects like this one, aimed at studying the diversity and function of marine ecosystems at a time of major changes on a global scale.
"The increase in water temperature, ocean acidification and the massive delivery of anthropogenic nutrients can alter the composition and function of the microbial community. To understand these effects, it is necessary to carry out continuous monitoring, which requires specific infrastructure and long-term funding commitment, and this does not usually exist" regrets Gasol.
A privileged location
The fact that the observatory is located in the bay of Blanes is not a coincidence. This was precisely the place that the pioneer of ecological and oceanographic research Ramon Margalef chose to carry out his first studies on marine microorganisms, published more than 75 years ago.
According to those in charge of the observatory, it is the combination of biogeochemical and oceanographic approaches together with the molecular analyses of the diversity and function of microbial plankton that makes the BBMO data unique. In addition, two repositories have been created over the last 20 years: one of genetic material and the other of pure cultures, which allow to analyse the trends and evolution of the marine microbial community.
In this sense, it has been observed that, during the last two decades, the amount of nutrients in the Bay of Blanes has decreased, which may be related to improved urban wastewater treatments. This has also led to a decrease in the number of marine microorganisms, which could lead to changes in the food webs established in this ecosystem.
In these 20 years, around a hundred articles dealing with Blanes Bay marine microorganisms have been published, some of them in high-profile journals. This has positioned the BBMO as an international reference point for studies of microbial diversity using molecular tools.
"The fact that oceanographic vessels such as the Tara Oceans or the Sorcerer II, owned by the head of the US consortium that sequenced the human genome, Craig Venter, have included Blanes as one of the sampling points in their campaigns to study the marine microbial community shows the relevance of our work over all these years", exposes the ICM researcher and also sampling coordinator Ramon Massana, who hopes to continue sampling in the bay for many more years "to make this the most emblematic place in the Mediterranean to study organisms that, despite being invisible to our eyes, are extraordinarily important for maintaining healthy marine ecosystems".