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Although ballast water and hull fouling are widely recognized as important vectors for marine invasions, the risk posed by commercial aquaculture remains poorly quantified. To understand the importance of aquaculture as an invasion vector in California, we conducted an analysis of both current and historical introductions of marine and estuarine species associated with aquaculture using a comprehensive database ('NEMESIS') and permitting records for species imported into California. Our results showed that 126 non-native species associated with commercial aquaculture have been reported from California waters and 106 of these have become established. The vast majority are unintentional introductions linked to historical importation practices of the aquaculture industry. To understand the consequences of these invasions, we reviewed the literature on the impacts of mollusk and algal species introduced into California via aquaculture. Of the few studies we found, the majority demonstrated negative impacts on native species. Finally and significantly, we found that changes in aquaculture importation practices over the past decade have resulted in most shellfish currently being imported as larvae or juveniles. Consequently, rates of unintentional introductions have been reduced. We cautiously conclude that current aquaculture importation in California represents a minor risk as a vector for introductions of NIS.

Invasive species can cause ecological and economic damage and can be transported by several vectors, many of which are connected to socioeconomic activities. This research presents a model that combines introduction likelihood and environmental suitability to characterize global patterns of invasion risk in coastal marine areas by identifying where a species is both likely to arrive and able to survive. The model projects environmental suitability using MaxEnt and considers commercial port locations, as a proxy for commercial shipping, to map patterns of relative invasion risk on a near global scale. A case study of five coastal marine crab species is presented. These models identify several regions that are at risk of new invasion where modeled environmental suitability and introduction likelihood overlap. The distribution of large commercial ports is near global but not evenly distributed; northern hemisphere temperate locations have a higher density of ports and tend to have more opportunities for invasion according to these models. This approach can be adapted to other marine and non-marine species and to current and future environmental and socioeconomic conditions, but it works best when occurrence data are representative of the complete range of conditions under which a species can survive.

Ornamental marine species (‘OMS’) provide valuable income for developing nations in the Indo-Pacific Coral Triangle, from which most of the specimens are exported. OMS culture can help diversify livelihoods in the region, in support of management and conservation efforts to reduce destructive fishing and collection practices that threaten coral reef and seagrass ecosystems. Adoption of OMS culture depends on demonstrating its success as a livelihood, yet few studies of OMS culture exist in the region. We present a case study of a land-based culture project for an endangered seahorse (Hippocampus barbouri) in the Spermonde Islands, Sulawesi, Indonesia. The business model demonstrated that culturing can increase family income by seven times. A Strengths Weaknesses Opportunities Threats (SWOT) analysis indicated good collaboration among diverse stakeholders and opportunities for culturing non-endangered species and for offshoot projects, but complicated permitting was an issue as were threats of market flooding and production declines. The OMS international market is strong, Indonesian exporters expressed great interest in cultured product, and Indonesia is the largest exporting country for H. barbouri. Yet, a comparison of Indonesia ornamental marine fish exports to fish abundance in a single local market indicated that OMS culture cannot replace fishing livelihoods. Nevertheless, seahorse and other OMS culture can play a role in management and conservation by supplementing and diversifying the fishing and collecting livelihoods in the developing nations that provide the majority of the global OMS.Electronic supplementary materialThe online version of this article (doi:10.1007/s00267-014-0343-6) contains supplementary material, which is available to authorized users.

The occurrence of problematic pest organisms is an increasing global phenomenon, adversely affecting a range of environments and associated values. In marine systems, the efficacy of pest control has to date been constrained by a lack of tools that are not only highly effective, but also applicable across broad spatial scales. Here we consider the extent to which biological control (biocontrol) has the potential to fulfil these needs. We describe different biocontrol approaches and potential ecological mechanisms (e.g. consumption, space competition, habitat modification) through which problematic species could be supressed. We also discuss the ideal traits of marine control agents within the context of the selection criteria commonly applied in terrestrial systems. Classical biocontrol based on the deliberate introduction of non-indigenous agents has a high risk of leading to adverse non-target effects in marine environments, and cannot be justified. By contrast, approaches that use indigenous species have a low risk of unacceptable non-target effects, and could be used as part of pest eradication, as a means of containing spread, or for the control of established pest populations to mitigate adverse effects. While biocontrol based on indigenous species can be highly effective for such purposes, it is unlikely that it could be feasibly applied at broad spatial scales, except in specific circumstances (e.g. in some types of aquaculture). There is clearly a need to develop new approaches to manage marine pests. Biocontrol when used in conjunction with traditional approaches can provide a valuable tool for pest eradication, containment and mitigation of adverse effects.

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