8 results on '"Kaufmann, Manfred"'
Search Results
2. Benthic harmful algal blooms occurrence in the south coast of Madeira Island, Portugal, from 2018 to 2020
- Author
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Silva, Teresa, Amorim, Ana, Sousa, Ana, and Kaufmann, Manfred
- Subjects
time-series ,Benthic dinoflagellates ,ecology ,Madeira Island ,bHAB community - Abstract
Ciguatera fish poisoning episodes have been recently reported in the Madeira Archipelago, requiring actions to protect both public health and economic sectors such as tourism and fisheries. Surveys on the occurrence of benthic harmful algal bloom (bHAB) species were performed during three consecutive years (from 2018 to 2020), at Cais do Carvão Bay, Funchal, Madeira. Samples collected on artificial substrates were analyzed for the presence of bHAB species, the seasonal succession of the bHAB community and the effects of abiotic factors on BHAB dynamics. The bHAB community was characterized by the presence of five genera: Gambierdiscus, Ostreopsis, Coolia, Prorocentrum, and Amphidinium. The abundance of the different genera showed marked differences. Ostreopsis displayed cell abundances several orders of magnitude higher than the other genera (841.05 x 103 cells 100 cm-2 (September 2018) and was recorded at all sampling dates. The second most abundant genus was Coolia, followed by Prorocentrum and Amphidinium. Gambierdiscus always showed the lowest cell densities (max. 0.43 x 103 cells 100 cm-2 (September 2018). During summer, Ostreopsis abundances exceeded, in several sampling dates the limits of level of concern for respiratory syndrome outbreaks (20 x 103 cells 100 cm-2) as referred to in the literature. In situ recorded abiotic data suggests that the increase of Ostreopsis densities could be linked to an increase in water temperature during summer. These results confirm Cais do Carvão Bay, as a potential high-risk area for bHAB development, especially concerning the genus Ostreopsis.
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- 2022
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3. Phthalates and fatty acid markers in free-ranging cetaceans from an insular oceanic region: Ecological niches as drivers of contamination.
- Author
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Sambolino, Annalisa, Alves, Filipe, Rodriguez, Marta, Weyn, Mieke, Ferreira, Rita, Correia, Ana M., Rosso, Massimiliano, Kaufmann, Manfred, Cordeiro, Nereida, and Dinis, Ana
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PHTHALATE esters ,DIETHYL phthalate ,TOOTHED whales ,FATTY acids ,PLASTIC additives ,BOTTLENOSE dolphin - Abstract
Plastic additives, such as phthalates, are ubiquitous contaminants that can have detrimental impacts on marine organisms and overall ecosystems' health. Valuable information about the status and resilience of marine ecosystems can be obtained through the monitoring of key indicator species, such as cetaceans. In this study, fatty acid profiles and phthalates were examined in blubber biopsies of free-ranging individuals from two delphinid species (short-finned pilot whale – Globicephala macrorhynchus , n = 45; common bottlenose dolphin – Tursiops truncatus , n = 39) off Madeira Island (NE Atlantic). This investigation aimed to explore the relations between trophic niches (epipelagic vs. mesopelagic), contamination levels, and the health status of individuals within different ecological and biological groups (defined by species, residency patterns and sex). Multivariate analysis of selected dietary fatty acids revealed a clear niche segregation between the two species. Di-n-butylphthalate (DBP), diethyl phthalate (DEP), and bis(2-ethylhexyl) phthalate (DEHP) were the most prevalent among the seven studied phthalates, with the highest concentration reached by DEHP in a bottlenose dolphin (4697.34 ± 113.45 ng/g). Phthalates esters (PAEs) concentration were higher in bottlenose dolphins (Mean ∑ PAEs: 947.56 ± 1558.34 ng/g) compared to pilot whales (Mean ∑ PAEs: 229.98 ± 158.86 ng/g). In bottlenose dolphins, DEHP was the predominant phthalate, whereas in pilot whales, DEP and DBP were more prevalent. Health markers suggested pilot whales might suffer from poorer physiological conditions than bottlenose dolphins, although high metabolic differences were seen between the two species. Phthalate levels showed no differences by ecological or biological groups, seasons, or years. This study is the first to assess the extent of plastic additive contamination in free-ranging cetaceans from a remote oceanic island system, underscoring the intricate relationship between ecological niches and contaminant exposure. Monitoring these chemicals and their potential impacts is vital to assess wild population health, inform conservation strategies, and protect critical species and habitats. [Display omitted] • Dietary fatty acids (FAs) analysis confirmed distinct trophic niches between the two species. • Phthalates (PAEs) were detected in all analyzed individuals. • PAE concentrations did not differ by sex, residency patterns, or over time. • Bottlenose dolphins exhibited notably higher levels of PAEs, particularly DEHP. • FA health markers may indicate poorer health conditions in pilot whales. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. New invertebrate vectors of Okadaic acid from the North Atlantic Waters - Portugal (Azores and Madeira) and Morocco
- Author
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Silva, Marisa, Rodriguez, Inés, Barreiro, Aldo, Kaufmann, Manfred Josef, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Alfonso, Amparo, Botana, Luis M., and Vasconcelos, Vitor
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Faculdade de Ciências da Vida ,Okadaic acid ,Morocco ,New vectors ,Madeira Island (Portugal) ,São Miguel Island ,São Miguel Island, Açores (Portugal) ,Madeira Island - Abstract
Okadaic acid and its analogues are potent phosphatase inhibitors that cause Diarrheic Shellfish Poisoning (DSP) through the ingestion of contaminated shellfish by humans. This group of toxins is transmitted worldwide but the number of poisoning incidents has declined over the last 20 years due to legislation and monitoring programs that were implemented for bivalves. In the summer of 2012 and 2013, we collected a total of 101 samples of 22 different species that were made up of benthic and subtidal organisms such echinoderms, crustaceans, bivalves and gastropods from Madeira, São Miguel Island (Azores archipelago) and the northwestern coast of Morocco. The samples were analyzed by UPLC-MS/MS. Our main objective was to detect new vectors for these biotoxins. We can report nine new vectors for these toxins in the North Atlantic: Astropecten aranciacus, Arbacia lixula, Echinaster sepositus, Holothuria sanctori, Ophidiaster ophidianus, Onchidella celtica, Aplysia depilans, Patella spp., and Stramonita haemostoma. Differences in toxin contents among the species were found. Even though low concentrations were detected, the levels of toxins that were present, especially in edible species, indicate the importance of these types of studies. Routine monitoring should be extended to comprise a wider number of vectors other than for bivalves of okadaic acid and its analogues.
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- 2015
5. New Invertebrate Vectors of Okadaic Acid from the North AtlanticWaters--Portugal (Azores and Madeira) and Morocco.
- Author
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Silva, Marisa, Rodriguez, Inés, Barreiro, Aldo, Kaufmann, Manfred, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Alfonso, Amparo, Botana, Luis M., and Vasconcelos, Vitor
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INVERTEBRATES as carriers of disease ,PHOSPHATASE inhibitors ,SHELLFISH ,GASTROPODA ,TOXINS - Abstract
Okadaic acid and its analogues are potent phosphatase inhibitors that cause Diarrheic Shellfish Poisoning (DSP) through the ingestion of contaminated shellfish by humans. This group of toxins is transmitted worldwide but the number of poisoning incidents has declined over the last 20 years due to legislation and monitoring programs that were implemented for bivalves. In the summer of 2012 and 2013, we collected a total of 101 samples of 22 different species that were made up of benthic and subtidal organisms such echinoderms, crustaceans, bivalves and gastropods from Madeira, São Miguel Island (Azores archipelago) and the northwestern coast of Morocco. The samples were analyzed by UPLC-MS/MS. Our main objective was to detect new vectors for these biotoxins. We can report nine new vectors for these toxins in the North Atlantic: Astropecten aranciacus, Arbacia lixula, Echinaster sepositus, Holothuria sanctori, Ophidiaster ophidianus, Onchidella celtica, Aplysia depilans, Patella spp., and Stramonita haemostoma. Differences in toxin contents among the species were found. Even though low concentrations were detected, the levels of toxins that were present, especially in edible species, indicate the importance of these types of studies. Routine monitoring should be extended to comprise a wider number of vectors other than for bivalves of okadaic acid and its analogues. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
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6. First Report of Ciguatoxins in Two Starfish Species: Ophidiaster ophidianus and Marthasterias glacialis.
- Author
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Silva, Marisa, Rodriguez, Inés, Barreiro, Aldo, Kaufmann, Manfred, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Alfonso, Amparo, Botana, Luis M., and Vasconcelos, Vitor
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STARFISHES ,CIGUATERA poisoning ,ALGAL toxins ,BIVALVES ,ECHINODERMATA - Abstract
Ciguatera fish poisoning (CFP) is a syndrome caused by the ingestion of fish contaminated with Ciguatoxins (CTXs). These phycotoxins are produced mainly by dinoflagellates that belong to the genus Gambierdiscus that are transformed in more toxic forms in predatory fish guts, and are more present in the Indo-Pacific and Caribbean areas. It is estimated that CFP causes per year more than 10,000 intoxications worldwide. With the rise of water temperature and anthropogenic intervention, it is important to study the prevalence of CFP in more temperate waters. Through inter- and subtidal sampling, 22 species of organisms were collected, in Madeira and Azores archipelagos and in the northwestern Moroccan coast, during September of 2012 and June and July of 2013. A total of 94 samples of 22 different species of bivalves, gastropods, echinoderms and crustaceans where analyzed by Ultra Performance Liquid Chromatography-Mass Spectometry-Ion Trap-Time of Flight (UPLC-MS-IT-TOF) and Ultra Performance Chromatography- Mass Spectrometry (UPLC-MS). Our main aim was to detect new vectors and ascertain if there were some geographical differences. We detected for the first time putative CTXs in echinoderms, in two starfish species—M. glacialis and O. ophidianus. We detected differences regarding uptake values by organisms and geographical location. Toxin amounts were significant, showing the importance and the need for continuity of these studies to gain more knowledge about the prevalence of these toxins, in order to better access human health risk. In addition, we suggest monitoring of these toxins should be extended to other vectors, starfish being a good alternative for protecting and accessing human health risk. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
7. Influence of disturbance and nutrient enrichment on early successional fouling communities in an oligotrophic marine system.
- Author
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Canning-Clode, João, Kaufmann, Manfred, Molis, Markus, Wahl, Martin, and Lenz, Mark
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FOULING organisms , *MARINE ecology , *MARINE sciences , *ECOLOGY , *AQUATIC ecology , *AQUATIC biology - Abstract
Disturbance and productivity are often cited as the main factors determining temporal and spatial patterns in species distribution and the diversity of communities. A field experiment was conducted to test the role of these factors in the structuring of early successional fouling communities in a nutrient limited system at the south coast of Madeira Island. Macro-benthic sessile communities, established on artificial settlement substrata, were manipulated and surveyed over a 9-week period. We applied mechanical disturbances of four different frequencies crossed with three levels of inorganic nutrient enrichment. Fertilization enhanced community diversity by favouring the establishment and growth of macroalgae. Disturbance reduced diversity by eliminating species – but only at the highest nutrient level. This is explained by a multiple-stressor model; species most sensitive to nutrient deficiency (only present in the highest enrichment treatment) were simultaneously the most sensitive to disturbance. [ABSTRACT FROM AUTHOR]
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- 2008
- Full Text
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8. Paralytic Shellfish Toxins Occurrence in Non-Traditional Invertebrate Vectors from North Atlantic Waters (Azores, Madeira, and Morocco).
- Author
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Silva, Marisa, Rey, Verónica, Barreiro, Aldo, Kaufmann, Manfred, Neto, Ana Isabel, Hassouani, Meryem, Sabour, Brahim, Botana, Ana, Botana, Luis M., and Vasconcelos, Vitor
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PARALYTIC shellfish poisoning ,INVERTEBRATE communities ,CYANOBACTERIAL toxins ,MICROALGAE - Abstract
Paralytic shellfish toxins (PSTs) are potent alkaloids of microalgal and cyanobacterial origin, with worldwide distribution. Over the last 20 years, the number of poisoning incidents has declined as a result of the implementation of legislation and monitoring programs based on bivalves. In the summer of 2012 and 2013, we collected a total of 98 samples from 23 different species belonging to benthic and subtidal organisms, such as echinoderms, crustaceans, bivalves, and gastropods. The sampling locations were Madeira, São Miguel Island (Azores archipelago), and the northwestern coast of Morocco. The samples were analyzed using post-column oxidation liquid chromatography with a fluorescence detection method. Our main goal was to detect new vectors for these biotoxins. After reporting a total of 59 positive results for PSTs with 14 new vectors identified, we verified that some of the amounts exceeded the limit value established in the EU. These results suggest that routine monitoring of saxitoxin and its analogs should be extended to more potential vectors other than bivalves, including other edible organisms, for a better protection of public health. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
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