Do the crabs Goniopsis cruentata and Ucides cordatus compete for mangrove propagules? A field-based experimental approach

Mangroves are under threat worldwide by deforestation, overexploitation and climate change. The availability and consumption rates of propagules influence mangrove recruitment and can play a major role in their viability and restoration potential. We assess the potential trophic competition between Goniopsis cruentata and Ucides cordatus, two dominant crab species in the New World, by experimentally comparing herbivory levels between forest stands with varying crab abundance. We hypothesize that herbivory rates (HR) of G. cruentata will be lower in mangroves where it coexists with U. cordatus than in mangroves where U. cordatus is absent. The removal of Rhizophora mangle propagules was very rapid, and HR were overall high and increased through time. However, HR did not differ significantly between mangroves with and without the potential trophic competitor U. cordatus. Our study did not support previous literature indications of food competition between these two crab species, which seem to have developed strategies for competition avoidance.

De patrones a parámetros : una evaluación de los patrones espaciales en los pabellones de la Serpentine Gallery (2000-2015)

La actual realidad socioeconómica, marcada por la (r)evolución tecnológica de los último años y la explosión demográfica y urbana, conlleva dos grandes problemas. Por un lado el cambio climático derivado de la sobreexplotación de los recursos y energías no-renovables, y por otro, la pérdida de las identidades y procesos culturales específicos provocada por la globalización. Ante ellos, diversos autores plantean sacar partido de las propias tecnologías y la nueva sociedad en red para dar una respuesta acorde al momento actual. Las herramientas computacionales permiten una mayor complejidad de los diseños alcanzando una optimización de recursos y procesos, minimizando su impacto ambiental. Frente a la producción en masa y la pérdida de identidad, el planteamiento informático de problemas globales permite pasar de la producción en masa del siglo pasado a la ‘customización’ en masa al dar respuestas específicas para cada contexto. Por otro lado es necesario que esos procesos computacionales conecten y hagan partícipes del diseño a los diferentes actores sociales implicados. Es por ello que esta investigación se basará en los patrones espaciales de Christopher Alexander y otros modelos algorítmicos de diseño por ordenador puesto que estos describen soluciones paramétricas a conflictos recurrentes de diseño de arquitectura. Su planteamiento permite que cada solución base genere respuestas específicas, a la vez que esta es corregida y optimizada por todos sus utilizadores al poder ser compartida digitalmente. Con ello se busca que el diseño de arquitectura responda a criterios objetivos basados en la experiencia y la crítica participativa y democrática basada en los patrones, de tal modo que los diseños no surjan de un planteamiento top-down impuesto y cerrado, sino que en ellos gane importancia la participación activa de los actores sociales implicados en la definición y uso de los mismos. Por último, esta investigación procura mostrar cómo los patrones pueden jugar un papel determinante en la conceptualización abstracta del diseño, mientras que otros métodos algorítmicos alcanzarán fases del proyecto más concretas. De este modo, los patrones digitales que se pretenden se centran en la customización del diseño, mientras que el uso que le dan otros autores persigue la optimización del mismo. Para ello la investigación recurrirá al análisis de los pabellones de verano de la Serpentine Gallery como casos de estudio en los que comprobar la repercusión de los patrones en el diseño de arquitectura actual y su posible adaptación al diseño paramétrico.

Size at maturity and length-weight relationships of the blurred lantern shark Etmopterus bigelowi (Squaliformes: Etmopteridae) caught off southeastern Brazil

The blurred lantern shark Etmopterus bigelowi, a deep-water squaloid shark, is globally widespread in temperate and tropical waters, but there is little available information about its biology owing to its relative rarity of capture and taxonomic confusion with its sibling species Etmopterus pusillus. Specimens used in this study were collected from July to December 2004 as by-catch in the commercial deepwater trawl fishery targeting red shrimp Aristaeomorpha foliacea in the southwestern Atlantic. We examined 55 specimens (22 males and 33 females) ranging in total length (TL) from 31.5 to 73 cm and in total weight from 103 to 1600 g. Length-weight relationships were explored for each sex and significant differences were found in the slope coefficients of the male and female regressions. The size at maturity for each sex was evaluated fitting a logistic regression. Females matured at larger sizes than males, with estimated sizes at first maturity of 56.0 cm TL for females and 45.1 cm TL for males. The present study provides important preliminary information about E. bigelowi that can be incorporated in risk assessment and stock assessment models, essential for efficient management practices aimed at avoiding overexploitation of these vulnerable deep-sea sharks.

Coastal lagoons and their watersheds as GWDE: a case study in the southwest coast of Portugal

The study of groundwater dependent ecosystems opened the opportunity to involve specialists of different areas of knowledge in order to obtain answers for complex interrelations between groundwater and the associated ecosystems. The actual study, carried out in two coastal lagoons of the Portuguese SW coast, showed the high dependency of the marine life and vegetation of the lagoons and associated streams discharging in the lagoons on the fresh water supply of these two lagoons and the high contribution they receive from groundwater in the dry period, which corresponds to more than half of each hydrologic year. Every year, the lagoons are artificially opened to the ocean for a few days to a few weeks, which dramatically changes the inside salinity. The sensitivity of these ecological niches is demonstrated by the strong dependence that some species that are more sensitive to high salinity waters show in relation to the entrance of freshwater resultant from the discharge of the phreatic aquifer of Sines sedimentary Basin. The great biodiversity of these lagoons and its precarious balance is only possible to preserve if the aquifer continue to act as a regulatory factor of the lagoon’s salinity. The equilibrium can be changed in the event of overexploitation of the phreatic aquifer, which is not at risk in the near future. In a scenario of climate change the lagoons will benefit from a slow increase in groundwater contribution, due to the rise of sea level, which will be accompanied by a rise in groundwater levels in the aquifer near the sea.

Study of Atlantic chub mackerel's (Scomber colias, Gmelin, 1789) landings evolution in Portugal: importance for purse seine fleet

The Portuguese purse seine fishery could be sustainable if measures to promote multi-specify catches are placed. Chub mackerel is one of the top three species landed by purse seine and landings have been increasing, which could be partly explained by Docapesca’s campaign promoting chub mackerel consumption. Therefore, it is necessary to understand if chub mackerel could represent a sustainable alternative. Results point to overexploitation levels, already exceeding estimated Maximum Sustainable Yield (MSY). The break point was registered in 2011, when chub mackerel landings surpassed 30 thousand tonnes landed, which is far beyond MSY estimates by Schaefer’s (24 703 ton), Gulland’s (21 750 ton) and Cadima’s (23 250 ton) models. Chub mackerel could represent an alternative to purse seine fisheries if: (i) a catch limit is established; (ii) measures to promote a regulated market on supply and demand laws are placed; (iii) research investment is augmented; Estudo da evolução dos desembarques de cavala (Scomber colias, Gmelin, 1782) em Portugal: sua importância para a pesca de cerco. Resumo: A pesca de cerco em Portugal poderá ser sustentável se forem implementadas medidas para a sua diversificação. A cavala é uma das três espécies mais capturadas pelo cerco, tendo-se observado um aumento dos desembarques nos últimos anos, parte explicado pela campanha focada no seu consumo, promovida pela Docapesa. Torna-se necessário compreender se a cavala poderá constituir uma alternativa sustentável. Os resultados apontam para níveis de exploração acima do Rendimento Máximo Sustentável (RMS) estimado, atingido em 2011, quando os desembarques de cavala ultrapassaram as 30 mil toneladas, acima do RMS estimado de acordo com Schaefer (24 703 ton), Gulland (21 750 ton) e Cadima (23 250 ton), mantendo-se a tendência de sobre-exploração. A cavala poderá ser uma alternativa para o cerco se: (i) estabelecido um limite de captura; (ii) criadas medidas de promoção de um mercado regulado pela lei da oferta e da procura (iii) aumentar o investimento em investigação.

ACTITUDES HACIA LA ACUACULTURA EN ALGUNAS COMUNIDADES DEL GOLFO DE NICOYA, COSTA RICA

General attitudes toward aquaculture and specifically their interest in and the capture of mullet (Migil spp) was the determined by interviewing 154 artisanal fishermen and 29 salt-evaporation pond owners along the eastern shore of the Gulf of Nicoya. The majority of the fishermen, who likely are already overexploiting the fishery resource of the gulf, knew nothing about aquaculture. Nevertheless, they indicated that agriculture (which includes aquaculture) would be an alternative economic activity in the event that they couldn’t continue fishing. Although mullet is not highly valued on the market, it is very common and utilized by this social group. During winter (rainy season) the salt-evaporation ponds are not utilized and their owners expressed interest in cultivating mullet and shrimp during that season. Aquaculture could help solve the overexploitation problems in the traditional fishery, the overproduction of salt and the underutilization of the salt=evaporation ponds during the rainy season.

Impact of anthropogenic stressors on the microbial communities in marine holobionts and ecosystems

Free-living or host-associated marine microbiomes play a determinant role in supporting the functioning and biodiversity of marine ecosystems, providing essential ecological services, and promoting the health of the entire biosphere. Currently, the fast and restless increase of World’s human population strongly impacts life on Earth in the forms of ocean pollution, coastal zone destruction, overexploitation of marine resources, and climate change. Thanks to their phylogenetic, metabolic, and functional diversity, marine microbiomes represent the Earth’s biggest reservoir of solutions against the major threats that are now impacting marine ecosystems, possibly providing valuable insights for biotechnological applications to preserve the health of the ocean ecosystems. Microbial-based mitigation strategies heavily rely on the available knowledge on the specific role and composition of holobionts associated microbial communities, thus highlighting the importance of pioneer studies on microbial-mediated adaptive mechanisms in the marine habitats. In this context, we propose different models representing ecologically important, widely distributed, and habitat-forming organisms, to further investigate the ability of marine holobionts to dynamically adapt to natural environmental variations, as well as to anthropogenic stress factors. In this PhD thesis, we were able to supply the characterization of the microbial community associated with the model anthozoan cnidaria Corynactis viridis throughout a seasonal gradient, to provide critical insights into microbiome-host interactions in a biomonitoring perspective. We also dissected in details the microbial-derived mitigation strategies implemented by the benthonic anthozoan Anemonia viridis and the gastropod Patella caerulea as models of adaptation to anthropogenic stressors, in the context of bioremediation of human-impacted habitats and for the monitoring and preservation of coastal marine ecosystems, respectively. Finally, we provided a functional model of adaptation to future ocean acidification conditions by characterizing the microbial community associated with the temperate coral Balanophyllia europaea naturally living at low pH conditions, to implement microbial based actions to mitigate climate change.

Unlocking ecological history using fish remains: Eco-evolutionary consequences of exploitation in the Atlantic bluefin tuna

During recent decades, the health of ocean ecosystems and fish populations has been threatened by overexploitation, pollution, and anthropogenic-driven climate change. Due to a lack of long-term data, we have a poor understanding of when intensive exploitation began and what impact anthropogenic activities have had on the ecology and evolution of fishes. Such information is crucial to recover degraded and depleted marine ecosystems and fish populations, maximise their productivity in-line with historical levels, and predict their future dynamics. In this thesis, I evaluate anthropogenic impacts on the iconic Atlantic bluefin tuna (Thunnus thynnus; BFT), one of the longest and recently most intensely exploited marine fishes, with a tremendous cultural and economic importance. Using a long-time series of archaeological and archived faunal remains (bones) dating back to approximately two millennia ago, I apply morphological, isotopic, and genomic techniques to perform the first studies on long-term BFT size and growth, diet and habitat use, and demography and adaptation, and produce the first genome-wide data on this species. My findings suggest that exploitation had impacted BFT foraging behaviour by the ~16th century when coastal ecosystem degradation induced a pelagic shift in diet and habitat use. I reveal that BFT biomass began to decline much earlier than hitherto documented, by the 19th century, consistent with intensive tuna trap catches during this period and catch-at-size increasing. I find that BFT juvenile growth had increased by the early 1900s (and more dramatically by the 21st century) which may reflect an evolutionary response to size selective harvest–which I find putative genomic signatures of. Further, I observed that BFT foraging behaviours have been modified following overexploitation during the 20th century, which previously included a isotopically distinct, Black Sea niche. Finally, I show that despite biomass declining from centuries ago, BFT has retained genomic diversity.

Towards a more sustainable aquaculture: diets effects and environmental impact of aquaculture from a microbiome perspective

There is a lot of interest to optimize aquaculture production due to its overexploitation of marine resources, ocean pollution and habitat destruction. Since feed production is one of the greatest issues in aquaculture, feeding strategy optimization is important. The study of several different feed additives or supplementation is important to secure optimal growth, gut health, and function in farmed fish. Feed additives are typically supplied to ensure good health and to help the animal ward off pathogens during both normal and challenging conditions, which could stress animals and promote insurgence of pathologies or pathogens invasions. In this context has an increasing interest the study of host associated microbiome to understand the influence of novel functional feed on the health and physiology of animals. To achieve a more sustainable aquaculture sector, show a great importance the understanding of the environmental impact of this human activity in terms of habitat destruction, ocean pollution and reduction marine environments biodiversity. Marine microbiomes, either free-living or associated with multicellular hosts, is acquiring an increasing interest because their role in supporting the functioning and biodiversity of marine ecosystems, providing essential ecological services. Becoming extremely important to understand how these activities can affect marine microbiomes by altering their function and diversity. In this thesis work, we were able to present a comprehensive evaluation of different functional feeds assessing their effects in terms of growth and gut health of three fish species, Rainbow Trout (Oncorhynchus mykiss), Gilthead seabream (Sparus aurata) and Zebrafish (Danio rerio). We also explored the impact of Aquaculture on the surrounding marine microbiomes, using Patella caerulea as a model holobionts. Finally, we provided a synoptical study on the microbiomes of the water column and surface sediments in North-Western Adriatic Sea (Italy), providing the finest-scale mapping of marine microbiomes in the Mediterranean Sea.

Analysis of the long-term subsidence in the urban area of Bologna

Land subsidence in urban areas represents a widespread geological hazard and a pressing challenge for modern society. This research focuses on the subsidence process affecting the city of Bologna (Italy). Since the 1960s, Bologna has experienced ground deformation due to aquifers overexploitation that peaked during the 1970s with rates of 10 cm/year. Despite a general reduction in these rates over the subsequent decades, thanks to groundwater regulations policies, recent data underscore a substantial subsidence resurgence. To reconstruct the subsurface stratigraphic architecture of Bologna’s urban area and generate a 3D geological model, a multidisciplinary approach centred on a stratigraphic analysis relying on the lithofacies criterion was adopted. The convergence of the analyses within this framework resulted in partitioning the study area into three geological domains exhibiting unique morphological features and depositional stacking patterns. Subsequently, since long-term data are crucial for a comprehensive understanding of ongoing subsidence, a methodology was developed to generate cumulative ground displacement time series and maps by integrating ground-based and remotely-sensed measurements. While the reconstructed long-term subsidence field consistently aligns with the primary geological variations summarised in the 3D model, the generated cumulative displacement curves systematically match pluriannual trends observed in groundwater level and pumping monitoring data. Lastly, to evaluate the expression of the observed relationships from a geotechnical perspective, a series of one-dimensional subsidence calculations were conducted considering the mechanical properties of the investigated deposits and piezometric data. These analyses provided valuable insight into the overall mechanical behaviour of the existing soils, as well as the post-pumping groundwater level and pore pressure distributions, consistent with field data. The methodological approach employed enables a comprehensive analysis of land subsidence in urban areas, allowing the exploration of individual factors governing the deformation process and their interactions, even within complex stratigraphic and hydrogeological environments such as Bologna’s urban area.