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Abstract Identifying and evaluating potentially suitable tools to assess the status of cetaceans in coastal waters with high levels of anthropogenic threat represents a first step towards effective conservation management. Local ecological knowledge (LEK) can often provide more extensive information on focal species and biological resources than is available from standard ecological surveys, and is increasingly recognized as an important source of data for conservation research and management, but it has rarely been used as a tool to assess the status of cetaceans. We investigated the efficacy of using LEK from local fishers combined with stranding records to characterise the diversity and distribution of coastal cetaceans in the northern South China Sea, a region with high historical levels of cetacean abundance and diversity but which is experiencing intensifying anthropogenic pressures. Fishers were unable to identify most regionally occurring cetaceans to species level. However, we were able to determine the distributions of eight categories of cetaceans that were observed by fishers, and a previously unknown population of Indo-Pacific humpback dolphin reported from the coastal waters of Hainan that was later confirmed through boat-based surveys. The number of sightings of different cetacean categories reported by fishers has a significant positive linear relationship with independent data on numbers of stranded cetaceans, validating the accuracy of our respondent data and indicating that LEK can provide useful, quantitative information on abundance rankings of different cetacean categories. Highlights • LEK can provide quantitative information on diversity and distribution for some coastal cetacean species or categories. • A new Indo-Pacific humpback dolphin population was found in southwest coastal water of Hainan Island. • Except for Indo-Pacific finless porpoise cetacean species mainly distribute in west coastal water of Hainan Island. • Small toothed dolphins are the most abundant species in the northern SCS. [ABSTRACT FROM AUTHOR]

Highlights: [•] The Cold War produced divergent socio-economic conditions across Europe. [•] This produced differences in species in aquaculture between East and West blocs. [•] This influenced the number of introduced species and their diversity between blocs. [•] Total aquaculture production predicted the number of introduced fish per country. [•] Thus, geopolitics shaped European aquaculture which then influenced allodiversity. [ABSTRACT FROM AUTHOR]

Abstract: Fungal and fungal-like parasites and the diseases which they cause have been increasingly associated with amphibians and fish population declines at a global scale. This review summarises our current knowledge of the Mesomycetozoea, a poorly-studied group of fungal-like parasites that includes emerging virulent parasites capable of causing high mortality rates in fish and amphibian populations. This review considers the potential impact of emerging parasites in this class on global aquatic biodiversity. Several aspects of the biology of mesomycetozoean parasites are associated with the potential to drive hosts to extinction, including their high virulence under certain conditions, low host specificity, and a free-living infectious stage. In addition, mesomycetozoeans are currently being introduced into novel environments and hosts via the global freshwater wildlife trade. These parasites have been linked to dramatic population declines in at least one native fish throughout Europe, and there are indications that they are already impacting amphibian populations in America and Europe. The impact of mesomycetozoeans on freshwater biodiversity is likely to increase in response to stressors such as global climate change and habitat modification. Surveillance for mesomycetozoean parasites in the field and in specimens transported in the aquatic wildlife trade needs to be increased, and a tighter control of the aquatic wildlife trade is urgently needed. [Copyright &y& Elsevier]

Abstract: A recent threat to European fish diversity was attributed to an infectious pathogen, a rosette-like intracellular parasite carried by invasive cyprinids. Here we show that the emerging rosette-like agent is Sphaerothecum destruens, originally found to be responsible for disease outbreaks in salmon in the United States. Sequencing of the ribosomal internal transcribed spacer (ITS) DNA highlights some level of geographical isolation. Unlike the situation in the United States, its occurrence in invasive fishes presents a risk of spread from wild invasive populations to sympatric populations of susceptible native fish and as such represents a risk for fisheries, as movement of fish for stocking purposes is common practice. [Copyright &y& Elsevier]

Abstract: The expansion of aquaculture and the demand for ornamental fish have resulted in the large-scale movements of aquatic animals and their pathogens. Here we review the most important non-native fish and shellfish pathogens in European waters and their global impacts on wild fish host populations. The role of theoretical models in the study of the impact of microbial pathogens is discussed, including its integration into risk assessments. [Copyright &y& Elsevier]

Abstract: In managing non-native species, surveillance programmes aim to minimise the opportunity for invasions to develop from initial introductions through early detection. However, this is dependent on surveillance methods being able to detect species at low levels of abundance to avoid false-negative recordings through imperfect detection. We investigated through field experimentation the ability to detect Pseudorasbora parva, a highly invasive pest fish in Europe, in relation to their known density and sampling method. Secure pond mesocosms of area 100m2 contained P. parva densities from 0.02 to 5.0m−2; each density was in triplicate. These were searched using point sampling electric fishing and deployment of fish traps (non-baited and baited). No fish were captured at densities <0.5m−2 using any method and this was considered their detection threshold. Point sample electric fishing was the least effective detection method, producing high proportions of false-negative data even at high fish densities. Baited traps were the most effective detection method. Probability of detection of P. parva was 1.0 for baited traps at all densities >0.5m−2, whereas for electric fishing it only exceeded 0.95 at 5.0m−2 using high searching effort. These data reveal that small pest fishes such as P. parva may be prone to imperfect detection when at low densities and this is consistent with a number of other invasive species. This indicates the importance of designing surveillance programmes using methods of known statistical power to optimise conservation resource expenditure and enhance management outcomes. [Copyright &y& Elsevier]