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Abstract: Several legislations worldwide require assessing the health status of marine ecosystems. In Europe, the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD) demand the evaluation of the status with the overall objective of achieving at least “Good Status”, by 2015 and 2020, respectively. For this purpose, Member States are required to evaluate different biological, physico-chemical and hydro-morphological quality elements (WFD), or qualitative descriptors (MSFD). The assessments of both, the phytoplankton element and the eutrophication descriptor should include several attributes, namely phytoplankton biomass, composition, abundance and blooms. However, few composition-based indicators have been proposed. Principally, phytoplankton still relies on chlorophyll-a concentration measurements, mainly due to the high cost of collecting information on this element and the difficulties establishing significant pressure–impact relationships. This investigation describes the difficulties in the development of a phytoplankton community composition indicator, the state of the art and the main challenges for the future. [Copyright &y& Elsevier]

Abstract: Inverted microscopy is widespread employed for the analysis of phytoplankton composition within water quality monitoring networks. However, the analysis at the lowest taxonomical level is not always required for ecological status assessment. In addition, inverted microscopy can underestimate the small phytoplankton, and not always distinguish photoautotrophic from heterotrophic cells. In this study, as alternative tools, epifluorescence microscopy and High Performance Liquid Chromatography (HPLC) were employed to characterize phytoplankton communities within waters of different trophic condition. Epifluorescence microscopy confirmed its effectiveness to count the small phytoplankton. Furthermore, significant correlations between nutrients of anthropogenic origin and nanoplankton abundances were found. However, this technique resulted very time-consuming. HPLC together with the CHEMTAX program was more appropriate than inverted microscopy, in terms of cost-effectiveness. Also, the main variability patterns observed in the phytoplankton community structure by HPLC coincided with previous findings in the study area. Nevertheless, a rapid screening at the inverted microscope is recommended. [Copyright &y& Elsevier]

Deterioration of the sediment environment and benthic ecosystem is an undesirable effect of eutrophication, but little is known about the response of macrobenthic communities to eutrophication and their long-term recovery. In the present study, temporal changes in benthic ecological status, associated with reductions in anthropogenic impacts on a largest semi-enclosed sea in Japan, were determined using long-term monitoring data from water and sediment quality based on the multivariate AZTI Marine Biotic Index (M-AMBI), focusing on spatial differences in anthropogenic impacts. Several sub-areas were classified based on Chlorophyll a (Chl. a) concentrations in surface water during the 1980s. Chl. a concentrations decreased in all sub-areas except the sub-area with <2 μg Chl. a L−1 from the 1990s–2010s. On the other hand, total organic carbon contents in sediment decreased and M-AMBI values increased in all sub-areas during this period may be due to reduced lateral organic matter advection from surrounding areas. • Long-term changes in benthic ecological status were evaluated in the Seto Inland Sea. • The sea was divided into five sub-areas based on Chl.a concentrations in the water. • Chl.a concentrations, TOC contents, and M-AMBI were compared in five sub-areas. • Chl.a concentrations decreased except the sub-area Type 5 over the past 30 years. • On the other hand, TOC contents decreased and M-AMBI increased in all sub-areas. [ABSTRACT FROM AUTHOR]