Public's perceptions of marine bioinvasive risks and responsible parties - Implications for social acceptability and better-informed communication in the marine biosecurity context.

Using the survey data on a representative sample of the New Zealand population, our study presents a process of understanding citizens' perceptions, identifying patterns in the perceptions, and recognising the knowledge gaps existing in the citizenry in the marine biosecurity context. While our findings show a healthy sign of the public accepting their own responsibility and the devolved responsibility of business/industry, there are considerable gaps between the general public's perceptions and (marine) biosecurity current practices and expectations. There is a moderately strong signal from survey respondents that suggest the need of significantly more effort and improved transparency in marine biosecurity communication. Our outcomes indicate an anthropocentric tendency, with influences of gender, age, education, income, frequency of beach visitation upon societal perceptions in terms of awareness, concern, perceived non-indigenous marine species impacts, and accountability in marine biosecurity management. The recognised socio-demographic patterns in societal perceptions would inform marine biosecurity communication strategies.

Trends in the detection of aquatic non-indigenous species across global marine, estuarine and freshwater ecosystems: A 50-year perspective.

Aim: The introduction of aquatic non-indigenous species (ANS) has become a major driver for global changes in species biogeography. We examined spatial patterns and temporal trends of ANS detections since 1965 to inform conservation policy and management. Location: Global. Methods: We assembled an extensive dataset of first records of detection of ANS (1965-2015) across 49 aquatic ecosystems, including the (a) year of first collection, (b) population status and (c) potential pathway(s) of introduction. Data were analysed at global and regional levels to assess patterns of detection rate, richness and transport pathways. Results: An annual mean of 43 (±16 SD) primary detections of ANS occurred-one new detection every 8.4 days for 50 years. The global rate of detections was relatively stable during 1965-1995, but increased rapidly after this time, peaking at roughly 66 primary detections per year during 2005-2010 and then declining marginally. Detection rates were variable within and across regions through time. Arthropods, molluscs and fishes were the most frequently reported ANS. Most ANS were likely introduced as stowaways in ships' ballast water or biofouling, although direct evidence is typically absent. Main conclusions: This synthesis highlights the magnitude of recent ANS detections, yet almost certainly represents an underestimate as many ANS go unreported due to limited search effort and diminishing taxonomic expertise. Temporal rates of detection are also confounded by reporting lags, likely contributing to the lower detection rate observed in recent years. There is a critical need to implement standardized, repeated methods across regions and taxa to improve the quality of global-scale comparisons and sustain core measures over longer time-scales. It will be fundamental to fill in knowledge gaps given that invasion data representing broad regions of the world's oceans are not yet readily available and to maintain knowledge pipelines for adaptive management.

Are our beaches safe? Quantifying the human health impact of anthropogenic beach litter on people in New Zealand.

The environmental, social and cultural importance of beaches permeates human society, yet the risk of human injury associated with increasing exposure to anthropogenic beach litter remains an unknown. While the impact of marine debris and beach litter on marine and coastal fauna and flora is a widely reported global issue, we investigate the impact on human health in New Zealand. Anthropogenic beach litter is ubiquitous, few beaches remain pristine, which consequently influences tourist choices and potentially negatively interacts with humans. Human impacts are not well-investigated, with no quantitative studies of impact but many studies qualitatively inferring impact. New Zealand has a socialised medical system allowing a quantitative, decadal assessment of medical insurance claims to determine patterns and trends across ecosystems and causes. We demonstrate for the first time that anthropogenic beach litter poses a common and pervasive exposure hazard to all ages, with specific risk posed to young children. The New Zealand system allows these hazards to be investigated to determine the true effects and costs across a nation, providing an evidence base for decision-makers to address this ubiquitous environmental issue.

Seabirds and plastics don't mix: Examining the differences in marine plastic ingestion in wedge-tailed shearwater chicks at near-shore and offshore locations.

Plastic ingestion by wedge-tailed shearwaters (WTS) nesting at near-shore and offshore sites along the east coast of Australia were investigated. Ingestion rates were at 20% in near-shore lavaged WTS, where the beaches were significantly more polluted, compared to 8% in birds at offshore sites. The material and colour of recovered plastics at offshore sites differed significantly between beach surveys and that ingested by seabirds in the same area. This pattern was not evident near-shore. Hence, in near-shore environments birds may feed locally and are influenced by nearby plastics, compared to birds offshore. The origins of marine debris between near-shore and offshore beaches differed; with land-based sources unsurprisingly having more influence on near-shore sites. The findings of this study indicate the need for localised data to address and manage this pollutant, with nesting seabirds at greater risk in near-shore environments. A preliminary modified ecological quality objective for WTS is presented.

Niche partitioning of intertidal seagrasses: evidence of the influence of substrate temperature.

The influence of soil temperature on rhizome depths of four intertidal seagrass species was investigated in central Queensland, Australia. We postulated that certain intertidal seagrass species are soil temperature-sensitive and vertically stratify rhizome depths. Below-ground vertical stratification of intertidal seagrass rhizome depths was analysed based upon microclimate (soil temperature) and microhabitat (soil type). Soil temperature profiles exhibited heat transfer from surface layers to depth that varied by microhabitat, with vertical stratification of rhizome depths between species. Halodule uninervis rhizomes maintain a narrow median soil temperature envelope; compensating for high surface temperatures by occupying deeper, cooler soil substrates. Halophila decipiens, Halophila ovalis and Zostera muelleri rhizomes are shallow-rooted and exposed to fluctuating temperatures, with broader median temperature envelopes. Halodule uninervis appears to be a niche specialist, with the two Halophila species considered as generalist niche usage species. The implications of niche use based upon soil temperature profiles and rhizome rooting depths are discussed in the context of species' thermal tolerances and below-ground biomass O2 demand associated with respiration and maintenance of oxic microshields. This preliminary evidence suggests that soil temperature interaction with rhizome rooting depths may be a factor that influences the distribution of intertidal seagrasses.

Aquaculture and urban marine structures facilitate native and non-indigenous species transfer through generation and accumulation of marine debris.

Both the invasion of non-indigenous marine species (NIMS) and the generation and accumulation of anthropogenic marine debris (AMD) are pervasive problems in coastal urban ecosystems. The biosecurity risks associated with AMD rafting NIMS have been described, but the role of aquaculture derived AMD has not yet been investigated as a biosecurity vector and pathway. This preliminary study targeted 27 beaches along the Coromandel Peninsula, New Zealand, collecting debris from belt transects. Plastic (specifically plastic rope) was the dominant AMD present on beaches. The most common biofouling taxa were hydroids, bryozoans, algae and polychaetes, with one NIMS pest species, Sabella spallanzanii, detected fouling plastic rope. Our findings demonstrate that aquaculture is an AMD (plastic rope) generating activity that creates biosecurity risk by enhancing the spread of NIMS. The rafting of S. spallanzanii on AMD generated at aquaculture facilities is currently an unmanaged pathway within New Zealand that needs attention.

Epibiotic pressure contributes to biofouling invader success.

Reduced competition is a frequent explanation for the success of many introduced species. In benthic marine biofouling communities, space limitation leads to high rates of overgrowth competition. Some species can utilise other living organisms as substrate (epibiosis), proffering a competitive advantage for the epibiont. Additionally, some species can prevent or reduce epibiotic settlement on their surfaces and avoid being basibionts. To test whether epibiotic pressure differs between native and introduced species, we undertook ex situ experiments comparing bryozoan larval settlement to determine if introduced species demonstrate a greater propensity to settle as epibionts, and a reduced propensity to be basibionts, than native species. Here we report that introduced species opportunistically settle on any space (bare, native, or introduced), whereas native species exhibit a strong tendency to settle on and near other natives, but avoid settling on or near introduced basibionts. In addition, larvae of native species experience greater larval wastage (mortality) than introduced species, both in the presence and absence of living substrates. Introduced species' ability to settle on natives as epibionts, and in turn avoid epibiosis as basibionts, combined with significantly enhanced native larval wastage, provides a comprehensive suite of competitive advantages contributing to the invasion success of these biofouling species.

Biosecurity messages are lost in translation to citizens: Implications for devolving management to citizens.

The increasing focus of marine biosecurity agencies on transferring management responsibilities to citizens and industry begs the question whether devolved responsibility is a viable option for creating biosecurity outcomes. We examined recreational marine users' self-declared awareness of non-indigenous marine species (NIMS) at six locations in Tasmania, Australia and evaluated the accuracy of their awareness through recognition of four well-known NIMS with active awareness campaigns. We also investigated whether the activities of recreational marine users influence the accuracy of their NIMS recognition skills. We generally found that respondents declare NIMS awareness (70.45%), yet we found their recognition accuracy was variable ranging from low to fair (<10% to 54.95%) and recreational activity did not influence accuracy. Based on our results, we conclude that marine users' awareness does not predict accuracy and therefore devolved management of biosecurity without additional resources may pose a risky biosecurity management strategy.

Burial Duration and Frequency Influences Resilience of Differing Propagule Types in a Subtidal Seagrass, Posidonia australis.

Sedimentation that leads to periodic, and often prolonged, burial events is becoming more common on the world's coastlines as human populations expand and create urbanised marine environments. Different seagrass species react differently to sediment burial but many species in the southern hemisphere are yet to be examined. How seagrasses react to burial has restoration implications. There is a need to critically assess seagrass transplant propagule responses to periodic (pulse) and prolonged (press) burial events before selecting the most appropriate species, transplant propagule, and transplant site. In my study, mesocosm experiments, coupled with field measurements were used to assess how sexual (seedlings) and vegetative (sprigs) propagules of Posidonia australis responded to pulse and press burial events. Seedlings were highly susceptible to burial (both pulse and press), with no survival at the end of the experimental period. In contrast, rhizome growth in vegetative propagules was stimulated by pulse burial, although press burial events resulted in mortality. The implication for Posidonia australis restoration efforts in areas where burial is periodic, was that vegetative propagules are optimal transplant units, in comparison to seedlings. Press burial however, renders a transplant site sub-optimal for both seedling and sprig transplants.

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.

Littering dynamics in a coastal industrial setting: the influence of non-resident populations.

We examined if there is truth to the preconceptions that non-resident workers (including FIFO/DIDO's) detract from communities. We used marine debris to test this, specifically focussing on littering behaviour and evidence of awareness of local environmental programs that focus on marine debris. Littering was most common at recreational areas, then beaches and whilst boating. Twenty-five percent of respondents that admit to littering, reported no associated guilt with their actions. Younger respondents litter more frequently. Thus, non-resident workers litter at the same rate as permanent residents, visitors and tourists in this region, within this study. Few respondents are aware of the environmental programs that operate in their local region. Awareness was influenced by a respondent's residency (non-residents are less aware), age, and level of education. To address this failure we recommend that industries, that use non-resident workers, should develop inductions that expose new workers to the environmental programs in their region.

The role of uncertainty and subjective influences on consequence assessment by aquatic biosecurity experts.

Expert judgement is often used to mitigate the knowledge gaps that limit understanding of aquatic non-indigenous species (ANS) impacts (consequences) to environmental, economic, social, cultural and human health values. To understand how this uncertainty may affect expert decision making, we explored the presence and effects of uncertainty on consequence assessment for 10 ANS by scientists and managers. We hypothesized species' distribution, taxonomy and impact type will affect assessment magnitude. These hypotheses were partially supported. We also hypothesized a difference in the relationship between consequence magnitude and uncertainty, based on assessor group. This set of hypotheses was not supported, as all group assessments had a significant negative correlation between consequence and uncertainty. Both scientists and managers assigned lower consequence when faced with knowledge gaps and other forms of uncertainty. This aligns with an "innocent until proven guilty" or hindsight approach, as opposed to a "guilty until proven innocent" or precaution approach. Based on these outcomes, the experts appeared to make decisions in violation of both the maximin principle and precaution, instead using a heuristic approach. We suggest several management strategies to prevent biases against environmental protection that occur due to use of the hindsight approach.

Linking social drivers of marine debris with actual marine debris on beaches.

The drivers (social) and pressures (physical) of marine debris have typically been examined separately. We redress this by using social and beach surveys at nine Tasmanian beaches, across three coastlines and within three categories of urbanisation, to examine whether people acknowledge that their actions contribute to the issue of marine debris, and whether these social drivers are reflected in the amount of marine debris detected on beaches. A large proportion (75%) of survey participants do not litter at beaches; with age, gender, income and residency influencing littering behaviour. Thus, participants recognise that littering at beaches is a problem. This social trend was reflected in the small amounts of debris that were detected. Furthermore, the amount of debris was not statistically influenced by the degree of beach urbanisation, the coastline sampled, or the proximity to beach access points. By linking social and physical aspects of this issue, management outcomes can be improved.

Assessing the port to port risk of vessel movements vectoring non-indigenous marine species within and across domestic Australian borders.

Biofouling of vessels is implicated as a high risk transfer mechanism of non-indigenous marine species (NIMS). Biofouling on international vessels is managed through stringent border control policies, however, domestic biofouling transfers are managed under different policies and legislative arrangements as they cross internal borders. As comprehensive guidelines are developed and increased compliance of international vessels with 'clean hull' expectations increase, vessel movements from port to port will become the focus of biosecurity management. A semi-quantitative port to port biofouling risk assessment is presented that evaluates the presence of known NIMS in the source port and determines the likelihood of transfer based on the NIMS association with biofouling and environmental match between source and receiving ports. This risk assessment method was used to assess the risk profile of a single dredge vessel during three anticipated voyages within Australia, resulting in negligible to low risk outcomes. This finding is contrasted with expectations in the literature, specifically those that suggest slow moving vessels pose a high to extreme risk of transferring NIMS species.

Assessing biosecurity risk associated with the importation of non-indigenous microalgae.

The importation and use of microalgae as live feeds for aquaculture and research poses significant marine biosecurity risks as it represents a poorly or unregulated mechanism for the introduction of non-native species. In many jurisdictions, the importation of a good is controlled by an Import Health Standard (IHS); however within New Zealand, no IHS explicitly exists for microalgae and no import risk assessments have occurred. This represents an unregulated pathway that requires urgent management attention. To address this problem, an 8-step decision-tree (based on non-probabilistic if/then statements) was developed. The decision-tree applies the same set of criteria to all species and strains, ensuring that future importation of microalgae could be assessed in a consistent, robust, transparent, and defensible manner. To assess the validity of the decision-tree, all New Zealand microalgae imports from 1998 to 2005 were assessed using the decision-tree and then compared against a derived risk assessment for the same dataset. Microalgae imports that pose a risk to New Zealand have been imported and released into the environment, indicating that this unregulated pathway needs improved biosecurity management. Both aquaculture and research agencies are responsible for releasing microalgae imports. The decision-tree was a more conservative method than a derived risk assessment process.

Mechanisms for the prevention of marine bioinvasions for better biosecurity.

Biosecurity management allows countries to meet a number of international obligations and provides some protection from potential degradation of environmental, economic, social and cultural values. Ocean governance relies on the precepts of ecologically sustainable development to manage the multiple uses in the coastal zone. The increasing reliance on aquaculture to provide food security and economic development has led to an increase in the use of non-native target species grown as food sources. Increased economic activity has led to shifting trade patterns and increased efficiencies in vessels with the resulting increase in the number of introduced marine species via ballast water and hull fouling. Herein we review the different marine biosecurity strategies and legislation that have been implemented internationally and locally that aid in preventing and managing introduced marine species, with some attention to Australia and New Zealand as examples. Typical tools being used include quarantine, Import Health Standards, voluntary cleaning guidelines, and risk assessment, all of which aim to prevent introductions.

Survey evaluations to assess marine bioinvasions.

Countries need to know what species are present within their waters to effectively manage the issue of non-indigenous marine species. Five survey methods are currently employed to detect introduced marine species: the Hewitt and Martin protocols (66% of effort; 73 ports, 12 countries); Rapid Assessment Surveys (7% of effort; 8 regions, 4 countries); the Bishop Museum protocols (7% of effort; 8 ports, 3 countries); the Chilean aquaculture surveys (1% of effort; numerous regions; 1 country); and Passive Sampling protocols (18% of effort; 20 ports, 2 countries). These methods use either quantitative, qualitative, or a mixture of the two sampling techniques and tend to target locations that are potential inoculation sites (i.e., such as ports, marinas and aquaculture facilities). To date, introduced marine species surveys have been implemented in 19 countries and have detected more than 1185 non-indigenous, 735 cryptogenic and 15,315 native species.

Evaluating vegetative transplant success in Posidonia australis: a field trial with habitat enhancement.

Seagrasses in Western Australia grow on open coastlines that are wave and surge exposed, which are known to reduce transplant success. This study investigated the use of habitat enhancement procedures to improve the survival and expansion of Posidonia australis transplants. Limited success transplanting P. australis vegetative propagules (plugs) was achieved after habitat enhancement was implemented, using artificial seagrass (ASG) mats to emulate a "surrogate" seagrass meadow. The ASG mats enhanced one aspect of the habitat (stabilised sediment grain size) but did not suitably stabilise erosion and accretion. Transplant survival was significantly increased (up to 50% survival) in 60% of the sites where ASG mats were present. However, only 8% of the total transplant population exhibited rhizome extension (3.2+/-0.11 mmd(-1)).