Saccostrea Glomerata Research Articles

The value and opportunity of restoring Australia's lost rock oyster reefs

Recognizing the historical loss of habitats and the value and opportunities for their recovery is essential for mobilizing habitat restoration as a solution for managing ecosystem function. Just 200 years ago, Sydney rock oysters (Saccostrea glomerata) formed extensive reef ecosystems along Australia's temperate east coast, but a century of intensive harvest and coastal change now confines S. glomerata to encrusting the hard‐intertidal surfaces of sheltered coastal waters. Despite the lack of natural reef recovery, there appears enormous potential for the restoration of intertidal S. glomerata ecosystems across Australia's east coast, with large anticipated benefits to water quality, shoreline protection, and coastal productivity. Yet, no subtidal reefs remain and the potential for subtidal restoration is a critical knowledge gap. Here, we synthesize historical, ecological, and aquaculture literature to describe a reference system for the traits of S. glomerata reefs to inform restoration targets, and outline the barriers to, and opportunities and methods for, their restoration. These reefs support extremely biodiverse and productive communities and can ameliorate the environmental stress experienced by associated communities. Rock oyster restoration, therefore, provides an ecosystem‐based strategy for assisting the adaptation of marine biodiversity to a changing climate and intensive human encroachment. Though an estimated 92% of S. glomerata ecosystems are lost, there remains great potential to restore these valuable and resilient ecosystems.

Habitat value of Sydney rock oyster (Saccostrea glomerata) reefs on soft sediments

Estimates of the ecological and economic value of ecosystems can provide important information for the prioritisation of conservation and restoration actions. Oyster reefs that were once common in temperate coastal waters have now been largely degraded or lost. Oyster reefs provide a suite of ecological services, including habitat and a food supply for a range of other species. In Australia, there is growing interest in oyster reef restoration, but there are knowledge gaps with regard to their structure and habitat value. Here, we describe the structure of eight remnant Sydney rock oyster (Saccostrea glomerata) reefs and estimate the density, biomass, productivity and composition of mobile macroinvertebrate and infaunal communities associated with them. The oyster reefs had a distinct assemblage of macroinvertebrates, with fivefold higher density of larger (≥2mm) macroinvertebrates, fivefold higher biomass and almost fivefold higher productivity, than that of adjacent bare sediments. The productivity of infaunal communities was twice as high under oyster reefs than in adjacent bare sediments. Therefore, S. glomerata reef restoration is likely to provide important habitat for macroinvertebrate communities and boost local secondary production.

Selectively bred oysters can alter their biomineralization pathways, promoting resilience to environmental acidification.

Commercial shellfish aquaculture is vulnerable to the impacts of ocean acidification driven by increasing carbon dioxide (CO2) absorption by the ocean as well as to coastal acidification driven by land run off and rising sea level. These drivers of environmental acidification have deleterious effects on biomineralization. We investigated shell biomineralization of selectively bred and wild‐type families of the Sydney rock oyster Saccostrea glomerata in a study of oysters being farmed in estuaries at aquaculture leases differing in environmental acidification. The contrasting estuarine pH regimes enabled us to determine the mechanisms of shell growth and the vulnerability of this species to contemporary environmental acidification. Determination of the source of carbon, the mechanism of carbon uptake and use of carbon in biomineral formation are key to understanding the vulnerability of shellfish aquaculture to contemporary and future environmental acidification. We, therefore, characterized the crystallography and carbon uptake in the shells of S. glomerata, resident in habitats subjected to coastal acidification, using high‐resolution electron backscatter diffraction and carbon isotope analyses (as δ13C). We show that oyster families selectively bred for fast growth and families selected for disease resistance can alter their mechanisms of calcite crystal biomineralization, promoting resilience to acidification. The responses of S. glomerata to acidification in their estuarine habitat provide key insights into mechanisms of mollusc shell growth under future climate change conditions. Importantly, we show that selective breeding in oysters is likely to be an important global mitigation strategy for sustainable shellfish aquaculture to withstand future climate‐driven change to habitat acidification.

Microplastics detected in haemolymph of the Sydney rock oyster Saccostrea glomerata

Plastic waste is ubiquitous in marine environments. Despite the sheer volume of plastic waste, it remains relatively unknown how marine invertebrates will interact with microplastics (plastic <1 mm). Microplastics (<2 μm) were ingested by the economically and ecologically significant Sydney rock oyster Saccostrea glomerata and translocated to the haemolymph, perhaps via phagocytosis. The presence of microplastics in the haemolymph indicates that filter feeding S. glomerata can ingest and accumulate microplastics which are prevalent in the environment. This research shows microplastics can enter marine molluscs and highlights the need to monitor microplastics in the marine environment and aquaculture to safeguard the seafood industry.

Seasonal Bioenergetic Changes in Saccostrea glomerata from Two Age Cohorts Farmed in Clyde River, Nsw, Australia

The study measured the mean and ranges of seasonal changes in whole body energetic values in two age groups of the Sydney rock oyster Saccostrea glomerata from the Clyde River, NSW, Australia. Oysters were collected over four seasons from two aquaculture-relevant age groups (24 and 36 mo) identified as key harvesting ages. Protein, lipid, glycogen energy equivalents, and electron transport system (ETS) activity were determined to identify seasonal changes in energy stores and consumption and to calculate cellular energy allocation. There were clear seasonal trends in energy changes, with glycogen and lipid energy equivalents highest in summer, decreasing to their lowest concentrations in autumn, and then slowly increasing through winter and into spring. Protein energy equivalents and ETS activity demonstrated an opposite trend, with increases in autumn and stable through the other seasons. Cellular energy allocation showed seasonal change, with highest values over summer, gradually decreasing in autumn and winter, and then starting to increase again in spring. These results indicate that seasonal changes in temperature, salinity, and food availability as well as reproductive cycles have a significant influence on S. glomerata energy storage and use. Developing an understanding of energetic responses in bivalves in response to environmental conditions can facilitate a more detailed understanding of growth potential and responses to aquaculture practices such as stocking density. As well, understanding natural energetic fluctuations allows a baseline for the assessment of other field-based stress responses such as anthropogenic contamination in S. glomerata.

Characterisation of the metallothionein gene in the Sydney rock oyster and its expression upon metal exposure in oysters with different prior metal exposure histories

The metal-binding protein metallothionein (MT) is widely used as a biomarker of metal contamination. In this study, we cloned a MT gene (sgMT) from the Sydney rock oyster Saccostrea glomerata. The gene encodes a MT-I protein with a classical αβ domain structure and is expressed as two transcripts resulting from alternative polyadenylation. The gene promoter contains two putative metal-responsive elements (MREs) which are known to be required for metal-inducible transcription. A specific and efficient qPCR assay was developed to quantify sgMT mRNA expression. Further, we assessed whether prior metal exposure history influences sgMT mRNA expression upon subsequent metal exposure. Oysters with varying prior metal exposure histories (contaminated and reference) were exposed to Cu, Cd and Zn. Expression of sgMT generally increased with metal dose, and oysters with an elevated past metal exposure history exhibited higher sgMT expression under Cd and Zn stress, representing a potential acclimatory response to prior metal exposure.

Imidacloprid and formulated product impacts the fatty acids and enzymatic activities in tissues of Sydney rock oysters, Saccostrea glomerata

The use of imidacloprid (IMI) and its formulated products in agriculture is a risk to aquatic organisms due to deposition into waterways from runoff and aerial spraying. However, there is limited information on the potential effects of this pesticide on commercially important shellfish, such as oysters. We investigated the impacts of IMI and Spectrum 200SC (IMI formulation) on the activity of the enzymes Glutathione-S-transferase (GST), Catalase (CAT) and Acetylcholinesterase (AChE), in different oyster tissues including the gill, adductor muscle and digestive gland. We also investigated the condition index and fatty acid composition of the flesh of oysters after 2 weeks exposure. The concentrations of IMI in the different tissues was assessed using Liquid Chromatography-Mass Spectrometry (LC-MS) after QuEChERS extraction. Higher concentrations of IMI residues were detected in the adductor muscle of the oysters, followed by the gills and with the lowest amounts recovered from the digestive gland across all the concentrations tested. IMI and Spectrum 200SC significantly affected the gill AChE activity at 2 mg/L, but digestive gland CAT, and gill and digestive gland GST were impacted at environmentally relevant concentrations (0.01 and 0.05 mg/L). In the whole oyster, 2 weeks exposure to IMI (≥0.01 mg/L) resulted in a proportional increase in saturated fatty acids (SFA), altered the polyunsaturated fatty acid (PUFA) to SFA ratio and altered the omega 3 fatty acids (n-3) to omega 6 fatty acids (n-6) ratio, but there were no effects on the condition index of the oyster. Although the oysters responded differently to the formulated product, there was no consistent difference in the sublethal effects of analytical IMI and Spectrum 200SC. This study showed that exposure to IMI and Spectrum 200SC can significantly affect the biochemical processes and metabolites in oysters, with implications for food quality and safety.

The sydney rock oyster microbiome is influenced by local environmental parameters and QX disease resistance

The sydney rock oyster microbiome is influenced by local environmental parameters and QX disease resistance

Metal concentrations in Sydney Cockle (Anadara trapezia) tissue and ambient sediment in a highly-modified estuary (Sydney estuary, Australia)

The influence of sedimentary metals on the cockle A. trapezia tissue was examined using a strong difference in sedimentary metal concentrations in an embayment (Hen and Chicken Bay) highly contaminated in Cu and an adjacent cove (Iron Cove), strongly enriched in Cd, Cu, Pb and Zn within the heavily-urbanised Sydney estuary catchment (Australia). Statistically significant differences were recorded for cockle tissue metal concentrations between the study locations reflecting differences in surficial sediment metal concentrations. Low metal uptake was apparent in A. trapezia tissue, which were considerably less than background sedimentary concentrations and was of low-risk for human consumption. Dissimilar bioconcentration of Cd, Cu, Pb and Zn was apparent in tissue of cockles (A. trapezia), prawns (Metapenaeus bennettae), mussels (Mytilus galloprovincialis) and oysters (Saccostrea glomerata), due possibly to different feeding patterns and biogeochemical conditions in bottom sediments.

Uptake, depuration and sublethal effects of the neonicotinoid, imidacloprid, exposure in Sydney rock oysters

The broad utilisation of imidacloprid (IMI) in agriculture poses an increasing risk to aquatic organisms. However, the potential impacts on commercially important shellfish and chemical residues after exposure, are yet to be assessed. We investigated the levels of IMI in Sydney rock oyster (SRO) tissue during a three-day uptake and four-day depuration cycle using liquid chromatography-mass spectrometry. IMI was absorbed from the water, with significantly higher concentrations in the adductor muscles than the gills and digestive glands. Depuration was also fast with a significant drop in tissue concentrations after one day in clean water and complete elimination from all tissues except the digestive gland after four days. The distribution of IMI in SRO after direct exposure using mass spectrometry imaging demonstrated uptake and spatially resolved metabolism to hydroxyl-IMI in the digestive gland and IMI-olefin in the gills. We assessed the effects of IMI on filtration rate (FR), acetylcholinesterase (AChE) activity in the gills, and gene expression profiles in the digestive gland using transcriptomics. Exposure to 2 mg/L IMI reduced the FR of oysters on the first day, while exposure to 0.5 and 1 mg/L reduced FR on day four. IMI reduced the gill AChE activity and altered the digestive gland gene expression profile. This study indicates that commercially farmed SRO can uptake IMI from the water, but negative impacts were only detected at concentrations higher than currently detected in estuarine environments and the chemical residues can be effectively eliminated using simple depuration in clean water.

Bioaccumulation and toxic effects of nanoparticulate and ionic silver in Saccostrea glomerata (rock oyster)

The increasing production of Ag nanoparticle (AgNP) containing products has inevitably led to a growing concern about their release into the aquatic environment, along with their potential behaviour, toxicity, and bioaccumulation in marine organisms exposed to NPs released from these products. Hence, this study is focused on the effects of AgNPs in Saccostrea glomerata (rock oyster) in artificial seawater (ASW); evaluating the NP's stability, dissolution, and bioaccumulation rate. AgNPs NM300K (20 ± 5 nm) in concentrations of 12.5 μgL−1 and 125 μgL−1 were used to conduct the experiments, and were compared to a blank and a positive control of 12.5 μgL−1 AgNO3. Dissolution in ASW was measured by ICP-OES and stability was assessed by TEM after 1 h and 3, 5, and 7 days of exposure. Bioaccumulation in gills and digestive glands was measured after 7 days of exposure. The higher concentration of AgNPs induced more aggregation, underwent less dissolution, and showed less bioaccumulation, while the lower concentration showed less aggregation, more dissolution and higher bioaccumulation. Five biomarkers (EROD: ethoxyresorufin-o-deethylase, DNA strand breaks, LPO: lipid peroxidation, GST: glutathione S-transferase and GR: glutathione reductase) were analysed at 0, 3, 5 and 7 days. Significant differences compared to the initial day of exposure (day 0) were reported in DNA strand breaks after 5 and 7 days of exposure, GST, from the third day of exposure, in all the Ag samples, and in some samples for LPO and GR biomarkers, while no significant induction of EROD was observed. A combined effect for each type of treatment and time of exposure was also reported for DNA strand breaks and GST biomarkers measured at the digestive glands. In general, the significant inductions measured showed the following trend: 125 μgL−1 AgNPs >12.5 μgL−1 AgNPs ∼12.5 μgL−1 AgNO3 even though bioaccumulation followed the opposite trend.

Assessment of trace elements pollution in the sea ports of New South Wales (NSW), Australia using oysters as bioindicators

In this study Sydney rock oysters (S. glomerata) from six major sea ports of NSW, Australia were used as bioindicators to assess the distribution and levels of trace element accumulation in the ports. Substantial enrichment of Cu, Pb and Zn in the oysters of the sea ports were detected when compared to their background samples and the US Environmental Protection Agency (USEPA) provisional tolerable intake standard. Enrichment of As, Al, Fe, Mn, Br, Sr were also found in the oysters at the port areas. The bioconcentration ratios of the trace elements illustrated significant Fe, Cu, Zn, As, Mn, Al, Pb and Cr accumulation in S. glomerate. The biota sediment accumulation factor suggested Cu, Mn and Zn accumulation at two of the ports (Port Yamba and Botany), indicating availability of these metals in the oysters as strong metal accumulators. In addition, integrated metal contamination illustrated notable Fe, Zn, Cu and Al contamination at port environment, whereas cluster analysis portrayed interconnection between the contaminants and the study sites.

Metallothionein expression on oysters ( Crassostrea cuculata and Crassostrea glomerata) from the southern coastal region of East Java

Background: This study aimed to analyse levels of heavy metals (Pb, Hg and Cd) in the aquatic body, gills and stomach of the oysters Crassostrea cuculata and Crassostrea glomerata, the metallothionein (MT) level in the gills and stomach of both oysters, and relationships between heavy metals level (Pb, Hg and Cd) in the gills and stomach to MT level in both species of oysters. Methods: The research method utilized was a descriptive method. The oyster samples were taken from three stations: Sendang Biru, Popoh and Prigi beaches. MT values were assessed using confocal laser scanning microscopy. The heavy metal levels were assessed using atomic absorption spectrophotometry method. Results: Both oyster heavy metal content obtained in the southern coastal waters exceeded the safe limit set by the State Minister of Environment No. 51 of 2004. In general, the expression of MT was found to be higher in stomach tissue compared to gill tissue. Conclusions: The levels of the heavy metals Pb, Hg, and has a strong relationship with MT levels in the gills and stomach in both types of oysters.

Molecular effects of a variable environment on Sydney rock oysters, Saccostrea glomerata: Thermal and low salinity stress, and their synergistic effect

Bivalves are frequently exposed to salinity and temperature fluctuations in the estuary. This study explored the molecular effect of these fluctuations by exposing Sydney rock oysters, (Saccostrea glomerata), native to Australia, to either low salinity, elevated temperature or a combined salinity and temperature stress. Following the exposures, RNA-Seq was carried out on the collected oyster tissues.Differential transcript analysis resulted in a total of 1473, 1232 and 2571 transcripts, which were differentially expressed in S. glomerata exposed to low salinity (10 ppt), elevated temperature (30 °C) or the combined stressor (15 ppt and 30 °C), respectively, when compared to control oysters. All stress treatments had some effect on molecular processes such as innate immune response or respiration, with overall the strongest effects seen in S. glomerata exposed to the combined stressor. Additionally, most transporters putatively involved in osmoregulation were found to be suppressed in response to the combined stressor and the low salinity exposure.This study provides insight into the oyster's responses to both, single and dual stressors commonly found in an estuarine environment.

Metal concentrations in waters, sediments and biota of the far south-east coast of New South Wales, Australia, with an emphasis on Sn, Cu and Zn used as marine antifoulant agents.

Tin, Cu, Zn, Cd, Pb, Ag and Hg concentrations were measured in waters, sediments and three ubiquitous sedentary molluscs: the oyster, Saccostrea glomerata, a rocky intertidal gastropod, Austrocochlea porcata, and a sediment-dwelling gastropod, Batillaria australis, at 12 locations along the far south coast of NSW, Australia, from Batemans Bay to Twofold Bay during 2009. Metal concentrations in water for Sn, Cd, Ag and Hg were below detection limits (< 0.005 μg/L). Measurable water metal concentrations were Cu: 0.01-0.08 μg/L, Zn: 0.005-0.11 μg/L and Pb: 0.005-0.06 μg/L. Mean metal concentration in sediments were Sn < 0.01-2 μg/g, Cu < 0.01-605 μg/g, Zn 23-765 μg/g, Cd < 0.01-0.5 μg/g, Pb < 0.01-0.3 μg/g, Ag < 0.01-0.9 μg/g and Hg < 0.01-2.3 μg/g. Several locations exceeded the Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand (Australian and New Zealand guidelines for fresh and marine water quality 2000) low and high interim sediment quality guidelines' levels for Cu, Zn, Cd and Hg. Some sites had measurable Sn concentrations, but these were all well below the levels of tributyltin known to cause harm to marine animals. Elevated metal concentrations are likely to be from the use of antifoulants on boats, historical mining activities and agriculture in the catchments of estuaries. All molluscs had no measurable concentrations of Sn (< 0.01 μg/g) and low mean Ag (< 0.01-1.5 μg/g) and Hg (< 0.01-0.5 μg/g) concentrations. Mean Cu (24-1516 μg/g), Zn (45-4644 μg/g), Cd (0.05-5μg/g) and Pb (0.05-1.1 μg/g) in oysters were close to background concentrations. Oysters have Cd and Pb concentrations well below the Australian Food Standards Code (2002).] There were no significant correlations between metal concentrations in sediments and in organisms within locations, and no relationship with levels of boating activity and suspected antifouling contamination. Although not pristine, the low levels of metal contamination in sediments and molluscs in comparison with known metal-contaminated areas indicate that this region is not grossly contaminated with metals and suitable for the development of mariculture.].

Diarrhetic Shellfish Toxin Monitoring in Commercial Wild Harvest Bivalve Shellfish in New South Wales, Australia.

An end-product market survey on biotoxins in commercial wild harvest shellfish (Plebidonax deltoides, Katelysia spp., Anadara granosa, Notocallista kingii) during three harvest seasons (2015–2017) from the coast of New South Wales, Australia found 99.38% of samples were within regulatory limits. Diarrhetic shellfish toxins (DSTs) were present in 34.27% of 321 samples but only in pipis (P. deltoides), with two samples above the regulatory limit. Comparison of these market survey data to samples (phytoplankton in water and biotoxins in shellfish tissue) collected during the same period at wild harvest beaches demonstrated that, while elevated concentrations of Dinophysis were detected, a lag in detecting bloom events on two occasions meant that wild harvest shellfish with DSTs above the regulatory limit entered the marketplace. Concurrently, data (phytoplankton and biotoxin) from Sydney rock oyster (Saccostrea glomerata) harvest areas in estuaries adjacent to wild harvest beaches impacted by DSTs frequently showed elevated Dinophysis concentrations, but DSTs were not detected in oyster samples. These results highlighted a need for distinct management strategies for different shellfish species, particularly during Dinophysis bloom events. DSTs above the regulatory limit in pipis sampled from the marketplace suggested there is merit in looking at options to strengthen the current wild harvest biotoxin management strategies.

Comparative De Novo transcriptome analysis of the Australian black-lip and Sydney rock oysters reveals expansion of repetitive elements in Saccostrea genomes.

Ostreid oysters (the ‘true oysters’) represent a large and commercially important family of bivalve molluscs. Several species, such as the Pacific oyster (Magallana gigas), the American oyster (Crassostrea virginica), the European oyster (Ostrea edulis) and the Sydney rock oyster (Saccostrea glomerata), are currently farmed at a large scale. However a number of other species may also be suitable for commercial-scale aquaculture. One such species is the ‘black-lip oyster’, a large Saccostrea species of uncertain taxonomic affinity found in northern Australia. Here, phylogenetic analysis of the COI gene places this oyster within a clade identified in a previous study of Japanese Saccostrea species, ‘Saccostrea lineage J’. To facilitate comparisons between this oyster and the better-studied S. glomerata, de novo transcriptomes were generated from larval stages and adult tissues of both species. Patterns of orthology indicated an expansion of repetitive elements within Saccostrea genomes when compared to M. gigas and C. virginica, which may be reflected in increased evolutionary rates and/or genome sizes. The generation of high-quality transcriptomes for these two commercially relevant oysters provides a valuable resource for gene identification and comparison of molecular processes in these and other mollusc species.

The genome of the oyster Saccostrea offers insight into the environmental resilience of bivalves.

Oysters are keystone species in estuarine ecosystems and are of substantial economic value to fisheries and aquaculture worldwide. Contending with disease and environmental stress are considerable challenges to oyster culture. Here we report a draft genome of the Sydney Rock Oyster, Saccostrea glomerata, an iconic and commercially important species of edible oyster in Australia known for its enhanced resilience to harsh environmental conditions. This is the second reference genome to be reported from the family Ostreidae enabling a genus-level study of lophotrochozoan genome evolution. Our analysis of the 784-megabase S. glomerata genome shows extensive expansions of gene families associated with immunological non-self-recognition. Transcriptomic analysis revealed highly tissue-specific patterns of expression among these genes, suggesting a complex assortment of immune receptors provide this oyster with a unique capacity to recognize invading microbes. Several gene families involved in stress response are notably expanded in Saccostrea compared with other oysters, and likely key to this species’ adaptations for improved survival higher in the intertidal zone. The Sydney Rock Oyster genome provides a valuable resource for future research in molluscan biology, evolution and environmental resilience. Its close relatedness to Crassostrea will further comparative studies, advancing the means for improved oyster agriculture and conservation.

Relationship between levels of the heavy metals lead, cadmium and mercury, and metallothionein in the gills and stomach of Crassostrea iredalei and Crassostrea glomerata

Background: The objective of this study was to compare the levels of heavy metals (Pb, Hg, and Cd) and metallothionein (MT) in the gills and stomach of two species of mussels ( Crassostrea iredalei and Crassostrea glomerata), and to observe the ability of the mussels to absorb the heavy metals Pb, Hg and Cd present in the water. Methods: The mussels were obtained from Mayangan, Kenjeran and Gresik ports, East Java, Indonesia. MT levels were determined using ELISA. Heavy metal levels of Pb, Hg and Cd were assayed using atomic absorption spectrophotometry. Results: The levels of Pb and Cd in water were below the maximum permissible levels for local water quality standards. By contrast, the level of Hg in the water was above the maximum permissible levels for water quality standards. At Mayangan Port (Station 1), the level of Pb was higher than Hg and Cd. Levels of MT and heavy metals varied greatly among of C. iredalei and C. glomerata individuals, but were always higher in the gills than in the stomach. The highest MT level (160,250 ng/g) was observed at Kenjeran Port (Station 2). MT levels were shown to be significantly associated with heavy metal level ( P<0.0001). Conclusions: This result indicates that MT may be responsible for the sequestration of these heavy metals, as has already been observed in terrestrial animals.

Coastal acidification impacts on shell mineral structure of bivalve mollusks.

Ocean acidification is occurring globally through increasing CO 2 absorption into the oceans creating particular concern for calcifying species. In addition to ocean acidification, near shore marine habitats are exposed to the deleterious effects of runoff from acid sulfate soils which also decreases environmental pH. This coastal acidification is being exacerbated by climate change‐driven sea‐level rise and catchment‐driven flooding. In response to reduction in habitat pH by ocean and coastal acidification, mollusks are predicted to produce thinner shells of lower structural integrity and reduced mechanical properties threatening mollusk aquaculture. Here, we present the first study to examine oyster biomineralization under acid sulfate soil acidification in a region where growth of commercial bivalve species has declined in recent decades. Examination of the crystallography of the shells of the Sydney rock oyster, Saccostrea glomerata, by electron back scatter diffraction analyses revealed that the signal of environmental acidification is evident in the structure of the biomineral. Saccostrea glomerata, shows phenotypic plasticity, as evident in the disruption of crystallographic control over biomineralization in populations living in coastal acidification sites. Our results indicate that reduced sizes of these oysters for commercial sale may be due to the limited capacity of oysters to biomineralize under acidification conditions. As the impact of this catchment source acidification will continue to be exacerbated by climate change with likely effects on coastal aquaculture in many places across the globe, management strategies will be required to maintain the sustainable culture of these key resources.