In a world where invasive alien species (IAS) are recognised as one of the major threats to biodiversity, leading scientists from five continents have come together to propose the concept of developing an international association for open knowledge and open data on IAS—termed “INVASIVESNET”. This new association will facilitate greater understanding and improved management of invasive alien species (IAS) and biological invasions globally, by developing a sustainable network of networks for effective knowledge exchange. In addition to their inclusion in the CBD Strategic Plan for Biodiversity, the increasing ecological, social, cultural and economic impacts associated with IAS have driven the development of multiple legal instruments and policies. This increases the need for greater co-ordination, co-operation, and information exchange among scientists, management, the community of practice and the public.

     INVASIVESNET will be formed by linking new and existing networks of interested stakeholders including international and national expert working groups and initiatives, individual scientists, database managers, thematic open access journals, environmental agencies, practitioners, managers, industry, non-government organisations, citizens and educational bodies. The association will develop technical tools and cyberinfrastructure for the collection, management and dissemination of data and information on IAS; create an effective communication platform for global stakeholders; and promote coordination and collaboration through international meetings, workshops, education, training and outreach.

     To date, the sustainability of many strategic national and international initiatives on IAS have unfortunately been hampered by time-limited grants or funding cycles. Recognising that IAS initiatives need to be globally coordinated and on-going, we aim to develop a sustainable knowledge sharing association to connect the outputs of IAS research and to inform the consequential management and societal challenges arising from IAS introductions. INVASIVESNET will provide a dynamic and enduring network of networks to ensure the continuity of connections among the IAS community of practice, science and management.

We developed a spatially-explicit, habitat suitability model that can be used to identify and predict areas at higher risk for non-native dwarf eelgrass (Zostera japonica) invasion. The niche-based model uses simple readily available environmental parameters (depth, near shore slope, and salinity) to quantitatively describe habitat suitable for Z. japonica invasion based on ecology and physiology from the primary literature. Habitat suitability is defined with values ranging from zero to one, where one denotes areas most conducive to Z. japonica and zero denotes areas not likely to support Z. japonica growth. Functional forms and equations for the ZJHSM were developed a priori, and the model was validated by comparison with multiple years of independent field-collected spatial Z. japonica maps from Yaquina Bay, Oregon, USA, an area that has well documented Z. japonica expansion over the last two decades. Sensitivity analysis performed to evaluate the contribution of each parameter to the model prediction revealed that depth was the most important factor. The highest suitability values for Z. japonica occurred in the mid to upper portions of the intertidal zone, with larger expanses occurring in the lower estuary. While the upper estuary did contain suitable habitat, most areas were not as large as in the lower estuary, due to inappropriate depth, a steeply sloping intertidal zone, and lower salinity. The lowest suitability values occurred below the lower intertidal zone, within the Yaquina River channel. Shallow sloping intertidal soft-bottom sediments appear to provide optimum habitat for this species. This model would allow resource managers to identify those areas at risk for future invasion, and develop proactive plans for limiting the opportunities for further introduction and spread in areas where it does not currently occur.

There is an urgent need to develop and test potential eradication agents to prevent biofouling by ascidian tunicates in sheltered harbor’s before they can spread to, and subsequently, disrupt benthic ecosystems and aquaculture ventures. We test the effects of bubble streams and suspended particles on two key stages in the early life cycle of Ciona intestinalis (Linnaeus, 1767); (i) Larval settlement 3 d after introducing free swimming larvae, and (ii) juvenile survival following exposure of ~ 21 d old juvenile recruits to the tested treatments for the first time. Larval settlement was effectively prevented after exposure to bubble streams at > 10 l min-1 or ≥ 25 Nephelometric Turbidity Units (NTU) of suspended particles. Suspended particles settling as a layer ≥ 0.3 mm thick onto the test substrate also reduced larval settlement by over 90%. None of the treatments were effective at eradicating juvenile C. intestinalis which proved more resistant to the tested treatments. Body size in juvenile recruits was also not significantly different across bubble stream rates. Juvenile recruits exposed to suspended particles were, however, significantly smaller than in the control treatment. In conclusion, as C. intestinalis settled, and grew, it became progressively more resilient to the tested treatments. Thus, continuous treatment is required during the spawning season to target larval settlement and prevent fouling by Ciona intestinalis.

The invasive tunicate species Ciona intestinalis (Linnaeus, 1767) has had an economic impact on the aquaculture of the blue mussel Mytilus edulis (Linnaeus, 1758) in Prince Edward Island (PEI). This tunicate fouls mussel socks suspended on long lines in the water and reduces both weight and numbers of mussels, decreasing overall productivity. This study determined the relative effects of high pressure water treatment schedules over a four month period on two sites in the Murray and Brudenell Rivers on PEI. Results indicated that initiating treatment early (July) in the season and treating another two or three times during the season had the greatest effect on reducing tunicate numbers and size and enabling greater mussel productivity. While the most effective treatment may ultimately be site-specific, the two sites in this study support the notion that beginning treatment when tunicates are small is one of the most significant parts of the treatment plan. Two or more treatments (approximately monthly) are then needed to effectively control C. intestinalis, and allow mussels to reach their full growth potential.

In order to evaluate the potential risk posed by transporting invasive tunicates away from infested sites it is important to be able to measure the viability of these organisms. A Neutral Red (NR) viability assay was developed using a colonial invasive tunicate, Botrylloides violaceus (Oka, 1927) that could be applied to other species. Unlike some colonial tunicates B. violaceus’ mortality can be determined under light microscopy by observing changes in the physiological parameters of filtration and reaction to tactile stimulus making them a good study organism. A total of 32 B. violaceus segments (3 cm²) were allocated to treatment and control groups. The treatment group was subjected to acetic acid which resulted in 100 % mortality. Viability was then assessed by comparing treatment and control group responses to NR uptake. There was no mortality in the control that demonstrated a response to tactile stimulus and a noticeable amount of stain uptake inside zooids. In contrast, the treatment groups did not respond to tactile stimulus and no stain was taken in by the zooids. In this study the viability of Didemnum vexillum (Kott, 2002) was assessed under controlled experimental conditions by simulating the air exposure encountered during the normal transportation and processing of tunicate fouled Pacific oysters, Crassostrea gigas (Thunberg, 1793). Clusters containing C. gigas and D. vexillum were collected from an aquaculture lease, in Lemmens Inlet, BC, for an air exposure trial comprised of 9 equally divided treatments (0, 0.5, 1.5, 3, 6, 12, 24, 48 and 72 hours). Three segments of D. vexillum on each cluster were removed and evaluated with the NR protocol developed for B. violaceus. Preserved tissues were analyzed and no sign of stain was noticeable, even with the control segments. The NR protocol developed worked efficiently with B. violaceus, but appeared to fail with D. vexillum. The findings are consistent with D. vexillum demonstrating a high tolerance in situations they are not accustomed to reflecting their ability to enter a dormant state during adverse environmental conditions (hence lack of response to clinical or NR markers via lack of filtering). Further studies are required to determine the viability of D. vexillum and potential risk movements pose.

The colonial tunicate Didemnum perlucidum has been identified from numerous tropical and temperate locations worldwide, but its native and introduced ranges remain largely unknown. In Australia, D. perlucidum is listed as a target species under the introduced marine pest national monitoring network. In order to investigate the introduced status and potential routes of introduction and dispersal of D. perlucidum, we developed 17 new polymorphic microsatellite markers using 454 shotgun sequencing. Two to six alleles per locus were detected. No evidence of linkage disequilibrium between pairs of loci was identified and 12 of the 17 loci were in Hardy-Weinberg equilibrium.

Early detection of invasive species is critical to increasing the probability of successful management. At the primary stage of an invasion, invasive species are easier to control as the population is likely represented by just a few individuals. Detection of these first few individuals can be challenging, particularly if they are cryptic or otherwise characterized by low detectability. The engagement of members of the public may be critical to early detection as there are far more citizens on the landscape than trained biologists. However, it can be difficult to assess the credibility of public reporting, especially when a diagnostic digital image or a physical specimen in good condition are lacking. DNA barcoding can be used for verification when morphological identification of a specimen is not possible or uncertain (i.e., degraded or partial specimen). DNA barcoding relies on obtaining a DNA sequence from a relatively small fragment of mitochondrial DNA and comparing it to a database of sequences containing a variety of expertly identified species. Herein we report the successful identification of a degraded specimen of a non-native, potentially invasive reptile species (Varanus niloticus) via DNA barcoding, after discovery and reporting by a member of the public.

The relatively uninvaded coastline of Alaska currently faces a heightened risk of novel biological introductions as a result of increasing regional vessel traffic, emerging Arctic trade routes, and proposed coastal and nearshore development. Alaska currently receives the majority of its ballast water discharge in the port of Valdez (86%), largely from crude oil tankers engaged in coastwise trade. These crude oil tankers were exempted from managing and reporting ballast water prior to the United States Environmental Protection Agency’s 2008 Vessel General Permit (VGP). Here we present a comprehensive statewide risk assessment of ballast-borne marine invasive species throughout coastal Alaska, and the first study to characterize the risk from the ballast water vector following inclusion of ballast water reporting by the VGP. We examined ballast water discharge volume, environmental similarity between source and discharge regions, ballast water age, and marine invasive species richness in source regions annually from 2009 – 2012 for the top 15 ports/discharge locations in Alaska. The majority (80%) of the more than 54 million metric tons of reported ballast water discharged during this time period was sourced from the west coast of North America, including highly invaded port systems such as San Francisco Bay, California and Puget Sound, Washington. Overall about 38% of the ballast water discharged to our focus locations was managed using ballast water exchange. We conclude that the risk of invasion is highest for the ports of Valdez and Drift River Terminal and lowest for the ports of Klawock, Skagway, and Tolstoi Bay. This analysis and risk matrix can inform further fine-scale assessments of ballast water management activity and identify areas of Alaska most likely to benefit from focused management efforts.