Coastal and shallow lakes are often subjected to eutrophication due to nutrients from catchment farming activities. Lake Ellesmere (Te Waihora) is a hyper-eutrophic lake which has gained recent attention because of concerns over its ecological health and fishery status. This study investigated the benthic ecology of the lake by extensive spatial and temporal sampling. Eight littoral sites were sampled on a single occasion, and 20 benthic sites were sampled once per season for one year. Water chemistry conditions, substrate and invertebrate communities varied significantly around the lake. Salinity, pH, DO and seston were primarily affected by freshwater inputs from inflow streams and salt water intrusion due to the lake opening to the sea. On these occasions, salinity reached 32 ‰ at the lake outlet. The lake invertebrate community was depauperate, comprising of only two species of invertebrate predators restricted to the littoral zone and eight benthic invertebrate taxa, dominated by oligochaetes, amphipods and chironomids. Benthic invertebrate abundances also reflect the dominant local substrate, where oligochaetes and chironomids preferred areas of silt substrate, whereas Potamopyrgus preferred harder substrate. Stable isotope and gut analysis determined that the primary food sources within the lake were phytoplankton and algae. Macrophytes provided a minimal contribution to the food web, possibly relating to the change in status from a clear water, macrophyte dominated lake to a turbid, phytoplankton dominated condition since the Wahine Storm in 1968. Isotope analysis also showed that the lake food web was markedly different in its carbon values from food webs of its inflow streams and nearby marine source. However the lake food web did show a marine-derived carbon signature. A mesocosm experiment testing the effect of common lentic predators on the abundance of the lake chironomid Chironomus zealandicus, showed that if invertebrate predators were present in the lake they could markedly reduce the abundance of the pest prey species. This study highlights that the frequent re-suspension of bottom sediments, lake level fluctuation resulting in wetting and drying of littoral zones, and the management of the lake opening to the sea all have an effect on the benthic ecology of Te Waihora.

Understanding of the fundamental ecology of deep-sea ecosystems remains immature relative to more familiar shallow-water and terrestrial habitats, despite more than two hundred years of scientific investigation. This thesis aims to progress knowledge of deep-sea benthic ecology by the analysis of over three hundred box core samples collected from the Northwest Atlantic continental slope as part of the international NEREIDA programme. Aspects of the ecology of Peracarida (Crustacea) are studied, and this is facilitated by the coupling of a large faunal dataset with extensive environmental information. To further enhance the power of this dataset, phylogenetic and functional characteristics of assemblages are investigated. Using community phylogenetic methodology, it is demonstrated that the peracarid assemblages studied are structured more strongly by variation in environmental parameters than they are by competitive interactions. Analyses demonstrate that the intensity of bottom trawling, seafloor temperature, current speed, food availability, sediment characteristics and physical habitat heterogeneity all influence deep-sea peracarid assemblage biodiversity metrics. Further, the importance of high poriferan biomass for the promotion of peracarid assemblages of high density, biomass, richness and diversity is highlighted. Of relevance to the management of deep-sea ecosystems, the results of this thesis suggest that caution should be exercised when applying species distribution models to data-deficient environments, whilst the location of spatial closures in the NAFO Regulatory Area may not be fully optimal for the protection of all components of diverse benthic assemblages against the impacts of bottom trawling. The importance of deep-sea diversity is demonstrated by the finding of positive biodiversity – ecosystem functioning relationships. However, the form of these relationships is found to be dependent on the biodiversity and ecosystem functioning metrics employed, and a hypothesis for a generalised form of biodiversity – ecosystem functioning relationships is proposed. Finally, this thesis calls for more ambitious deep-sea ecological investigations, and it is hoped that its findings will encourage future research initiatives, helping to further illuminate this enigmatic and fascinating environment.

Coastal and shallow lakes are often subjected to eutrophication due to nutrients from catchment farming activities. Lake Ellesmere (Te Waihora) is a hyper-eutrophic lake which has gained recent attention because of concerns over its ecological health and fishery status. This study investigated the benthic ecology of the lake by extensive spatial and temporal sampling. Eight littoral sites were sampled on a single occasion, and 20 benthic sites were sampled once per season for one year. Water chemistry conditions, substrate and invertebrate communities varied significantly around the lake. Salinity, pH, DO and seston were primarily affected by freshwater inputs from inflow streams and salt water intrusion due to the lake opening to the sea. On these occasions, salinity reached 32 ‰ at the lake outlet. The lake invertebrate community was depauperate, comprising of only two species of invertebrate predators restricted to the littoral zone and eight benthic invertebrate taxa, dominated by oligochaetes, amphipods and chironomids. Benthic invertebrate abundances also reflect the dominant local substrate, where oligochaetes and chironomids preferred areas of silt substrate, whereas Potamopyrgus preferred harder substrate. Stable isotope and gut analysis determined that the primary food sources within the lake were phytoplankton and algae. Macrophytes provided a minimal contribution to the food web, possibly relating to the change in status from a clear water, macrophyte dominated lake to a turbid, phytoplankton dominated condition since the Wahine Storm in 1968. Isotope analysis also showed that the lake food web was markedly different in its carbon values from food webs of its inflow streams and nearby marine source. However the lake food web did show a marine-derived carbon signature. A mesocosm experiment testing the effect of common lentic predators on the abundance of the lake chironomid Chironomus zealandicus, showed that if invertebrate predators were present in the lake they could markedly reduce the abundance of the pest prey species. This study highlights that the frequent re-suspension of bottom sediments, lake level fluctuation resulting in wetting and drying of littoral zones, and the management of the lake opening to the sea all have an effect on the benthic ecology of Te Waihora.

As global change alters the chemical and physical dynamics of the ocean, it is increasingly necessary to determine ecological responses across environmental gradients. The benthic ecosystems of fjords often contain a multitude of environmental gradients conducive to multivariate field studies. In this thesis, I describe the benthic community structure of two British Columbian fjords in relation to markedly different environmental variables. In Chapter 2, I show a strong correlation between suspension-feeder abundance and flow structure on the steep fjord walls of Douglas Channel, BC. I also describe distinct assemblages with depth and with location along the fjord head-mouth axis. Using a suite of biological traits, I show that the deep portion (> 400 m depth) of the most seaward site is the most taxonomically and functionally diverse in the fjord. My results suggest fjord walls form an expansive ecosystem containing diverse and dense assemblages of suspension feeders relevant to the flow of energy through fjord basins and as biodiversity reservoirs. In Chapter 3, I extend a long-term hypoxia time-series (2006 -2016) to document the response of soft-bottom epibenthic megafauna of Saanich Inlet, BC to a prolonged hypoxic event in 2016 that caused abundance declines, community aggregation and shifts in species composition more extreme than those seen in the 2013 hypoxia cycle. I also assess community threshold responses along the oxygen gradient; I found community transitions consistent across years and with Northeast Pacific oxygen thresholds based in ecophysiological studies. Taken together, these studies show a strong coupling between oceanographic conditions and the community structure of fjord benthos. I suggest that climate-driven alterations in North Pacific oceanographic regimes may portend major changes in fjord ecosystems. / Graduate

Projetos de monitoramento de longo prazo estão sendo desenvolvidos internacionalmente a fim de monitorar continuamente os impactos que as mudanças climáticas globais vêm gerando nas comunidades marinhas bentônicas, entretanto, no âmbito nacional, há uma carência desse tipo de estudo e dados para a costa brasileira. O objetivo do presente estudo foi a instalação de uma estação de monitoramento de longo prazo, bem como a caracterização da comunidade bentônica presente no médiolitoral do costão rochoso à direita da Enseada de Palmas, no Parque Estadual da Ilha Anchieta (Ubatuba, SP) seguindo as diretrizes do \"Protocolo de Médiolitoral para Monitoramento de Comunidades de Costão Rochoso\" da ReBentos (Rede de Monitoramento de Habitats Bentônicos Costeiros). As amostragens dependentes semestrais (n = 3) foram realizadas no período de um ano, compreendendo o inverno de 2014 e o verão de 2015, utilizando fotoquadrados de 10x10 cm na faixa superior e 25x25 cm nas faixas intermediária e inferior. A análise variância ANOVA two way para dados repetidos revelou variação sazonal na largura das faixas das unidades operacionais (UO) Tetraclita (39,1 cm) e Macroalgas (27 cm) e no recobrimento percentual médio (RPM) das UO Cianobactéria (12,6%) na faixa superior, T. stalactifera (16,6%), Espaço vazio (38,4%) e Algas Calcárias Articuladas (55,7%) na faixa intermediária. As análises multivariadas (Cluster, nMDS e PCA) revelaram alta similaridade para as faixas superior (80%) e inferior (85%) e baixa (65%) para a faixa intermediaria, indicando que as maiores diferenças entre verão e inverno foram encontradas nesta faixa. Como o médiolitoral apresenta UO bioindicadoras de monitoramento, como T. stalactifera, A. beauvoisii e Sargassum vulgare, e de variação sazonal, então eleva-se a importância da realização, integração e continuidade de projetos de monitoramento de longo prazo em costões rochosos a fim de gerar dados históricos ao longo do litoral brasileiro / The development of long-term monitoring projects around the world aims to monitor continuously the impacts that global environmental changes (GEC) have been causing in the benthic marine communities. However, nationally, there are few monitoring studies and data for the Brazilian coast. In this study, we aimed to install a long-term monitoring station and characterize the benthic community located in the intertidal zone of the rocky shore in the right of the Cove of Palmas at the Anchieta Island State Park (Ubatuba, São Paulo state). We intended to do that by following the guidelines of the \"Intertidal Protocol for the Monitoring of Rocky Shore Communities\" (Rocky Shores Working group, ReBentos). We studied the rocky shore for a year and collected the dependent samples every semester (n = 3), encompassing the winter of 2014 and the summer of 2015. We used photoquadrats in the intertidal zone (10x10 cm in the upper band and 25x25 cm in the intermediate and lower bands). Two-way analysis of variance (ANOVA) for repeated measures reveled seasonal variation in the bandwidth of Tetraclita (39,1 cm) and Macroalgae (27 cm) operational units (OU) and in the average percentage overlap for Cyanobacteria (12,6%) at upper band, T. stalactifera (16,6%), Empty space (38,4%) and Articulated Calcareous Algae (55,7%) at intermediate band. Multivariate analysis (Cluster, nMDS and PCA) revealed high similarity for upper (80%) and lower (85%) bands and low similarity for intermediate band (65%), suggesting major differences between summer and winter in the intermediate band. As the intertidal zone has monitoring bioindicators operational units, like T. stalactifera, A. beauvoisii and Sargassum vulgare, and seasonal variation, it is of great importance to implement, integrate and continue long-term monitoring projects in rocky shores in order to generate Brazilian coast historical data

Como os processos que definem distribuições de espécies operam em diferentes escalas espaciais, abordagens multi-escalares são necessárias para que a variabilidade do sistema seja considerada no desenvolvimento de desenhos amostrais. Estudos sobre padrões espaciais de distribuição são necessários para servir de base para monitoramento e avaliações de impactos. Este trabalho avaliou a variação espacial de comunidades de infralitoral, em costões rochosos de três ilhas na Estação Ecológica dos Tupinambás. Os padrões espaciais foram investigados em quatro escalas, que variam de poucos metros a dezenas de quilômetros. Foram amostradas as profundidades de 1 a 5 e de 5 a 10 metros, no verão e inverno de 2013 e verão de 2014. O recobrimento percentual das unidades biológicas foi extraído a partir de foto-quadrados de 50x50 cm, aleatorizados, seguindo um desenho amostral aninhado. Os dominantes foram analisados individualmente com análise de variância univariada. Algas Calcárias Articuladas (ACA) foram o grupo dominante em todas as ilhas, períodos e profundidades, além de influenciar padrões multivariados, evidenciados pelo PCA. O recobrimento médio de ACA variou de 36% a 89.56%, considerando toda a amostragem. Outros dominantes variaram de acordo com o período e profundidade de coleta, dentre eles, Sargassum sp., Codium intertextum e Asparagopsis taxiformis. Todas as análises multivariadas (PERMANOVA, Pairwise Comparisons e nMDS) revelaram alta variação entre ilhas. Todas as outras escalas apresentaram variabilidade significativa, exceto a de poucos metros. Estimativas de variação revelaram que a variação residual e a entre ilhas foram sempre maiores do que as das outras escalas, confirmando a heterogeneidade intrínseca em pequena escala e a complexidade de comunidades insulares. O monitoramento nesta UC deverá incorporar todas as escalas investigadas. / As processes that define species distributions operate at different spatial scales, multi-scale approaches are needed to account for the system\'s natural variability, when developing sampling designs. Research about spatial patterns is essential to generate data to drive monitoring initiatives and impact assessments. The present study evaluated the spatial variability of subtidal rocky shore communities in three islands within the Ecological Station of Tupinambás. Spatial patterns were investigated across four scales, ranging from few meters to tens of kilometers, from 1 to 5 and from 5 to 10 m depth, in the summer and winter of 2013 and summer of 2014. Percent cover of the biological units was evaluated from photo-quadrats of 50x50 cm, randomly scattered, following a nested design. Dominant species and morphological groups were analyzed individually by univariate analyses of variance. Articulated Calcareous Algae (ACA) were the dominant group in all islands, depths and periods, and the main driver of multivariate patterns, as evidenced by the PCA. Mean cover of ACA varied from 36% to 89.56%, considering all occasions. Other dominant species were the algae Sargassum sp., Codium intertextum and Asparagopsis taxiformis, which varied according to sampling period and depth. All multivariate procedures (PERMANOVA, Pairwise Comparisons and nMDS plots) showed the highest variability among islands. All the other scales, except of few meters, presented significant variability. Estimates of variation showed that residual and intra-island variability were always higher than in other scales, confirming the intrinsic small-scale patchiness of marine assemblages and the complexity of insular communities. Monitoring efforts in this MPA should incorporate all the examined scales.

The Arctic region has experienced the largest degree of anthropogenic warming, causing rapid, yet variable sea-ice loss. The effects of this warming on the Canadian Beaufort Shelf have led to a longer ice-free season which has assisted the expansion of northern development, mainly in the oil and gas sector. Both these direct and indirect effects of climate change will likely impact the marine ecosystem of this region, in which benthic fauna play a key ecological role. The aim of this thesis was to expand the current baseline knowledge of benthic fauna in the interest of developing the capacity to identify, predict and manage benthic change. The distribution of benthic macro- and megafauna was characterized utilizing community data from two recent benthic surveys on the Canadian Beaufort shelf and slope. Fauna were collected from 63 stations using box core and trawl sampling gear over the summers of 2009 through 2012 between depths of 30 and 1,000 m. Spatial patterns of abundance, biomass and α and β diversity metrics were examined. Megafaunal abundance and α diversity were elevated on the shelf compared to the slope while the macrofauna did not vary significantly with depth. Multivariate analyses illustrated that both macro- and megafaunal community composition varied more across the depth gradient than from east to west along the shelf. However the change across the depth gradient was greater for the megafauna than for the macrofauna. I proposed that megafaunal slope taxa were differentiated from shelf taxa, as faunal replacement not nestedness appeared to be the main driver of megafaunal β diversity across the depth gradient. The lack of correlation between macro- and megafauna in abundance, biomass and α and β diversity suggests that these faunal components vary at different spatial scales. These results demonstrate how separately sampling the different benthic components can yield different spatial patterns, with implications for future benthic monitoring in the region. This work contributes to the current regional baselines by providing the first comprehensive description of megafaunal distribution on the Canadian Beaufort shelf and by extending our knowledge of benthic distribution patterns deeper on the slope. / Graduate / 0329

The development of offshore wind farms and marine renewable energy devices in the Mediterranean is central to both national, and international, energy strategies for countries bordering the Mediterranean Sea. The ecological impacts of marine renewable energy development in the Mediterranean region, although essential for policy makers, are as yet unknown. The Northern Adriatic is identified as a plausible site for offshore wind farm development. Using the wider region (Adriatic and Northern Ionian) as a case study, this thesis examines the likely impact to the marine environment if an offshore wind farm is established. Site suitability, based on wind speed, bathymetry, and larvae connectivity levels are investigated along with the plausibility of the turbines operating as artificial reefs in the area. As offshore wind farms may alter the larval connectivity and supply dynamics of benthic populations, a connectivity map was constructed to identify areas of high and low connectivity in the Adriatic Sea. The Puglia coast of Italy is a likely larval sink, and displays some of the highest connectivity within the region, suggesting potential inputs of genetic materials from surrounding populations. Considering offshore wind farms could operate as artificial reefs, an in-situ pilot project was established to simulate the presence of wind turbines. Macroinvertebrates colonized the new substrata within the first few months but were lower in abundance when compared to a natural hard substrata environment. Time, turbine location, and the material used for turbine construction all affected the macro-invertebrate communities. In addition, fish abundances, and diversity were lower around the simulated OWF foundations in comparison to a natural hard substrata environment, and no increases in fish abundance occurred around the simulated turbines when compared to reference sites of soft substrata. This observation was validated with the use of an ecosystem modelling software (Ecopath with Ecosim), which simulated the overall ecosystem level impacts that would occur if 50 offshore monopile wind turbines were introduced to the Northern Ionian and colonized by macroinvertebrate communities. When compared to the baseline scenario (no simulated introduction of an OWF), the introduction of new habitat had no discernible impacts to the structure or functioning of the marine ecosystem. Noticeable changes to the ecosystem were only apparent if fishing restrictions were enforced in parallel with the simulated offshore wind farm; the ecosystem appears to become more structured by top down predation. In addition seabirds are also impacted by the reduction of fishing discards as a food source. These results are the first attempt to quantify the suspected benefits of offshore wind farms operating as de-facto marine protected areas.

Como os processos que definem distribuições de espécies operam em diferentes escalas espaciais, abordagens multi-escalares são necessárias para que a variabilidade do sistema seja considerada no desenvolvimento de desenhos amostrais. Estudos sobre padrões espaciais de distribuição são necessários para servir de base para monitoramento e avaliações de impactos. Este trabalho avaliou a variação espacial de comunidades de infralitoral, em costões rochosos de três ilhas na Estação Ecológica dos Tupinambás. Os padrões espaciais foram investigados em quatro escalas, que variam de poucos metros a dezenas de quilômetros. Foram amostradas as profundidades de 1 a 5 e de 5 a 10 metros, no verão e inverno de 2013 e verão de 2014. O recobrimento percentual das unidades biológicas foi extraído a partir de foto-quadrados de 50x50 cm, aleatorizados, seguindo um desenho amostral aninhado. Os dominantes foram analisados individualmente com análise de variância univariada. Algas Calcárias Articuladas (ACA) foram o grupo dominante em todas as ilhas, períodos e profundidades, além de influenciar padrões multivariados, evidenciados pelo PCA. O recobrimento médio de ACA variou de 36% a 89.56%, considerando toda a amostragem. Outros dominantes variaram de acordo com o período e profundidade de coleta, dentre eles, Sargassum sp., Codium intertextum e Asparagopsis taxiformis. Todas as análises multivariadas (PERMANOVA, Pairwise Comparisons e nMDS) revelaram alta variação entre ilhas. Todas as outras escalas apresentaram variabilidade significativa, exceto a de poucos metros. Estimativas de variação revelaram que a variação residual e a entre ilhas foram sempre maiores do que as das outras escalas, confirmando a heterogeneidade intrínseca em pequena escala e a complexidade de comunidades insulares. O monitoramento nesta UC deverá incorporar todas as escalas investigadas. / As processes that define species distributions operate at different spatial scales, multi-scale approaches are needed to account for the system\'s natural variability, when developing sampling designs. Research about spatial patterns is essential to generate data to drive monitoring initiatives and impact assessments. The present study evaluated the spatial variability of subtidal rocky shore communities in three islands within the Ecological Station of Tupinambás. Spatial patterns were investigated across four scales, ranging from few meters to tens of kilometers, from 1 to 5 and from 5 to 10 m depth, in the summer and winter of 2013 and summer of 2014. Percent cover of the biological units was evaluated from photo-quadrats of 50x50 cm, randomly scattered, following a nested design. Dominant species and morphological groups were analyzed individually by univariate analyses of variance. Articulated Calcareous Algae (ACA) were the dominant group in all islands, depths and periods, and the main driver of multivariate patterns, as evidenced by the PCA. Mean cover of ACA varied from 36% to 89.56%, considering all occasions. Other dominant species were the algae Sargassum sp., Codium intertextum and Asparagopsis taxiformis, which varied according to sampling period and depth. All multivariate procedures (PERMANOVA, Pairwise Comparisons and nMDS plots) showed the highest variability among islands. All the other scales, except of few meters, presented significant variability. Estimates of variation showed that residual and intra-island variability were always higher than in other scales, confirming the intrinsic small-scale patchiness of marine assemblages and the complexity of insular communities. Monitoring efforts in this MPA should incorporate all the examined scales.

Projetos de monitoramento de longo prazo estão sendo desenvolvidos internacionalmente a fim de monitorar continuamente os impactos que as mudanças climáticas globais vêm gerando nas comunidades marinhas bentônicas, entretanto, no âmbito nacional, há uma carência desse tipo de estudo e dados para a costa brasileira. O objetivo do presente estudo foi a instalação de uma estação de monitoramento de longo prazo, bem como a caracterização da comunidade bentônica presente no médiolitoral do costão rochoso à direita da Enseada de Palmas, no Parque Estadual da Ilha Anchieta (Ubatuba, SP) seguindo as diretrizes do \"Protocolo de Médiolitoral para Monitoramento de Comunidades de Costão Rochoso\" da ReBentos (Rede de Monitoramento de Habitats Bentônicos Costeiros). As amostragens dependentes semestrais (n = 3) foram realizadas no período de um ano, compreendendo o inverno de 2014 e o verão de 2015, utilizando fotoquadrados de 10x10 cm na faixa superior e 25x25 cm nas faixas intermediária e inferior. A análise variância ANOVA two way para dados repetidos revelou variação sazonal na largura das faixas das unidades operacionais (UO) Tetraclita (39,1 cm) e Macroalgas (27 cm) e no recobrimento percentual médio (RPM) das UO Cianobactéria (12,6%) na faixa superior, T. stalactifera (16,6%), Espaço vazio (38,4%) e Algas Calcárias Articuladas (55,7%) na faixa intermediária. As análises multivariadas (Cluster, nMDS e PCA) revelaram alta similaridade para as faixas superior (80%) e inferior (85%) e baixa (65%) para a faixa intermediaria, indicando que as maiores diferenças entre verão e inverno foram encontradas nesta faixa. Como o médiolitoral apresenta UO bioindicadoras de monitoramento, como T. stalactifera, A. beauvoisii e Sargassum vulgare, e de variação sazonal, então eleva-se a importância da realização, integração e continuidade de projetos de monitoramento de longo prazo em costões rochosos a fim de gerar dados históricos ao longo do litoral brasileiro / The development of long-term monitoring projects around the world aims to monitor continuously the impacts that global environmental changes (GEC) have been causing in the benthic marine communities. However, nationally, there are few monitoring studies and data for the Brazilian coast. In this study, we aimed to install a long-term monitoring station and characterize the benthic community located in the intertidal zone of the rocky shore in the right of the Cove of Palmas at the Anchieta Island State Park (Ubatuba, São Paulo state). We intended to do that by following the guidelines of the \"Intertidal Protocol for the Monitoring of Rocky Shore Communities\" (Rocky Shores Working group, ReBentos). We studied the rocky shore for a year and collected the dependent samples every semester (n = 3), encompassing the winter of 2014 and the summer of 2015. We used photoquadrats in the intertidal zone (10x10 cm in the upper band and 25x25 cm in the intermediate and lower bands). Two-way analysis of variance (ANOVA) for repeated measures reveled seasonal variation in the bandwidth of Tetraclita (39,1 cm) and Macroalgae (27 cm) operational units (OU) and in the average percentage overlap for Cyanobacteria (12,6%) at upper band, T. stalactifera (16,6%), Empty space (38,4%) and Articulated Calcareous Algae (55,7%) at intermediate band. Multivariate analysis (Cluster, nMDS and PCA) revealed high similarity for upper (80%) and lower (85%) bands and low similarity for intermediate band (65%), suggesting major differences between summer and winter in the intermediate band. As the intertidal zone has monitoring bioindicators operational units, like T. stalactifera, A. beauvoisii and Sargassum vulgare, and seasonal variation, it is of great importance to implement, integrate and continue long-term monitoring projects in rocky shores in order to generate Brazilian coast historical data