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Main locations of green-lipped mussel aquaculture areas in New Zealand, illustrating their proximity to international shipping ports (circles)

Main locations of green-lipped mussel aquaculture areas in New Zealand, illustrating their proximity to international shipping ports (circles)

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Article
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The endemic green-lipped mussel (GLM) Perna canaliculus is a key cultural and economic species for New Zealand. Unlike other cultured shellfish species, GLMs have experienced relatively few disease issues. The apparent absence of diseases in both wild and farmed GLM populations does not preclude risks from environmental changes or from the introduc...

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... have experienced relatively few disease issues. GLMs are, economically, the most important aquaculture species in New Zealand, where production is around 94 000 t annually (which represents ca. NZ$300 million of annual sales), and several thousand hectares of water space across 6 temperate coastal or offshore growing regions are occupied ( Fig. 1). Beyond its marketable value, the green-lipped mussel, or ku ¯ tai, is an iconic species protected by New Zealand's indigenous Ma ¯ ori through their kaitiakitanga, or guardianship of the natural environment. Various endemic pathogens and parasites have been reported for this species, but with the exception of the condition described ...

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... The presence of Vibrio spp. is to be expected as they are ubiquitous in marine and estuarine environments, and on surfaces and intestinal contents of marine animals [40]. Although many Vibrio species are harmless, several can be highly pathogenic for humans and/or marine animals [41][42][43][44]. Warm temperature favours the proliferation of Vibrio spp. ...
Article
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Poor health and mortality events of the commercially important and endemic New Zealand green-lipped mussel ( Perna canaliculus ) pose a threat to its industry. Despite the known importance of microbiomes to animal health and environmental resilience, the host-associated microbiome is unexplored in this species. We conducted the first baseline characterization of bacteria and fungi within key host tissues (gills, haemolymph, digestive gland, and stomach) using high-throughput amplicon sequencing of 16S rRNA gene and ITS1 region for bacteria and fungi, respectively. Tissue types displayed distinctive bacterial profiles, consistent among individuals, that were dominated by phyla which reflect (1) a fluid exchange between the circulatory system (gills and haemolymph) and surrounding aqueous environment and (2) a highly diverse digestive system (digestive gland and stomach) microbiota. Gammaproteobacteria and Campylobacterota were mostly identified in the gill tissue and haemolymph, and were also found in high abundance in seawater. Digestive gland and stomach tissues were dominated by common gut bacterial phyla, such as Firmicutes , Cyanobacteria , Proteobacteria , and Bacteroidota , which reflects the selectivity of the digestive system and food-based influences. Other major notable taxa included the family Spirochaetaceae , and genera Endozoicomonas , Psychrilyobacter , Moritella and Poseidonibacter , which were highly variable among tissue types and samples. More than 50% of fungal amplicon sequence variants (ASVs) were unclassified beyond the phylum level, which reflects the lack of studies with marine fungi. However, the majority of those identified were assigned to the phylum Ascomycota . The findings from this work provide the first insight into healthy tissue microbiomes of P. canaliculus and is of central importance to understanding the effect of environmental changes on farmed mussels at the microbial level.
... 79 There are many potential pathogens of mussel seed. 80 However, the risks associated with pathogens and parasites are poorly understood and will depend on interactions among factors such as resilience in the crop species, environmental conditions, pathogen identity and origins and farm practices. 80 One significant pathogen is digestive epithelial virosis, a virus-like particle that caused 50%-100% mortality of large (>15 mm) seed in 1994. ...
... 80 However, the risks associated with pathogens and parasites are poorly understood and will depend on interactions among factors such as resilience in the crop species, environmental conditions, pathogen identity and origins and farm practices. 80 One significant pathogen is digestive epithelial virosis, a virus-like particle that caused 50%-100% mortality of large (>15 mm) seed in 1994. 81 Such pathogens can cause mortality, reduce performance and indirectly impact mussel production due to measures to reduce their spread. ...
Article
The substantial loss of seed mussels during the early stages of longline aquaculture—often exceeding 95%—is a major issue that erodes the security and profitability of production while limiting the sustainable expansion of this industry in many parts of the world. There are many biological, environmental and procedural factors that potentially cause seed losses. The present understanding of these factors is highly limited, based on disparate lines of evidence and constrained by the challenges associated with quantifying the fate of minute organisms in the field. Addressing these knowledge gaps is a prerequisite for meeting the growing global demand for farmed seafood and requires significant and coherent research. We identify the diverse range of potential drivers of seed loss in mussel aquaculture and review existing knowledge around these factors to identify critical knowledge gaps and research priorities. Losses appear to be caused by a complex suite of interacting factors that include stress during transfer between regions, underlying variations in seed condition, change in the farm environment, predation, competition from biofouling organisms and migratory behaviour of seed mussels. Solutions to the losses of mussel seed in commercial culture are mostly likely to be achieved through research directed at evaluating a range of practical interventions during the critical phase of nursery culture of mussel seed.
... The exact causes of high spat losses during the early stages of mussel aquaculture are unclear, although they may be caused by mortality (Castinel et al., 2019) through density dependent competition (Capelle et al., 2014) and stress (Calderwood et al., 2014), predation (Morrisey et al., 2006;Kamermans et al., 2009;Š egvić-Bubić et al., 2011;Capelle et al., 2016a), or the innate migratory behaviour of mussel spat (Buchanan and Babcock, 1997). Following a pelagic larval stage, mussel pediveligers undergo primary settlement and metamorphosis and transition to a benthic mode of existence (Bayne, 1964;Ackerman et al., 1994). ...
Article
The early stages of mussel aquaculture can be extremely inefficient, with large numbers of seed mussels, also known as spat, lost from production shortly after seeding out. The exact causes of these losses are unclear, although factors such as local environmental conditions at farm sites, fish predation, mortality and the secondary settlement behaviour of spat are likely to play a role. Spat losses are an acute problem for Greenshell™ mussel (Perna canaliculus) aquaculture in New Zealand, where up to 100% of spat can be lost within a few months of seeding onto coastal farms. However, the timing and pattern of spat losses on Greenshell™ farms has not been well documented. This study aimed to quantify spat losses to determine if they occur consistently at individual locations at different times of the year, or if they vary among spat from different sources (i.e., Kaitaia and line-caught spat). Wild spat harvested from two sources were seeded onto commercial Greenshell™ mussel farms in four experiments, which measured their subsequent performance over 3 months, while also measuring a range of environmental conditions for comparison. Spat losses were considerable (frequently in excess of 70%) and occurred early in the production cycle (within the first month following seeding out). Local environmental conditions appeared to play a minimal role in influencing secondary settlement behaviour, as spat retention varied little among individual farm sites, and between experiments conducted at different times of the year. However, the movement of spat among the substrata used for seeding spat suggests that improvements in spat retention may come from altering the arrangements for deploying spat to mussel farms, such as seeding out with larger, single seed spat.
... Both Mytilus edulis (Bower, Figueras 1989) and M. galloprovincialis (Robledo, Figueras 1995) are susceptible to Marteilia, and Mytilus spp. are arriving in New Zealand on shipping (Castinel et al. 2019). There is thus the potential for this pathogen to enter NZ waters. ...
... comm.). The degrees of impact are comparative and range through negligible, minor, moderate, severe to extreme.Risk pathways and health threats have been discussed byCastinel et al. (2019). Two likely exotic threat scenarios to NZ are explored below based on information from Webb 2013) as examplesone posed by Marteilia spp. ...
Technical Report
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A comparative analysis of endemic pathogens affecting greenshell™ mussels (Perna canaliculus) and blue mussels (Mytilus galloprovincialis) in New Zealand (NZ) and a knowledge gap analysis of common pathogens or conditions currently affecting NZ flat oysters, (Ostrea chilensis), including their distribution and prevalence was carried out. This work is based on health and disease monitoring from 2007 to 2017 at the Cawthron Aquaculture Park (CAP). Two dozen different parasites, pathogens or conditions were noted in a survey of 9,119 bivalves comprising 3,415 greenshell™ mussels (Perna canaliculus), 2,889 Pacific oyster (Crassostrea gigas), 922 blue mussels (Mytilus galloprovincialis) and 1,893 flat oyster (Ostrea chilensis). These results are combined with reports from the literature and with scientific and industry inputs to develop: 1. A comparative analysis of endemic pathogens affecting greenshell™ mussels and blue mussels in New Zealand to form the basis for a GSM health profile for industry. 2. A knowledge gap analysis of common pathogens or conditions currently affecting NZ flat oysters, including their distribution and prevalence around New Zealand. For the comparative analysis of endemic pathogens affecting greenshell™ mussels and blue mussels in NZ twenty-three pathology conditions were detected across the two mussel species with twelve of these in common. A short list of the more important endemic threats to mussels includes apicomplexan X (APX), digestive epithelial virosis (DEV), rickettsia-like organisms/chlamydia-like organisms/endozoicomonas like organisms (RLO/CLO/ELO), Perkinsus olseni, Vibrio splendidus, Tergestia agnostomi and Enterogonia orbicularis. Important exotic pathology threats were identified from the literature. These include: Marteilia maurini/refringens, hemic neoplasia HN, Steinhausia mytilovum, and Vibrio harveyi. Likely consequences following introduction of hosts with Marteilia maurini/refringens and hemic neoplasia are outlined. Essential information for the compilation of a Perna canaliculus health profile for the NZ industry was determined, including characterisation of relevant populations/localities, production parameters, assessment of losses, diseases and their causes, basic disease biology, host/pathogen/environment interactions, mitigations and management. This will facilitate forecasts of disease susceptibility changes and new host/vector incursions. For NZ flat oysters, a review of parasites/pathogens/diseases based on examination of 1,893 Ostrea chilensis and the literature was carried out. The significant conditions Bonamia ostreae, Bonamia exitiosa, Bucephalus longicornutus, Apicomplexan X, Ostreid herpes virus, RLO/CLO/ELO and Microsporidium rapuae were identified. The exotic conditions Marteilia maurini/refringens, hinge ligament disease, Sirolpidium zoophthorum, Vibrio harveyi and hemic neoplasia were identified as potential threats. Significant Ostrea chilensis disease knowledge gaps were identified with the top ten (most important first) being Perkinsus olseni – basic biology, Perkinsus olseni – epidemiology, Vibrio spp. – epidemiology, Bonamia spp. – mitigation, APX and Bonamia spp. interactions – epidemiology, OSHV – epidemiology, OSHV – genomics, rickettsia-basic biology, Nocardia species basic biology, Nocardiosis-epidemiology. Insights derived from above, and also provided by expert opinions allowed an outline of health management challenges and provided recommendations that dealt with specific topics pertinent to this work. These include disease detection, surveillance, data management, health issues and culture conditions, pathogen basic biology, securing industry’s risk pathways, preparedness for future threats and farming in the face of disease. It was found that Perna canaliculus and Mytilus galloprovincialis have several pathogens in common but not all. It is suggestive that Mytilus is not entirely satisfactory as a disease surrogate for Perna and that simple projections from one taxon to another may require refinement. This shortcoming has prompted a novel mitigation proposed in the appendix in which a multi-stage process of inference is used to embrace current knowledge to arrive at an estimate of potential pathological threat.
... For example, the ability of the virus to persist in the environment and the role of other fauna as infection reservoirs are poorly understood (Pernet et al. 2016;Bookelaar et al. 2020). New Zealand's main aquaculture species by production and value is green-lipped mussels (GLM) Perna canaliculus (Castinel et al. 2019). GLM are free from significant production diseases (Castinel et al 2019). ...
... New Zealand's main aquaculture species by production and value is green-lipped mussels (GLM) Perna canaliculus (Castinel et al. 2019). GLM are free from significant production diseases (Castinel et al 2019). Common parasites, the New Zealand pea crab Nepinnotheres novaezelandiae and digenean trematode Cercaria cercaria rarely induce mortalities although their presence can affect product quality (Hickman 1978;Trottier et al. 2012). ...
Article
Dedicated studies on aquatic disease in New Zealand began in 1974, inspired by a developing aquaculture industry. Since then, two main aquatic disease study areas have emerged: (1) aquatic disease ecology and (2) diseases of commercial species. Progress over the past 20-years has been made by only a small number of researchers and aquatic disease in New Zealand has not received much attention from the wider marine science community. In 2020, the aquaculture industry continues to grow, and disease remains a threat to the industry’s viability. However, additional factors such as climate change, invasive species, and pollution, have emerged as future threats for aquatic disease in wild and farmed populations, which are currently understudied. Here, we provide a review of studies on aquatic disease ecology and commercial species carried out in New Zealand. We also present how climate change, pollution and invasive species could influence future aquatic disease dynamics and identify where future research effort is required to address knowledge gaps. The emergence of consequential aquatic diseases overseas highlights wider attention across marine science disciplines is needed to progress and diversify aquatic disease studies in New Zealand.
... Ontario, Canada (Drake & Mandrak, 2014b) or New England, USA (Rosa & Porter, 2020)), as well as other disease risk pathways such as shellfish aquaculture (Castinel et al., 2019) or the ornamental aquarium trade (Ebner et al., 2020). More importantly, this framework has broad applicability for conservation management requiring a balance between prevention of invasion risks and the economic, cultural and societal benefits associated with live animal imports. ...
Article
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As global trade of live animals expands, there is increasing need to assess the risks of invasive organisms, including pathogens, that can accompany these translocations. The movement and release of live baitfish by recreational anglers has been identified as a particularly high‐risk pathway for the spread of aquatic diseases in the United States. To provide risk‐based decision support for preventing and managing disease invasions from baitfish release, we developed a hazard identification and ranking tool to identify the pathogens that pose the highest risk to wild fish via this pathway. We created a screening protocol and semi‐quantitative stochastic risk ranking framework, combining published data with expert elicitation (n=25) and applied the framework to identify high‐priority pathogens for the bait supply in Minnesota, USA. Normalized scores were developed for seven risk criteria (likelihood of transfer, prevalence in bait supply, likelihood of colonization, current distribution, economic impact if established, ecological impact if established, and host species) to characterize a pathogen’s ability to persist in the bait supply and cause impacts to wild fish species of concern. The generalist macroparasite Schizocotyle acheilognathi was identified as presenting highest overall threat, followed by the microsporidian Ovipleistophora ovariae, and viral hemorrhagic septicemia virus. Our findings provide risk‐based decision support for managers charged with maintaining both the recreational fishing industry and sustainable, healthy natural resources. Particularly, the identification of several high‐risk but currently unregulated pathogens suggests that focusing risk management on pathogens of concern in all potential host species could reduce disease introduction risk. The ranking process, implemented here for a single state case study, provides a conceptual framework for integrating expert opinion and sparse available data that could be scaled up and applied across jurisdictions to inform risk‐based management of the live baitfish pathway.
... Likewise, impacts of bivalve culture on phytoplankton communities are well known (Hulot et al., 2020) and form the basis of most studies on carrying capacity (Grant and Pastres, 2019) whereas impacts on zooplankton and other pelagic groups are less well-known (Hulot et al., 2020). Interactions between farmed bivalves and wild bivalves with respect to pathogens are understudied, although, together with aquatic invasive species (AIS), they form the basis of many Introduction and Transfer screening protocols (Fernández Robledo et al., 2018;Castinel et al., 2019). The implications of bivalve farming as vectors and habitats for AIS are well-recognized, as are the risks associated with the introduction of bivalves for aquaculture, whether related to hitchhiking species or to escapes of farmed bivalves to the surrounding environment (McKindsey et al., 2007;Padilla et al., 2011). ...
... Due to its geographic isolation, New Zealand has relatively few pests or diseases associated with either its terrestrial or marine farming activities. The Government invests significantly in biosecurity to protect primary industries such as aquaculture from pest incursions and to manage any incursions that do occur (Castinel et al. 2014(Castinel et al. , 2019MPI 2016). Examples of this can be seen from the impact of, and response to, the arrival of the Oyster Herpes Virus in 2010/11 and the Bonamia ostreae parasite in 2015. ...
Article
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The New Zealand aquaculture industry is based primarily on the production of Greenshell™ mussels, Chinook salmon and Pacific oysters. The industry is primed for development and is anticipating increasing its export earnings to NZ$3 billion by 2035. To achieve this target and retain its ‘clean and green’ image, the industry must be able to demonstrate that its practices are sustainable. Integrated multi-trophic aquaculture (IMTA) systems provide an avenue to address this challenge, with most of the work in New Zealand focusing on the integration of low trophic level high-value species such as sea cucumbers and seaweeds with mussels, providing environmental bioremediation and provision of valuable secondary products (nutraceuticals and pharmaceuticals). Ecophysiological, hydrodynamic and benthic diagenesis models have been developed to underpin this IMTA research into sustainable farming designs. However, many regulatory barriers are still in place, which together with the current lack of investment, market security for these new products and associated operational costs form the main constrains to development. Nevertheless, the recent emergence of aquaculture fora where industry, researchers, and regulators meet to discuss future research and development has invigorated interest in diversification of the sector, inclusive of IMTA within existing coastal areas and upcoming land-based and open-ocean operations.
Article
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Background Green-lipped mussels, commercially known as Greenshell™ mussels (Perna canaliculus Gmelin 1791), contribute > $300 million to New Zealand’s aquaculture exports. However, mortalities during summer months and potential pathogenic outbreaks threaten the industry. Thermal stress mechanisms and immunological responses to pathogen infections need to be understood to develop health assessment strategies and early warning systems. Methods P. canaliculus were collected during a mortality event at a commercial aquaculture farm in Firth of Thames, New Zealand. Gill tissues from six healthy and six unhealthy mussels were excised and processed for metabolomic (GC–MS) and label-free proteomic (LC–MS) profiling. Univariate analyses were conducted separately on each data layer, with data being integrated via sparse multiple discriminative canonical correlation analysis. Pathway enrichment analysis was used to probe coordinated changes in functionally related metabolite sets. Results Findings revealed disruptions of the tricarboxylic acid (TCA) cycle and fatty acid metabolism in unhealthy mussels. Metabolomics analyses also indicated oxidative stress in unhealthy mussels. Proteomics analyses identified under-expression of proteins associated with cytoskeleton structure and regulation of cilia/flagellum in gill tissues of unhealthy mussels. Integrated omics revealed a positive correlation between Annexin A4 and CCDC 150 and saturated fatty acids, as well as a negative correlation between 2-aminoadipic acid and multiple cytoskeletal proteins. Conclusions Our study demonstrates the ability of using integrative omics to reveal metabolic perturbations and protein structural changes in the gill tissues of stressed P. canaliculus and provides new insight into metabolite and protein interactions associated with incidences of summer mortality in this species.