Dario Savini

In vitro evaluation of nematophagous activity of fungal isolates

Four filamentous fungi associated with nematodes were isolated and identified from litter samples collected in the Integral Natural Reserve “Bosco Siro Negri” (PV, Italy): Arthrobotrys dactyloides, Arthrobotrys oligospora var. oligospora, Pochonia bulbillosa, and Pochonia chlamydosporia var. catenulata. Their capacity to break down the nematode population was evaluated in vitro by means of simple and reproducible multiwell plates method. All fungal strains were able to cause a death‐rate significantly different from the controls (p < 0.05). Precisely, A. dactyloides caused, on average, a 26% death rate increase in the nematode population compared to the control, A. oligospora var. oligospora 25%, P. bulbillosa 12%, and P. chlamidosporia var. catenulata 17%. The method has also allowed to determine the more active fungi as regards the preys life cycle stage. The most active strains against nematodes (adults) were A. dactyloides and A. oligospora var. oligospora, known to attack adults or larval stages by means of tridimensional traps. On the contrary P. bulbillosa and P. chlamydosporia, known to attack mainly the nematode life stage of cysts, showed lower activity against adult nematodes.

Small craft and the spread of exotic species

This chapter describes how an increasing number of marine non-indigenous species (NIS) have been recorded from urban and port environments worldwide over the past centuries. This spread has for many species been attributed to the shipping industry. Ships are capable of spreading exotic species in ballast water (taken on board to provide stability at sea) or attached to submerged hull surfaces (hull fouling). Worldwide, more than 2,000 different species have been identified from hull-fouling assemblages. Despite a likely decline in the rate of species transfers on ship hulls through the development of modern toxic “antifouling paints”, NIS continue to be transported on the hulls of domestic and international vessels. This chapter examines hull fouling on small craft as a transportation vector for NIS in widely dispersed regions including temperate and tropical environments. The chapter provides summaries of NIS incursions associated with small craft movements, outlines the factors that make small craft susceptible to fouling, and it documents a recent general increase in the abundance of small craft and associated industries. The chapter also discusses the likely dispersal routes of NIS by small craft and it makes recommendations for managing the risks of small craft fouling and NIS transportation.

The alien mollusc Rapana venosa (Valenciennes, 1846; Gastropoda, Muricidae) in the Northern Adriatic Sea: Population structure and shell morphology

Rapana venosa (Valenciennes, 1846; Gastropoda, Muricidae), ‘Rapa whelk’, is a predator of bivalves, native to the Japanese seas. It has been reported in the Northern Adriatic Sea since 1973. Recently, its biogeographical distribution has been widening (probably favoured by ship traffic) including the Atlantic coasts of the USA, Argentina and France, where the species colonised transition zones, such as estuaries or lagoons, economically important for shellfish harvesting. This work investigates the population structure of the Rapa whelk (size classes distribution, sex ratio) in Cesenatico (Emilia-Romagna coast), where local fishermen have been recently observing increasing numbers of Rapana in their by-catches. During summer 2001, analyses were performed on sexually mature adult specimens obtained from sandy bottoms and artificial rocky breakwaters. Male and female individuals were reported in approximately equal numbers with a minimum shell length of 67.0 and a maximum of 136.7 mm. Rapana collected on breakwaters were significantly larger and heavier than Rapana from sand substratum (ANOVA, P < 0.05). Sand shells and rock (breakwater) shells differed also in colour and epibiont cover. The role of man-made hard structures such as breakwaters in maintaining and promoting a further expansion of R. venosa is discussed.

Opportunities for Web-Based Indicators in Environmental Sciences

This paper proposes a set of web-based indicators for quantifying and ranking the relevance of terms related to key-issues in Ecology and Sustainability Science. Search engines that operate in different contexts (e.g. global, social, scientific) are considered as web information carriers (WICs) and are able to analyse; (i) relevance on different levels: global web, individual/personal sphere, on-line news, and culture/science; (ii) time trends of relevance; (iii) relevance of keywords for environmental governance. For the purposes of this study, several indicators and specific indices (relational indices and dynamic indices) were applied to a test-set of 24 keywords. Outputs consistently show that traditional study topics in environmental sciences such as water and air have remained the most quantitatively relevant keywords, while interest in systemic issues (i.e. ecosystem and landscape) has grown over the last 20 years. Nowadays, the relevance of new concepts such as resilience and ecosystem services is increasing, but the actual ability of these concepts to influence environmental governance needs to be further studied and understood. The proposed approach, which is based on intuitive and easily replicable procedures, can support the decision-making processes related to environmental governance.

First record of Tricellaria inopinata (Bryozoa: Candidae) in the harbours of La Spezia and Olbia, Western Mediterranean Sea (Italy)

In summer 2010, a systematic survey was carried out in the harbours of La Spezia (Ligurian Sea) and Olbia (western Tyrrhenian Sea) with the aim of studying alien species in Italian commercial harbours. Biological samples were collected by replicate scraping on the concrete walls of docks at the beginning and at the end of the summer season. Identification to species level revealed the presence of Tricellaria inopinata , an invasive alien cheilostome bryozoan of Pacific origin, first introduced to Europe in the Lagoon of Venice (Italy) in 1982. Thereafter it has been reported in other ports in Britain, Belgium, The Netherlands, France, Spain, Portugal, Tunisia, Ireland, Scotland, Germany and Massachusetts (USA). Its finding in the harbours of La Spezia and Olbia represents the first record of the species in the Ligurian Sea and in the western-central Tyrrhenian Sea, respectively. Commercial harbours are common sites of biotic invasions due to the presence of the most important vectors of alien species introduction, namely aquaculture, and shipping. The occurrence of T. inopinata in the harbours of La Spezia and Olbia is discussed, taking into consideration possible pathways of introduction into the western Mediterranean Sea, which very likely is the transfer of molluscs from the northern Adriatic (namely the Lagoon of Venice).

Range expansion and biometric features of Pinctada imbricata radiata (Bivalvia: Pteriidae) around Linosa Island, Central Mediterranean Sea (Italy)

Abstract In the summer of 2011, the infralittoral fringe of Linosa Island (Sicilian Channel, Italy) was surveyed through visual census, by both scuba diving and snorkelling, with the aim of collecting updated data on marine alien species distribution and abundance on the island. Surveys revealed the presence of Pinctada imbricata radiata, an invasive alien bivalve of Indo-Pacific origin, first recorded in the Mediterranean Sea at the end of the 19th century in Egyptian waters. Since then, the species has successfully spread throughout the Mediterranean, systematically colonizing new habitats of the eastern basin and becoming very abundant in the Levantine Sea. Conversely, occurrences in the western basin have been reported only sporadically. Many studies have been carried out on P. imbricata radiata in its native range (Indian Ocean and Red Sea) while the Mediterranean populations have been investigated only in Tunisia. The finding of P. imbricata radiata around Linosa Island (Sicilian Channel, Italy) is discussed analysing the biometric features of the species and taking into consideration its ecological characteristics and possible pathways of introduction in the Marine Protected Area of Linosa Island.