Agnese Marchini

International arrivals: widespread bioinvasions in European Seas

The European Union lacks a comprehensive framework to address the threats posed by the introduction and spread of marine non-indigenous species (NIS). Current efforts are fragmented and suffer substantial gaps in coverage. In this paper we identify and discuss issues relating to the assessment of spatial and temporal patterns of introductions in European Seas (ES), based on a scientifically validated information system of aquatic non-indigenous and cryptogenic species, AquaNIS. While recognizing the limitations of the existing data, we extract information that can be used to assess the relative risk of introductions for different taxonomic groups, geographic regions and likely vectors. The dataset comprises 879 multicellular NIS. We applied a country-based approach to assess patterns of NIS richness in ES, and identify the principal introduction routes and vectors, the most widespread NIS and their spatial and temporal spread patterns. Between 1970 and 2013, the number of recorded NIS has grown by 86, 173 and 204% in the Baltic, Western European margin and the Mediterranean, respectively; 52 of the 879 NIS were recorded in 10 or more countries, and 25 NIS first recorded in European seas since 1990 have since been reported in five or more countries. Our results highlight the ever-rising role of shipping (commercial and recreational) as a vector for the widespread and recently spread NIS. The Suez Canal, a corridor unique to the Mediterranean, is responsible for the increased introduction of new thermophilic NIS into this warming sea. The 2020 goal of the EU Biodiversity Strategy concerning marine Invasive Alien Species may not be fully attainable. The setting of a new target date should be accompanied by scientifically robust, sensible and pragmatic plans to minimize introductions of marine NIS and to study those present.

‘Double trouble’: the expansion of the Suez Canal and marine bioinvasions in the Mediterranean Sea

‘‘Egypt to build new Suez canal... ‘This giant project will be the creation of a new Suez canal parallel to the current channel’ said Mohab Mamish, the chairman of the Suez Canal Authority, in a televised speech.’’ (http://www.theguardian.com/world/2014/aug/05/ egypt-build-new-suez-canal, viewed August 13, 2014). This is ominous news. Expected to double the capacity of the Suez Canal, the expansion is sure to have a diverse range of effects, at local and regional scales, on both the biological diversity and the ecosystem goods and services of the Mediterranean Sea. Of nearly 700 multicellular non-indigenous species (NIS) currently recognized from the Mediterranean Sea, fully half were introduced through the Suez Canal since 1869 (Galil et al. 2014). This is one of the most potent mechanisms and corridors for invasions by marine species known in the world. Further, molecular methods demonstrate high levels of gene flow between the Red Sea and the Mediterranean populations

Functions and ecological status of eight Italian lagoons examined using biological traits analysis (BTA)

The soft-bottom communities of eight Italian lagoons were analyzed for eight biological traits (feeding, mobility, adult life habitat, body size, life span, reproductive technique, type of larva and reproductive frequency) in order to identify the dominant traits in different transitional environments. We considered the ecological quality status (EcoQS) of the stations, assessed by two biotic indices, AMBI and Bentix. Stations were categorized into EcoQS classes to investigate the relationship between biological functions and ecological quality. The results indicate that the variability of the data was governed by traits linked to resource utilization rather than to life cycle. Lagoons affected by chronic disturbance displayed a poor functional composition, which usually corresponded to poor EcoQS in some cases, correlations between ecological groups and traits modalities were ecologically relevant; however, classes of EcoQS were found to be relatively independent from the functional structure of the considered stations.

Classification of Non-Indigenous Species Based on Their Impacts: Considerations for Application in Marine Management

Assessment of the ecological and economic/societal impacts of the introduction of non-indigenous species (NIS) is one of the primary focus areas of bioinvasion science in terrestrial and aquatic environments, and is considered essential to management. A classification system of NIS, based on the magnitude of their environmental impacts, was recently proposed to assist management. Here, we consider the potential application of this classification scheme to the marine environment, and offer a complementary framework focussing on value sets in order to explicitly address marine management concerns. Since existing data on marine NIS impacts are scarce and successful marine removals are rare, we propose that management of marine NIS adopt a precautionary approach, which not only would emphasise preventing new incursions through pre-border and at-border controls but also should influence the categorisation of impacts. The study of marine invasion impacts requires urgent attention and significant investment, since we lack the luxury of waiting for the knowledge base to be acquired before the window of opportunity closes for feasible management.

Porifera and Bryozoa on artificial hard bottoms in the Venice Lagoon: Spatial distribution and temporal changes in the northern basin

The spatial distribution and temporal changes of demosponges and bryozoans in the northern basin of the Venice Lagoon were studied from samples collected from wooden piles and artificial rocks in June and October 2001. Twenty species of demosponges and 18 species of bryozoans were recorded. Sponges were found at 10 out of 11 sampling stations, while bryozoans were found at all 11 sampling stations. The studied taxocoenoses showed a high percentage cover of the lagoon hard bottoms. Eleven out of the 20 detected species of sponges were reported in a previous study on this taxocoenosis carried out on material collected in 1954–1955. Moreover, the most abundant species were also recorded during a study in 1989. These observations suggest a remarkable degree of persistence of the sponge community. Among bryozoans, the comparison with literature data showed a wider variation in species composition, with the occurrence of five new species in the studied area. The Indo‐Pacific invasive Tricellaria inopinata replaced the native Bugula spp. in the role of dominant species. Finally, a significant increase in species richness along the salinity gradient, more evident for sponges than for bryozoans, was identified.

The sessile benthic community patterns on hard bottoms in response to continental vs. marine influence in northern Adriatic lagoons

Abstract The sessile hard bottoms zoobenthos community was studied in three northern Adriatic lagoons (Venice, Caorle and Grado-Marano). On the basis of previous researches (1993–1994 in Venice; 1997 in Grado-Marano), these lagoons had been subdivided into ecological sectors. The time consistency of such a subdivision has been assessed. The largest number of species was found in the lagoon of Venice, showing a high heterogeneity of environments and an intense shipping traffic, coupled with aquaculture activities that favoured the arrival of exotic species. A very poor community of obligate oligohaline species was found in Caorle. The natural and stable environment of Grado-Marano lagoon, with its large area of freshwater influence, hosted an intermediate number of species. The multi-dimensional scaling ordination plot of 27 representative stations from the three lagoons (samples of July 2000) clearly distinguished a cluster of “estuarine” sites from the remaining ones, that could be classified as “inner lagoon” sites, “vivified lagoon” sites and “lagoon mouth” sites. When compared with past results by Anosim test and Simper analysis, a lesser degree of discrimination between clusters of sites could be observed. In the following year (samples of July 2001), a larger number of sampling stations was considered in Venice and Grado-Marano. The multi-dimensional scaling plot for the community data of Grado-Marano showed fairly recognisable clusters, that substantially repeated those defined in 1997. As far as Venice is concerned, about 25% of the examined stations had shifted towards a different group, compared with those identified in 1993–1994; in particular, the “urban”, “inner lagoon” and “estuarine” sectors and their peculiar assemblages survived only in small areas with unique features of harsh environmental conditions. The progressively enhanced marine influx in all the lagoon sectors (but the ones directly affected by the outflow of the only river still discharging into the lagoon) has, on the one hand, reduced the most evident effects of eutrophication and urban pollution, and on the other, led to a banalisation of the lagoon communities.

Developing a scuba trail vulnerability index (STVI): a case study from a Mediterranean MPA

Scuba diving is now one of the major form of commercial use of marine protected areas (MPAs) around the world and the control of its potential impacts on the marine environment represents a fundamental key to manage this recreational activity in highly dived areas. A potential tool to tackle such issues has been thought to be the definition of a value of recreational carrying capacity of an area, but this approach has been rarely considered management-effective. Therefore, the first step for effectively managing scuba-diving should be ‘bottom-up’: characterizing the benthic communities potentially affected by diving and evaluating their vulnerability. Aim of this paper is to propose a tool to define an index of vulnerability for dive trails (STVI: scuba trail vulnerability index). This has taken into consideration both physical and biological features of each trail. All the considered features are represented by non-quantitative variables, because either they are purely qualitative or their quantitative measurement is impractical. The management of such qualitative information and its translation into a formal methodology was performed by means of fuzzy logic, which has been repeatedly proposed as a powerful technique to develop indices of environmental quality. The approach adopted in this study provided a useful tool for the preliminary assessment of the potential vulnerability of benthic assemblages to scuba-diving and may represent an alternative method to the assessment of carrying capacity. The application of this index will enable management strategies for potentially reducing the degradation of benthic organisms/assemblages, and allowing a sustainable use of MPAs.

The fuzzy index of ecosystem integrity (FINE): a new index of environmental integrity for transitional ecosystems

The European Water Framework Directive (WFD) (2000/60/EC) requires assessing the ecological quality status of water bodies, and gives great importance to the biological components of the ecosystem. Within this framework, a multimetric, fuzzy-based index for the evaluation of environmental quality (FINE: fuzzy index of ecosystem integrity) has been developed using data from several Italian coastal lagoons, gathered with seasonal frequency at diverse sites in each lagoon. The rationale of FINE is that certain attributes, selected on the basis of established principles of benthic ecology, are fundamental for lagoon ecosystem function. FINE is composed of seven ecosystem attributes (variables) each of which have ecological relevance for lagoon ecosystems. Individually, all these attributes are themselves useful indices of environmental conditions. However, the combination of these attributes into a single fuzzy index, provides a more robust, overall index of the response of the natural communities to environmental perturbations and avoids misleading or ambiguous results. Each variable is not represented by a single numerical value, but by several categories that describe its properties: in the present model we considered a total of seven variables: two with four modalities (low–medium–high–very high), one with three (low–medium–high) and three with two (low–high), plus a qualitative variable (yes–no), that altogether generate 768 rules. FINE is a low-cost, flexible and robust routine index of lagoon ecosystem impairment and could be of particular benefit to environmental managers and policymakers who require tools capable of expressing the degree of degradation or environmental quality of different lagoon habitats. For its relative simplicity in the application, FINE could be a good candidate to assess the environmental quality of Mediterranean transitional ecosystems.

Modelling Ecological Processes with Fuzzy Logic Approaches

The development of an ecological model may involve problems of uncertainty. Ecologists have to deal with imprecise data, ecosystem variability, complex interactions, qualitative aspects, and expert knowledge expressed in linguistic terms. In all these cases, fuzzy logic could provide a suitable solution. Fuzzy logic allows to: use uncertain information such as individual knowledge and experience; to combine quantitative and qualitative data; to avoid artificial precision and to produce results that are found more often in the real world. Developed in the late sixties as a method to create control systems when using imprecise data, fuzzy logic has been used for a very large number of engineering applications, and more recently to develop models of air, water and soil ecosystems.The following sections of this chapter introduce the basic structure of a fuzzy model, describing the variety of options that exist at each stage. An example of fuzzy model is also outlined: the knowledge-driven development of an index of water quality having five qualitative output classes. Finally, possible future developments of fuzzy modelling in ecology are suggested.

The non-indigenous Paranthura japonica Richardson, 1909 in the Mediterranean Sea: travelling with shellfish?

An anthurid isopod new to the Mediterranean Sea has recently been observed in samples from three localities of the Italian coast: the Lagoon of Venice (North Adriatic Sea), La Spezia (Ligurian Sea) and Olbia (Sardinia, Tyrrhenian Sea). The specimens collected showed strong affinity to a species originally described from the NW Pacific Ocean: Paranthura japonica Richardson, 1909. The comparison with specimens collected from the Bay of Arcachon (Atlantic coast of France), where P. japonica had been recently reported as non-indigenous, confirmed the identity of the species. This paper reports the most relevant morphological details of the Italian specimens, data on the current distribution of the species and a discussion on the pathways responsible for its introduction. The available data suggest that the presence of this Pacific isopod in several regions of coastal Europe might be due to a series of aquaculture-mediated introduction events that occurred during the last decades of the 1900s. Since then, established populations of P. japonica, probably misidentified, remained unnoticed for a long time.