Browsing by Author "Pierce, Graham"
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- Accumulation of mercury in the tissues of the common octopus Octopus vulgaris (L.) in two localities on the Portuguese coastPublication . Seixas, Sónia; Bustamante, Paco; Pierce, GrahamMercury concentrations were measured in tissues of 12 individuals of Octopus vulgaris, captured by the commercial fishery at two points along the Portuguese coast, Viana do Castelo and Cascais, in spring 2002. Concentrations were determined in six tissues (digestive gland, branchial hearts, gills, mantle, arms, and gonads). Correlations between mercury concentrations in different tissues were examined as were correlations between mercury levels and total length, mantle length, weight, gonadosomatic index, digestive gland index, and state of maturation. Differences between sexes and localities were analysed. The concentration of mercury in the digestive gland (Viana, 0.58F0.08, and Cascais, 3.43F2.57 mg/kg dry weight) was higher than in the other tissues, and values were generally similar to those recorded in previous studies on octopods. Arm muscle contained most of the mercury with 56% of the total body burden followed by the digestive gland with 31%, mantle with 11%, gills with 0.8%, gonad with 0.5%, and branchial heart with 0.2%. In all tissues, mercury concentrations were slightly higher in samples from Cascais than in Viana do Castelo, which is consistent with higher concentrations recorded in seawater at Cascais. Levels of mercury determined in octopus were within the range of values legally defined as safe for human consumption.
- Bioaccumulation of lead, calcium and strontium and their relationships in the Octopus Octopus vulgarisPublication . Seixas, Sónia; Pierce, GrahamOctopuses (Octopus vulgaris) landed from commercial fishing were sampled and the concentrations of lead, calcium and strontium, in digestive gland, branchial heart, gills, mantle and arms, were determined using PIXE (particle-induced X-ray emission). Lead was detected in all tissues, although not in samples from all animals analysed. Female octopuses accumulated more lead in digestive gland than did males. The digestive gland index, an indicator of nutritional status, showed a negative correlation with lead concentration in both sexes. There were positive correlations between the concentration of lead and those of calcium and strontium in digestive gland and a negative correlation between lead and calcium in branchial heart tissue. Concentrations of calcium in arms were lower in autumn and spring than in winter and summer. Lead content increased with increasing body weight and mantle length so we can conclude that lead continues to accumulate during the animal’s life. Concentrations of lead in two samples were higher than the maximum legally permitted concentration of lead in food.
- Biology and ecology of cephalopod species commercially exploited in Europe : species accountsPublication . Jereb, Patrizia; Piatkowski, Uwe; Allcock, Louise; Belcari, Paola; Tasende, Manuel; González, Angel; Guerra, Angel; Hastie, Lee; Lefkaditou, Eugenia; Moreno, Ana; Pascual, Santiago; Pereira, João; Pierce, Graham; Sánchez, Pilar; Sartor, Paolo; Seixas, Sónia; Sobrino, Ignacio; Villanueva, Roger
- Eledone moschata (Lamarck, 1798)Publication . Sobrino, Ignacio; Moreno, Ana; Jereb, Patrizia; Balguerias, Eduardo; Seixas, Sónia; Pierce, Graham; Lefkaditou, Evgenia; Allcock, Louise
- Generic skills needs for graduate employment in the aquaculture, fisheries and related sectors in EuropePublication . Pita, Cristina; Eleftheriou, Margaret; Fernández-Borrás, Jaime; Gonçalves, Susana; Mente, Eleni; Santos, Begoña; Seixas, Sónia; Pierce, GrahamThere is an increasing demand for highly skilled workers in all advanced industrialised economies. Although most jobs require occupation-specific skills to carry them out, it is widely recognised that generic skills are ever more needed by job seekers, to increase job opportunities and maintain employability; this applies to all sectors of the economy, from selling cars to undertaking marine research. Several recent European Union strategy documents emphasise the importance of generic skills. However, the apparent mismatch between the skills sets that employers seek and that job seekers offer remains a major challenge. This paper focuses on perceptions of and attitudes to generic skills training for university graduates intending to gain employment in aquaculture, fisheries or other marine sectors and presents the results of a survey administered to academics, industry representatives, students (at different stages of their academic career) and graduates. The various respondents regarded most of the 39 generic skills under investigation as important, with none classified as unimportant. However, students undertaking different types of degree (i.e. B.Sc., M.Sc. and Ph.D.) prioritized different generic skills and the level of importance ascribed to generic skills training increased as students progressed in their university careers. On the other hand, university staff and other employers were fairly consistent in their choice of the most important generic skills. We argue that there remains a need to place generic skills and employability attributes and attitudes at the centre of the higher education curriculum.
- Gonatus fabricii (Lichtenstein, 1818)Publication . Piatkowski, Uwe; Zumholz, Karsten; Jereb, Patrizia; Seixas, Sónia; Oesterwind, Daniel; Lefkaditou, Evgenia; Allcock, Louise; Pierce, Graham; Oleg, Katugin
- Impacts of anthropogenic activities on cephalopodsPublication . Pierce, Graham; Abad, Esther; Allcock, Louise; Badouvas, Nicholas; Barrett, Christopher; González-Gómez, Roberto; Hendrickson, Lisa; Lefkaditou, Evgenia; Lonsdale, Jemma; Matos, Fábio; Moustahfid, Hassan; Oesterwind, Daniel; Perales-Raya, Catalina; Pita, Cristina; Power, Anne Marie; Roumbedakis, Katina; Seixas, Sónia; Valeiras, Julio; Villasante, Sebastián; Laptikhovsky, Vladimir; Robin, Jean-Paul; Lishchenko, FedorIn past centuries, the impacts on cephalopods from humankind were negligible. The first documented small-scale exploitation of cephalopods occurred in the Mediterranean and Asia. Between 1950-2019, global cephalopod catches increased by about an order of magnitude, from 0.5 million tones to a peak of 4.85 million tons. The human impact on the oceans also increased substantially in this period. Human-induced climate change, habitat destruction, increased marine traffic, development of coastal infrastructure, pollution and growing fishing effort, may all have had negative impacts on cephalopod populations. But while the responses to anthropogenic impacts have been investigated for many ecosystem components, those for cephalopods are largely unknown. Cephalopods are sensitive to multiple environmental variables such as ocean temperature and dissolved oxygen concentrations, while geographic shifts in distribution in response to temperature changes are already documented. Their sensitivities to other human pressures are beginning to emerge, but most of these still need to be examined. How much habitat has been lost? How does noise affect cephalopods? What are the lethal thresholds for various chemical pollutants, or how may these act to inhibit reproduction? Does light pollution impact cephalopods? With such knowledge gaps, it is difficult to predict how cephalopods will respond to increasing human impacts. Our study aims to provide a review of what is known about anthropogenic impacts on cephalopods and their potential responses to these impacts. This information can be used to identify the research priorities for improving our understanding of human-induced impacts on cephalopods and the development of mitigation measures.
- Interannual patterns of variation in concentrations of trace elements in arms of Octopus vulgarisPublication . Seixas, Sónia; Bustamante, Paco; Pierce, Graham
- Interannual patterns of variation in concentrations of trace elements in arms of Octopus vulgarisPublication . Seixas, Sónia; Bustamante, Paco; Pierce, GrahamConcentrations of essential (copper, iron, manganese, selenium, andzinc) andnon-essential (arsenic, cadmium, mercury, andlead ) trace elements were measuredin arms of Octopus vulgaris. The cephalopods were sampled from commercial fishery landings at two sites on the Portuguese coast in spring 2002 and 2003. Mercury was determined using an Advanced Mercury Analyser Spectrophotometer (AMAS) and other trace elements were measured using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Since high levels of arsenic were detected, identification of the forms present was carriedout using high performance liquid chromatography (HPLC) followedby ICP-MS. Mean concentrations of trace elements analysedw ere in the following order: As > Zn > Fe > Cu Cd> Pb > Se >Mn Hg. The results of speciation of arsenic demonstrate that virtually all arsenic was in the arsenobetaine form, which is the less toxic form. The concentrations of several trace elements were generally high in samples from Viana in 2002. Cadmium concentrations were above the legal limit for human consumption in samples from Viana in 2002 and two of these animals alsohadleadconcentrations that exceededlegal limits.Mercury appearedin all samples but levelswerewithin legally defined safe limits.No relationshipwas detected between trace element concentrations and size ormaturity of octopus.
- Loligo vulgaris Lamarck, 1798Publication . Moreno, Ana; Lefkaditou, Evgenia; Robin, Jean-Paul; Pereira, João; González, Angel F.; Seixas, Sónia; Villanueva, Roger; Pierce, Graham; Allcock, Louise; Jereb, Patrizia
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