Zróżnicowanie struktury leśnych zgrupowań ślimaków jako efekt uwarunkowań naturalnych i antropogenicznych na przykładzie grądów w Wielkopolsce

Wydział Biologii

Impact of Hypoxia on the Community Structure of Benthic Macroinvertebrates of Lagos Lagoon, Nigeria

Study of the Lagos lagoon was conducted for two years to investigate the impact of hypoxia on the benthic macroinvertebrates. Water and benthic samples were collected monthly along the study stretch and analysed in a standard laboratory. Temporal variation in water physico-chemistry was largely controlled by rainfall pattern while the spatial variation was influenced by proximity to the Harbour as well as the pollution sources and types. A total of 3,159 individuals comprising three phyla, five classes, nineteen families and twenty three species were recorded. Iddo I, Iddo II, Ogudu and Agboyi study stations recorded very low individuals, but relatively high number of polychaetes. Benthic macro- invertebrate community was dominated by the molluscs. Margalef’s index of species richness ranged from 0.79 to 2.57 while Shannon-Wiener index ranged from 0.40 to 2.19. Species evenness index ranged from 0.29 to 0.80. There was generally low biodiversity indicating the stressed nature of the study area.

Diagnosis of vibriosis in the era of genomics: lessons from invertebrates

Global changes linked to increases in temperature and ocean acidification, but also to more direct anthropogenic influences such as aquaculture, have caused a worldwide increase in the reports of Vibrio-associated illnesses affecting humans and also animals such as shrimp and molluscs. Investigation of the emergence of Vibrio pathogenesis events requires the analysis of microbial evolution at the gene, genome and population levels, in order to identify genomic modifications linked to increased virulence, resistance and/or prevalence, or to recent host shift. From a more applied point of view, the elucidation of virulence mechanisms is a prerequisite to devising prophylactic methods to fight infectious agents. In comparison with human pathogens, fairly little is known about the requirements for virulence in vibrios pathogenic to animals. However, the advent of genome sequencing, especially next-generation technologies,the possibility of genetically manipulating most of the Vibrio strains, and the recent availability of standardised animals for experimental infections have now compensated for the considerable delay in advancement of the knowledge of non-model pathogens such as Vibrio and have led to new scientific questions.

Salinity influences disease-induced mortality of the oyster Crassostrea gigas and infectivity of the ostreid herpesvirus 1 (OsHV-1)

Mortality of young Pacific oysters Crassostrea gigas associated with the ostreid herpesvirus 1 (OsHV-1) is occurring worldwide. Here, we examined for the first time the effect of salinity on OsHV-1 transmission and disease-related mortality of C. gigas, as well as salinity-related effects on the pathogen itself. To obtain donors for OsHV-1 transmission, we transferred laboratory-raised oysters to an estuary during a disease outbreak and then back to the laboratory. Oysters that tested OsHV-1 positive were placed in seawater tanks (35‰, 21°C). Water from these tanks was used to infect naïve oysters in 2 experimental setups: (1) oysters acclimated or non-acclimated to a salinity of 10, 15, 25 and 35‰ and (2) oysters acclimated to a salinity of 25‰; the latter were exposed to OsHV-1 water diluted to a salinity of 10 or 25‰. The survival of oysters exposed to OsHV-1 water and acclimated to a salinity of 10‰ was >95%, compared to only 43 to 73% survival in oysters acclimated to higher salinities (Expt 1), reflecting differences in the levels of OsHV-1 DNA and viral gene expression (Expts 1 and 2). However, the survival of their non-acclimated counterparts was only 23% (Expt 2), and the levels of OsHV-1 DNA and the expression of 4 viral genes were low (Expt 1). Thus, OsHV-1 may not have been the ultimate cause of mortality in non-acclimated oysters weakened by a salinity shock. It appears that reducing disease risk by means of low salinity is unlikely in the field.

Natural recovery of the benthic nematode assemblages associated to Zostera noltii seagrass beds after physical disturbance caused by digging harvest activity

Seagrass beds are productive ecosystems that maintain high levels of biodiversity, making them susceptible to anthropogenic pressures such as bivalve harvesting. Nematodes are considered great ecological indicators as changes in their density, diversity and structure may represent changes in the environment. This experimental fieldwork aimed to assess the impact of the bivalve harvesting on the nematodes assemblage of a seagrass bed in the Mira estuary by simulating the digging activity. Two plots were subjected to the digging (D1 and D19) and two plots were control (C11 and C18). The sampling took place in five occasions: T0 – before digging; T1 – 14 days; T2 – 45 days; T3 – 75 days; and T4 – 165 days after digging. The results showed no significant difference in the nematode assemblages’ density, diversity and trophic composition between treatments and sampling times, evidencing their high tolerance for naturally stressed environments and to the level of digging they were exposed; Recuperação natural das comunidades de nematodes bentónicos associados aos povoamentos de Zostera noltii após atividade de marisqueio Resumo: As pradarias marinhas são ecossistemas produtivos que suportam elevados níveis de biodiversidade, pelo que estão sujeitos a pressões antropogénicas. Os nematodes são bons indicadores ecológicos pois respondem rapidamente a qualquer perturbação por alterações na densidade, diversidade e estrutura. Este trabalho experimental teve como finalidade o estudo da recuperação natural das comunidades de nematodes associados aos povoamentos de Zostera noltii pela simulação da atividade de marisqueio. Dois plots foram sujeitos a revolvimento (D1 e D19) e dois plots serviram como controlo (C11 e C18) e foram efetuadas amostragens em cinco ocasiões: T0 – antes do revolvimento; T1 – 14 dias; T2 – 45 dias; T3 – 75 dias; e T4 – 165 dias após revolvimento. Os resultados obtidos não mostraram diferenças significativas na diversidade, densidade e composição trófica das comunidades de nematodes entre tratamentos e tempos de amostragem, evidenciando a sua elevada tolerância a ambientes naturalmente dinâmicos e ao nível de revolvimento a que foram expostas.

Bivalves marinhos do miocénio superior (Tortoniano superior) de Cacela (Algarve, Portugal)

Dissertação de mestrado em Estudos Marinhos e Costeiros, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Univ. do Algarve, 2000

Tafonomia e paleoicnologia do neogénico superior do sector Cacela-Huelva (SE da Ibéria)

Tese de doutoramento em Paleontologia. Faculdade de Ciências do Mar e do Ambiente, Univ. do Algarve, 2005

Multibiomarker assessment of cadmium-based quantum dots effects in the marine mussel Mytilus galloprovincialis

Tese de Doutoramento, Ciências do Mar, da Terra e do Ambiente, Ramo: Ciências e Tecnologias do Ambiente, Especialização em Ecotoxicologia, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016

Highly polymorphic microsatellite markers for the Mediterranean endemic fan mussel Pinna nobilis

Pinna nobilis is an endemic bivalve of the Mediterranean Sea whose populations have decreased in the last decades due to human pressure; as a consequence, it was declared a protected species in 1992. Despite its conservation status, few genetic studies using mitochondrial markers have been published. We report on the isolation and development of 10 microsatellite loci for the fan mussel, Pinna nobilis. All loci (2 di-nucleotide, 5 tri-nucleotide, 2 tetra-nucleotide and 1 penta-nucleotide) are characterized by high levels of polymorphism in 76 individuals tested from two populations in the Balearic Islands (Spain, Western Mediterranean Sea). The number of alleles ranged from 4 to 24 and expected heterozygosity ranged from 0.4269 to 0.9400. These microsatellites could be very useful for the assessment of the genetic diversity and connectivity patterns of P. nobilis and the establishment of new conservation strategies.

Limnoperna fortunei (Dunker, 1857) (Mollusca, Bivalvia, Mytilidae): first record in the São Francisco River basin, Brazil.

Limnoperna fortunei (Dunker, 1857) is a small mytilid native to Southeast Asia. It was introduced in South America in early 1990 and has dispersed from Argentina to central Brazil, and until 2014 has been restricted mainly to the Paraná and Uruguay river basins. The present note reports the occurrence of Limnoperna fortunei for the first time in the São Francisco River basin in northeastern Brazil. The establishment of L. fortunei in these regions will require close attention from the government and also by society.

Enzymatic activity on sediments and nematode assemblage responses during seagrass beds habitat recovery following the disturbance of the traditional digging activity of bivalves harvesting.

Sediment digging is an anthropogenic activity connected to the exploitation of living resources in estuarine and marine environments. The knowledge on the functional responses of the benthic assemblages to the physical disturbance is an important baseline to understand the ecological processes of the habitat recovery and restoration and to develop tools for the management of the harvesting activities. To investigate the effects of the digging activity of the bivalves on Zostera noltii seagrass beds a manipulative field experiment was conducted that included the enzymatic activity of sediments and the associated nematode assemblages. Four plots (two undisturbed serving as control and two dug to collect bivalves - treatment) with 18 subplots were randomly located at seagrass beds in the Mira estuary at the SW coast of Portugal. Samples were randomly and unrepeatably collected from three subplots of each plot in five different occasions, before sediment digging (T0) up to six months after disturbance (T5). Microbial activity in sediments was assess by determining the extracelular enzymatic activity of six hydrolytic enzymes (sulfatase, phosphatase, b -N-acetilglucosaminidase, b-glucosidase, urease, protease) and two oxidoreductases (phenol oxidase and peroxidase). The microbial community status was also assessed through the measurement of dehydrogenase, which reflects microbial respiration. The nematode assemblages composition, biodiversity and trophic composition at different sampling occasions were also analyzed. The fluorometric and biochemical parameters analysed of the Z. noltii plants during the experimental period showed a recovery of the seagrass beds, and it was detected an increase of the enzymatic activity of the sediments after disturbance. The nematodes assemblages were similar in all sampling occasions. The seagrass beds and the nematodes assemblages associated showed a high resilience to the stress caused by the traditional bivalves digging activity. The obtained results allow the development of a management programme for the commercial fishing activity to maintain the good environmental status and minimized the secondary environmental effects on marine and estuarine habitats through the establishment of a baseline for the regulation of the harvesting frequency.

Sistemas de produção de peixes e bivalves em aquacultura: crescimento e indicadores de qualidade

O presente relatório refere-se ao estágio curricular realizado na Estação Piloto de Piscicultura de Olhão, no período compreendido entre janeiro e julho de 2016, no âmbito do Mestrado Integrado em Medicina Veterinária da Universidade de Évora. Este trabalho divide-se em duas partes. A primeira parte descreve as atividades e respetiva casuística desenvolvidas nas diferentes áreas de produção aquícola. Na segunda parte é abordado o tema “Produção Aquícola de Peixes e Ostras em regime Semi-intensivo”, onde são enquadrados os conceitos relacionados com aquacultura, sistemas de produção e pesquisa de biomarcadores na qualidade e bem-estar animal. São ainda descritas as ações de acompanhamento, durante o estágio, de um projeto de investigação em sistemas de produção em tanques de terra exteriores e um caso clínico. Este relatório atesta a importância da Medicina Preventiva em aquacultura; Abstract: Fish and bivalve aquaculture production systems: growth and quality indicators The following report was elaborated after the externship conducted at the Olhão Pilot Aquaculture Station, between January and July of 2016, in order to fulfill the requirements for a Masters degree in Veterinary Medicine at the University of Évora. This report is divided in two parts. The first part contains a description of the developed activities and the casuistic at the different aquaculture production areas. The second part will focus on the development of the theme “Fish and Oyster aquaculture production in a semi-intensive culture system”, with a theoretical framework about aquaculture concepts, production systems and identifying biomarkers in animal healthcare. At last, are presented and supported the monitoring actions taken in an investigation study case about inshore production systems and a clinic case followed during the externship. This report attests the importance of Preventive Medicine in aquaculture.

The red swamp crayfish Procambarus clarkii in Europe: Impacts on aquatic ecosystems and human well-being

Procambarus clarkii is currently recorded from 16 European territories. On top of being a vector of crayfish plague, which is responsible for large-scale disappearance of native crayfish species, it causes severe impacts on diverse aquatic ecosystems, due to its rapid life cycle, dispersal capacities, burrowing activities and high population densities. The species has even been recently discovered in caves. This invasive crayfish is a polytrophic keystone species that can exert multiple pressures on ecosystems. Most studies deal with the decline of macrophytes and predation on several species (amphibians, molluscs, and macroinvertebrates), highlighting how this biodiversity loss leads to unbalanced food chains. At a management level, the species is considered as (a) a devastating digger of the water drainage systems in southern and central Europe, (b) an agricultural pest in Mediterranean territories, consuming, for example, young rice plants, and (c) a threat to the restoration of water bodies in north-western Europe. Indeed, among the high-risk species, P. clarkii consistently attained the highest risk rating. Its negative impacts on ecosystem services were evaluated. These may include the loss of provisioning services such as reductions in valued edible native species of regulatory and supporting services, inducing wide changes in ecological communities and increased costs to agriculture and water management. Finally, cultural services may be lost. The species fulfils the criteria of the Article 4(3) of Regulation (EU) No 1143/2014 of the European Parliament (species widely spread in Europe and impossible to eradicate in a cost-effective manner) and has been included in the “Union List”. Particularly, awareness of the ornamental trade through the internet must be reinforced within the European Community and import and trade regulations should be imposed to reduce the availability of this high-risk species.

Using sclerochronology to estimate the growth rate in Pinna nobilis: a case study of Les Alfaques Bay population (Ebro Delta, Spain).

Pinna nobilis is the biggest Mediterranean bivalve, endemic and semi-infaunal. Provide hard substrates to colonize, increasing the spatial heterogeneity of the softbottom communities. P. nobilis suffer a drastic decline due to the anthropogenic pressures. It’s included in the Habitats Directive, in the Barcelona Convention, and in the red lists of many Mediterranean countries. Estimates the growth rate allows to understand the population dynamics of species and yield knowledge to improve protection efforts. In this study a new methodology based on sclerochronology was used to estimate the age and the growth rate of a P. nobilis population located in Les Alfaques bay. The shells of 35 specimens were cataloged. A subsample of 20 individuals was selected, and one valve of each specimens was cut into radial sections along PAMS (Posterior Adductor Muscle Scar) to study the inner register. Thus, the positions of PAMS obscured by nacre were identified, and the number of missing records was estimated by the width of the calcitic layer in the anterior part of the shell. The first growth curve for the Les Alfaques bay population was calculated from the length/age data. To simulate the growth rate of this population, the growth model based on the modified Von Bertalanffy equation was used. Shallow water usually hosts small sized populations of P. nobilis, while in deeper waters specimens reaches larger size. In Les Alfaques bay the population is composed by large size individuals though it’s located in shallows waters. This unusual size pattern is probably due to a sand bar that offers protection from hydrodynamic stress, allowing individuals to elongate more. This study contributes to the knowledge on P. nobilis biology and, with the aim to monitor this species, the growth curve could be used as baseline for future studies on habitat characteristics that may affect the population structure and dynamics in Les Alfaques Bay.

Analysis of the Variability of Carbonate System Parameters in the North-East Atlantic.

The purpose of this thesis is to analyse the spatial and temporal variability of the aragonite saturation state (ΩAR), commonly used as an indicator of ocean acidification, in the North-East Atlantic. When the aragonite saturation state decreases below a certain threshold, ΩAR <1, calcifying organisms (i.e. molluscs, pteropods, foraminifera, crabs, etc.) are subject to dissolution of shells and aragonite structures. This objective agrees with the challenge 'Ocean, climate change and acidification' of the EU COST Ocean Governance for Sustainability project, which aims to combine the information collected on the state of health of the oceans. Two open-sources data products, EMODnet and GLODAPv2, have been integrated and analysed for the first time in the North-East Atlantic region. The integrated dataset contains 1038 ΩAR vertical profiles whose time distribution spans from 1970 to 2014. The ΩAR has been computed from CO2SYS software considering different combinations of input parameters, pH, Total Alkalinity (TAlk) and Dissolved Inorganic Carbon (DIC), associated with Temperature, Salinity and Pressure at in situ conditions. A sensitivity analysis has been performed to better understand the data consistency of ΩAR computed from the different combinations of pH, Talk and DIC and to verify the difference among observed TAlk and DIC parameters and their output values from the CO2SYS tool. Maps of ΩAR have been computed with the best data coverage obtained from the two datasets, at different levels of depth in the area of investigation and they have been compared to the work of Jiang et al. (2015). The results are consistent and show similar horizontal and vertical patterns. The study highlights some aragonite undersaturated values (ΩAR <1) below 500 meters depth, suggesting a potential effect of acidification in the considered time period. This thesis aims to be a preliminary work for future studies that will be able to design the ΩAR variability on a decadal distribution based on the extended time-series acquired in this work.