Thesis (Ph.D.) in Marine Biology--University of Maine, 2007. / Includes vita. Includes bibliographical references (leaves 104-115).

Mémoire (M.Sc.B.)-- Université du Québec à Chicoutimi, 1988. / Egalement publie sur microfiche. Document électronique également accessible en format PDF. CaQCU CaQCU

Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: John S. Boyer, College of Marine and Earth Studies. Includes bibliographical references.

Made available in DSpace on 2014-12-17T14:03:45Z (GMT). No. of bitstreams: 1 MariaLC.pdf: 493490 bytes, checksum: ba60f2812dd358a875dfd794b36dacc3 (MD5) Previous issue date: 2007-06-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The fucoidan from Fucus vesiculosus is known for having diverse biological properties. This study analyzed the therapeutic action of populations of commercial fucoidan (F. vesiculosus) on zymosan-induced arthritis. Three populations of fucoidan were obtained after acetone fractionation; these were denominated F1 (52.3%), F2 (36.7%) and F3 (10.7%). Chemical analyses showed that F1 contained the largest amount of sulfate ion. The electrophoretic profile shows that the commercial or total fucoidan (TF), different from the other fucoidans and from glycosaminoglycan patterns, is quite polydisperse, which indicates that it is composed of a mixture of sulfate polysaccharides. On the other hand, the fucoidans obtained from TF showed only an electrophoretic band with much lower polydispersion than that observed for TF. Fucoidan F2 showed a migration between fucoidans F1 and F3. Owing to the small amount of mass obtained from F3, we used only fucoidans F1 and F2 in the induced arthritis tests. After 1 hour of induction, we administered F1 or F2 (10, 25 and 50 mg/kg i.p.) or diclofenac sodium (10 mg/kg i.p.) or lumiracoxib (5 mg/kg o.a.) or L-NAME (30 mg/kg i.p.). After 6 hours, we performed analyses of cell influx and nitrite levels in addition to histopathological analysis. Fucoidans F1 and F2 were more potent both in decreasing the number of leukocytes and the amount of nitric oxide found in the synovial fluid. This indicates that the anti-inflammatory mechanism of these fucoidans is not only related to selectin block, but also to nitric oxide synthesis inhibition / A fucoidana de Fucus vesiculosus ? conhecida por exibir fun??es biol?gicas diversas. Este trabalho analisou a a??o terap?utica de popula??es obtidas da fucoidana comercial (F. vesiculosus) no modelo de artrite induzida por zymosan. Ap?s fracionamento com acetona obteve-se tr?s popula??es de fucoidana que foram denominadas de fucoidanas F1 (52,3%), F2 (36,7%) e F3 (10,7%). As an?lises qu?micas demonstraram que F1, dentre as fucoidanas obtidas, foi a que apresentou a maior quantidade do ?on sulfato. O perfil eletrofor?tico mostra que a fucoidana comercial ou total (FT), diferente das outras fucoidanas e dos padr?es de glicosaminoglicanos, se mostrou bastante polidisperso, o que indicou que essa ? constitu?da por uma mistura de polissacar?deos sulfatados. Por outro lado, as fucoidanas obtidas a partir de FT mostraram apenas uma banda eletrofor?tica com uma polidispers?o bem menor do que aquela observada para FT. A fucoidana F2 apresentou uma migra??o intermedi?ria entre as fucoidanas F1 e F3. Devido a pequena quantidade de massa obtida de F3, utilizou-se apenas as fucoidanas F1 e F2 nos ensaios da artrite induzida. Ap?s 1 hora da indu??o foram administradas F1 ou F2 (10, 25 e 50 mg/Kg i.p) ou diclofenaco s?dico (10 mg/Kg i.p) ou lumiracoxibe (5 mg/Kg v.o) ou L-NAME (30 mg/Kg i.p). Ap?s 6 h, foram realizadas as an?lises do influxo celular e n?veis de nitrito e a an?lise histopatol?gica. As fucoidanas F1 e F2 foram mais potentes tanto na diminui??o do n?mero de leuc?citos, quanto na quantidade de oxido n?trico encontrado no lavado. O que indica que o mecanismo antiinflamat?rio dessas fucoidanas n?o est? s? relacionado com o bloqueio das selectinas, mas tamb?m com a inibi??o da s?ntese do oxido n?trico

Made available in DSpace on 2014-12-17T14:03:43Z (GMT). No. of bitstreams: 1 CarolineACX.pdf: 623551 bytes, checksum: 6aed4455120c14dc04af31815ec90ea1 (MD5) Previous issue date: 2005-10-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Rheumatoid arthritis (RA) is systemic auto imune disorder. It is caracterized by chronic inflammation of joints leading to progressive erosion of cartilage and bone. We investigated the effect of the administration of fucoidan, sulfated polysaccharides, from algae Fucus vesiculosus in the acute (6h) in zymosan-induced arthritis (AZy). Wistar rats (180-230 g) were used for all groups experimental. Non-treated animals received just intraarticular injection of 1 mg the zymosan, control group received intraarticular injection of 50 ?L the saline, groups received either fucoidan of Fucus vesiculosus (15, 30, 50 or 70 mg/Kg) or parecoxib (1 mg/Kg) 1 hour after injection of zymosan. After 6 h, the articular exudates were collected for evaluation of the cell influx and nitrite (Griess reaction) release. The sinovial membranes and articular cartilages were excised for histopathological analysis and by determination of the glycosaminoglycan (GAG), respectively. ZyA led to increased NO and cell influx into the joints. Therapeutic administration of the fucoidan or parecoxib did significantly inhibited the cell influx and the synovitis, as compared to non-treated rats (p<0,05), though being able to reduced NO release. Representative agarose gel electrophoresis of the GAGs, the content of condroitin-sulphate was observed during the process. These findings suggest that the fucoidan from Fucus vesiculosus has potential anti-inflammatory activity / A artrite reumat?ide (AR) ? uma doen?a auto-imune sist?mica, caracterizada por inflama??o cr?nica das articula??es, resultando em progressiva eros?o cartilaginosa e ?ssea. Neste trabalho foi investigado o efeito da administra??o do fucoidam, polissacar?deos sulfatados, da alga marinha Fucus vesiculosus na fase aguda (6h) da artrite induzida por zymosan (AZy). Ratos Wistar (180-230 g) foram utilizados para todos os grupos experimentais. Animais n?o tratados receberam apenas 1 mg de zymosan intraarticular (i.a), o grupo controle recebeu 50 ?L de solu??o salina intraarticular (i.a.), os outros grupos receberam fucoidam de Fucus vesiculosus (15, 30, 50 ou 70 mg/Kg,) ou parecoxib (1 mg/Kg), por via intraperitoneal (i.p.) 1 hora ap?s a inje??o de zymosan (i.a.). Ap?s 6 h, o exsudato articular foi coletado para an?lises do influxo celular e libera??o de nitrito (reagente de Griess). As membranas sinoviais e as cartilagens articulares foram retiradas para an?lises histopatol?gicas e para a determina??o dos glicosaminoglicanos, respectivamente. A AZy caracterizou-se por libera??o aumentada de NO e influxo de c?lulas inflamat?rias, nas juntas. A administra??o terap?utica do fucoidam ou parecoxib inibiu (p<0,05) o influxo celular, a libera??o de ?xido n?trico e a sinovite, comparado ao grupo n?o tratado. Por eletroforese em gel de agarose e tamp?o PDA 0,05M pH9,0 foi observado bandas com migra??es semelhantes ao condroitim sulfato (CS). Estes resultados sugerem que o fucoidam de Fucus vesiculosus tem um potencial anti-inflamat?rio

En milieu intertidal rocheux, les communautés dominées par des canopées d'algues brunes (Phaeophyceae) sont particulièrement répandues. Malgré leur accessibilité, leur fonctionnement reste encore largement méconnu. En particulier, l'influence de la saisonnalité et du gradient d'émersion sur le métabolisme, le réseau trophique ou encore le processus de succession a été peu étudiée. Ce travail de thèse a donc eu pour objectif d'analyser le fonctionnement de deux communautés de Fucus établies à des niveaux marégraphiques différents, en portant une attention particulière aux conditions environnementales. Sur les côtes bretonnes (France), les communautés de Fucus vesiculosus Linnaeus et de Fucus serratus Linnaeus sont respectivement caractéristiques des étages médiolittoral moyen et inférieur. Des mesures de métabolisme (production primaire et respiration) réalisées in situ à différentes périodes de l'année ont mis en évidence une forte influence de la saisonnalité et le rôle primordial de la canopée dans les flux de carbone. Le métabolisme s'est avéré être plus élevé à l'émersion qu'à l'immersion, où l'intensité lumineuse constitue régulièrement un facteur limitant pour la production primaire. Par une approche de modélisation basée sur ces mesures et sur des données environnementales acquises à haute fréquence, un bilan annuel de production primaire a été calculé pour chaque communauté. Ces bilans confirment que ces systèmes sont fortement productifs et permettent de préciser leur régulation à l'échelle des cycles de marées. Le réseau trophique de ces communautés, analysé via les isotopes stables du carbone et de l'azote, apparait basé sur l'utilisation de nombreuses sources. / Along intertidal rocky shores, communities dominated by canopy-forming brown algae (Phaeophyceae) are particularly widespread. Their functioning is however largely understudied, especially concerning the influence of seasonality and shore height on primary production and respiration, on food webs or on successional process. The aim of this study was to investigate the functioning of two intertidal Fucus communities which are established at different tidal levels. During this study, a special consideration was given to the effects of environmental conditions. On the coasts of Brittany (France), communities dominated by Fucus vesiculosus Linnaeus and Fucus serratus Linnaeus are characteristic of mid-intertidal and low mid-intertidal levels, respectively. In situ measurements of metabolism (primary production and respiration) carried out at different periods of a year highlighted a strong seasonal influence on carbon fluxes and emphasized the importance of canopies in the metabolism of whole communities. Metabolism was higher during emersion than during immersion periods, for which light intensity regularly limits the primary production. Based on these measurements and on high-frequency measurements of environmental parameters, an annual primary production was calculated by modelling for both communities. These annual estimations confirmed that these communities are among the most productive systems of coastal region and specify their regulation at the tidal cycles scale. Food webs, which were analysed through carbon and nitrogen stable isotopes, are based on the use of almost all available sources of organic matter by consumers, and revealed a strong conservation of food webs across seasons. Thecolonisation survey of bare substrates shows that Fucus species improve the settlement success of numerous species and increase rapidly primary production of whole assemblages. Overall, despite some differences in metabolism and successional sequences according to the shore height at whichthey are located, these communities exhibited similar functioning due to the canopy which damns the environmental conditions.

Fucus vesiculosus et Ascophyllum nodosum sont des algues brunes comestibles et abondantes au Québec. Cependant, elles ont été négligées en raison de leur valeur potentielle inconnue et de la période de récolte limitée. Afin de valider leur utilité, la composition chimique de ces algues et l’activité inhibitrice des enzymes digestives de l'amidon par les fucoïdanes extraits de ces deux espèces d'algues ont été étudiés en fonction de la saison. Les composants principaux des algues sont dans l’ordre: les polysaccharides&gt; minéraux&gt; protéines&gt; fucoïdane&gt; lipides&gt; &gt; composés phénoliques, et leur quantité est très variable selon la période de récolte. F. vesiculosus contenait une plus grande quantité de protéines et de minéraux, alors que A. nodosum avait relativement plus de polysaccharides. Par conséquent, F. vesiculosus serait plus avantageux comme source d’éléments nutritifs. L’algue A. nodosum récoltée en Juillet a permis d’obtenir le fucoïdane ayant la pureté la plus élevée et le meilleur rendement. Les fucoïdanes extraits des deux espèces d’algues ont inhibé l’activité de l’α-glucosidase alors que seul celui extrait d’A. nodosum a pu, de plus, inhiber l’α-amylase. Le fucoïdane d’A. nodosum était un inhibiteur plus puissant que le fucoïdane de F. vesiculosus pour l’α-glucosidase avec des IC50 variant de 0,013 ~ 0,047 mg/ml, tout comme pour l’α-amylase avec des IC50 de 0,12 ~ 4,62 mg/mL selon le mois. Pour comprendre les facteurs clés expliquant les différences d’inhibition d’α-amylase entre les fucoïdane d’A. nodosum et F. vesiculosus, certaines caractéristiques structurales ont été analysées et comparées à du galactofucoidane qui a servi de contrôle. A partir des résultats obtenus, il est confirmé que la masse moléculaire plus faible (637 kDa) du fucoïdane d’A. nodosum et la présence de sulfates sont liées à son activité inhibitrice. Nous avons émis l’hypothèse que les faibles masses moléculaires permettent d’exposer facilement les groupements sulfate qui peuvent agir sur l’α-amylase par interaction électrostatique, et donc d'inhiber son activité. En conclusion, les algues brunes du Québec présentent un potentiel d’utilisation important pour leur valeur nutritionnelle et leurs composés bioactifs. Le fucoïdane a montré une activité d'inhibition des enzymes digestives de l'amidon (α-amylase et α-glucosidase) et cette activité est différente selon les espèces d'algues et la période de récolte. Une meilleure compréhension du mécanisme inhibiteur par le fucoïdane peut être utile afin de développer un ingrédient fonctionnel permettant de prévenir le diabète de Type-2. / Fucus vesiculosus and Ascophyllum nodosum are edible brown seaweed and abundantly available in Quebec. However, they have been neglected because of their unknown value and technical limitation in harvest. In order to validate their usefulness, chemical composition in seaweeds and starch digestive enzyme inhibition activity by fucoidan extracted from two seaweed species were investigated with different seasons. The major components in both seaweeds were in order: polysaccharide &gt; minerals &gt; protein &gt; fucoidan &gt; lipid &gt; phenol, and their quantity was quite variable depending on harvesting timing. F. vesiculosus contained larger amount of proteins and minerals, while A. nodosum had relatively more polysaccharides. Therefore, F. vesiculosus are advantageous as a nutritional source. Especially, from A. nodosum harvested in July, a fucoidan having higher purity and better yield was obtained. Fucoidans from two seaweeds species inhibited α-glucosidase activity while, only fucoidan from A. nodosum could inhibit α-amylase activity. A. nodosum fucoidan was a more potent inhibitor than F. vesiculosus fucoidan for α-glucosidase with IC50 of 0.013 ~ 0.047 mg/mL, and for α-amylase with IC50 of 0.12 ~ 4.62 mg/mL depending on harvest month. To understand the key factors explaining the difference in α-amylase inhibition between A. nodosum fucoidan and F. vesiculosus fucoidan, structural characteristic was analyzed and compared with galactofucoidan as a control. From the obtained results, it is confirmed that smaller molecular weight (637 kDa) of A. nodosum fucoidan and the presence of sulfates are related to its inhibitory activity. It is proposed that small molecular weight permits to expose easily sulfate groups for interaction with α-amylase throughout electrostatic interactions, and therefore inhibiting its activity. In conclusion, brown seaweeds in Quebec have a considerable importance for nutrition and bioactive products. Fucoidan shows the inhibition activity for starch digestive enzymes (α-amylase and α-glucosidase) and its activity is different depending on seaweed species and harvesting period. Further understanding of the inhibitory mechanism by fucoidan can be useful to develop a functional ingredient to help preventing for Type-2 diabetes.

Östersjön är ett stressat hav som i stor utsträckning påverkas av mänskliga aktiviteter, och under de senaste 100 åren har mycket i ekosystemet förändrats. I Östersjön har blåstången en viktig och dominerande roll på grunda hårdbottnar, då den bildar sammanhängande vegetationsbälten som utgör habitat för andra organismer. I mitten på 70-talet kom rapporter om att blåstångens utbredning minskade och senare också att fisksamhället förändrades. Blåstången var förr ett viktigt inslag som t ex jordförbättringsmedel och fisket var en stor och viktig näring för ortsbefolkningen på Öland. Dokumentation om hur ekosystemet utmed Ölands östra kust såg ut innan 70-talet är dock begränsad. För att få fram en beskrivning av hur kusten har förändrats sedan 1930-talet har en kvalitativ intervjustudie genomförts med personer som levt och verkat vid Ölands östra kust. Undersökningsgruppen bestod av 13 personer i åldrarna 70-90 år, alla med någon slags anknytning till jordbruk eller fiske. Intervjuerna tog i genomsnitt 90 minuter och genomfördes under januari och februari månad 2006. Alla de intervjuade kunde berätta om förändringar i alg- och fisksamhället. Till exempel upplevdes algerna som ett bekymmer i fiskeredskapen och fiskfångsten minskade. Utöver resultatet av intervjustudien har en nutida miljöundersökning bidragit till att ge en bredd i beskrivningen till 2015. Mycket har förändrats och därmed påverkat alg- och fisksamhället i Östersjön sedan 30-talet. Genom att göra delvis strukturerade intervjuer med människor som levt och verkat längs Ölands östra kust ville jag få fram en tydligare bild av utvecklingen än vad som hittills funnits dokumenterad. Speciellt har jag fokuserat på förändringar i fisksamhället och på förekomsten av blåstång från 1930-talet och framåt. / The Baltic Sea is under severe stress which is mainly caused by human activities and for the past 100 years, much of the ecosystem has changed. The bladderwrack (Fucus vesiculosus) has a key role in shallow rocky shores where it can cover large areas forming belts from a few decimeters below the surface to a depth of several meters. These habitats serve as shelter and nursery for many fish and invertebrate species. In the mid-70s bladderwrack started to decline in some Baltic coastal areas, and later also the fish communities changed in these areas. In the past, bladderwrack was used by local farmers on Öland to improve and fertilize soils and coastal fishing was a comparatively large and important industry for people living on the island. There is limited information on how the status of the ecosystem (e.g. distribution of bladderwrack and status of coastal fish communities) along Öland's eastern coast was before the 70s. To obtain a description of how the coastal ecosystems have changed since the 1930s, qualitative interviews were carried out with people who lived and worked on Öland's eastern coast. The study group consisted of 13 persons aged 70-90 years, all with some sort of connection to agriculture or fishing. Each interview took on average 90 minutes and was conducted during January and February 2006. By making the semi-structured interviews with people who lived and worked along Öland's east coast, I wanted to bring out a clearer picture of changes in coastal fish and macroalgal communities than previously has been documented. Specifically, I have focused on changes in the fish community and the occurrence of bladder wrack from the 1930s onwards. All the people interviewed had experienced and could tell about changes in algal and fish community. They describe a decline in the catches of several fish species, a decline in bladderwrack communities and a simultaneously increase of filamentous algae both on the shores and as epiphytes on fishing gears. In addition to the results of the interview study I have used more recent reports and research papers to discuss the result.

Within temperate coastal seascapes, macroalgae provide habitats for different organisms such as invertebrates and fish. In analogy to seagrass meadows, macroalgae beds are known for their importance as fish nurseries. However, within the Baltic Sea the importance of the canopy forming macroalgae Fucus vesiculosus for coastal fish communities, especially the juveniles, is unclear. In order to address this knowledge gap, fish communities in areas with and without F. vesiculosus were investigated around Askö, an island in the archipelago of the Baltic Sea. Sites were subjected to different exposures (sheltered, exposed or very exposed) and three different methods were used for sampling (underwater visual census (UVCs), beach seine netting and remote underwater videos (RUVs)). Overall, fish community composition differed significantly among locations and fish abundance and fish biomass were significantly higher in sites with F. vesiculosus than sites without. There was no significant relationship between algae cover or habitat complexity and fish abundance/biomass in sites with F. vesiculosus. Fish behaviour differed between sites with and without F. vesiculosus, with fish feeding more in sites with F. vesiculosus and traveling more in sites without F. vesiculosus. Only one location, Knabberskär, had significantly higher species richness in F. vesiculosus than in sites without F. vesiculosus. There were no differences in juvenile abundance among sites with or without F. vesiculosus and abundance of adult fish was higher than juvenile fish, regardless of location, site or species. Mean invertebrate abundance was a twice as high in the sheltered location Husbåtsviken than in Knabberskär. Higher fish abundance, fish biomass and species richness in sites with F. vesiculosus compared to sites without, suggest that macroalgae may play an important role in the Baltic Sea, however it might not be as important for juvenile fishes as predicted. The three different sampling methods provided similar results for fish abundance, but not for fish biomass. Continued studies where the relationship between fish communities and aspects of F. vesiculosus structure (such as canopy height) as well as linkage with other habitats is recommended for further understanding and better protection of F. vesiculosus habitats.

The world's seas are without a doubt being changed by global warming, affecting all species, causing ecosystem changes. The overall low biodiversity in the Baltic Sea leads to sensitive unique qualities. Understanding how climate change in the Baltic Sea will affect key species is important to understanding how the Baltic Sea coastal environment will look in the future. Fucus vesiculosus, and Zostera marina, are key habitat building vegetation in the Baltic Sea, building up most of the canopies by the coasts on rocky and sandy bottoms. How are these species affected by climate change in the Baltic Sea? The result showed that both Fucus and Zostera growth is stimulated during most of the year with rising temperatures, but during summer heatwaves inhibit the plants, raising the mortality. Fucus will migrate more south, as the Baltic Sea will likely become fresher, and Zostera will continue to thrive if nutrients are reduced. Both species will experience die-offs during summer heatwaves. / Världens hav förändras utan tvekan av den globala uppvärmningen, vilket påverkar alla arter och leder till ekosystem förändringar. Den övergripande låga biologiska mångfalden i Östersjön leder till känsliga unika förhållanden. Att förstå hur klimatförändringarna i Östersjön kommer att påverka nyckelarter är viktigt för att förstå hur Östersjöns kustmiljö kommer att se ut i framtiden. Fucus vesiculosus och Zostera marina, är viktiga habitatsbildande växter i Östersjön, som bygger upp majoriteten av ekosystemen vid kusterna på steniga och sandiga bottnar. Hur påverkas dessa arter av klimatförändringar i Östersjön? Resultatet visade att tillväxten av både Fucus och Zostera stimuleras under större delen av året med stigande temperaturer, men under sommaren hämmar värmeböljor växterna, vilket ökar dödligheten. Huvudslutsatserna är att Fucus kommer att vandra mer söderut, eftersom Östersjön med största sannolikhet kommer att bli sötare från norr, och Zostera kommer fortsätta trivas om näringsmängden minskar. Båda arterna kommer drabbas av dödsfall under värmeböljor på sommaren.