Invasive birds cause damage to economies, natural resources, and human safety across the globe. In the United States, rock doves (Columba livia), Eurasian collared doves (Streptopelia decaocto), rose-ringed parakeets (Psittacula krameri), monk parakeets (Myiopsitta monachus), common mynas (Acridotheres tristis), European starlings (Sturnus vulgaris), and house sparrows (Passer domesticus) are among the invasive and often harmful small-bodied birds inhabiting periurban habitats. The destructive nature of these species warrants a review of methods to reduce or eradicate populations along with methods to reduce damage when population eradication cannot be achieved. We reviewed damage management literature from these species’ native and introduced ranges. Additionally, we used the behavior and ecology of these species to inform tool recommendations and potential efficacy under various damage scenarios, while being sensitive to cultural preferences and location of implementation (residential, commercial, and agricultural). Although this review focuses on invasive birds in the United States, it is applicable to other pest species across the globe. Our review highlights areas where research is needed to validate promising damage management methods (lethal control, fertility control, habitat modification, exclusionary methods, frightening devices, and chemical repellents). Where birds are invasive, integrated pest management techniques should focus on eradication or population reduction (toxicants, shooting, and trapping) to keep populations at levels where nonlethal tools can reduce damage. We acknowledge the efficacy of an eradication campaign depends on biological, environmental, and economic factors, along with social license for lethal removal. We recommend integrated pest management strategies including lethal and nonlethal tools specific to the damage problem. Sustained efforts to reduce invasive populations should be used along with integrated deterrent strategies for short-term damage relief.

Horticultural trade is a well-documented pathway of introduction for numerous invasive species globally, including ferns. In this study, we analysed trade in terrestrial true ferns (Polypodiophyta) in selected anglophone countries: Canada, the United States of America, the United Kingdom and the Republic of Ireland, South Africa, Australia, and New Zealand. The study provides an overview of fern trade and explored the relationship between trade and alien fern introductions with a view to prioritise risk assessment and ultimately inform management interventions. Through consulting horticultural catalogues, in a period of just six months we identified a total of 382 fern species currently traded by 148 traders. International trade was observed in only three countries with most trade occurring at national scales and e-commerce did not clearly dominate over on-ground trade. Alien species accounted for more than 60% of the total number of traded species in most countries except in Australia and New Zealand. A total of 193 species have not previously been recorded as alien in plant species inventories in their countries of trade and were assigned the status of introduced. Several species (2–10 species per country; 38 species in total) known to be invasive in their country of trade remain actively traded there and are immediate priorities for regulation pending climate, risk and impact assessments. We categorised another 78 species with the status of naturalised or introduced in their trade countries in terms of their priority for risk or climate suitability assessment, and identified 101 potential candidates (approximately 20% of alien species traded per country) for Safe listing. This research constitutes one of few studies that have used horticultural catalogues to identify alien species, and highlights the efficiency of this approach as a tool for the early detection and prioritisation of potentially invasive species for management responses.

Parthenium weed (Parthenium hysterophorus L.) is a noxious weed and a flagship invasive that has been spreading throughout Israel and the Palestinian Authority since 1980. In other regions affected by this invader, parthenium weed has been managed through classical biological control releases of Epiblema strenuana, a stem-galling tortricid moth native to North America. More recently, a congeneric moth, Epiblema minutana has been identified from Israel. To better understand the implications of E. minutana for controlling parthenium weed, we investigated the spread of E. minutana within Israel and the Palestinian Authority from 2012 to 2019 and explored its host range. We used a series of no-choice experiments in field cages to evaluate damage on naturalized Ambrosia spp., Xanthium italicum and parthenium weed as well as potential non-target, commercial cultivars of sunflower (Helianthus annuus L.) and niger (Guizotia abysinnica (L. f.) Cassini). We also evaluated damage in the field, where we found substantial gall formation on Ambrosia spp., but none on P. hysterophorus or other genera. The geographical distribution increased from an estimated 424 km² in 2017 to 1671 km² in 2019. While E. minutana shows promise as a biological control agent of Ambrosia spp. and does not attack the oil crops sunflower and niger, it is not a suitable biological control agent of parthenium weed.

Zebra mussels (Dreissena polymorpha) are an aquatic invasive species that cause extensive economic and ecological impacts and are a management priority in areas outside of their native range. Survivorship and distribution of zebra mussels within a waterbody are thought to be influenced by temperature and dissolved oxygen conditions, but detailed information to confirm the importance of these environmental controls is necessary to inform management efforts. We measured planktonic zebra mussel veliger density and adult survivorship in San Justo Reservoir in central California to determine distribution and timing of spawning in relation to temperature and dissolved oxygen throughout winter, spring, and summer. We found seasonal patterns in adult survivorship, with high mortality late in the summer and higher than expected survivorship during the spring when dissolved oxygen concentrations were approximately 1 mg/L. Veliger abundance peaked several meters above the thermocline from June to August. Dissolved oxygen concentrations limited veliger distribution, with few to no veligers collected in the anoxic hypolimnion. Veliger settlement out of the water column appears to be possible in San Justo Reservoir at any time of year. A better understanding of how veligers, juveniles, and adult mussels respond to fluctuating dissolved oxygen and temperature conditions will further knowledge of timing and duration of water drawdowns or other control methods for managing this harmful invasive species.

Biological invasions of exotic plant species affect nutrient cycling, soil characteristics, ecosystem stability, and biodiversity. Therefore, management measures to protect the ecosystem and native species against invasive species are becoming more important. The tall goldenrod, Solidago altissima L., is an invasive alien plant with currently limited distribution on Jeju island, South Korea, while successfully invading areas with similar climates in China and Japan. Therefore, it has a high possibility of invasion and may have an adverse effect on the ecosystem of Jeju Island. This study aimed to develop an environmentally friendly management strategy to control S. altissima while understanding the major factor that makes the difference of invasion success between Japan and Jeju island. Plant communities were monitored and allelopathic effects of S. altissima were tested. Furthermore, the effectiveness of mowing at varying frequencies and timing for the control of S. altissima were applied. S. altissima already dominates several plant communities on Jeju Island, harms the plant community via allelopathy, and reduces biodiversity. However, our study shows that mowing is an effective method to control S. altissima populations. Mowing inhibits early invasion of S. altissima and also reduces dominance and reproductive features of S. altissima where invasion has already been processed. Therefore, mowing should be adopted for the management of S. altissima invasion. Mowing is an environmentally friendly management method for the control of S. altissima and could be applied to other invasive species.

The threats posed by invasive freshwater crayfish species are one of the greatest concerns for freshwater ecologists, environmental managers, policy makers and local communities in the invaded regions. The invasive Australian redclaw crayfish Cherax quadricarinatus is rapidly spreading in southern Africa. Fishers in the Zambezi Basin have reported that crayfish affect their catch through partial consumption of fish caught on static gillnets. Owing to the immeasurable contributions of fishery to socioeconomic livelihoods in Africa, the catch losses that are due to crayfish are of concern. With this problem in Africa, it is imperative to continue researching on adaptive strategies to cope with the invasion. This study tested the effectiveness of “misdirection traps” to prevent fish spoilage and gear damage for gillnet catches by crayfish in Lake Kariba, Zimbabwe. The method involved placing baited traps along a gillnet to misdirect crayfish into the traps rather than fishing gear to prevent fish spoilage by scavenging. The misdirection traps significantly lowered the amount of catch spoilage. Gillnet damage by crayfish in general was minimal, although it was higher for gillnets without baited traps. The misdirection traps pose a pragmatic management initiative to reduce socioeconomic fishery costs from crayfish. We consider this method to be applicable in all the invaded regions where artisanal fishers are experiencing catch spoilage problems making a huge step towards preventing socioeconomic impacts associated with crayfish invasion.

Ship hull fouling is recognized as an important vector for the introduction of non-indigenous species (NIS), which has been studied globally but no empirical works exist in the Southeast Pacific. The present study examined fouling organisms on the hulls of three ships in one international Chilean port, and compared them with those on settling plates and natural substrates. Also, genetic analyses were perfomed on the most common NIS recorded in order to explore number and potential origin of the genetic linages found. The highest number of total taxa and NIS were found on ship hulls, with three species identified as NIS in ship samplings. Settling plates displayed the largest number of taxa, with a large abundance of the invasive tunicate Ciona robusta, which also showed high mitochondrial genetic diversity. This study showed that Chilean coasts are subjected to both NIS colonization and propagule pressure through ship hulls. Biosecurity measures should urgently be taken on ship hulls along these coasts.

A study was conducted on the biological compliance of discharged ballast water at Shanghai port from vessels with ballast water management systems (BWMS) installed. Samples were taken from 17 ships covering three ship types (cargo, tankers and containers) from 2019 to 2020. In addition, abiotic parameters including temperature, salinity, DO, pH and biotic parameters were measured. It was observed that over 80% of analyzed samples exceeded the D-2 standard. For ≥ 50 μm organisms, the average density of living organisms ranged from 0 to 2.3×10⁴ ind.•m^-3, including 6 phyla and 13 genera of which the dominant species was Arthropoda. The species number of living ≥ 50 μm organisms found in ballast water samples was as high as 6. For 10–50 μm organisms, the density of living organisms ranged from 0 to 156.5 cells•mL^-1, including 5 phyla and 38 species of which the dominant species were Gymnodinium sp., Prorocentrum donghaiense, Cyclotella sp., Prorocentrum sp. and Platymonas sp. The species number of living 10–50 μm organisms found in ballast water samples was as high as 11. Another noteworthy result is that bacterial indicators detected in more than 40% of the ballast water samples were higher than the D-2 standard limit. Management decisions need to be made to prevent and control biosecurity issues caused by ship routes and reduce intestinal infections among residents in coastal port areas. The high percentage of non-compliant ballast water discharge after treatment at Shanghai port would significantly increase the risk of biological invasion to the local water, and preventive/mitigating measures shall be taken jointly by all involved parties.

Clonal species Agave fourcroydes and A. sisalana from ancient crops have become invasive in Mediterranean drylands, posing a severe threat to ecologically valuable native plant communities. However, we barely know the relative contribution of clonal mechanisms underlying their invasive behaviour. Therefore, environmental managers must face this problem without scientific evidence on the most effective methods to eradicate or control these invasions. In this study, we monitored populations of A. fourcroydes and A. sisalana and carried out field and experimental plantings (in situ and under controlled environmental conditions) to assess the efficacy of three clonal mechanisms: shoots from rhizomes, shoots from rosettes, and aerial bulbils from floral scapes). Both species showed very similar performance in their clonal expansion. Shoot production from rhizomes was the primary mechanism for densifying Agave populations, emerging to the soil 1.5 ± 2.1 shoots per individual. Moreover, we did not observe mortality of new shoots from rhizomes. These new clonal individuals seemed to ensure their survival by connecting to the mother plant (clonal integration). In addition, contractile roots, only recorded in shoots from rhizomes, could represent an advantage allowing them to react to harsh environmental conditions. Regarding shoots from rosettes, individuals produced 0.63 ± 1.01 shoots on average, with no mortality recorded, but without guaranteeing the replacement of mother plants. Finally, bulbil production and their rooting under controlled and favourable conditions were very high, although their establishment success under arid conditions proved irrelevant. These results suggest that management actions should focus on the removal of shoots from rhizomes. This approach could be an efficient, feasible, and cost-effective medium- to long-term habitat management strategy to control these Agave invasions, with widespread application worldwide in similar invasion processes.