| Title | The phytobenthos of the Mar Piccolo of Taranto (Ionian Sea, southern Italy): a novel of ninety years of disappearances, new arrivals and returns |
| Abstract | Long-term studies allow to evaluate all the significant changes which an ecosystem encounters with time. In this respect, the Mar Piccolo of Taranto represents a good example for the studies on the phytobenthos. Indeed: in the Twenties the first researches were carried out; up to the Seventies they were occasionally performed; in the Eighties they became
continuous and are still ongoing as such. Therefore, the presence of historical series of data gives the chance of assessing both qualitative and quantitative modifications, which occurred against the phytobenthic communities of the basin in almost a ninety-year period, showing that they are strongly linked to anthropogenic activities.
In the Twenties up to the Fifties, the Mar Piccolo was depicted as a basin with limpid and clean seawater where Cystoseira spp., Halimeda tuna, Flabellia petiolata and many other seaweed species, typical of healthy environments, commonly lived. Most of them also sexually reproduced. Among the phanerogams, Cymodocea nodosa formed a luxuriant meadow. At that time, mussel farming, Navy dockyard and sewages pollution were already present, but their pressure was low.
In the Sixties and the Seventies, since the pressure of these polluting activities became stronger, less resistant species disappeared, such as most of brown macroalgae, in particular Cystoseira spp. In that period, the Mar Piccolo bottom was mainly colonized by rhizophytic green algae, such as Caulerpa prolifera. Cymodocea nodosa meadow dropped to sparse and scarce spots.
In those years a considerable rise of the Taranto population occurred, leading to the expansion of the town, and so, all of 14 not preventively cleansed sewages began to discharge in the Mar Piccolo. Therefore, in the Eighties and the Nineties, phytobenthic populations shifted towards assemblages typical of eutrophic environments characterized by unattached Ulvales and Gracilariales, vegetatively reproducing, which reached high biomasses, especially in spring and summer. Cymodocea nodosa almost disappeared, except some rare tuft.
Moreover, in those years, another type of pollution came out in the basin, the biological pollution due to the introduction of alien species. Indeed, in 1986, two red macroalgae, native from the Atlantic Ocean, were recorded, representing the first report for the Mediterranean, that is Agardhiella subulata and Solieria filiformis. In a short time, they became the dominant summer species in the unattached community of the Mar Piccolo up to the end of the Nineties. In 1998, the Pacific brown seaweed Undaria pinnatifida was found attached onto the docks of the old town.
In 2000, the increase of importation of extra-Mediterranean mussels to satisfy the local market caused the rise, up to 13, of the number of alien seaweeds in the Mar Piccolo. They came from different areas and showed different behaviours. In the same period, the progressive closing of waste-water plants began and the Navy dockyard activities were moved to the Mar Grande basin. Consequently, seaweed and phanerogam assemblages in the Mar Piccolo changed again. Concerning seaweeds, in the last years, several species present in the Twenties reappeared and sexually reproduced, such as Padina pavonica, Peyssonnelia spp. With respect to phanerogams, Cymodocea nodosa not only considerably widened its distribution in the basin, but also began to sexually reproduce, sprouting flowers and fruits. Moreover, in the last years, Ruppia cirrhosa appeared and formed a luxuriant meadow.
Research carried out within the framework of the Flagship Project RITMARE and the Italian network LTER |
| Source | ANNUAL MEETING OF THE ITALIAN PHYCOLOGICAL GROUP, Padova, Italy, 14-15 November 2014 |
| Year | 2014 |
| Type | Presentazione |
| Authors | PETROCELLI A., PORTACCI G., CECERE E. |
| Text | 318157 2014 The phytobenthos of the Mar Piccolo of Taranto Ionian Sea, southern Italy a novel of ninety years of disappearances, new arrivals and returns PETROCELLI A., PORTACCI G., CECERE E. Istituto per l Ambiente Marino Costiero IAMC Long term studies allow to evaluate all the significant changes which an ecosystem encounters with time. In this respect, the Mar Piccolo of Taranto represents a good example for the studies on the phytobenthos. Indeed in the Twenties the first researches were carried out; up to the Seventies they were occasionally performed; in the Eighties they became continuous and are still ongoing as such. Therefore, the presence of historical series of data gives the chance of assessing both qualitative and quantitative modifications, which occurred against the phytobenthic communities of the basin in almost a ninety year period, showing that they are strongly linked to anthropogenic activities. In the Twenties up to the Fifties, the Mar Piccolo was depicted as a basin with limpid and clean seawater where Cystoseira spp., Halimeda tuna, Flabellia petiolata and many other seaweed species, typical of healthy environments, commonly lived. Most of them also sexually reproduced. Among the phanerogams, Cymodocea nodosa formed a luxuriant meadow. At that time, mussel farming, Navy dockyard and sewages pollution were already present, but their pressure was low. In the Sixties and the Seventies, since the pressure of these polluting activities became stronger, less resistant species disappeared, such as most of brown macroalgae, in particular Cystoseira spp. In that period, the Mar Piccolo bottom was mainly colonized by rhizophytic green algae, such as Caulerpa prolifera. Cymodocea nodosa meadow dropped to sparse and scarce spots. In those years a considerable rise of the Taranto population occurred, leading to the expansion of the town, and so, all of 14 not preventively cleansed sewages began to discharge in the Mar Piccolo. Therefore, in the Eighties and the Nineties, phytobenthic populations shifted towards assemblages typical of eutrophic environments characterized by unattached Ulvales and Gracilariales, vegetatively reproducing, which reached high biomasses, especially in spring and summer. Cymodocea nodosa almost disappeared, except some rare tuft. Moreover, in those years, another type of pollution came out in the basin, the biological pollution due to the introduction of alien species. Indeed, in 1986, two red macroalgae, native from the Atlantic Ocean, were recorded, representing the first report for the Mediterranean, that is Agardhiella subulata and Solieria filiformis. In a short time, they became the dominant summer species in the unattached community of the Mar Piccolo up to the end of the Nineties. In 1998, the Pacific brown seaweed Undaria pinnatifida was found attached onto the docks of the old town. In 2000, the increase of importation of extra Mediterranean mussels to satisfy the local market caused the rise, up to 13, of the number of alien seaweeds in the Mar Piccolo. They came from different areas and showed different behaviours. In the same period, the progressive closing of waste water plants began and the Navy dockyard activities were moved to the Mar Grande basin. Consequently, seaweed and phanerogam assemblages in the Mar Piccolo changed again. Concerning seaweeds, in the last years, several species present in the Twenties reappeared and sexually reproduced, such as Padina pavonica, Peyssonnelia spp. With respect to phanerogams, Cymodocea nodosa not only considerably widened its distribution in the basin, but also began to sexually reproduce, sprouting flowers and fruits. Moreover, in the last years, Ruppia cirrhosa appeared and formed a luxuriant meadow. Research carried out within the framework of the Flagship Project RITMARE and the Italian network LTER ANNUAL MEETING OF THE ITALIAN PHYCOLOGICAL GROUP in conjunction with the Annual General Meeting AGM of the Federation of European Phycological Societies FEPS Isabella Moro, Katia Sciuto and Marion A. Wolf ANNUAL MEETING OF THE ITALIAN PHYCOLOGICAL GROUP Padova, Italy 14 15 November 2014 Internazionale Contributo The phytobenthos of the Mar Piccolo of Taranto in ninety years Risultati di attivta svolte nell ambito del progetto RITMARE e della rete I LTER Long Term Ecological Research Petrocelli_et_al_.doc Presentazione giuseppe.portacci PORTACCI GIUSEPPE antonella.petrocelli PETROCELLI ANTONELLA ester.cecere CECERE ESTER TA.P04.002.001 Fascia Costiera e Ambienti di Transizione analisi strutturale e funzionale delle componenti biotiche ed abiotiche degli ecosistemi per lo sviluppo sostenibile delle attivita |
