Periodic Reporting for period 1 - ETOXPT (Emergent toxins on the Portuguese coast: occurrence, transfer kinetics and toxicity)
Período documentado: 2021-09-01 hasta 2023-08-31
In recent years, toxins typically found in tropical waters have occasionally been reported in the coastal waters of the European Union (EU), often following cases of human poisoning. To protect public health, we need better monitoring programs, appropriate laws, and improved methods for detecting these toxins. However, because there is very little data on the occurrence of these toxins and no validated methods for analyzing them, we currently can't determine the risk of exposure to these emerging toxins in the EU.
In the ETOXPT project, we examined the presence and pathways of these emerging toxins in Portuguese coastal waters. We used advanced liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) methodology to ensure our results were reliable.
Our year-long sampling campaign revealed consistently high levels of Tetrodotoxin (TTX) in trumpet shells along the Algarve Coast, with 80% of samples exceeding the EFSA's recommended limit, underscoring the need for thorough cleaning and TTX monitoring in the region. TTXs and analogues were also detected in sea stars and edible crabs, indicating widespread toxin presence in local marine species. In contrast, β-N-methylamino-L-alanine (BMAA) levels in top marine predators were low, suggesting minimal risk from this toxin in the studied area.
In the ETOXPT project, we examined the presence and pathways of these emerging toxins in Portuguese coastal waters. We used advanced liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) methodology to ensure our results were reliable.
Our year-long sampling campaign revealed consistently high levels of Tetrodotoxin (TTX) in trumpet shells along the Algarve Coast, with 80% of samples exceeding the EFSA's recommended limit, underscoring the need for thorough cleaning and TTX monitoring in the region. TTXs and analogues were also detected in sea stars and edible crabs, indicating widespread toxin presence in local marine species. In contrast, β-N-methylamino-L-alanine (BMAA) levels in top marine predators were low, suggesting minimal risk from this toxin in the studied area.
In the first year of the ETOXPT project, as part of Work Package 1 objective, we developed methods to analyze various toxins, both regulated and emerging, using advanced techniques. These toxins included okadaic acid (OA), dinophysistoxins (DTX-1 and DTX-2), pectenotoxins (PTXs), yessotoxins (YTXs), azaspiracids (AZAs), amnesic shellfish toxin (AST), paralytic shellfish toxins (PSTs), tetrodotoxin (TTX), and β-N-methylamino-L-alanine (BMAA). With these methods, we could also identify related compounds (analogues) that don’t have commercial standards and whose toxicity is unknown. Developing these methods was essential for the project's success.
In Work Package 2, we began with a preliminary study that confirmed the presence of the emerging toxin TTX and its analogues (collectively named as TTXs) in the gastropod trumpet shell, Charonia lampas, found along the Algarve Coast. We discovered that contaminated trumpet shells had reached local markets. High concentrations of TTX in the digestive and excretory tissues suggested that these toxins accumulate through food ingestion.
These findings led us to conduct a year-long sampling campaign, working with local fishermen to collect trumpet shells and their primary prey, the starfish Astropecten aranciacus, both often caught as by-catch. We found consistently high TTX concentrations in trumpet shells throughout the year, with no seasonal variation. The toxins were mainly in gastrointestinal tissues but were also found in muscle tissue. Throughout the campaign, 60% of the gastrointestinal tissues of the trumpet shells had TTX levels above the European Food Safety Authority (EFSA) recommended limit of 44 µg TTX/kg. Proper cleaning (evisceration) of these organisms is essential to avoid poisoning, as TTXs are heat-stable and water-soluble, meaning they do not degrade with cooking or preservation. This is particularly important in the Algarve region, where trumpet shells are sold whole in markets and served as delicacies in restaurants. TTXs were also found in the starfish, but less frequently and in lower concentrations, supporting the idea that TTX accumulates in trumpet shells through their diet. Moreover, we discovered that edible crabs Afruca tangeri and Carcinus maenas, also found along the Algarve coast, contain TTX analogues. This indicates that TTXs are present in multiple marine species in the region. Therefore, it is advisable to implement TTX monitoring programs in Portugal, especially along the southern coast.
We also looked into the presence of BMAA, another toxin, in top marine predators in the Iberian Peninsula. According to bioaccumulation theory, high levels of BMAA would be expected in these predators. However, we did not find BMAA in 22 stranded cetaceans of three different species in North-West Spain, nor in 12 common gulls from Málaga, Spain, which had shown symptoms of a paralytic syndrome of unknown origin. This suggests that the presence of BMAA in these top predators is likely low.
In Work Package 3, we aimed to study how exudates from the macrophyte Zostera marina affect the profile of both classical (regulated and monitored) and emerging (M-toxins and GC-toxins) PST analogues from the dinoflagellate Alexandrium minutum. However, the samples will be analyzed at a later stage.
The results of the ETOXPT project were published in several open-access, peer-reviewed journals, which can be easily accessed on the project's website. We also presented our findings at 13 international and national conferences, including the ASLO Aquatic Sciences Meeting 2023, the SETAC Europe 34th Annual Meeting, the XIV and XV Reunião Ibérica sobre Microalgas Tóxicas e Biotoxinas Marinhas, and the Encontro Ciência 2024 + Science for Health and Global Well-being.In addition, we shared our results with 8th and 9th graders at schools in the Faro district through the Cientificamente Provável program.
In Work Package 2, we began with a preliminary study that confirmed the presence of the emerging toxin TTX and its analogues (collectively named as TTXs) in the gastropod trumpet shell, Charonia lampas, found along the Algarve Coast. We discovered that contaminated trumpet shells had reached local markets. High concentrations of TTX in the digestive and excretory tissues suggested that these toxins accumulate through food ingestion.
These findings led us to conduct a year-long sampling campaign, working with local fishermen to collect trumpet shells and their primary prey, the starfish Astropecten aranciacus, both often caught as by-catch. We found consistently high TTX concentrations in trumpet shells throughout the year, with no seasonal variation. The toxins were mainly in gastrointestinal tissues but were also found in muscle tissue. Throughout the campaign, 60% of the gastrointestinal tissues of the trumpet shells had TTX levels above the European Food Safety Authority (EFSA) recommended limit of 44 µg TTX/kg. Proper cleaning (evisceration) of these organisms is essential to avoid poisoning, as TTXs are heat-stable and water-soluble, meaning they do not degrade with cooking or preservation. This is particularly important in the Algarve region, where trumpet shells are sold whole in markets and served as delicacies in restaurants. TTXs were also found in the starfish, but less frequently and in lower concentrations, supporting the idea that TTX accumulates in trumpet shells through their diet. Moreover, we discovered that edible crabs Afruca tangeri and Carcinus maenas, also found along the Algarve coast, contain TTX analogues. This indicates that TTXs are present in multiple marine species in the region. Therefore, it is advisable to implement TTX monitoring programs in Portugal, especially along the southern coast.
We also looked into the presence of BMAA, another toxin, in top marine predators in the Iberian Peninsula. According to bioaccumulation theory, high levels of BMAA would be expected in these predators. However, we did not find BMAA in 22 stranded cetaceans of three different species in North-West Spain, nor in 12 common gulls from Málaga, Spain, which had shown symptoms of a paralytic syndrome of unknown origin. This suggests that the presence of BMAA in these top predators is likely low.
In Work Package 3, we aimed to study how exudates from the macrophyte Zostera marina affect the profile of both classical (regulated and monitored) and emerging (M-toxins and GC-toxins) PST analogues from the dinoflagellate Alexandrium minutum. However, the samples will be analyzed at a later stage.
The results of the ETOXPT project were published in several open-access, peer-reviewed journals, which can be easily accessed on the project's website. We also presented our findings at 13 international and national conferences, including the ASLO Aquatic Sciences Meeting 2023, the SETAC Europe 34th Annual Meeting, the XIV and XV Reunião Ibérica sobre Microalgas Tóxicas e Biotoxinas Marinhas, and the Encontro Ciência 2024 + Science for Health and Global Well-being.In addition, we shared our results with 8th and 9th graders at schools in the Faro district through the Cientificamente Provável program.
The ETOXPT project aimed to significantly advance scientific knowledge, enhance public health safety, promote economic stability in marine industries, and increase public awareness about marine toxin risks.
We discovered, for the first time in Europe, that trumpet shells have consistently high levels of TTX and its analogues throughout the year, often exceeding the European Food Safety Authority (EFSA) recommended limit, primarily in their gastrointestinal tissues. This information is crucial for consumers, the seafood industry, and public health agencies, as proper seafood processing can greatly reduce the risk of toxin-related illnesses. We also evaluated for the first time how temperature affects TTX concentration in trumpet shells and assessed its distribution among tissues. Additionally, we provided the first European report of TTX in sea stars and TTX analogues in edible crab species. These results should encourage authorities to create policies and regulations regarding TTX monitoring to ensure seafood safety and improve public health. Furthermore, in ETOXPT, we were the first in Europe to test top marine predators from the European coastline for BMAA, which was not detected, suggesting minimal risk from this toxin in the studied area.
We are committed to sharing our findings with a wide audience, including public health officials, local communities, and schools, to raise awareness and help people make informed decisions about seafood consumption and safety.
We discovered, for the first time in Europe, that trumpet shells have consistently high levels of TTX and its analogues throughout the year, often exceeding the European Food Safety Authority (EFSA) recommended limit, primarily in their gastrointestinal tissues. This information is crucial for consumers, the seafood industry, and public health agencies, as proper seafood processing can greatly reduce the risk of toxin-related illnesses. We also evaluated for the first time how temperature affects TTX concentration in trumpet shells and assessed its distribution among tissues. Additionally, we provided the first European report of TTX in sea stars and TTX analogues in edible crab species. These results should encourage authorities to create policies and regulations regarding TTX monitoring to ensure seafood safety and improve public health. Furthermore, in ETOXPT, we were the first in Europe to test top marine predators from the European coastline for BMAA, which was not detected, suggesting minimal risk from this toxin in the studied area.
We are committed to sharing our findings with a wide audience, including public health officials, local communities, and schools, to raise awareness and help people make informed decisions about seafood consumption and safety.