Habitat Shift for Plankton: The Living Side of Benthic-Pelagic Coupling in the Mar Piccolo of Taranto (Southern Italy, Ionian Sea)

Resting stages represent the answer for species to the variability of environmental conditions. In confined marine habitats, variability of conditions is high, and bottoms host plankton resting stages in the so-called “marine cyst banks”. The Mar Piccolo of Taranto was chosen as a pilot site in which to investigate how marine cyst banks and plankton affect each other in the living part of the benthic–pelagic coupling. The attempt was based on the use of multiple devices for integrated sampling of benthic and pelagic stages and allowed us to identify 207 taxa/categories in the whole system (127 as active forms, 91 as resting stages). The sediments added 80 taxa to the plankton list obtained only from the water column, thus confirming the importance of this kind of approach in perceiving the actual diversity of the studied site. The sediment cyst bank involved 0.15–1.00% of its content in daily benthic-pelagic exchanges, in terms of cyst germination and import, respectively. In addition, the cyst production, which was higher than the cyst germination, is responsible for the existence of a permanent biological reservoir in the sediments. The benthic-pelagic coupling, however, was completely depicted in the present investigation only for seven taxa. This result is due to the still scant knowledge of the life cycles and life histories of single species. Apart from the identification difficulties that still have to be clarified (which cysts belong to which species), the cycle presence/absence is also characterized by the diversification of strategies adopted by each species. The observation of plankton dynamics from the benthos point of view was useful and informative, unveiling a huge assemblage of resting forms in the sediments only minimally affected by cyst import/export, because it is more devoted to a storing role over long periods. Consequently, the continuation of life cycle studies appears necessary to understand the diversity of strategies adopted by the majority of plankton species.

Temporal and Spatial Variations of Geodia cydonium (Jameson) (Porifera, Demospongiae) in the Mediterranean Confined Environments

Confined marine environments are particularly susceptible to climate change and anthropic pressures. Indeed, the long-term monitoring of benthic assemblages in these environments allows us to understand the direction of changes over time. The demosponge Geodia cydonium is a suitable study case, since it is widely represented in many Mediterranean environments, while being a long-living and important habitat-forming species. Here, we report the results of a descriptive study on temporal and spatial variations of this demosponge in three semi-enclosed environments along the Italian coast: Marsala Lagoon, Porto Cesareo Bay, and Mar Piccolo of Taranto. At Marsala and Porto Cesareo, the study compares the present data with those reported by the literature at the end of the 1990s. Caused by the modification of its preferential habitats, the data indicated the loss and a remarkable regression of this species at Porto Cesareo and Marsala, respectively. In addition, we hypothesized that the increase in severe weather phenomena in the small Bay of Porto Cesareo recorded during the last 20 years may have had a marked impact on water mass, thus affecting the sponge assemblages. At Taranto, despite a remarkable environmental degradation, G. cydonium has appeared stable and persistent in the last 45 years, thus representing one of the richest and most well-preserved populations in the Mediterranean Sea.

Towards Sustainable Management of Mussel Farming through High-Resolution Images and Open Source Software—The Taranto Case Study

This research activity, conducted in collaboration with the Aero-Naval Operations Department of the Guardia di Finanza of Bari as part of the Special Commissioner for urgent measures of reclamation, environmental improvements and redevelopment of Taranto’s measurement, is based on the use of a high-resolution airborne sensor, mounted on board a helicopter to identify and map all in operation and abandoned mussel farming in the first and second inlet of Mar Piccolo. In addition, factors able to compromise the environmental status of the Mar Piccolo ecosystem were also evaluated. The methodological workflow developed lets extract significant individual frames from the captured video tracks, improves images by applying five image processing algorithms, georeferences the individual frames based on flight data, and implements the processed data in a thematic Geographical Information System. All mussel farms, in operation and derelict, all partially submerged and/or water-coated invisible to navigation poles and other elements such as illegal fishing nets and marine litter on the seabed up to about 2 m deep, have been identified and mapped. The creation of an instant, high-precision cartographic representation made it possible to identify the anthropogenic pressures on the Mar Piccolo of Taranto and the necessary actions for better management of the area.

DPSIR Model Applied to the Remediation of Contaminated Sites. A Case Study: Mar Piccolo of Taranto

The study critically analyses the complex situation of the Mar Piccolo of Taranto (South of Italy), considered one of the most polluted marine ecosystems in Europe. In order to investigate possible cause–effect relationships, useful to plan appropriate planning responses or remediation technologies to be adopted, the Driver–Pressure–State–Impact–Response (DPSIR) model was applied. Methodologically, about 100 references have been considered, whose information was organized according to the logical scheme of the DPSIR. The results showed how the Mar Piccolo is the final receptor of pollutants coming from all industrial and agricultural activities, especially due to its natural hydrogeological network conformation. The anthropic activity represents a critical impact on the ecosystem due to the subsequent marine litter. The mobility of contaminants from sediments to the water column showed the potential risk related to the bioaccumulation of organisms from different trophic levels, posing a threat of unacceptable magnitude to human safety. The paper concludes by discussing the actions currently implemented by the authorities in response to the anthropogenic impacts as well as the need for new ones concerning both plans, programs, and remediation interventions. The case study shows how the DPSIR is a useful framework to organize extensive and heterogeneous information about a complex environmental system, such as the one investigated. This preliminary organization of the available data can represent the starting point for the development of a DPSIR-based Environmental Decision Support System (EDSS) with robust cause–effect relationships.

Settlement and Spreading of the Introduced Seaweed Caulacanthus okamurae (Rhodophyta) in the Mediterranean Sea

In this study, we report the first finding of the non-indigenous seaweed Caulacanthus okamurae (Rhodophyta) in the Ionian and Adriatic Seas (Mediterranean). Specimens were identified through molecular analyses based on the plastid ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) marker. The sequences obtained during this study represent the first molecular evidence of the presence of this taxon in the Mediterranean Sea. Stable populations have been detected in some areas of the Mar Piccolo of Taranto (Italy) and in the whole lagoon of Venice, forming dense patches of low turf that reach high biomasses. Turf-forming algae are common in the intertidal zones of tropical regions, but are rare in temperate ones. The particular environmental conditions of transitional water systems, such as the Mar Piccolo of Taranto and the Venice Lagoon, together with the water temperature increase observed in the last years could have favored the settlement and spread of this introduced species.