Marine Institute Open Access Repository
Welcome to the Marine Institute Open Access Repository
The Marine Institute Open Access Repository facilitates full text access to the publications of the Marine Institute in accordance with copyright permissions. The aim of the Repository is to collect, preserve and provide open access to the publications of the Marine Institute, including the research publications supported by National and European funded marine research programmes.
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Explorers Turtle Talk with Sea Turtles: My Sea Turtle Illustrations for design and creative activitiesThe Explorers Turtle Talk with Sea Turtles: My Sea Turtle Illustrations for design and creative activities is designed to accompany the activities in the My Turtle Talk Workbook, and the designs can be used as templates for activities like making a turtle tote bag or drawing a life-size turtle. The book can also be used as a colouring book for younger classes.
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Environmental Survey of Coastal Waters (Galway - Dublin – Galway): – Winter nutrients, benthic macro-invertebrate and contaminants monitoring 2022 (CV22-0013)The 2022 survey continues the Marine Institute’s Winter Nutrients monitoring that commenced in 1990/91. The survey has evolved and expanded during this time period with respect to target areas, parameters and sampling strategy. In 2011 this survey was re-established as a winter environmental survey with a broader remit to provide supporting information for OSPAR and Water Framework Directive (WFD- Directive 2000/60/EC) assessments and also to maintain the winter time series on key biogeochemical parameters in Irish waters in response to pressures such as land based inputs of nutrients and climate change. Since 2011 the survey circumnavigates the Island of Ireland every two years, alternating south-about and north-about, starting in the Irish Sea and ending in Galway. This provides a complete coverage of Ireland’s coastal waters over 2-year periods. However, given the timing of the surveys, winter by necessity to ensure minimal biological activity and therefore highest concentrations of dissolved nutrients, the weather is a significant factor in determining the actual as opposed to planned coverage of the target stations. The 2022 survey was designed to collect multidisciplinary information on physical conditions, water chemistry (dissolved nutrients, total alkalinity (TA), dissolved inorganic carbon (DIC) and salinity), sediment chemistry (persistent organic pollutants POPs and trace metals), sediment particle size distribution and benthic macroinvertebrates (at targeted waterbodies around the coast). This contributes to data collection needs of various statutory drivers (WFD and the Marine Strategy Framework Directive (MSFD) Directive 2008/56/EC) as well as providing a research dataset on status and changing conditions (trends and variations) for key environmental variables. As a result of the COVID pandemic, in 2021 operational adjustments were implemented such that scientific complement on-board was limited to 2-3 persons at any one time. In light of this, the survey plan was adjusted to allow the survey to be completed in two legs (both south-about): 1. Leg 1 – Galway – Dublin: benthic macro-invertebrate sampling 2. Leg 2 – Dublin – Galway: winter nutrient, carbon and contaminants sampling. This survey structure was continued in 2022. Furthermore, and in order to fully achieve this plan, the number of survey days was increased to 17.
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Epimers of Azaspiracids: Isolation, Structural Elucidation, Relative LC-MS Response, and in Vitro Toxicity of 37-epi-Azaspiracid-1Since azaspiracid-1 (AZA1) was identified in 1998, the number of AZA analogues has increased to over 30. The development of an LC-MS method using a neutral mobile phase led to the discovery of isomers of AZA1, AZA2, and AZA3, present at ∼2–16% of the parent analogues in phytoplankton and shellfish samples. Under acidic mobile phase conditions, isomers and their parents are not separated. Stability studies showed that these isomers were spontaneous epimerization products whose formation is accelerated with the application of heat. The AZA1 isomer was isolated from contaminated shellfish and identified as 37-epi-AZA1 by nuclear magnetic resonance (NMR) spectroscopy and chemical analyses. Similar analysis indicated that the isomers of AZA2 and AZA3 corresponded to 37-epi-AZA2 and 37-epi-AZA3, respectively. The 37-epimers were found to exist in equilibrium with the parent compounds in solution. 37-epi-AZA1 was quantitated by NMR, and relative molar response studies were performed to determine the potential differences in LC-MS response of AZA1 and 37-epi-AZA1. Toxicological effects were determined using Jurkat T lymphocyte cells as an in vitro cell model. Cytotoxicity experiments employing a metabolically based dye (i.e., MTS) indicated that 37-epi-AZA1 elicited a lethal response that was both concentration- and time-dependent, with EC50 values in the subnanomolar range. On the basis of EC50 comparisons, 37-epi-AZA1 was 5.1-fold more potent than AZA1. This data suggests that the presence of these epimers in seafood products should be considered in the analysis of AZAs for regulatory purposes.
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Structure Elucidation, Relative LC–MS Response and In Vitro Toxicity of Azaspiracids Isolated from Mussels (Mytilus edulis)Azaspiracids (AZAs) are marine biotoxins produced by dinoflagellates that can accumulate in shellfish, which if consumed can lead to poisoning events. AZA7–10, 7–10, were isolated from shellfish and their structures, previously proposed on the basis of only LC–MS/MS data, were confirmed by NMR spectroscopy. Purified AZA4–6, 4–6, and 7–10 were accurately quantitated by qNMR and used to assay cytotoxicity with Jurkat T lymphocyte cells for the first time. LC–MS(MS) molar response studies performed using isocratic and gradient elution in both selected ion monitoring and selected reaction monitoring modes showed that responses for the analogues ranged from 0.3 to 1.2 relative to AZA1, 1. All AZA analogues tested were cytotoxic to Jurkat T lymphocyte cells in a time- and concentration-dependent manner; however, there were distinct differences in their EC50 values, with the potencies for each analogue being: AZA6 > AZA8 > AZA1 > AZA4 ≈ AZA9 > AZA5 ≈ AZA10. This data contributes to the understanding of the structure–activity relationships of AZAs.
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Identification of 21,22-Dehydroazaspiracids in Mussels (Mytilus edulis) and in Vitro Toxicity of Azaspiracid-26Azaspiracids (AZAs) are marine biotoxins produced by the genera Azadinium and Amphidoma, pelagic marine dinoflagellates that may accumulate in shellfish resulting in human illness following consumption. The complexity of these toxins has been well documented, with more than 40 structural variants reported that are produced by dinoflagellates, result from metabolism in shellfish, or are extraction artifacts. Approximately 34 μg of a new AZA with MW 823 Da (AZA26 (3)) was isolated from blue mussels (Mytilus edulis), and its structure determined by MS and NMR spectroscopy. AZA26, possibly a bioconversion product of AZA5, lacked the C-20–C-21 diol present in all AZAs reported thus far and had a 21,22-olefin and a keto group at C-23. Toxicological assessment of 3 using an in vitro model system based on Jurkat T lymphocyte cells showed the potency to be ∼30-fold lower than that of AZA1. The corresponding 21,22-dehydro-23-oxo-analogue of AZA10 (AZA28) and 21,22-dehydro analogues of AZA3, -4, -5, -6, -9, and -10 (AZA25, -48 (4), -60, -27, -49, and -61, respectively) were also identified by HRMS/MS, periodate cleavage reactivity, conversion from known analogues, and NMR (for 4 that was present in a partially purified sample of AZA7).