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Este artículo contiene 14 páginas, 6 figuras, 3 tablas., Herbivory is a widespread biotic interaction with important ecological and evolutionary implications. Benthic marine systems show greater producer consumption than any other aquatic or terrestrial environment. Marine algae and plants have a variety of defensive mechanisms such as structural, chemical, and nutritional traits with the capacity to reduce herbivore consumption. These mechanisms can function simultaneously. Here, we quantified consumption by juvenile Diadema africanum and Paracentrotus lividus on 15 algal species (1) to investigate the relative contribution of algal nutritional, chemical, and structural traits to the patterns of consumption and (2) to assess whether this relative contribution varies as a function of herbivore species. Differences in consumption were found between sea urchins; however, changes differed across algal and herbivore species.There was no clear relationship between the nutritional contents and consumption rates on the studied species of algae. The structure and chemical defenses of algae species played an important role in the feeding behavior of the studied herbivores. Our results suggest that multiple defensive traits may be necessary to deter herbivores in the field., This study was funded by the ‘Fundación Caja Canarias’ under postgraduate fellowship (awarded to Adriana Rodríguez). This research is a contribution of the Consolidated Research Group "Grupo de Ecología Bentónica" (SGR2009-655) of the Catalan Government.

Purpose: The aim of this paper is to examine the state of knowledge management research in supply chain management from three standpoints, methodological approach, supply chain management area, and knowledge management processes. Design/methodology/approach: To achieve this, a systematic review is conducted over the period 2000-2014 on the basis of a qualitative content analysis. Findings: Major results showed that knowledge management can be viewed as a leverage mechanism for: (i) supply chain integration; (ii) the enhancement of intra and inter-relations across the supply chain; (iii) supply chain strategy alignment; and (iv) the reinforcement of knowledge transfer in product development. Some supply chain management areas such as reverse logistics, inventory management, forecasting/demand planning, outsourcing, and risk management have been explored only to some extent. Furthermore, knowledge transfer is being studied in the majority of the articles, mainly by both case study and survey approach; mathematical models and simulation techniques are used in very limited articles. Findings concerning theoretical perspectives and managerial issues are also described. Research limitations/implications: The limitation of our study encompasses the aspects of search period (2000-2014), selection of search databases (Web of Science and SCOPUS and language selection (English). Practical implications: The exhibition of the KM processes within the SC context may help practitioners and managers interested in implementing KM initiatives to replicate the methodologies in order to increase the possibilities of a successful KM adoption. Originality/value: The systematic review will contribute to the understanding of the present state of research in the knowledge management theory, with focus on the supply chain, as there are no state-of-knowledge studies that report a systematic literature review approach.

Arbaciella elegans (Mortensen, 1910) es un equinoideo de pequeño tamaño cuyo estatus taxonómico ha sido muy discutido desde su descripción como especie. A pesar de sus diferencias a nivel morfológico, diversos autores sugieren que en realidad se trata del juvenil de Arbacia lixula (Linnaeus, 1758), una especie conspicua cuya distribución se solapa con la de A. elegans. Análisis genéticos actuales realizados en Azores han demostradoque A.elegans no está presente en las Islas, tratándose en realidad de los juveniles de A. lixula. Sin embargo, la descripción morfológica de estos individuos no coincide con la del material original descrito por Mortensen, por lo que no podemos afirmar que Arbacia lixula y Arbaciella elegans son la misma especie. En este estudio corroboramos mediante el análisis de un fragmento del gen mitocondrial citocromo c oxidasa I (COI), que A. elegans tampoco está presente en las islas Canarias y proponemos una revisión de esta especie en el Catálogo de Invertebrados de Canarias.

Natural CO2 vents are considered the gold standard of ocean acidification (OA) studies. In coastal areas these rare vents have only been investigated at the Mediterranean temperate rocky reefs and at Indo-Pacific coral reefs, although there should be more at other volcanic shores around the world. Substantial scientific efforts on investigating OA effects have been mostly performed by laboratory experiments. However, there is a debate on how acute this kind of approach truly represents the responses to OA scenarios, since it generally involves short-term, rapid perturbation and single variable and species experiments. Due to these limitations, world areas with natural CO2 vents are essential to understand long-term marine ecosystem responses to rising human derived atmospheric CO2 concentrations. Here, we presented a new vent found in the subtropical North East Atlantic reefs (28°N, La Palma Island) that shows moderate CO2 emission (900ppm), reducing pH values to an annual average of 7.86±0.16.

We evaluated the effects of potential predators from intertidal habitats on Strongylocentrotus purpuratus survival using laboratory experiments and assessed abundances of main predatory species along the Pacific coast of North America. The interactive effects of urchins’ and predators’ sizes in mediating predation were quantified. Habitat complexity (substrate pits, adult spine canopy) was manipulated to examine its effects on predation of most susceptible individuals (

Intraspecific life history attributes of growth, survival, and reproduction can vary in response to changes in the physical environment. These changes can induce a cascading effect across trophic levels. In marine systems, shifts in ocean conditions such as warm and cold phases of ENSO can change primary production in benthic algae, which in turn modify resources avail- able to benthic omnivores. Monthly gonad samples of the purple sea urchin Strongylocentrotus purpuratus were taken from 2007 to mid-2009 at sites from Vancouver Island, Canada, to Punta Baja, Mexico. Although mean sea surface temperature (SST) changed by ~8°C from north to south, latitudinal patterns of size-specific gonad weight were not detected, although differences existed across sites. At individual sites, mean SST changed by

Rapid declines in the sea urchin Diadema aff. antillarum densities and shifts in community states of sublittoral rocky reefs have been observed over a short period (between 2004 and 2008) for the first time in an area with fishing restrictions (the MPA of La Palma, Canary Islands, eastern Atlantic Ocean). Changes were spatially variable according to the MPA's use area considered. During this period there was a sea urchin density reduction (in some cases from 3.34 to 0.45 indv·m −2 ), and an increase of erect seaweed (up to 30% of cover) in the sites of the no-take area. In the partially restricted fishing area, the effect was less clear and only some sites, near to the no-take area, showed the sea urchin reduction and seaweed growth, in contrast to the increase of sea urchin densities outside the MPA. In addition to increased coverage, there was also a replacement of the ephemeral species by the perennial seaweed Lobophora variegata . These changes were related to increases in the abundance of fish predators of the sea urchins. In the no-take area, where there is total fishing restriction, predators were so abundant to induce shifts in the benthic community, while in the partially protected area such as outside the MPA, fishing prevented the top-down process and the changes in the communities.

This study aimed to evaluate the effects of protection from extractive activities on the population structure of two limpets of commercial interest, Patella ulyssiponensis and Patella candei crenata. We evaluated the status of these populations in La Palma Marine Protected Area (MPA), Canary Islands, and in comparable unprotected areas in the lower intertidal zone of the same island. We showed that the density of P. ulyssiponensis depended greatly on the level of protection, whereas the effects of protection on the density of P. candei crenata were less clear and only differences between sites were found. These results are probably linked to the different habitat affinities of the two species studied and demonstrate the need to tailor conservation strategies in MPAs to individual species for appropriate management of local shellfish resources. Este estudio tiene por objetivo evaluar el efecto de la protección frente a actividades extractivas sobre la estructura poblacional de las especies de lapas de interés marisquero, Patella ulyssiponensis y Patella candei crenata. Para ello, se evaluó el estado de sus poblaciones en el intermareal inferior de localidades situadas tanto dentro de la Reserva Marina de La Palma (islas Canarias) como en zonas no protegidas de características similares. Se observó que la densidad de P. ulyssiponensis depende en gran medida del nivel de protección, mientras que en el caso de P. candei crenata el efecto de la protección sobre la densidad no fue tan claro, observándose diferencias sólo entre localidades. Estos resultados probablemente se relacionan con las distintas afinidades de hábitat entre las especies estudiadas, lo que indica la necesidad de proteger áreas más heterogéneas que incluyan una variedad de hábitat adecuada para la diversidad de especies de una región, asegurando una correcta regulación y conservación de los recursos marisqueros.

An outbreak of bald sea urchin disease was detected affecting intertidal popula- tions of the edible temperate species Paracentrotus lividus at its southernmost geographical limit. The mortality event was detected in three sites (Gu¨imar, Palmar and Alcala´) off Tenerife, Canary Islands (Northeastern Atlantic), in October 2003, coinciding with the highest sea surface temperatures (SST) and the lowest wave heights of the year. The prevalence of infection reached 100% but did not affect equally all studied sites or the different size classes. The dis- ease was more prevalent in large sea urchins (>40 mm). The prevalence appeared to be positively correlated with the environmental variable SST and negatively correlated with wave height. In October 2004, only two infected urchins were found (prevalence 1%) at one of the studied sites. However, dur- ing 2004 no such extreme values of temperature and wave height were observed. We conclude that high SSTs and low wave heights such as those observed during 2003 are conditions that may trigger outbreaks of urchin disease.

We studied the effects of marine protected areas (MPAs) on predatory interactions at a regional scale of 3 different islands across the geographical gradient of the Canary Islands. Protection measures positively affected predatory fish assemblages, enhancing the intensity of predatory inter- actions in comparison to equivalent unprotected areas (UAs), and causing indirect effects on popula- tions of the key herbivorous sea urchin Diadema aff. antillarum. Results of tethering experiments and the strong negative correlation found between predation rate and prey density strongly suggest that predation controls sea urchin populations. Overall urchin density was lower in MPAs than in UAs; however, species composition of predatory fish assemblages and the size of sea urchin effectively preyed upon differed significantly between studied islands, as did urchin size-frequency distribu- tions. Only in locations where key predatory species (balistids, diodontids and large labrid species) were present was there the potential to promote top-down control on sea urchins. The present study shows the importance of both protection measures and environmental context to enhance the strength of predatory fish activity. Protection under different contexts can produce different conse- quences of predation interactions, even over relatively small spatial scales. Therefore, regional and local-scale environmental gradients should not be overlooked as a factor affecting the occurrence and magnitude of predatory interactions in benthic marine communities, especially in systems that are markedly variable at small scales.

Reproduction of Diadema aff. antillarum was examined between 2002 and 2005 at subtidal rocky bot- toms around the Canary Islands. Two contrasting habitats (urchin barrens and grazing fronts) characterized by dif- ferent levels of food availability were chosen, and factors thought to influence reproductive periodicity were moni- tored, including temperature, photoperiod, phytoplankton abundance and benthic food availability. Histological analyses showed that D. aff. antillarum had an annual reproductive cycle that was relatively synchronous across the studied sites and habitats. Photoperiod was the most significant factor that correlated with gonad periodicity; benthic food availability of 2 month lag was also corre- lated. However, some differences were detected between males and females in the timing of the onset of gameto- genesis. Spawning was synchronized between both sexes from June to August. Results suggest that the optimum time of year to harvest urchin gonads would be between May and June when gonads were maximal in size but not full of gametes. This species may not provide optimal conditions for an industrial scale fishery, as sea urchins occurring in high density had small gonads and those producing larger volume or more marketable gonad tissue occurred in low densities where harvesting costs would exceed profit.

The occurrence of a hydrocoral of the genus Millepora has been recorded for the first time in the eastern subtropical Atlantic (Tenerife, Canary Islands), at a latitude of 11o N of its previously known northernmost limit of distribution in the Cape Verde Islands. The moderate development of the colonies, their fast growth rate and very restricted location indicate a recent colonization process, possibly related to an extreme climatic event that took place in the summer of 2004, adding to the rising seawater temperatures in the region during recent years.

The gonad index, GI, is widely used as a measure of changes in reproductive state. There are, however, problems with its use because it is based on the implicit assumption of an isometric relationship between gonad size and some measure of total size. If, for example, gonad weight and total weight are used, the exponent for an allometric relationship usually is ignored and hence assumed to be 1.0. It is further assumed that this exponent is fixed for all states of the reproductive cycle and that gonads begin to develop at size = 0. Data for the purple sea urchin Strongylocentrotus purpuratus at Gregory Point, Oregon, USA, gathered over a period of 31 months showed that these assumptions cannot be supported. The relation- ship is better modeled with a function that (1) takes into account size of initial gonad production and (2) allows allometric exponents that vary with site or season. Thus, a better approach is to use a wide range of sizes to estimate size when gonads begin to develop and then, with this correction, ANCOVA to test for differences of gonad size among samples. Gonad changes at Gregory Point were estimated using fixed sizes of 5 cm diameter and 60 g total weight. Publishing means for X and Y, the standard error of the estimate, R 2 , and slope for each regression are shown to

Large populations of the sea urchin Diadema aff. antillarum occur in the east Atlantic archipelagos. The origin and stability of these large herbivorous populations are not well known. Variability in settlement, recruitment and adult urchin density were quantified and compared over a 7 yr period (2002 to 2008) within the Canary Islands. Variables that potentially affect urchin settle- ment such as gonad index, temperature and primary productivity (phytoplankton) were measured. Settlement was found to be high during warm years; temperatures >24°C induced important settle- ment pulses. Postsettlement survival in barren areas of Tenerife was exponentially and positively cor- related with seawater temperature changes, while very low to 0 survival was found at macroalgal beds off El Hierro. Assuming that climate change predictions are correct, the strong positive relation- ship between thermal history and postsettlement survival of this ecologically important species sug- gests that barren grounds will persist as seawater warms up if no mass mortality occurs. This future scenario will have important implications for the stability of algal beds and coastal ecosystems as a whole.

Understanding the role of predatory fish within a community is essential to predict how ecosystem structure and function may respond to loss of fish species and to ensure conservation strategies are effective. The aim of the present study was to characterize relationships between predatory fish assemblages, sea urchin abundances and ecosystem function and services. By means of diet analyses and direct observations in the field, we identified key fish species with the potential to control the herbivore Diadema aff. antillarum and hence preserve fishing resources and coastal productivity in sublittoral rocky reefs around the Canary Islands. Differences in the composition and relative importance of predatory assemblages were observed along a gradient of fishing intensities comprising highly fished, lesser fished and marine protected areas. Increased fishing activity was associated with lower fish predator richness and higher urchin density. Most measures of predatory performance (frequency of predation, ingestion time, urchin size selection) differed between preda- tory fish species, showing that most predators of Diadema aff. antillarum are not functionally similar. This level of functional variation highlights the relevance of predator richness in controlling sea urchin populations. Depletion in species diversity leads to a loss of functional roles and cascading effects that may constrain ecosystem processes.

INTRODUCTION: Nowadays, many machine learning tasks involve learning from imbalanced datasets,leading to the miss-classification of the minority class. One of the state-of-the-art approaches to ”solve” thisproblem at the data level is Synthetic Minority Over-sampling Technique (SMOTE) which in turn uses KNearest Neighbors (KNN) algorithm to select and generate new instances.OBJECTIVES: This paper presents SMOTE-Cov, a modified SMOTE that use Covariance Matrix instead ofKNN to balance datasets, with continuous attributes and binary class.METHODS: We implemented two variants SMOTE-CovI, which generates new values within the interval ofeach attribute and SMOTE-CovO, which allows some values to be outside the interval of the attributes.RESULTS: The results show that our approach has a similar performance as the state- of-the-art approaches.CONCLUSION: In this paper, a new algorithm is proposed to generate synthetic instances of the minorityclass, using the Covariance Matrix.

SUMMARYWe assessed the influence of rock cavities, or pits, on the growth dynamics and behavior of the purple sea urchin, Strongylocentrotus purpuratus. In a paired-designed, laboratory experiment, sea urchins were assigned to sandstone blocks that were either ‘Flat’ or had a ‘Pit’ drilled into the center. At the start, both groups were approximately the same shape and size. In just 2 months, the shapes of the tests were significantly different between the two treatments, with the Pit urchins having an increased height:diameter profile. This result demonstrates the plastic nature of the sea urchin test and that, despite its apparent rigidity, it is capable of deforming during growth. In addition, the presence of pits modified behavior and food consumption as well as allometric growth of the test and Aristotle's lantern. Sea urchins on Pit sandstone blocks tended to stay in the cavities and not move about the flat areas, whereas individuals on Flat blocks changed position. Sea urchins in the Pit treatment consumed less food and had relatively larger demipyramids (the ‘jaw’ ossicle in Aristotle's lantern). These morphological and allometric changes occurred over a short time-period (8–20 weeks). We conclude that microhabitat is an important factor in controlling the behavior and growth dynamics of the bioeroding sea urchin S. purpuratus.

Clemente, S., Hernández, J. C., and Brito, A. 2009. Evidence of the top–down role of predators in structuring sublittoral rocky-reef communities in a Marine Protected Area and nearby areas of the Canary Islands. – ICES Journal of Marine Science, 66: 64–71. Differences in the sea urchin Diadema aff. antillarum population structure, which have been attributed to removal of predatory fish through overfishing, are observed throughout the Canary Islands. Low urchin abundances and a “desired conservation state” are currently found in Mar de Las Calmas Marine Protected Area and nearby fished areas (FAs) in El Hierro Island, in contrast to the occurrence of high urchin densities and the “undesired conservation state” in the highly FAs (HFAs) of Tenerife Island. Under these different levels of fishing pressure, we consider a set of ecological variables potentially affecting urchin populations (settlement, recruitment, adult urchin densities, predation rates, and abundance of urchin fish predators) to infer their magnitude and relative importance in addressing community-wide changes. No differences in settlement and recruitment rates were found, but predation pressure was higher in El Hierro, where adult density was low and predation rates were high. The combination of these factors provides evidence of a top–down control of sublittoral reef communities. Although the effect of protection was less clear, we demonstrate the positive effects of reduced fishing effort in enhancing trophic cascade processes and reducing the establishment of barren grounds.

1. The aim was to determine the status of subtidal rocky benthic assemblages in three marine protected areas (MPAs) of the Canary Islands: (1) La Graciosa; (2) Mar de Las Calmas; (3) La Palma. Sea urchin (Diadema aff. antillarum) populations and non-crustose macroalgal cover were surveyed, and used as an indicator of conservation status in the three MPAs as well as in a highly fished area (HFA-Tenerife Island). 2. Comparing characteristics between each MPA and the HFA, and considering issues of management and design, it was concluded that the three MPAs each have a different conservation status. ‘Mar de Las Calmas’ marine reserve was found to have the most desirable conservation status, followed by ‘La Palma’ marine reserve based on sea urchin populations and non-crustose macroalgae assemblages. 3. Conversely, ‘La Graciosa’ had the highest density of D. aff. antillarum and the lowest cover of non-crustose macroalgae out of the three MPAs. Values were comparable to those at the HFA, which shows ‘La Graciosa’ to have the undesired conservation status. 4. Different spatial distribution patterns of non-crustose macroalgal as well as different algal composition cover were observed between the three MPAs and the HFA. These differences were principally attributed to the intensity of grazing activity of the key herbivore D. aff. antillarum. It is suggested that the different study areas correspond to different phase shifts that imply differing resilience of systems that should be taken into a count in future conservation strategies. Copyright © 2007 John Wiley & Sons, Ltd.

Las Lagunas de Echentive constituyen uno de los ambientes marginales de formación más reciente en las islas. La erupción del volcán Teneguía (1971) provocó un avance del frente litoral en el extremo sur de La Palma que originó las pequeñas lagunas objeto de este estudio. Las poblaciones de organismos que se establecen en este ambiente presentan la particularidad de desarrollarse en un sistema parcialmente aislado del mar abierto. Las comunidades de este ecosistema se caracterizan por poseer una estructura trófica simplificada, dominada por microalgas e invertebrados como Eurythoe complanata, Aiptasia mutabilis y gasterópodos. La ausencia de poblaciones de carnívoros provoca que los niveles tróficos superiores estén ocupados por herbívoros y detritívoros y que la funcionalidad del ecosistema esté condicionada por la entrada de energía o por un control “bottom-up”.

Experimental studies were carried out to determine the effects of predation on populations of the sea urchin Diadema aff. antillarum in barren grounds at the Canary Islands. The studied urchin populations were dominated by small to medium sized individuals (24-38 mm) and were variable in space. Tethering experiments showed that predation rates on D. aff. antillarum were very low and no differences were found between sites. Predation was found to be most intense on juveniles (< 20 mm) and on 20-30 mm sized adults, the size range at which most individuals cease to exhibit cryptic behaviour. Urchins with test diameter > 40 mm were not preyed upon whatsoever. We have experimentally demonstrated that there is an absolute predator ‘escape size’ of around 40 mm for D. aff. antillarum individuals in barren grounds. Predation rates obtained for juveniles show that a sufficient number may escape predation and sustain the adult population, maintaining the urchin barren habitat. Recruitment and topographic complexity, rather than predation, seem to determine the structure of urchin populations in barren grounds. We conclude that predation in fished barren grounds of the Canarian Archipelago is not of sufficient magnitude to substantially alter dense urchin populations and cause community-level effects. Se realizaron unos estudios experimentales para valorar el efecto de la depredación sobre las poblaciones del erizo Diadema aff. antillarum, en zonas de blanquizales de las islas Canarias. Las poblaciones de erizos aparecieron dominadas por erizos de tallas pequeñas a medianas (24-38 mm) y resultaron variables en el espacio. Los experimentos de atado mostraron que D. aff. antillarum soporta una presión de depredación muy baja y no se encontraron diferencias entre las estaciones de estudio. La tasa de depredación fue más intensa sobre juveniles (< 20 mm) y adultos de entre 20-30 mm, rango de talla en el que la mayoría de los individuos dejan de tener comportamiento críptico. Los erizos de más de 40 mm de diámetro no fueron depredados en ningún caso. Demostramos experimentalmente la existencia de una talla de escape de D. aff. antillarum frente a la depredación en zonas de blanquizal en torno a los 40 mm. La tasa de depredación obtenida para juveniles indica que un número suficiente debe escapar de la depredación, manteniendo las poblaciones adultas y los blanquizales. Las tasas de reclutamiento y la complejidad topográfica, más que el nivel de depredación, parecen determinar la estructura de las poblaciones de erizos en los blanquizales. Concluimos que la depredación en los fondos rocosos sobreexplotados de las islas Canarias no tiene la magnitud suficiente para alterar substancialmente las densas poblaciones de erizos y causar efectos sobre la comunidad.

Gonad histological examination of the Canary Islands populations of the echinoid Diadema antillarum was conducted in two types of habitats («barrens», i.e. habitats characterised by high visible crustose coralline algal cover typical of urchin-barren grounds, and by absence of macroalgae; and «fringe», i.e. habitats characterised by high macroalgal biomass and few D.antillarum). Sex ratio did not differ significantly from 1:1 at either habitat. One hermaphrodite echinoid was found at the barren habitat out of the total of 572 echinoids examined. Diadema antillarum did not show labile gonochorist and sex determining mechanisms influenced by habitat.

Diadenia africanum sp. nov. Rodríguez et al. 2013 occurs in the eastern Atlantic Ocean at depths of 1-80 meters off Ma- deira Islands, Salvage Islands, Canary Islands, Cape Verde Islands, Sâo Tome Islands and at the continental coast off Sen- egal and Ghana. This species was previously considered an eastern Atlantic population of D. antillarum. Genetic distances between the holotype of D. africanum and the neotype of D. antillarun herein designated, measured 3.34% in Cytochrome oxidase I, 3.80% in ATPase-8 and 2.31% in ATPase-6. Such divergence is similar to that already highlighted between other accepted species of Diadena. Morphometric analysis of test, spine and pedicellarial characters also separated D. africanum from D. antillartn and reveals that this new species is morphologically similar to D. antillarum ascensionis from the mid Atlantic. The tridentate pedicellariae, which have been shown to have diagnostic characters which discriminate among species of Diadema, occur as both broad and narrow valved forms in D. antillarumn from the western Atlantic. In D. africanum the tridentate pedicellariae occur only as a single form which is characterized by moderately broad and curved valves, with an expanded distal gripping region. This form of tridentate pedicellaria is very similar to that of D. antillarum ascensionis from the central Atlantic, with only slight variations in valve serration and valve curvature differ- entiating the two forms.

Ocean warming and acidification both impact marine ecosystems. All organisms have a limited body temperature range, outside of which they become functionally constrained. Beyond the absolute extremes of this range, they cannot survive. It is hypothesized that some stressors can present effects that interact with other environmental variables, such as ocean acidification (OA) that have the potential to narrow the thermal range where marine species are functional. An organism's response to ocean acidification can therefore be highly dependent on thermal conditions. This study evaluated the combined effects of predicted ocean warming conditions and acidification, on survival, development, and settlement, of the sea urchin Paracentrotus lividus. Nine combined treatments of temperature (19.0, 20.5 and 22.5 °C) and pH (8.1, 7.7 and 7.4 units) were carried out. All of the conditions tested were either within the current natural ranges of seawater pH and temperature or are within the ranges that have been predicted for the end of the century, in the sampling region (Canary Islands). Our results indicated that the negative effects of low pH on P. lividus larval development and settlement will be mitigated by a rise in seawater temperature, up to a thermotolerance threshold. Larval development and settlement performance of the sea urchin P. lividus was enhanced by a slight increase in temperature, even under lowered pH conditions. However, the species did show negative responses to the levels of ocean warming and acidification that have been predicted for the turn of the century.

The presence of a mosaic of habitats, largely determined by sea urchin grazing, across shallow rocky reefs may potentially influence in differences in the distribution patterns of invertebrates. The aim of this paper was to assess, using a correlative approach, whether the type of habitat influences the abundance patterns of holothurians in the eastern Atlantic. We hypothesized that abundances of large (>10 cm) holothurians varied among four types of habitat (3 vegetated habitats with low abundances of the sea urchin D. antillarum vs. ‘barrens’ with hyperabundances of sea urchins), and that these differences were consistent at a hierarchy of spatial scales, including two islands and several replicated sites within each type of habitat and island. Three species of large holothurians were found, accounting for a total of 300 specimens. We found remarkable differences in abundances of holothurians between the ‘barrens’ and the three vegetated habitats. This pattern was strongest for the numerically dominant species, Holothuria sanctorii. Total abundances of holothurians were between 5 and 46 times more abundant in ‘barrens’ compared with the vegetated habitats. Inter-habitat differences were species-specific with some inconsistent patterns from one island to the other. The total abundances of holothurians tended to increase with the abundance of sea urchins within ‘barrens’. Our study suggests that there may be a link, at least for the dominant species Holothuria sanctorii, between the distribution and abundances of large holothurians and the habitat across shallow-waters of the eastern Atlantic.

Clinical risk management improves quality in health care by increasing patient safety and by trying to eliminate avoidable errors. Implementing risk management programs requires the creation of risk management units in hospitals that will be responsible of all the activities related to patient safety. This article describes the development one of the first clinical risk management units in Europe directed by medical and nursing staff who continue to work at the same time in their departments.

Size, growth, and density have been studied for North American Pacific coast sea urchins Strongylocentrotus purpuratus, S. droebachiensis, S. polyacanthus, Mesocentrotus (Strongylocentrotus) franciscanus, Lytechinus pictus, Centrostephanus coronatus, and Arbacia stellata by various workers at diverse sites and for varying lengths of time from 1956 to present. Numerous peer-reviewed publications have used some of these data but some data have appeared only in graduate theses or the gray literature. There also are data that have never appeared outside original data sheets. Motivation for studies has included fisheries management and environmental monitoring of sewer and power plant outfalls as well as changes associated with disease epidemics. Studies also have focused on kelp restoration, community effects of sea otters, basic sea urchin biology, and monitoring. The data sets presented here are a historical record of size, density, and growth for a common group of marine invertebrates in intertidal and nearshore environments that can be used to test hypotheses concerning future changes associated with fisheries practices, shifts of predator distributions, climate and ecosystem changes, and ocean acidification along the Pacific Coast of North America and islands of the north Pacific. No copyright restrictions apply. Please credit this paper when using the data.

A wide variety of organisms show morphologically plastic responses to environmental stressors but in general these changes are not reversible. Though less common, reversible morphological structures are shown by a range of species in response to changes in predators, competitors or food. Theoretical analysis indicates that reversible plasticity increases fitness if organisms are long-lived relative to the frequency of changes in the stressor and morphological changes are rapid. Many sea urchin species show differences in the sizes of jaws (demi-pyramids) of the feeding apparatus, Aristotle's lantern, relative to overall body size, and these differences have been correlated with available food. The question addressed here is whether reversible changes of relative jaw size occur in the field as available food changes with season. Monthly samples of the North American Pacific coast sea urchinStrongylocentrotus purpuratuswere collected from Gregory Point on the Oregon (USA) coast and showed an annual cycle of relative jaw size together with a linear trend from 2007 to 2009.Strongylocentrotus purpuratusis a long-lived species and under field conditions individuals experience multiple episodes of changes in food resources both seasonally and from year to year. Their rapid and reversible jaw plasticity fits well with theoretical expectations.

An in situ tagging technique for the long-spined sea urchin Diadema aff. antillarum, suitable for carrying out short and medium term ecological studies is described. It is a simple method in which external nylon tags are anchored in holes drilled through the urchin test. The technique was tested in the field and found to be effective for individuals of more than 20 mm test diameter in terms of survival and tag retention rates.

A pronounced, widespread and persistent regime shift among marine ecosystems is observable on temperate rocky reefs as a result of sea urchin overgrazing. Here, we empirically define regime-shift dynamics for this grazing system which transitions between productive macroalgal beds and impoverished urchin barrens. Catastrophic in nature, urchin overgrazing in a well-studied Australian system demonstrates a discontinuous regime shift, which is of particular management concern as recovery of desirable macroalgal beds requires reducing grazers to well below the initial threshold of overgrazing. Generality of this regime-shift dynamic is explored across 13 rocky reef systems (spanning 11 different regions from both hemispheres) by compiling available survey data (totalling 10 901 quadrats surveyed in situ) plus experimental regime-shift responses (observed during a total of 57 in situ manipulations). The emergent and globally coherent pattern shows urchin grazing to cause a discontinuous ‘catastrophic’ regime shift, with hysteresis effect of approximately one order of magnitude in urchin biomass between critical thresholds of overgrazing and recovery. Different life-history traits appear to create asymmetry in the pace of overgrazing versus recovery. Once shifted, strong feedback mechanisms provide resilience for each alternative state thus defining the catastrophic nature of this regime shift. Importantly, human-derived stressors can act to erode resilience of desirable macroalgal beds while strengthening resilience of urchin barrens, thus exacerbating the risk, spatial extent and irreversibility of an unwanted regime shift for marine ecosystems.

A widespread mass mortality event of the sea urchin Diadema africanum was detected in the subtropical eastern Atlantic, extending from Madeira to the Canary Islands, covering a straight- line distance of >400 km. This is the first disease- related die-off of a diadematid documented in the eastern Atlantic Ocean. Diseased individuals showed deterioration of the epidermis and water-vascular system, resulting in epidermal necrosis and release of spines. Despite some spatial heterogeneity in disease incidence at the study sites, there was a 65% overall reduction in urchin abundance after the mortality event compared to numbers pre-mortality. However, the reduction in urchin numbers did not compromise the species' reproductive success; the settlement peak following the mortality event was of a similar magnitude to that in prior years. Bacterial isolation and cul ture techniques, and subsequent laboratory in fection experiments, strongly suggested that Vibrio alginolyticus was involved in the disease. We hypo thesize that the mass mortality event devel- oped due to anomalously high seawater tempera- tures recorded in the 2 studied archipelagos and that warmer temperatures enabled infection of D. africa - num by waterborne pathogenic bacteria. Fluctua- tions in urchin populations are key in de termining the structure and functioning of benthic ecosystems: under the current seawater warming scenario, dis- ease may result in more frequent phase shifts, aiding the persistence of macroalgae.

Crustose algal communities were studied in Diadema africanum urchin barrens around Tenerife (Canary Islands, NE Atlantic). A hierarchical nested sampling design was used to study patterns of community variability at different spatial scales (sectors, three sides of the island; sites within each sector, 5–10 km apart; stations within each site, 50–100 m apart). Although noncrustose species contributed the most to community richness, cover was dominated by crustose forms, like the coralline algae Hydrolithon farinosum, H. samoe¨nse, H. onkodes, Neogoniolithon orotavicum and N. hirtum, and the phaeophycean Pseudolithoderma adriaticum. The structure of these communities showed high spatial variability, and we found differences in the structure of urchin barrens when compared across different spatial scales. Multivariate analysis showed that variability in community structure was related to the five environmental variables studied (wave exposure, urchin density, substrate roughness, productivity and depth). Wave exposure was the variable that contributed most to community variability, followed by urchin density and substrate roughness. Productivity and depth had limited influence. The effects of these variables differed depending on the spatial scale; wave exposure and productivity were the main variables influencing community changes at the largest scale (between different sectors of the island), while D. africanum density, roughness and depth were the most influential at medium and small scales.

We investigated the current patterns of diversity by country and by class of echinoderms, and analyzed their biogeographical, depth, and habitat or substratum affinities, using the database of the appendix of this book. Traditionally, the area has been divided into five biogeographical Regions and nine Provinces that cover a wide climate range. Currently, the echinoderm fauna of Latin America and Canary islands is constituted by 1,539 species, with 82 species of Crinoidea, 392 species of Asteroidea, 521 species of Ophiuroidea, 242 species of Echinoidea and 302 species of Holothuroidea. Species richness is highly variable among the different countries. The number of species for the countries is highly dependent on its coast length. The echinoderm fauna of the Panamic, Galapagos and the Chilean regions are biogeographically related. Other regions that are closely related are the Caribbean, West Indian, Lusitania and Brazilian. Cosmopolitan species are an important component in all the regions. Affinities between faunas are a consequence of the combination of climatic and trophic factors, connectivity as a function of distance, currents patterns and historical processes. Moreover, different environmental factors would be responsible for the faunal composition and species distribution at different spatial scales. The bathymetrical distribution of the echinoderm classes and the species richness varies according to the depth range and the ocean. Most species occurred at depths between 20 and 200 m. The Caribbean-Atlantic regions are richest in shallow depths, while the Pacific coast has higher values in deeper waters. The domination of each class in each substrate and habitat categories also varies differentially along each coast.

The work presented here summarizes the studies on echinoderms in the Canary Islands, Spain. The geographical and geological contexts of the islands, as well as oceanographic and general characteristics of ecosystems and communities of the archipelago are discussed to better understand the composition of echinoderm species in the islands. A research section is divided into three subsections: ‘pioneering studies’, studies done ‘between 1980 and 1990’ when the first taxonomic, bionomical, biogeographical and ethological studies were done, and finally ‘the recent past’ where the latest studies on echinoderm ecology are described. The subsequent section deals with the diversity and biogeographic relationships of the echinoderm fauna present in the islands. The final two sections consider echinoderm ecology and fisheries, with special emphasis on the conservation of echinoderm populations and of the whole benthic ecosystem. We make recommendations for future research on the biology and ecology of echinoderms in the Canary Islands.

Diadema aff. antillarum performs a key role in organizing and structuring rocky macroalgae assemblages in the Canary Islands. Densities of D. aff. antillarum higher than 2 individuals m−2 are found to drastically reduce non-crustose macroalgal cover to below 30% and wave exposure appears as a major factor determining sea urchin density, which decreases with exposure level. Substrates containing >20% sand limit urchin to under 1 individual m−2 but high relief rocky habitats show higher density. Moreover, several anthropogenic factors (number of islanders and tourists per coastal perimeter, and number of operational fishing boats) were positively correlated with urchin abundance. A trend of increasing urchin density through time was found, although well structured marine systems found at Mar de Las Calmas Marine Protected Area and at the no-take area of La Graciosa Marine Protected Area do not seem to follow this general trend.

Total body size, mass or linear measurements, and gonad mass or volumes have been recorded for the North American Pacific coast sea urchins Strongylocentrotus purpuratus, Mesocentrotus (Strongylocentrotus) franciscanus, and Lytechinus pictus by various workers at diverse sites and for varying lengths of time from 1954 to 2009. Some dissections included other body components such as the gut, body wall, and Aristotle's lantern, and some dissections included both wet and dry mass. There are numerous peer-reviewed publications that have used some of these data, but some data have appeared only in graduate theses or in the gray literature. There also are data that have never appeared outside the original data sheets. Historically, data were used to describe reproductive cycles and then to compare responses to stressors such as food limitation or pollution. Differences in temperature among sites also have been explored. More recently, dissection data have linked gonad development to ocean conditions, so called bottom-up forcing. The data set presented here is a historical record of gonad development for a common group of marine invertebrates in intertidal and nearshore environments, which can be used to test hypotheses concerning future changes associated with climate change and ocean acidification along the Pacific Coast of North America.

Diadenia africanum sp. nov. Rodriguez et al. 2013 occurs in the eastern Atlantic Ocean at depths of 1-80 meters off Ma- deira Islands, Salvage Islands, Canary Islands, Cape Verde Islands, Sâo Tome Islands and at the continental coast off Sen- egal and Ghana. This species was previously considered an eastern Atlantic population of D. antillarum. Genetic distances between the holotype of D. africanum and the neotype of D. antillarun herein designated, measured 3.34% in Cytochrome oxidase I, 3.80% in ATPase-8 and 2.31% in ATPase-6. Such divergence is similar to that already highlighted between other accepted species of Diadena. Morphometric analysis of test, spine and pedicellarial characters also separated D. africanum from D. antillartn and reveals that this new species is morphologically similar to D. antillarum ascensionis from the mid Atlantic. The tridentate pedicellariae, which have been shown to have diagnostic characters which discriminate among species of Diadema, occur as both broad and narrow valved forms in D. antillarumn from the western Atlantic. In D. africanum the tridentate pedicellariae occur only as a single form which is characterized by moderately broad and curved valves, with an expanded distal gripping region. This form of tridentate pedicellaria is very similar to that of D. antillarum ascensionis from the central Atlantic, with only slight variations in valve serration and valve curvature differ- entiating the two forms.

We tested the suitability of three different kinds of artificial collectors designed for quantitative assessment of echinoid settlement rates: (1) nylon nets containing plastic biofilter balls, (2) vertical scrub brushes with vegetal bristles and (3) horizontal triangular mats of coconut fibre. We measured the collecting efficiency by counting the number of post-larvae of two sea urchin species (Paracentrotus lividus and Arbacia lixula) gathered by each collector and deployed in two geographic areas: Tenerife (Canary Islands, eastern Atlantic) and Tossa de Mar (Costa Brava, northwestern Mediterranean). The plastic biofilter ball collector proved to be the most efficient design, collecting more settlers of both sea urchin species under all assayed conditions and showing a higher reproducibility than the other two designs. We therefore suggest using plastic biofilter balls in future studies aimed at quantifying echinoid settlement rates., En este trabajo comparamos la eficacia de tres tipos diferentes de colectores artificiales diseñados para cuantificar la tasa de asentamiento larvario en equinoideos. Los tres tipos de colectores utilizados en el estudio fueron: (1) mallas de nylon rellenas con biofiltros esféricos de plástico, (2) cepillos verticales con cerdas de fibra vegetal y (3) alfombras horizontales triangulares de fibra de coco. Se determinó la eficacia de recolección mediante el recuento de las post-larvas de dos especies de erizo de mar (Paracentrotus lividus y Arbacia lixula) capturadas por cada colector, en dos áreas geográficas diferentes: Tenerife (Islas Canarias, Atlántico Oriental) y Tossa de Mar (Costa Brava, Mediterráneo noroccidental). El colector de biobolas de plástico demostró ser el diseño más eficaz de los tres comparados, al capturar un mayor número de post-larvas de ambas especies de erizo en todas las condiciones ensayadas y con una mayor reproducibilidad que los otros dos diseños. Por tanto, recomendamos el uso de los colectores de “biofilters balls” de plástico para el diseño de futuros experimentos que tengan como objetivo la cuantificación de las tasas de asentamiento de equinoideos.