Ecosystem vulnerability to alien and invasive species: a case study on marine habitats along the Italian coast

Abstract

Spread of alien species (AS) is a serious threat to marine habitats and analysis of principal descriptors of their occurrence is pivotal to set reliable conservation strategies. In order to assess the susceptibility of marine habitats to biological invasions, a dataset was gathered of the occurrence of 3899 species from 29 phyla, taken from 93 marine sites located along the Italian coast in the period 2000-2012. In total, 61 AS belonging to 11 phyla have been recorded. Invertebrates were the most represented (63%). Alien species were found in all the habitats examined (EUNIS, level 2), although they showed highest abundance in benthic habitats. Most of the AS were associated with a single EUNIS habitat, while some of them were present in more than one habitat. Trans-habitat occurrence suggests the potential invasiveness of AS. According to statistical analysis, AS recorded could have been more numerous, since some of the marine habitats seemed to be still unsaturated. The model that best describes the spread of AS takes account of both native species richness (Rn) and EUNIS habitat type as explanatory variables. The number of observed AS was directly related to Rn and it was highest in rocky circalittoral and infralittoral habitats. The results of this macro-ecological study focus on the importance of performing large-scale studies, since adopting ecosystem approaches to marine invasion management seems especially fruitful. The results, moreover, highlight the importance of AS monitoring of different habitats, from those subjected to anthropogenic pressure, historically considered to be hubs of introduction of AS, to the most biologically rich and diverse marine habitats. Indeed, it is necessary to set monitoring strategies to detect the introduction, the distribution and persistence of AS over time. These recommendations are especially significant in the light of the strategic plans currently under formulation in Mediterranean countries with regard to AS monitorin

The Mediterranean in check: Biological invasions in a changing sea

“…Invasion ecology is an interdisciplinary field where ecology, social sciences, resource management and public perception overlap. The problem of bioinvasions is of regional importance, with the potential of altering the exchange patterns between regions and neighbourhoods (Corriero et al, 2016; Vanderhoeven & Branquart, 2010).…”

“…Although the scientific interest in the presence of AS in the marine environment started later than in the terrestrial environment, biological invasions are a growing concern also in the marine environment for both conservation and economic activities (Giakoumi et al, 2019; Katsanevakis et al, 2014; Occhipinti‐Ambrogi & Galil, 2010; Perrings et al, 2002), and a lot of studies claim that the introduction of AS affects diversity, structure and functioning of marine ecosystems (Corriero et al, 2016; Galil, 2007; Pimentel, Lach, Zuniga, & Morrison, 2000; Stachowicz & Byrnes, 2006; Thomsen, Olden, Wernberg, Griffin, & Silliman, 2011).…”

Alien species in aquatic environments: a selective comparison of coastal and inland waters in tropical and temperate latitudes

“…National inventories of established aliens will need to be updated regularly, and public engagement will also be needed, not least to discourage the import and release of non‐native species. More research should be directed towards measuring the ecological impacts of species that have become established (Junqueira, ; Corriero et al, ), so that priorities for management can be directed towards the most harmful aliens. Such investigations would need to involve rigorous experimentation, and not simply correlative studies of changes that took place after the arrival of an invasive species (although such data can be useful).…”

A geographic distribution data set of biodiversity in Italian freshwaters

“…This vast data set was created under the umbrella of a case study on Alien Species (AS) that was proposed and coordinated by LifeWatch Italy at the European level. The case study is designed using species occurrence data to assess the vulnerability of different Italian ecosystems to AS arrival (Boggero et al 2014, Corriero et al 2016. The taxonomic resolution adopted in the data set is at the species level for all the included taxonomic groups across different phyla.…”