Estimation of secondary production of the Faro/Ancão artificial reefs

Um dos aspectos menos estudados sobre o funcionamento dos recifes artificiais prende-se com a sua produção secundária. Nesse sentido, ao longo dos primeiros 12 meses após a implantação do recife artificial de Faro/Ancão (Algarve, Portugal), desenvolveu-se um estudo com o objectivo de avaliar o efeito da orientação do substrato na produção secundária de epibentos, usando o método de Boysen-Jensen. Nos casos em que não foi possível aplicar este método, a produção secundária foi estimada a partir da taxa P/B. Os resultados mostraram que a produção epibêntica foi mais elevada na superfície horizontal. No entanto, no final do período de estudo, a produção média apresentou valores semelhantes. As superfícies de orientação horizontal tiveram uma produção média entre 128 e 103 g m-2yr-1, enquanto as superfícies verticais apresentaram uma produção média entre 103 e 98 g m-2 yr-1. A partir destes valores extrapolou-se a produção média anual para o complexo recifal da costa algarvia, tendo-se concluído que após um ano de implantação este complexo recifal gera cerca de 5 toneladas de fauna epibêntica.The secondary productivity of reef epifauna is one of the least investigated aspects in artificial reef research. During the first 12 months after the deployment of the Faro/Ancão (Algarve, Portugal) artificial reef, we assessed the effect of substratum orientation on the secondary production of epibenthos, using the Boysen-Jensen method. Whenever the method could not be applied, secondary production was estimated by the P/B ratio. The results showed that the epibenthic production was higher on the horizontal surface throughout the study. However, at the end of the study period, the mean production showed similar values. The horizontally oriented surfaces showed a mean production between 128 and 103 g m-2 yr-1, while at the vertical surfaces the mean production varied between 103 and 98 g m-2 yr-1. Furthermore, the mean annual production was extrapolated for all the Algarve artificial reef complex,and we concluded that after one year of deployment theses artificial reefs were able to generate around 5 MT of epibenthic fauna

Defining the importance of landscape metrics for large branchiopod biodiversity and conservation: the case of the Iberian Peninsula and Balearic Islands

The deficiency in the distributional data of invertebrate taxa is one of the major impediments acting on the bias towards the low awareness of its conservation status. The present study sets a basic framework to understand the large branchiopods distribution in the Iberian Peninsula and Balearic Islands. Since the extensive surveys performed in the late 1980s, no more studies existed updating the information for the whole studied area. The present study fills the gap, gathering together all available information on large branchiopods distribution since 1995, and analysing the effect of human population density and several landscape characteristics on their distribution, taking into consideration different spatial scales (100 m, 1 km and 10 km). In overall, 28 large branchiopod taxa (17 anostracans, 7 notostracans and 4 spinicaudatans) are known to occur in the area. Approximately 30% of the sites hosted multiple species, with a maximum of 6 species. Significant positive co-occurring species pairs were found clustered together, forming 4 different associations of large branchiopod species. In general, species clustered in the same group showed similar responses to analysed landscape characteristics, usually showing a better fit at higher spatial scales.Brazilian Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq [401045/2014-5]Spanish Ministry of Education, Culture and Sport [FPU014/06783]info:eu-repo/semantics/publishedVersio

Analysis of competitive interactions between the limpets Patella depressa Pennant and Patella vulgata L. on the northern coast of Portugal

Inter- and intraspecific competitive interactions among the species Patella depressa Pennant and P vulgata L. were analysed on the northern coast of Portugal, where both species co-occur in similar proportions. Increased (x 2, x 4), normal and decreased (x 1/2 intraspecific only) densities of limpets were used to test the effects of competition on the growth and mortality of the limpets, and competitive interactions between the different species. Fenced plots of 25 x 25 cm enclosing marked limpets at various densities were set up at a mid tidal level on the shore. Twelve treatments with three replicates of different combinations of densities and species were established. Mortality was recorded every 15 days and length was measured monthly during the 5 months of the experiment. At the end of the experiment, limpets were collected for biometry, sex determination and gonad staging. Both species of grazing molluscs showed increased mortality and reduced size and weight in increased density treatments. Limpets in decreased density treatments showed lower mortality and higher size. There were no significant differences between the effect of P. vulgata on R depressa and the effect of P. depressa on P. vulgata on mortality and length. There were, however, decreases in weight due to intraspecific effects for both species. For P. vulgata, interspecific effects were much less than intraspecific effects and for P. depressa, the interspecific effects depended on density. The analysis of the gonad stage at the end of the experiment showed that the lower stages of development were most prevalent at increased densities and the occurrence of neuter individuals only in increased densities single species plots corroborated the evidence of a stronger intraspecific interaction. The availability of food was indirectly assessed by determination of chlorophyll concentration with spectrophotometric analysis of rock chips. Microalgal food assessment in this experiment, however, did not show any clear trends. The results were compared with previous studies of competition in grazing molluscs and discussed in relation to the limits of distribution of P vulgata on the Portuguese coast

Intertidal Rocky Shore Communities of the Continental Portuguese Coast: Analysis of Distribution Patterns

A general description of rocky shore distribution patterns (“zonation”) along the whole Portuguese coast is given to provide the context for comparisons of distribution patterns of mid-shore organisms. In order to test if there was any variation in species distribution and abundance in the upper and lower mid-shore zone (eulittoral) along the entire intertidal Portuguese coast, three main regions were studied (north, centre and south) and nine shores were visited in each region. At each one of the 27 locations, the shore was levelled and a general qualitative description was made, which also aided stratification of subsequent quantitative sampling. An upper zone (littoral fringe) characterised by the presence of encrusting lichens, small littorinid gastropods and cyanobacteria was found on most of the shores along the Portuguese coast. The mid-shore zone (eulittoral) is essentially dominated by barnacles and sometimes mussels. The distribution patterns observed on the lower shore (sub-littoral fringe) showed a distinction between northern shores, where large brown algae are present, and shores located in the central and southern regions, essentially dominated by red algal turf species. Multidimensional analysis and the ANOSIM test have revealed clear differences in the structure of the upper and lower mid-shore zone. Within each level, the northern region was considerably different from the south and central regions. SIMPER analysis revealed the species which contributed to the separation between shore levels and regions. It has also given important information on the geographical decline in abundance of species

Las características del mercado de poliquetos no autóctonos en Portugal y sus implicaciones ecológicas

Sci. Mar. 70, Suppl. 3 (2006) bears the title: Scientific Advances in Polychaete Research / R. Sardá, G. San Martín, E. López, D. Martin and D. George (eds.)The importance of the market for polychaetes dramatically increased after the discovery of their potential as food in aquaculture. In Portugal, the gathering of polychaetes solely from natural populations is not sufficient to meet market demand, both as bait for sea anglers and as a food item in aquaculture. The requests for worms to polychaete dealers by Portuguese and Spanish seafarms have increased during recent years. Due to the lack of intensive culture of these worms in Portugal and the proximity of southern Spanish farms, a large component of imported polychaetes that arrive in Portugal at Lisbon Airport go directly to Spain by road. In 2002 and 2003 a total of 12,728,379 and 16,866,839 polychaetes respectively were imported to Europe via Lisbon Airport from China and the USA. In 2003 the imports from China and the USA realised 716,180 and 291,845 US dollars respectively. Two species were reported to have been imported in these years, namely the Korean blue ragworm Perinereis aibuhitensis and the American bloodworm Glycera dibranchiata. Imports of non-indigenous species, which are traded and sold alive, may increase the risk of accidental introduction into the wild. This is of special concern as Perinereis aibuhitensis has been successfully reared in captivity within the range of environmental conditions existing in the Ria Formosa coastal lagoon. Other risks associated with introduced species are the transport of foreign pathogens and other associated non-native organisms, which may act as carriers of disease.La importancia de la comercialización de los poliquetos aumentó de forma notable con el descubrimiento de su potencial como alimento en la acuicultura. En Portugal, la recogida de poliquetos únicamente de las poblaciones naturales no es suficiente para cubrir la demanda del mercado, que se centra tanto en cebo para la pesca con caña como en alimento para la acuicultura. En los últimos años, los pedidos de gusanos a los proveedores de poliquetos por parte de las piscifactorías portuguesas y españolas han aumentado. Debido a la ausencia de cultivos intensivos de estos gusanos en Portugal y a la proximidad de las piscifactorías del sur de España, una gran parte de los poliquetos importados que llegan a Portugal a través del Aeropuerto de Lisboa van directamente a España por carretera. En los años 2002 y 2003, un total de 12,728,379 y 16,866,839 poliquetos de China y EE.UU., respectivamente, fueron exportados a Europa vía el Aeropuerto de Lisboa. En el año 2003 estos dos orígenes representaron por este mismo orden, 716.180 y 291.845 dólares americanos. Las dos especies importadas durantes estos años fueron el gusano coreano Perinereis aibuhitensis y el americano Glycera dibranchiata. La importación de especies no autóctonas, que son comercializadas y vendidas vivas, puede incrementar el riesgo de ser introducidas accidentalmente en el ambiente. Esto es especialmente preocupante ya que la especie Perinereis aibuhitensis ha sido criada con éxito en cautividad en condiciones ambientales próximas a las encontradas en la laguna costera de Ria Formosa. Otros riesgos asociados con las especies introducidas son el transporte de patógenos extraños y otros organismos asociados no nativos, que pueden actuar como portadores de enfermedades.Peer reviewe

First record of the tadpole shrimp Triops cancriformis (Lamarck,1801) (Crustacea: Branchiopoda: Notostraca) in Portugal

Notostracan crustaceans identified as Triops cancriformis according to the presently accepted morphological criteria were recorded for the first time in Portugal in 2007. All previous records of Triops in Portugal belong to mauritanicus lineage species i.e. T vicentinus or T baeticus. A specimen purportedly belonging to T cancriformis (Carvalho, 1944) has been re-identified by Machado in 2014 as T. baeticus after morphological examination. During 2007, hundreds of individuals of T. cancriformis were observed throughout the rice paddies on the northern margin of Sorraia River (Vale do Sorraia, Coruche). In the last 9 years, monthly checks during the rainy season have failed to record high population abundances and only a few specimens have been observed in the flooded tracks left by trucks and other heavy machinery on the elevated margins of the paddies. The low number of individuals observed in the latter years possibly results from changes of ecological conditions. Thus far, males of T cancriformis have not been recorded, which may indicate that the observed population is either androdioecious or made of hermaphrodite or parthenogenetic populations. This situation contrasts with the other confirmed populations of this species in the Iberian Peninsula that are gonochoric. Parthenogenetic/hermaphrodite/androdioecious lineages, present in Northern and Central Europe, are considered to have derived from gonochoric Iberian populations in the Pleistocene which makes this finding all the more interesting in evolutionary terms. Has this population resulted from a recent recolonization from non-Iberian populations? Or has it derived directly from the assumed Iberian Pleistocene refuge? The potentially high dispersal abilities of Triops diapausing cysts and the possibility of hermaphrodite/parthenogenetic reproduction favour the 1st hypothesis of recolonization. Possible sources of individuals are (i) cysts attached to migratory birds arriving possibly from Southern France or Northern Italy and that are regularly seen feeding at these rice fields or ii) cysts unwittingly transported with the rice seeds used in the Vale do Sorraia. Both are in accordance with the assumption that nongonochoric reproductive mode confers a colonization advantage over gonochoric populations, which lack evidence of fast long distance dispersal ability. Future multilocus phylogenetic analysis is expected to clarify the origin of T. cancriformis found in the Sorraia's rice fields.info:eu-repo/semantics/publishedVersio

Contra a maré cremos,crianças, que basta edificar mais cubos e muralhas de areia: reflexões interdisciplinares sobre a gestão costeira

Este trabalho – que não é um artigo científico e por isso não segue a sua estrutura – reúne um conjunto de opiniões de vários investigadores que se dedicam ao estudo das zonas costeiras. A todos se pediu que reflectissem – com base na sua experiência pessoal e profissional – sobre a gestão actual deste espaço, partindo da frase do artista plástico Carlos Augusto Ribeiro, que serve de título a este texto. Aqui se discute sobre populações e saberes tradicionais, obras de engenharia costeira, gestão de conflitos, destruição de ecossistemas e insustentabilidade, necessidade de cooperação e conhecimento multidisciplinar, novos modelos de gestão do litoral e de cidadania.This work is not a scientific paper and therefore does not follow the typical structure. This text is a collection of the opinions of several researchers that share a common interest in coastal areas. They were asked to reflect – based on their personal and professional experience – about present coastal management, using as a start the phrase of the plastic artist Carlos Augusto Ribeiro – Like children we believe that stopping the tide is only a matter of building more sand walls. Several themes are addressed: traditional populations and knowledge, maritime engineering works, conflict management, ecosystems destruction and unsustainability, new models for coastal management and participative citizenship.info:eu-repo/semantics/publishedVersio

The effects of grazing on the distribution and composition of low-shore algal communities on the central coast of Portugal and on the southern coast of Britain

A red algal turf is often found just below the barnacle/limpet zone of many European shores, especially on steep shores of moderate exposure. The hypothesis that grazing by limpets determines the upper limit of distribution of this red algal turf was tested on moderately exposed shores in Portugal and Britain. We also aimed to assess whether the grazing effect is modified at various spatial scales. Grazers were excluded by fences, with half-fenced and unfenced controls. Exclusion plots were rapidly colonised by green ephemeral algae in the months immediately after the beginning of the experiment (summer); these algae were later replaced by perennial algae. The percentage cover of turf-forming macroalgae showed a significant increase at both locations. The upper limit of distribution extended more than 50 cm on most of the shores studied. In contrast, control and half-fenced plots remained devoid of algae. After 2 years, ungrazed plots were mainly colonised by a red algal turf (e.g. Caulacanthus ustulatus, Gelidium spp., Laurencia pinnatifida) in Portugal, while canopy cover (Fucus serratus and Himanthalia elongata) dominated in Britain in marked contrast to the grazed plots. Physical factors acting at both local and geographical scales may explain these differences. However, although physical factors probably have an important influence on the identity, size and abundance of sublittoral fringe macroalgae, grazers play a major role in directly setting their upper limits. The effect of grazing by limpets was not consistent for all of the morphological algal groups and spatial scales considered in the present study. The effect of grazing on the cover of turf algae varied between Portugal and Britain (location scale), while effects on ephemeral and canopy algal cover varied at the shore scale within location

Size matters: competition within populations of the limpet Patella depressa

Competitive interactions within and between size-classes of the limpet Patella depressa Pennant were investigated in central Portugal. Experimental enclosures of 25 x 25 cm containing marked limpets were set up at mid-tidal level on the shore. Twelve treatments with different combination of densities and size-classes were assigned to the plots, with three replicates of each. Mortality was recorded every 15 days and length was measured monthly during the approximately 6 months of the experiment. 2. At the end of the experiment limpets were collected for determination of length, height, dry weight, sex and gonad development. The availability of food was assessed indirectly by determination of chlorophyll concentration with spectrophotometric analysis of rock chips. Reduced density treatments showed very low mortality and substantially increased growth. Both size-classes of limpets showed increased mortality and reduced growth in increased density treatments. This effect was, however, more marked for large than small limpets when caged separately.3. Although both size-classes could negatively affect each other, the effect of large limpets on small was greater than the reverse. Large limpets are superior competitors that may modulate the abundance of small limpets on the shore. It is unlikely, however, that they will totally exclude small limpets due to intensity of competition within the large size-class. Niche differentiation and high recruitment at low shore levels are other possible factors that can contribute to reduce competition between the size-classes.<br/