Monitoring and Assessment of Environmental Quality in Coastal Ecosystems Volume III

Establishing the transition between the marine and terrestrial domains, coastal environments are very dynamic and complex ecosystems with unique biodiversity. They provide a multitude of ecological services, on which humans have relied on for centuries, namely for extractive activities. Nevertheless, the increasing trend of the settlement of human populations, together with a vast array of human activities that take place on the shorelines, cause negative impacts and environmental stress on coastal ecosystems. In addition, there is the growing underlying threat of receding coastlines caused by rising sea levels and global warming, and the acidification of the marine environment due to global climate change. To sustain coastal environments and the ecological services that they provide, it is essential to assure their environmental quality. In this complex and highly uncertain setting, the third volume of the Special Issue on “Monitoring and Assessment of Environmental Quality in Coastal Environments” gathers a range of different approaches to assess and monitor contrasting aspects of the environmental quality of coastal environments, often using challenging environments from throughout the world as case studies.

Ferrentino et al. [1] presented an innovative approach, centered on the abiotic compartment, which used satellite Synthetic Aperture Radar (SAR) imagery to support the monitoring of the evolution of complex coastal environments. A challenging Ionian coastline of the Basilicata region (Southern Italy) was selected as the study area, and the results demonstrated that SAR measurements have a good precision for surveying erosion/accretion processes, with an accuracy better than 15 m. Therefore, SAR imagery has been found to be an efficient tool to assist in the monitoring and sustainable development of coastal environments. In another study performed in a transitional environment in the northern Adriatic Sea, Acquavita et al. [2] characterized and classified the water quality of Marano and Grado Lagoon in accordance with the implementation of the Water Framework Directive from the European Union (WFD/2000/60/EU [3]. The seasonal and interannual variability of the trophic state of the lagoon was assessed along an 11-year time series. Their results showed that the lagoon presents high variability in the trophic state, ranging from an oligotrophic to hypertrophic condition, and that careful management and long-term series monitoring should be maintained, especially in the face of the current climate change scenario.

Marine sediments can act as environmental records of the presence of all kinds of substances in the water column and in the sea bottom, functioning as reservoirs for most of those substances. Benthic communities are in close contact with marine sediments and are therefore exposed to this panoply of substances. In a complex Arctic marine environment, Caruso et al. [4] assessed the environmental state of Svalbard Fjord sediments by simultaneously applying an ecological and a biochemical approach, analyzing the functional diversity of the benthic microbial community and the role of these environments as potential reservoirs for antibiotic resistance by screening bacterial isolates. The study showed that the functional diversity of microbial communities rapidly reacts to changing conditions, being nutritionally versatile, and that the analyzed bacterial communities were multi-resistant to enrofloxacin and tetracycline, which highlights the relevance of these sediments as possible reservoirs of antibiotic residues. Macrophytes are another group of benthic organisms widely used to assess and monitor the ecological status of coastal environments and their associated transition water systems. In this context, Sfriso et al. [5] proposed the monitoring of changes in the vegetation cover of the Venice Lagoon and the application of the MaQI index (Macrophyte Quality Index) over a time series of 10 years as tools to assess the ecological status of this Transition Water System (TWS). Their study demonstrated that assessing macrophyte species composition and biomass is pivotal to determining ecological quality changes in TWS’s.

Multi-scale environmental changes with regional extents can induce changes in the state of an ecosystem that often repercuss in the ecosystem’s functions and services. As a result of the rise in global temperatures of the last decades, a shift from salt marsh to mangrove ecosystems has been documented to have been occurring at the poleward limits of the distribution of worldwide mangroves (e.g., [6]). In the east and west coasts of Florida (USA), transitional phases of a regime shift from intertidal oyster reefs to mangrove islands have been found [7]. In the scope of this Special Issue, Walters et al. [8] analyzed which abiotic and biotic variables were determinant for the survival and growth of mangrove seedlings on the intertidal oyster reefs at the Mosquito Lagoon, with the aim of comprehending if oyster reefs enable mangrove colonization. Their study revealed that close proximity to adult mangroves, a partial upright burial of propagules in the sediment, and the arrival of seedlings after the annual high-water season were the main factors that promoted red mangrove success.

The rise in machine learning tools in recent years has enabled researchers to better understand, to determine the driving factors, and to better manage an array of issues related to the marine domain. In the scope of an assessment of environmental quality specifically focused on the preservation of marine biodiversity, Klaoudatos et al. [9] proposed the use of statistical and soft computing methodologies to identify the main factors that influence endangered teleost fish species in the Mediterranean Sea. According to their results, overfishing, bycatch, pollution, and age at maturity are the main factors that affect the extinction risk of teleosts. Plus, their study highlights the need for integrated ecosystem approaches, namely in the Mediterranean Sea.

Assessing ecosystem services is a crucial step for the monitoring and assessment of environmental quality at the ecosystem level. In fact, the assessment of ecosystem services pushes forward the comprehension of the structures and of the interactions and dependencies between humans and the environment [10]. In this Special Issue, Schernewski et al. [11] propose the use of 3D ecosystem model simulations and historical-socioeconomic data to assess the ecosystem services of the Baltic Sea during the last 150 years. The tools and approach used provided consistent data for several provisioning, regulating, and cultural ecosystem services, together with the corresponding monetary evaluations.