BENFES, a new biotic index for assessing ecological status of soft-bottom communities. Towards a lower taxonomic complexity, greater reliability and less effort

From ecological functions to ecosystem services: linking coastal lagoons biodiversity with human well-being

In this review we highlight the relevance of biodiversity that inhabit coastal lagoons, emphasizing how species functions foster processes and services associated with this ecosystem. We identified 26 ecosystem services underpinned by ecological functions performed by bacteria and other microbial organisms, zooplankton, polychaetae worms, mollusks, macro-crustaceans, fishes, birds, and aquatic mammals. These groups present high functional redundancy but perform complementary functions that result in distinct ecosystem processes. Because coastal lagoons are located in the interface between freshwater, marine and terrestrial ecosystems, the ecosystem services provided by the biodiversity surpass the lagoon itself and benefit society in a wider spatial and historical context. The species loss in coastal lagoons due to multiple human-driven impacts affects the ecosystem functioning, influencing negatively the provision of all categories of services (i.e., supporting, regulating, provisioning and cultural). Because animals' assemblages have unequal spatial and temporal distribution in coastal lagoons, it is necessary to adopt ecosystem-level management plans to protect habitat heterogeneity and its biodiversity, ensuring the provision of services for human well-being to multi-actors in the coastal zone.

Ecological quality assessement of marinas: An integrative approach combining biological and environmental data

The importance of marinas as infrastructures for recreational boating is increasing substantially. However, information on their soft-bottom benthic communities, a key tool for managing programmes, is still scarce. We combined environment features with macro- and meiofaunal soft-bottom community information for assessing the ecological status of marinas with an integrative approach. To address this issue, we focused on eight marinas of the Southern Iberian Peninsula. Macro- and meiofauna data revealed high benthic heterogeneity at a spatial scale. The environmental variables which correlated best with macrofauna were mainly phosphorus, granulometry, and total organic carbon, and secondarily important variables were faecal coliforms, the biocide Irgarol, and heavy metals; total hydrocarbon concentration was also significant for meiofauna. Annelida was the dominant phylum in terms of number of species (37%) and abundance (66%) and were better descriptors of the environmental conditions than Arthropoda and Mollusca. Although identification to the species level is desirable and mandatory for assessing biological pollution, significant differences among marinas and correlations between fauna and abiotic variables were already detected at the level of family and order. This implies that biota assessment at higher levels may still be useful in monitoring programmes limited by time and budget constraints. The major novelty of this study lies in the development of an integrative assessment method based on the following selected ecological indicators: Marinas Environmental Pollution Index (MEPI), Biocontamination Index (BCI), macrofaunal biotic indices (AMBI, M-AMBI, BENTIX, MEDOCC and BENFES), macrofaunal taxa richness and Shannon-Wiener's diversity, and nematode:copepod index. This approach was able to discriminate marinas of the Southern Iberian Peninsula based on their ecological status, which ranged from poor to good. The method can be useful to design standards for assigning "sustainable quality seals" to those marinas with better values of ecological indicators.

Human pressures on two estuaries of the Iberian Peninsula are reflected in food web structure

As a result of the increased urban and agricultural development in coastal environments, estuaries are among the most modified and threatened aquatic ecosystems. This study used stable isotopes to examine the effects of human impacts by contrasting the food web structures of two Iberian estuaries exposed to different degrees of human pressure. More complex feeding pathways were found in the more altered estuary (Guadalquivir). Greater spread among species along the carbon axis suggests that the primary consumers exploit organic matter with various origins, whereas different nitrogen signals of the secondary consumers suggest that they feed on different suites of prey. In contrast, the similar isotopic signals of secondary consumers in the relatively little influenced estuary (Guadiana) suggests similarity in diet composition and feeding on the same organic matter sources. Understanding trophic interactions in estuaries is vital for defining proper management and conservation, and the preliminary data provided here are one step in this direction.

Modelling the effects of climate change on the distribution of benthic indicator species in the Eastern Mediterranean Sea

The potential effects of climate change on the distribution of benthic species commonly used in marine ecological quality assessment were investigated using a spatial modelling approach. In this work, the relevance of the ecological groups that macrofaunal molluscs are assigned according to their sensitivity or tolerance to environmental disturbance was examined under the scope of the RCP 8.5 severe emissions scenario. The effects of climate change were more profound on species that are indicative of a specific suite of climatic conditions regarding temperature and salinity. Significant loss of habitat suitability was observed for the tolerant species Corbula gibba and Abra prismatica whereas the sensitive species Moerella donacina was least affected. In contrast, an overall expansion of the distributional potential was observed for the sensitive species Flexopecten hyalinus as newly suitable habitats are formed. As hypothesised, the current ecological grouping that depicts the sensitivity of a benthic species to an environmental stressor is irrelevant when assessing the effects of climate change. We propose a new standpoint of using benthic species as biotic tools based on their ecological niche requirements.

Ecological quality status evaluation of a monsoonal tropical estuary using benthic indices: comparison via a seasonal approach

The use of biotic indices has garnered attention during the last decade due to its extensive application in evaluating ecological quality status (EcoQS) of marine waters and estuaries. Three seasonal surveys were conducted in the Kundalika estuary, India to evaluate the ecostatus using five benthic indices and comparing their effectiveness considering the estuarine salinity gradient and seasonality. All indices gave divergent results displaying a wide range of classes (good to bad) across salinity zones and seasons. Comparatively, M-AMBI discriminated the EcoQS suitably than other indices. Hence, a seasonally averaged approach for M-AMBI was proposed to obtain a final mean EcoQS which assigned moderate status to the euhaline and poly-mesohaline zones and poor status to the oligohaline zone. Considering the high degree of spatial heterogeneity and seasonality in the estuary, the monsoon data was found to lower the EcoQS due to natural stress in some cases; the exclusion of the monsoon season resulted in a more valid ecostatus. Therefore, this approach which combines information from the non-monsoon seasons stands out in providing a useful basis for ecological management by scrutinizing responses of macrobenthos. Also, we suggest salinity zone-wise evaluation for more effective classification chiefly in tropical monsoonal estuaries. An effort to establish a final EcoQS was performed; however, future in-depth studies are necessary to ascertain the reliability of the successful biotic index (M-AMBI) in estuaries with different stressors.

Assessing the effectiveness of surrogates for species over time: Evidence from decadal monitoring of a Mediterranean transitional water ecosystem

The use of higher taxa or alternative approach to species surrogacy, such as the BestAgg procedure, could represent cost-effective solutions to avoid expensive species-level identifications in monitoring activities, especially on the long term. However, whether a set of surrogates would be effective in subsequent reiteration of the same assessment remains largely unsolved. We used a long-term dataset on macro-benthic assemblages to test the hypothesis that family-level and BestAgg surrogates which are effective for a limited period of monitoring could be successfully applied to quantify community patterns also in subsequent monitoring programmes. The effectiveness of surrogates in detecting temporal variations in assemblage structure as at species level remained basically unaffected over a decade. Recognizing once and for all if species surrogacy may have a practical value for monitoring will strongly depend on future assessments of the potential of surrogates to reflect community changes and to retain this prerogative over time.