“This multidisciplinary paper describes the typology and distribution of mucilaginous aggregates in the northern Adriatic in the period 1999-2002.”

This multidisciplinary paper describes the typology and distribution of mucilaginous aggregates in the northern Adriatic in the period 1999-2002. Most of the citations come about because, as part of the special issue of Science of the Total Environment, on "Mucilages in the Adriatic and Tyrrhenian Seas" it describes the phenomenon on which most of the papers are based.

In this work, for the first time, data collected with underwater cameras are used for a semi-quantitative estimation of marine algal flocs abundance in the watercolumn, and to build a descriptive scale of macroaggregate types that most frequently appear in the northern Adriatic,(a semi-enclosed body of water with densely populated coastal watersheds). Such a scale can be used for a detailed description of the mucilage phenomenon in time and space.

Organic aggregates are ubiquitous in the world oceans and occupy an important place on the marine food/ecology web. Hypertrophic production of mucilaginous material—aggregates of up to several metres in dimension, forming surface, subsurface, and benthic layers tens of kilometres long—has occurred in the Adriatic with increased frequency and intensity.

In addition to negative consequences for the ecosystem, extended mucilage events—formation of very large organic aggregates and gelatinous surface layers—both pelagic and benthic, cause significant financial damage to the tourism industry through unsightliness and a reduction in the quality of bathing water. Extended mucilage events also affect fisheries by hampering their work with nets. Also affected are mariculture facilities and their operations. The success of these industries depends on a healthy marine ecosystem.

We tried to build an objective scale, using underwater camera data, for a description of the mucilage phenomenon in time and space.

As staff members of our institutions we were involved in the framework of the Project "Monitoring and study of processes of mucilage formation in the Adriatic and Tyrrhenian Seas—MAT") supported by the Italian Ministry of the Environment and Protection of the Territory and the Istituto Centrale per la Ricerca Scientifica e Tecnologica Applicata al Mare (ICRAM).

The scientific activities were designed to be carried out over a four-year period (June 1999–May 2003) and were performed by 150 scientists and technicians from 24 Italian and two Croatian institutions.

Michele Giani was one of the leading scientists on the project. The main problem encountered along the way was maintaining the scheduled monthly sampling strategy for 36 months, with three operating sea vessels and all their crews and scientific staffs.

Our work has no major social implications. It does, however, show that ecosystems are not divided by political borders and that the only approach to ecosystem studies is multidisciplinary.

We also hope that our work will contribute to correctly inform the public on the natural origins of the phenomenon of mucilage formation and to prevent misinterpretations linking this phenomenon to pollution.