Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 123-128).

Thesis (M.S.)--Simon Fraser University, 1997. / Includes bibliographical references (leaves 70-78).

Only one species, Macrocvatls integrifolia Bory, is present in British Columbia coastal waters. It is found distributed along the whole coast in regions approaching open ocean conditions, but protected against the full ocean force, where the seawater has a specific gravity of over 1.018 at 15 degrees Centigrade and where a suitable rocky bottom, between three feet above to twenty feet below zero tide level, is available. The method of growth of the sporophyte, which is partly dichotomous and partly unilateral, is fully described from the time it is first discernible to the naked eye up to maturity. Dichotomous and subdichotomous divisions of the basal growth region are responsible for the extensive development and perennial habit of the plant. Active zoospore liberation from mature plants and young sporophytes (single, undivided blade stage) were found at least from July 1 to September but the limits were not determined. The gametophytic stages were not followed. Maximum growth (elongation) of Macrocystis recorded was 3.10" per day for a period of 29 days at the north-east of Vancouver Island. No regeneration from the holdfast or at the cut surfaces of stipes were shown as a result of cutting. Stipes of Macro cystis may continue to grow after being severed from their holdfasts. Plants removed to deeper water are retarded in rate of growth. Various practical aspects of this economically important plant are considered. It is believed two harvests per year are possible if proper precautions are taken with respect to the relative position of the terminal laminae of the plants when harvesting. A method of estimating quantities using the diameter of the stipe as an index is suggested. / Science, Faculty of / Botany, Department of / Zoology, Department of / Graduate

This study examined the demography of giant kelp Macrocystis pyrifera (Linnaeus) and its interactions with understorey algae and invertebrates in southern New Zealand over two and a half years. Most of the study was done at two sites within Akaroa Harbour (Banks Peninsula) but ancillary sites at Tory Channel (Marlborough Sounds) were used for parts of the study. The kelp forests within Akaroa Harbour were generally highly productive, with a high annual turnover of giant kelp. Macrocystis plants were mostly annual and rarely reached ages greater than 12 months. Peak recruitment occurred in spring (November) during 1995-97, but lesser recruitment episodes occurred throughout the year. The maximum growth rates of Macrocystis fronds were comparable to rates reported elsewhere in southern hemisphere populations (22 mm - 24.5 mmlday), but considerably lower than those in northern hemisphere populations. The major experiment incorporated in the study tested the effects of the Macrocystis canopy and the understorey canopy of the stipitate laminarian Ecklonia radiata on macroalgae and invertebrates. The experiment was structured so that the effects of clearances at different times could be determined. One impetus for this experiment was the need to address issues relating to the commercial harvesting of giant kelp, its sustainability and its effects on other species. The effects of canopy removals on understorey algae, mostly juvenile Macrocystis, Ecklonia and Carpophyllum spp, were highly dependent on the timing of canopy removals and the combinations of canopies removed. For example, winter harvests of the Macrocystis canopy alone enhanced the survival of post-settlement Macrocystis recruits, but had little effect on Ecklonia recruitment. However, when both Macrocystis and Ecklonia canopies were removed in spring, there was heavy recruitment of Ecklonia that grew to dominate the understorey. Strong inter and intraspecific interactions from the Macrocystis surface canopy appeared to have been reduced by physical factors including water turbidity, sedimentation and the deterioration of the surface canopy during summer. These physical factors were not as limiting in Tory Channel. Fine scale extrinsic factor effects including nutrients, light and grazing on the early life history of Macrocystis were investigated in small experiments. Results suggest that recruitment may be nutrient limited even at moderately low temperatures, and that small herbivorous gastropods are an important source of mortality in the early life stages of Macrocystis. Culturing and transplantation cultivation techniques were also examined as a means of supplementing algal supplies. Macrocystis was cultured successfully through its life cycle onto culture ropes, but generally failed to produce visible sporophytes when placed in the field. Cultured plants did grow in Tory Channel, however. Juvenile plants transplanted to ropes for on-farm cultivation showed little growth during summer, but the addition of nutrients significantly enhanced growth rates of these plants during warmer months when natural nutrient levels were low. Increased growth rates at the onset of winter and with the addition of nutrients during summer confirmed that low nutrient levels during summer are growth limiting. Akaroa Harbour kelp forests exhibited considerable variation in Macrocystis canopy biomass through time. For example, the 32,000 m2 kelp forest at Wainui had a biomass of 144 t in October 1995, which then decreased to 21 t in October 1996. Canopies tended to deteriorate during summer. Thus, at Ohinepaka Bay kelp forest had a biomass of 31 t during winter 1997, which decreased to 0.06 t the following summer. The greatest reduction in biomass, however, coincided with a period of hugely increased sediment, which smothered blades in the sea-surface canopy, covered the substratum, and prevented successful recruitment of kelp for over a year. Nutrient depletion was one of several factors thought to cause the summer deterioration of the Macrocystis sea-surface canopy, which has important ramifications for the commercial harvesting of Macrocystis pyrifera in summer. Management considerations and options are discussed in relation the commercial harvesting of Macrocystis in New Zealand. The major conclusion of this study is that although Macrocystis was able to form dense surface canopies during winter its ability to dominate kelp forests was constrained by physical factors, especially sedimentation, high turbidity, nutrients, and storms. The lack of strong interactions between Macrocystis and Ecklonia are also largely a result of their different life history characteristics. Overall, there appear to be no significant negative flow-on effects resulting from kelp harvesting and it appears that Macrocystis can be harvested sustainably.

Memoria para optar al título de Ingeniera Civil en Biotecnología / Las algas se utilizan desde tiempos inmemoriales para consumo humano y extracción de subproductos. Entre los más conocidos estas los ficocoloidales como el alginato, agar y carragenano, de gran valor en la industria alimenticia. Actualmente, existe interés por la utilización de biomasa algal en la producción de biocombustibles, lo cual abre una potencial explotación de otros subproductos de algas, creando procesos sustentables y amigables medioambientalmente. Dadas las condiciones naturales extremas en que se desarrollan estos organismos, uno de los compuestos de mayor interés que producen son los antioxidantes, moléculas bioactivas de distinta naturaleza, ya sea carbohidratos, lípidos, terpenoides y compuestos polifenólicos. En el marco del proyecto de cooperación CONICYT-Chile AKA-Finlandia (AKA ERNC-009) para la producción de biocombustibles de tercera generación, se plantea la obtención de compuestos polifenólicos con actividad antioxidante como subproducto, afectando mínimamente la degradación de los azúcares disponibles en las algas, para su utilización en biocombustible El presente trabajo consistente en la determinación de las mejores condiciones de extracción de compuestos antioxidantes polifenólicos desde macroalgas verdes (Ulva rigida) y pardas (Macrocystis pyrifera), evaluando diferentes variables: solvente, tiempo de extracción, temperatura de extracción y relación sólido líquido. Para ello se empleó un diseño experimental estadístico basado en el método Taguchi. Para este diseño se realizó un extenso análisis de la literatura existente en torno al tema y selección de los métodos de evaluación de actividad antioxidante, condiciones y metodología de extracción. Se cuantificó los compuestos fenólicos totales por método de Folin-Ciocalteu, capacidad antioxidante por reducción del radical DPPH y las azúcares reductores por método del ácido 3,5-dinitrosalicílico. Los resultados obtenidos se analizaron por métodos estadísticos, utilizando Análisis de Componentes Principales para determinar los factores que aportan mayor variabilidad a la actividad antioxidante durante el proceso extractivo. Como principales resultados fue que se seleccionó el alga M. pyrifera como fuente de antioxidantes polifenólicos. Se logró determinar una metodología que permite extraer una cantidad de polifenoles totales de 374,4 ± 27,4 [mg GAE/100gPS], actividad de 84,9 % de captura del radical DPPH y ausencia de azúcares reductores en el extracto bioactivo. Las mejores condiciones de extracción determinadas corresponden a utilizar como solvente etanol al 75%, una relación sólido-líquido de 1:10 p/v, temperatura de extracción de 37°C por 180 minutos, siendo el tiempo de extracción el factor con mayor efecto en el tratamiento de extracción determinado por el Análisis de Componentes Principales. El método desarrollado sirve como primera aproximación al potencial del alga parda como fuente de antioxidantes industriales y siendo un punto de partida en un proceso de optimización. Estos resultados representan un rendimiento másico de los polifenoles extraídos de un 0,4%. Considerando los niveles de producción actual de M.pyrifera en la X región del país se lograría una producción de alrededor de 2 ton/año de antioxidantes polifenólicos desde el alga, representando un 0,015% del mercado global de polifenoles al año 2011. Este valor podría ser promisorio si se piensa en las posibilidades de aumentar el cultivo de estas algas en la región.

This study examined the demography of giant kelp Macrocystis pyrifera (Linnaeus) and its interactions with understorey algae and invertebrates in southern New Zealand over two and a half years. Most of the study was done at two sites within Akaroa Harbour (Banks Peninsula) but ancillary sites at Tory Channel (Marlborough Sounds) were used for parts of the study. The kelp forests within Akaroa Harbour were generally highly productive, with a high annual turnover of giant kelp. Macrocystis plants were mostly annual and rarely reached ages greater than 12 months. Peak recruitment occurred in spring (November) during 1995-97, but lesser recruitment episodes occurred throughout the year. The maximum growth rates of Macrocystis fronds were comparable to rates reported elsewhere in southern hemisphere populations (22 mm - 24.5 mmlday), but considerably lower than those in northern hemisphere populations. The major experiment incorporated in the study tested the effects of the Macrocystis canopy and the understorey canopy of the stipitate laminarian Ecklonia radiata on macroalgae and invertebrates. The experiment was structured so that the effects of clearances at different times could be determined. One impetus for this experiment was the need to address issues relating to the commercial harvesting of giant kelp, its sustainability and its effects on other species. The effects of canopy removals on understorey algae, mostly juvenile Macrocystis, Ecklonia and Carpophyllum spp, were highly dependent on the timing of canopy removals and the combinations of canopies removed. For example, winter harvests of the Macrocystis canopy alone enhanced the survival of post-settlement Macrocystis recruits, but had little effect on Ecklonia recruitment. However, when both Macrocystis and Ecklonia canopies were removed in spring, there was heavy recruitment of Ecklonia that grew to dominate the understorey. Strong inter and intraspecific interactions from the Macrocystis surface canopy appeared to have been reduced by physical factors including water turbidity, sedimentation and the deterioration of the surface canopy during summer. These physical factors were not as limiting in Tory Channel. Fine scale extrinsic factor effects including nutrients, light and grazing on the early life history of Macrocystis were investigated in small experiments. Results suggest that recruitment may be nutrient limited even at moderately low temperatures, and that small herbivorous gastropods are an important source of mortality in the early life stages of Macrocystis. Culturing and transplantation cultivation techniques were also examined as a means of supplementing algal supplies. Macrocystis was cultured successfully through its life cycle onto culture ropes, but generally failed to produce visible sporophytes when placed in the field. Cultured plants did grow in Tory Channel, however. Juvenile plants transplanted to ropes for on-farm cultivation showed little growth during summer, but the addition of nutrients significantly enhanced growth rates of these plants during warmer months when natural nutrient levels were low. Increased growth rates at the onset of winter and with the addition of nutrients during summer confirmed that low nutrient levels during summer are growth limiting. Akaroa Harbour kelp forests exhibited considerable variation in Macrocystis canopy biomass through time. For example, the 32,000 m2 kelp forest at Wainui had a biomass of 144 t in October 1995, which then decreased to 21 t in October 1996. Canopies tended to deteriorate during summer. Thus, at Ohinepaka Bay kelp forest had a biomass of 31 t during winter 1997, which decreased to 0.06 t the following summer. The greatest reduction in biomass, however, coincided with a period of hugely increased sediment, which smothered blades in the sea-surface canopy, covered the substratum, and prevented successful recruitment of kelp for over a year. Nutrient depletion was one of several factors thought to cause the summer deterioration of the Macrocystis sea-surface canopy, which has important ramifications for the commercial harvesting of Macrocystis pyrifera in summer. Management considerations and options are discussed in relation the commercial harvesting of Macrocystis in New Zealand. The major conclusion of this study is that although Macrocystis was able to form dense surface canopies during winter its ability to dominate kelp forests was constrained by physical factors, especially sedimentation, high turbidity, nutrients, and storms. The lack of strong interactions between Macrocystis and Ecklonia are also largely a result of their different life history characteristics. Overall, there appear to be no significant negative flow-on effects resulting from kelp harvesting and it appears that Macrocystis can be harvested sustainably.

Thesis (Ph. D.)--Simon Fraser University, 1976. / Includes bibliographical references (leaves 85-93).

A field study in three parts was undertaken to investigate the relationships between the habit of Macrocystis integrifolia Bory and water movement. Morphological variation in time within populations was related to seasonal changes in wind direction and speed. Four sites covering a wide range of exposures, yet characterized by essentially the same water properties were sampled throughout a period of one year. In this way valid comparisons could also be made between populations. The sites were all situated in the vicinity [sic] of Barn-field on the west coast of Vancouver Island, B.C. A spot sampling study was undertaken to determine whether the trends established in the above study apply consistently throughout the range of exposures covered by Macrocystis in local waters. Samples were obtained from Ucluelet on Vancouver Island to Warren Island in southern Alaska. Through these studies several aspects of the habit were found to reflect the prevailing dynamic conditions to which the plant had been subjected throughout its development. A transplant study was carried out among the continuous sampling sites to establish the mechanism of response to dynamic conditions. Growth data obtained through the transplant study indicated that stipe elongation and blade initiation vary directly with water movement. Growth of individual blades appears to be independent of this factor. The results of the transplant study supported by variations observed within plants and within populations with time strongly suggest that the mechanism of response is phenotypic plasticity. However, plants observed on the outer coast were, in some respects, markedly distinct. Thus the possibility of a second mechanism operating under conditions of genetic isolation has not been discounted. / Science, Faculty of / Botany, Department of / Graduate

Tesis para optar al grado de Doctora en Ciencias de la Ingeniería, Mención Ingeniería Química y Biotecnología / La macroalga parda Macrocystis pyrifera es una especie de algas marinas que posee una amplia distribución en aguas templadas y frías tanto del hemisferio norte como sur, formando bosques productivos de alta diversidad biológica. En Chile M. pyrifera se distribuye a lo largo de la costa desde Iquique al Cabo de Hornos. La importancia comercial de esta especie se ha incrementado en la última década, especialmente en la extracción de alginato y su uso como alimento de abalones. El alga se compone principalmente de carbohidratos heterogéneos (> 50% peso seco del alga) como fucoidano, alginato y laminarina, los cuales pueden ser empleados como plataforma para la producción de variados compuestos. Además, posee compuestos polifenólicos únicos en su especie conocidos como florotaninos los cuales han sido ampliamente estudiados por sus beneficios potenciales para la salud como anti-oxidantes, anti-cáncer, anti-diabetes, anti-inflamación y anti-microbianas, entre otras. En este trabajo se estudió el diseño de un proceso de extracción de florotaninos y carbohidratos desde M. pyrifera, usando enzimas marinas en la etapa de hidrolisis de los carbohidratos. Para lo cual se procedió en un primer paso a determinar condiciones que mejoran la extracción de florotaninos desde el alga, tales como temperatura de secado del alga, parámetros de extracción e identificación de los compuestos. En una segunda etapa se optimizó la producción de enzimas carbohidrasas, alginato liasa, fucoidanasa y 1,3-β-D-glucanasa, desde microorganismos marinos asociado a la macroalga, para ser empleadas posteriormente en el pre-tratamiento enzimático de M. pyrifera. En una tercera etapa se determinó condiciones de extracción simultánea de carbohidratos y florotaninos desde el alga incorporando la etapa previa de pre-tratamiento enzimático. Finalmente, se estudió la separación de florotaninos desde el extracto final usando resinas macroporosas. La evaluación de estas etapas permitió determinar que un pre-tratamiento enzimático del alga con carbohidrasas, producidas por el hongo marino Alternaria sp, a 25°C por 36 horas a un pH 7.0 y una razón alga/extracto enzimático de 1/20, seguido por extracción alcalina de fase solida con NaOH 0.5N a 100°C por 180 min en una razón sólido/líquido de 1/20. Obteniendo un extracto con concentración final de 452 mg carbohidrato/g alga y 2.14 mg florotaninos/g alga, lo cual representa un rendimiento de extracción específico de 89.6% para carbohidratos y 21.4% para florotaninos. Posteriormente, el uso de resina XAD-16N permitió la separación del 42% de los florotaninos desde el extracto. La fracción enriquecida en florotaninos fue liofilizada presentando una concentración de 14.2 mg florotaninos/g liofilizado. / The brown macroalgae Macrocystis pyrifera is a kind of seaweed that has a wide distribution in temperate and cold waters of both the Northern and Southern hemispheres, forming productive forests of high biological diversity. In Chile M. pyrifera it is distributed along the coast from Iquique to Cape Horn. The commercial importance of this species has increased in the last decade, especially in alginate extraction and use as food abalones. M. pyrifera (>50 % of the alga dry weight) as fucoidan, laminarin and alginate, which can be used as a platform for the production of many compounds is mainly composed of heterogeneous carbohydrate. In addition, the brown seaweeds have unique polyphenolic compounds in their species known as phlorotannins which have been widely studied for their potential health benefits such as prevention of oxidative stress-mediated radical, anti-cancer, anti-diabetes, anti-inflammation and anti-microbial, among others. In this work was studied in this paper the design of an extraction process phlorotannins and carbohydrates from Macrocystis pyrifera, using marine enzymes in the hydrolysis step carbohydrates. For which we proceeded in a first step to determine the conditions that improve phlorotannins extraction from algae such as seaweed drying temperature, parameters extraction and identification of compounds. In a second stage production carbohydrate active enzymes, alginate lyase, fucoidanase and 1,3-β-D-glucanase was optimized from microorganisms associated with marine macroalgae, to be employed subsequently in the enzymatic pretreatment of M. pyrifera. In a third stage of simultaneous extraction conditions of carbohydrate and phlorotannins was determined from M. pyrifera incorporating the previous stage enzymatic pretreatment. Finally, the separation of phlorotannins was studied from the final extract using macroporous resins. Evaluation of these stages allowed to determine that an enzymatic pretreatment with carbohydrate active enzymes, alginate, fucoidanasa and 1,3-β-D-glucanase produced by the marine fungus Alternaria sp, at 25°C for 36 hours pH 7.0 and algae/enzyme extract of 1/20, followed by alkaline extraction of the solid phase with 0.5 N NaOH at 100°C for 180 min in a solid/liquid ratio of 1/20 allowed obtain a final extract with a concentration 452 mg carbohydrate/g of alga and 2.14 mg phlorotannins/g of alga, which represents a specific extraction yield of 89.6% for carbohydrates and 21.4% for phlorotannins. Subsequently, the use of macroporous resin XAD- 16N allowed separation of the 42% of phlorotannins from the extract. Finally, the enriched fraction with phlorotannins was lyophilized presenting a concentration of 14.2 mg phlorotannins/g lyophilized. / Este trabajo es financiado por una beca CONICYT para estudio de doctorado en Chile, el proyecto AKA-ERNC 0009 OPTIFU; y por el Centro Basal financiado por CONICYT CeBiB FB0001

Kelp forests are highly productive three-dimensional marine ecosystems that provide valuable ecosystem services globally. Along the coast of British Columbia, Macrocystis pyrifera and Nereocystis luetkeana are two key species that form surface-canopies that are vulnerable to both biotic and abiotic drivers; making it imperative to monitor and understand whether these ecosystems are changing in the face of climate change. The monitoring of kelp forests is commonly enhanced by use of remote sensing, which allows researchers to survey large portions of the coast where it would otherwise be difficult to collect data, and to use archived imagery for comparisons of historic and contemporary kelp forest trends. Generally, the remote sensing of kelp surface-canopy relies on differences in the high near-infrared (NIR; 700-1000 nm) signal of kelp and the low NIR signal of water. However, kelp surface-canopy reflectance signals can be affected by submergence under water, caused by oceanographic features like tides and currents, or simply due to differences in the morphology and buoyancy of kelp canopy structures. This submersion may cause uncertainties when estimating the surface-canopy area of kelp beds in remote sensing imagery. This research aims to understand the effects of submersion on the remote sensing of kelp surface-canopy. To address our goal, (i) Nereocystis canopy structures (bulb and blade) were submerged while collecting above-water hyperspectral measurements. The hyperspectral data into the bandwidths of high-resolution multispectral aerial and space-borne sensors and vegetation indices were calculated to understand the kelp detection limits when using shorter red-edge wavelengths (RE; 690-750 nm) instead of the longer NIR wavelengths. The results showed that submerged kelp can be detected deeper in the water column using shorter RE wavelengths compared to the more commonly used NIR wavelengths. Further, (ii) in situ hyperspectral data were also collected for the different surface-canopy structures and compared with UAV imagery, which showed that the buoyancy of the kelp canopy structures at the surface affected the relative magnitude of reflectance in both the RE and NIR and supported the findings of the submersion experiment. The total surface-canopy area derived from classification with both RE and NIR vegetation indices were compared in the UAV imagery, and the RE index detected roughly 18% more kelp than the NIR index, with no differences seen between Macrocystis and Nereocystis, or between high and low tide in beds larger than 150m2. Finally, (iii) to understand how submersion by tides and currents affect the ability to estimate surface-canopy area for both Macrocystis and Nereocystis, surface-canopy area was derived from multispectral unoccupied aerial vehicle (UAV) imagery and compared with in situ tide and current data, which showed that surface-canopy area had a strong negative linear relationship with tidal height at all sites regardless of species. Macrocystis occupied sites where currents were low (<10cm/s) and did not affect the surface-canopy. Therefore, the extent of all Macrocystis beds decreased at a similar rate over their tidal range (22.7 + 2.8%/m). Nereocystis beds occupied a wider range of current speeds (0.0 - 19.0 cm/s), and at sites with high current speeds (> 10 cm/s) increasing current and tidal height decreased surface-canopy area simultaneously, resulting in both a higher and more variable rate of decrease (30.5 + 9.1%/m) with increasing tidal height than Macrocystis. Together, this thesis addressed critical questions related to the effects of kelp submersion on the remote sensing of surface-canopy forming kelps, and we provide recommendation for remote sensors who wish to minimize errors when using remote sensing to map kelp forests. / Graduate