Efeitos da urbanização nos ecossistemas costeiros

A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Com o objetivo de analisar as implicações ecológicas resultantes da urbanização costeira e sugerir alternativas para minimizar alguns dos seus impactos, o grupo de Investigação Aquática Macaronésia (integrado no CIIMAR e composto por elementos do Departamento de Biologia da Universidade dos Açores) está a coordenar o projeto Estruturas urbanas: um fator de mudança na biodiversidade dos ecossistemas costeiros (http://www.bus-project.info/), financiado pela FCT e contando com a colaboração da Faculty of Science and Environment da Universidade de Plymouth. Este projeto, que teve inicio em Maio de 2013, está focado nos processos que influenciam as relações entre as espécies marinhas e o seu habitat. […].info:eu-repo/semantics/publishedVersio

A urbanização nos ecossistemas costeiros : implicações para a biodiversidade

A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. A urbanização dos habitats costeiros, incluindo a construção de estruturas de defesa costeiras, como paredões, quebra-mares ou espigões, tem vindo a aumentar como resposta às previsões para o aumento do nível do mar, maior ocorrência de tempestades e aumento do transporte marítimo. O efeito destes habitats artificiais numa variedade de organismos marinhos tem recebido pouca atenção, apesar de ser fundamental para estabelecer diretrizes para a correta gestão das áreas costeiras urbanizadas. Existe, por tanto, um claro interesse em compreender as consequências ambientais da urbanização, razão que esteve na base do desenvolvimento dum projeto de investigação levado a cabo pelo grupo de Investigação Aquática Macaronésia (IAM) entre os anos 2013 e 2015. O IAM, integrado no CIIMAR é composto por elementos do Departamento de Biologia da Universidade dos Açores, coordenou o projeto “Estruturas urbanas: um fator de mudança na biodiversidade dos ecossistemas costeiros”. O projeto foi financiado pela Fundação para a Ciência e a Tecnologia e contou com a Prof. Ana I. Neto como investigadora responsável e com a Faculty of Science and Environment da Universidade de Plymouth como entidade colaboradora externa. […].info:eu-repo/semantics/publishedVersio

Ecological features of Terebellida fauna (Annelida, Polychaeta) from Ensenada de San Simón (NW Spain)

Ecological features of Terebellida (Annelida, Polychaeta) inhabiting the intertidal and subtidal soft-bottoms of Ensenada de San Simon (NW Spain) were analysed by means of quantitative sampling. A total of 4,814 specimens belonging to five families (Ampharetidae, Pectinariidae, Terebellidae, Trichobranchidae and Sabellariidae) and ten species were collected in a variety of substrata and depths. Ampharetidae was the numerically dominant family mostly due to the abundance of Ampharete finmarchica and Melinna palmata; these species accounted for up to 94% of the total Terebellida abundance. Intertidal areas colonised by the seagrasses Zostera marina L. and Z. noltii Hornern. One thousand eight hundred and thirty-two harboured low densities of Terebellida, whereas the deeper subtidal muddy bottoms showed high abundances of ampharetids. Multivariate analyses suggested that Terebellida assemblages are highly correlated with sediment compositio

Impacte para o ecossistema e benefícios socioeconómicos da alga exótica Asparagopsis armata nos Açores

A secção UAciência é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Desde novembro de 2016, o Subgrupo de Investigação em Ecologia Aquática Insular do Grupo de Biodiversidade dos Açores - Centro de Ecologia, Evolução e Alterações Ambientais (GBA/cE3c), com base na Universidade dos Açores, esta a desenvolver o projeto intitulado “Impacte ecossistemático e benefícios socioeconómicos de Asparagopsis armata nos Açores” (ASPAZOR, AÇORES-01-0145-FEDER-00060), financiado em 85% pelo FEDER e 15% pela ORAA, e aprovado pela Autoridade de Gestão do Programa Operacional AZORES 2020. A alga exótica A. armata e considerada como uma das espécies com maior potencial invasor nas aguas europeias, onde foi observada pela primeira vez em 1925, encontrando-se agora bem estabelecida na RAA. Aqui proliferam as duas fases do seu ciclo de vida, a fase produtora de gametas conhecida por A. armata e a fase produtora de esporos, anteriormente considerada como uma espécie distinta, Falkenbergia rufolanosa. Uma particularidade importante dos espécimes do género Asparagopsis e a produção de uma variedade de metabolitos com reconhecidas atividades antibacteriana, antimicrobiana, citotóxica e antioxidante, com aplicação em piscicultura, cosmética, e mesmo em medicina como alternativa a antibióticos convencionais. […].info:eu-repo/semantics/publishedVersio

Distribución de los poliquetos de fondos blandos en una ría gallega (NO España)

Macrobenthic polychaete distributions were studied along the soft-bottoms of the Ensenada de San Simón (Galicia, NW Spain). Results suggest that the distribution and abundance of polychaetes in the inlet were highly dependent on depth, sediment characteristics (grain size, organic matter and calcium carbonate content) and bottom water temperature. In the inner area of the inlet, intertidal bottoms colonised by the seagrasses Zostera marina and Z. noltii were dominated by spionids and capitellids, and showed low species number and diversity. Shallow muddy bottoms of central areas were mostly dominated by ampharetids, terebellids and cirratullids. These families along with paraonids, maldanids and syllids were the most abundant families in the deeper subtidal muddy bottoms at the mouth of the inlet. These sediments also showed the highest number of species, diversity and density of individuals.La distribución de los poliquetos macrobentónicos ha sido estudiada en los fondos blandos de la Ensenada de San Simón (Galicia, NO España). La profundidad, las características del sedimento (granulometría, contenido en materia orgánica y carbonatos) y la temperatura del agua del fondo fueron los principales factores que determinaron la distribución y abundancia de los poliquetos en la ensenada. En la zona más interna, los fondos intermareales colonizados por las fanerógamas Zostera marina y Z. noltii estuvieron dominados numéricamente por espiónidos y capitélidos, y mostraron bajos valores de diversidad y número de especies. Los fondos fangosos someros del área central presentaron una fauna de poliquetos dominada principalmente por anfarétidos, terebélidos y cirratúlidos. Asimismo, estas familias estuvieron presentes en los fondos más profundos de la boca de la ensenada, donde paraónidos, maldánidos y sílidos mostraron una dominancia numérica importante. Los máximos valores de diversidad, número de especies y densidad de individuos se registraron en estos fondos submareales fangosos

Composición y distribución de las asociaciones de crustáceos submareales e intermareales en fondos blandos de la Ría de Vigo (NO España)

The intertidal and subtidal soft-bottoms of the inner area of the Ria de Vigo (NW Spain) were sampled in November and December 1999, and spatial distribution of crustacean species was examined. Environmental variables from water and sediment were measured at each sampling site. Amphipods and myocopids were the numerically dominant orders (49.9 and 26.9% dominance), amphipods accounting for more than 54% of identified taxa. The highest crustacean densities occurred with 55-41 species and 5953.6-4346.4 ind. m–2 in external areas, where the diversity index reached the maximum values. Multivariate techniques revealed that distribution of crustaceans in the inlet was highly dependent on depth. Ordination analysis determined three major assemblages: Intertidal bottoms colonized by seagrasses and subjected to strong variations of salinity were dominated by the amphipod Melita palmata, harpacticoids and the isopod Idotea baltica (Group A). The amphipod Corophium cf. runcicorne and the cumacean Iphinoe tenella predominated in the muddy bottoms of central areas (Group B). These species were also present in the deep muddy bottoms of the mouth of the inlet, with high carbonate and gravel contents, and with the myocopids and the amphipod Microdeutopus cf. armatus displaying maximum dominances (Group C).Los fondos blandos intermareales y submareales de la parte interna de la Ría de Vigo (NO España) fueron estudiados en relación a la distribución de los crustáceos y a las variables ambientales asociadas a sus aguas y sedimentos. Los anfípodos y miocópidos fueron los órdenes más abundantes (49.9 y 26.9%), presentando los anfípodos más del 54% de los taxa identificados. Las mayores densidades de crustáceos aparecieron en las áreas externas, con 55-41 especies y 5953.6-4346.4 individuos por m2, alcanzándose aquí los máximos valores de diversidad. Se emplearon técnicas multivariantes para analizar los datos, demostrando que la distribución de los crustáceos en la ensenada dependía principalmente de la profundidad. Se observaron tres principales asociaciones de crustáceos: Los fondos intermareales, colonizados por las fanerógamas marinas Zostera marina y Z. noltii y sometidos a drásticos cambios de salinidad, estuvieron dominados por el anfípodo Melita palmata, los harpacticoideos y el isópodo Idotea baltica (Grupo A). El anfípodo Corophium cf. runcicorne y el cumáceo Iphinoe tenella predominaron en los fondos fangosos de la zona central (Grupo B). Estas especies también estuvieron presentes en los fondos profundos de la boca de la ensenada, donde los miocópidos y el anfípodo Microdeutopus cf. armatus presentaron sus máximas dominancias (Grupo C)

The Role of Sea-Urchins in Marine Forests from Azores, Webbnesia and Cabo Verde: human pressures, climate-change effects and restoration opportunities

Marine forests ecosystems are typical of temperate rocky benthic areas. These systems are formed by canopy-forming macroalgae (Laminariales, Tilopteridales, and Fucales) of high ecological value that provide numerous ecosystem services. These key species are also indicators of good environmental status. In recent decades, marine forests have been threatened by different impacts of local and global origin, putting their stability and survival in question. On a global scale, in many temperate areas of the planet, marine forests have been replaced by “sea-urchins barrens.” We present a general overview of sea-urchins’ population status in the archipelagos of Azores, Webbnesia (Madeira, Selvagens, and Canary Islands) and Cabo Verde, focusing on their role in the maintenance of the so-called “alternate stable state.” After an in-depth evaluation of the different anthropogenic and environmental pressures, we conclude that sea-urchins population explosion has been facilitated in the benthic habitats of Madeira and Canary Islands, preventing the recovery of canopy-forming macroalgae assemblages and being one of the main drivers in maintaining a stable barren state. Diadema africanum is the main barrens-forming species in Webbnesia, where it reaches high densities and strongly impacts macroalgal assemblages. On the other hand, in the most pristine areas, such as the Selvagens Islands and other Marine Protected Areas from the Canary Islands, the density of D. africanum is up to 65% lower than in the nearby Madeira Island, and macroalgal communities are preserved in good status. This information is critical for marine environmental management, highlighting the urgent need for implementation of appropriate control mechanisms and restoration actions headed to the conservation of marine forests in Macaronesian archipelagos

Assessing climatic conditions and biotic interactions shaping the success of Cystoseira foeniculacea early-life stages

Early-life stages of canopy-forming macroalgae are critical for the maintenance of natural populations and the success of restoration actions. Unfortunately, the abiotic conditions and biotic interactions shaping the success of these stages have received less attention than the interactions shaping the success of adults. Here, we combined field and mesocosm experiments to explore the effects of temperature, herbivory, and canopy presence on the development of early-life stages of the brown seaweed Cystoseira foeniculacea. We assessed these effects by examining changes in recruit density and size. After recruiting zygotes under laboratory conditions, we conducted one laboratory and three field experiments. In the first field experiment, the density of recruits decreased over time in all rockpools and was negatively affected by rising temperatures and turf cover. Additionally, a marine heatwave (MHW; 11 days >25°C) was recorded in the donor pools, producing strong decay in the density of transplanted recruits and a significant reduction of the mature canopy. The second field experiment tested the survival of recruits based on their positioning within the canopy. We observed a higher density of recruits when placed at the edge or outside the canopy compared to recruits placed under the canopy. In the third field experiment, an herbivory-exclusion experiment, we show how density of recruits decreased in less than 48 h in noncaged treatments. In the laboratory, we conducted a thermotolerance experiment under controlled conditions, exposing the recruits to 19, 22, 25, 28, and 31°C for 7 weeks to assess thermal impacts on their survival and growth. Temperatures above the 25°C threshold reduced the density and size of the recruits. This study sheds light on the performance of the early-life stages of a Cystoseira spp. in Macaronesia, showing a low survival ratio against the current pressures even in the context of the potential refuge provided by the intertidal rockpools

Marine fouling communities from artificial and natural habitats: comparison of resistance to chemical and physical disturbances

Assessing the resistance of fouling communities to anthropogenic disturbances is an important goal for the development of effective management and control strategies. In this context, we conducted a manipulative experiment on natural and artificial habitats to examine fouling communities that developed outside and inside a marina on Madeira Island (NE Atlantic Ocean) following the application of two types of stressors frequently observed in coastal habitats, namely chemical and physical disturbances. The tested fouling communities, dominated by native and non- indigenous species respectively, were in general strongly affected by the chemical but not by the physical disturbance applied, and a higher resistance to disturbance was observed in the communities outside the marina. This suggests higher capacities for communities richer in native species to tolerate anthropogenic disturbances, while non-indigenous species did not play a key role. Further research can assess the resilience of natural and artificial fouling communities when exposed to disturbances

The collapse of marine forests: drastic reduction in populations of the family Sargassaceae in Madeira Island (NE Atlantic)

Species of the genera Cystoseira, Ericaria, Gongolaria, and Sargassum (family Sargassaceae) are key components of the Mediterranean-Atlantic marine forests, essential for biodiversity and ecosystem functioning. Populations of these foundational species are particularly vulnerable to anthropogenic impacts, likely to be intensified under future scenarios of climate change. The decline and even disappearance of these species have been reported in different areas of the world. At Madeira Island (NE Atlantic), populations of Gongolaria abies-marina, Ericaria selaginoides, Sargassum vulgare, and Sargassum filipendula, the most ecologically relevant species in Macaronesian marine forests, have been suffering a drastic decline during the last decades, especially on the southern coast of the island, where anthropogenic pressure is higher than on the north coast. The lack of sufficient temporal coverage on qualitative and quantitative studies of Sargassaceae communities in Madeira poses a challenge to establish a specific period for this decline. Consulting qualitative studies and historical records, we have set for the first time a timeline that shows an evident decrease in Sargassaceae populations in the last 20 years on Madeira Island. Following this timeline, we pinpoint the start of this decline in the first decade of the 2000s. This can be particularly confirmed for places like Funchal and Reis Magos, with significantly higher historical records. Currently, most benthic communities on shallow subtidal rocky reefs along the south coast are dominated by sea urchins and crustose coralline algae, the so-called sea urchin barrens. However, in some cases, they are entirely covered by a layer of sediment. We discuss the possible factors contributing to these drastic changes, bringing Madeira’s marine forests to a dramatic decline. As many animal species rely on marine forests, the decline of Sargassaceae populations represents an invaluable ecological loss for the coastal ecosystem of the island.M1420-09-5369-FSE-000002, CEECINST/00098/2018, MAC2/1.1a/347, MAC2/4.6d/249, UIDB/04292/2020info:eu-repo/semantics/publishedVersio