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Introduction: Echinoderms are strictly aquatic animals and one of the groups of marine invertebrates whose ecological importance is crucial for the environments where they inhabit. The most outstanding characteristic is their pentaradial symmetry. These organisms can be distributed in a wide variety of oceanic environments, and are not exclusive inhabitants of reef formations. A total of 1 539 species have been registered, of which 717 belong to the Pacific and 60 of them have been registered for El Salvador. Objective: The objective of the work was to record the richness and density of echinoderm species in rocky reefs of Punta Amapala (La Unión). Methods: The sampling was conducted in five sites, two of them at 3 m of depth and three at 6 m. For this, snorkeling and autonomous diving were used, covering two band transects of 30 x 1 m. Within the transects, the identification (richness) and counting (abundance) of the organisms was carried out. Results: The species that presented the highest density at 3 m reefs was Echinometra vanbrunti (0.83 indv/m2), followed by the ophiuroid Ophiocomella alexandri (0.16 indv/m2) and Ophiocoma aethiops (0.16 indv/m2). And at the 6 m reefs were Ophiothela mirabilis (0.83 indv/m2), Ophionereis annulata (0.21 indv/m2), Ophiothrix rudis (0.08 indv/m2) and Ophiocomella alexandri (0.01 indv/m2). Conclusions: These organisms fulfill various ecological roles, such as being bioindicators of water quality by tolerating certain changes in physicochemical conditions and fulfilling the role of macrofauna hosts due to the cavities formed by some sea urchins. That is why sampling efforts must increase in these areas to monitor the quality and health of the rocky reefs, whose role is key, as they are, together with Los Cóbanos, the largest in the country. [ABSTRACT FROM AUTHOR]

The Bjeshket e Nemuna/Alpet Shqiptare National Park is located in the western and southwestern part of Kosovo and features unique freshwater fauna. The aquatic invertebrate communities here are nearly unrecognised and need extensive studies. Ecological and faunistic research on benthic communities of rheocrenes in the Bjeshket e Nemuna show that the most important component of invertebrate fauna of local springs and streams are Chironomidae (non-biting midges). We present the preliminary list of crenobiontic macroinvertebrates in the mountain springs of Bjeshket e Nemuna/Alpet Shqiptare. The list includes crenobionts from the following groups: Hirudinea (2), Gastropoda (2), Hydrachnidia (2) and Insecta (13). [ABSTRACT FROM AUTHOR]

The study of the functioning of the high Andean ecosystems is of great importance since any change will influence the entire basin. However, knowledge of these environments is still limited. Therefore, we sought to determine the effect of seasonality on the macrobenthos assemblage of a high Andean River and to determine the limnological, geomorphological, and hydrologicalhydraulic variables that most influence it. In the El Salto River, located 4,500 meters above sea level, in high Andean environments in southern Peru, macrobenthos was collected in 2020 in 11 hydro morphological units, recording limnological variables (dissolved oxygen, saturation percentage, conductivity, TSD, temperature, pH, turbidity and SS), geomorphological (granulometry) and hydrological-hydraulic (flow, velocity, depth, channel width) in dry and wet seasons. The principal component analysis (PCA) of the physicochemical variables showed that the flow rate, conductivity, pH, and total dissolved solids explained the greatest variability of the data (70 %). The predominance of boulders and silt was found. The number of species and density were higher in the dry season than in the wet season. However, the diversity, richness, and equity were higher in the wet season. The ordination analysis (nMDS, stress=0.09) showed a different structure of the macrobenthic assemblage between both seasons. It is concluded that seasonality, given by various factors, mainly flow rate and flow velocity, determine variations in the macrobenthos assemblage, confirming the drastic changes to which these high Andean ecosystems with extreme climates are subjected. [ABSTRACT FROM AUTHOR]

La conservación de los arrecifes coralinos radica en el manejo adecuado de estos ecosistemas marinos, sin embargo es necesario dotar de información biológica para saber que se debe proteger, por lo tanto, disponer con descripciones de las comunidades coralinas contribuye en gran medida a formular estrategias de manejo eficaces. Bajo este contexto se describe la distribución de los hábitats bentónicos dominantes de la planicie del arrecife Enmedio. Durante el periodo noviembre 2014-abril 2016 se recabaron datos geográficos de los componentes bentónicos de la llanura arrecifal mediante buceo libre, esencialmente la información espacial se obtuvo a partir de registros fotográficos utilizando una cámara digital con receptor de posicionamiento global (GPS), con los datos recabados se generó un mapa temático mediante el método kriging simple. Las descripciones de los hábitats arrecifales se complementó con base al número de ensamblajes de especies principalmente de macroinvertebrados bentónicos y peces. Básicamente se diferencian ocho hábitats bentónicos en la planicie del arrecife Enmedio, fundamentalmente están constituidos por las especies Acropora palmata, Millepora alcicornis, Orbicella annularis, Pseudodiploria clivosa, Porites furcata, Palythoa caribaeorum, Eunicea flexuosa y por dos fondos bentónicos: cresta arrecifal y escombros. Los hábitats ben-tónicos: O. annularis y de A. palmata presentaron un mayor número de especies asociadas, mismas que comparten mayor semejanza en el ensamblaje de especies en comparación al resto de los componentesbentónicos. La distribución que manifiestan los componentes bentónicos con respecto a la cresta arrecifal es parecido al de otras regiones del Atlántico.

Situ Patengan is one of the highland lakes in West Java which is at an altitude of 1600 meters above sea level. Upland lakes have unique characteristics and are inhabited by various organisms including benthic macroinvertebrates. The purpose of this study was to examine the biodiversity of benthic macroinvertebrates at the family level and their relationship with aquatic environmental conditions. This study was carried out from August to October 2022 in three areas with 9 observation points. The results of this study obtained 9 families (Atyiidae, Glossiphonidae, Isotomidae, Chironomidae, Culicidae, Perlidae, Naididae, Lumbriculidae and Tubificidae) from 6 orders. The Chironomidae family is the dominating family in terms of number of species and abundance. Based on the Canonical Correspondence Analysis (CCA), each observation area has different water characteristics and correlations with benthic macroinvertebrates according to the environmental pressures that exist around the area. Even though some areas have quite high environmental pressure, there are still species of macroinvertebrates that are sensitive to environmental pressure, such as the Atyiidae and Perlidae families, especially in areas with relatively low environmental pressure, especially around protected forest areas. [ABSTRACT FROM AUTHOR]

Introduction: Pollution by microplastics is a global problem in marine environments, which impacts microorganisms and ecosystems at several spatial levels. Sandy beaches are depositional environments where microplastics tend to accumulate in large quantities. The co-occurrence of interstitial meiofauna and microplastics in sand grains raises the question on whether the accumulation of microplastics in the sediments affects the abundance and composition of the meiofaunal communities. Objective: To test the hypothesis that microplastics affect the meiofauna of urban sandy beaches. Methods: We studied the three main urban sandy beaches of Santa Marta, Colombia: El Rodadero, Santa Marta Bay, and Taganga. All are similar in morphology and external pressures, and differ from other beaches in the region. In April 2019 we collected 81 sand samples, equally distributed in the intertidal zone (upper, mid, and lower intertidal levels). We applied generalized linear models to abundance, and multivariate permutational tests to community composition. Results: We identified 17 taxonomic groups of meiofauna, and microplastic particles (mainly 45-500 micron fibres) evenly distributed across beaches and intertidal levels. There was more meiofauna at the mid intertidal level, and in fine and medium grain sediment. At the lower intertidal level, sites with more microplastics had less meiofauna. Abundance of microplastics explained 39 % of the variation in meiofaunal community composition at lower intertidal levels. Conclusions: The accumulation of microplastics might have a negative impact on these meiofaunal interstitial communities. This is not surprising: if microplastics occupy the same physical space as these animals, they might presumably modify the structure of sediments and the composition of interstitial water. [ABSTRACT FROM AUTHOR]

Se recolectaron los moluscos y crustáceos de la epifauna en los manglares de La Honda y Che Paulito, Los Santos, durante los meses de junio, julio y agosto de 2019 y 2020, en dos cuadrantes de 100 m2 cada uno, en ambos manglares, muestreados manualmente. Se sumaron los organismos de ambos períodos y resultaron 5 314 individuos en el primer manglar y 4 669 en el segundo, con dominancia del cangrejo Uca sp1 en ambos; no se observó diferencias de abundancia entre años en ninguno de los dos sitios. Se obtuvo una alta diversidad con respecto a otros manglares, a pesar del efecto de borde, con valores del índice H’ entre 1,10 y 2,04 en ambos manglares, con diferencias estadísticas interanuales. Esta variación no se pudo atribuir al fenómeno El Niño/La Niña, ni al efecto de la extracción de invertebrados por los moradores de las zonas aledañas, restringidos por el confinamiento producto del SARCOV-2.

Introduction: Cephalochordates are benthic organisms that represent an important link in the evolution of chordates. Coastal human communities use them as food in some Asian countries. Objective: To register the presence of B. californiense in El Salvador. Methods: We collected specimens during different benthic surveys at Jiquilisco and La Union Bays in April 2018 and November 2019, with a Petite Ponar grab and core in subtidal as well as intertidal sediments, respectively. Results: Ten specimens were collected from sandy-muddy sediments at Jiquilisco and La Union bays. Conclusion: B. californiense inhabits estuarine areas in El Salvador.

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V številnih evropskih državah so umetni podvodni grebeni (UPG) dobro sprejet način za povečevanje lokalne biodiverzitete. Ideja o umestitvi UPG na dno slovenskega morja je stara 25 let. Ta ideja še vedno ni realizirana, kljub jasnim dokazom, da imajo UPG pozitiven vpliv na lokalno morsko okolje in biocenozo, kar nam sporočajo izkušnje z italijanske strani Tržaškega zaliva. Zaradi različnih vzrokov tako na uresničitev postavitve prvega UPG v slovenskem morju še vedno čakamo. Prepričani smo, da bi bile take potopljene strukture pomemben substrat za naselitev (repopulacijo) morskih habitatov z bentoškimi vrstami, ki zaradi občasnih hipoksij in anoksij na morskem dnu množično poginjajo.

Las pesquerías dirigidas a especies bentónicas pueden tener un impacto negativo sobre la fauna acompañante y el fondo marino; sin embargo, las artes de pesca pasivas como las trampas se consideran menos nocivas. El objetivo de este trabajo fue evaluar el impacto de la pesca con trampas para centolla (Lithodes santolla) sobre las comunidades macrobentónicas que se distribuyen en el Área Central Patagónica (44° S-47° S). Se comparó la composición de la fauna presente en las comunidades bentónicas del área donde se desarrolla la pesquería dirigida a la centolla (fauna potencialmente capturable) con la fauna macrobentónica que queda retenida en las trampas (fauna efectivamente capturada o retenida). La fauna bentónica “potencialmente capturable” se determinó mediante recolección por red de arrastre mientras que la fauna “efectivamente capturada” se obtuvo a partir de la pesca con líneas de trampas empleadas por buques centolleros. En ambos casos los datos fueron recabados durante 2016 en el Área Central Patagónica. El número de taxones registrados fue considerablemente mayor para la fauna “potencialmente capturable” (80 versus 15), representando los taxones efectivamente capturados en trampas solo un 18,7% del total de los taxones que potencialmente pueden ser capturados. La fauna “potencialmente capturable” está caracterizada (en biomasa y frecuencia de aparición) por langostino, esponjas, braquiópodos y tunicados, todas especies sésiles a excepción del langostino. La fauna “efectivamente capturada” por las trampas fue caracterizada por organismos de comportamiento predatorio activo (cangrejos y equinodermos), con una predominancia del cangrejo araña (Libidoclaea granaria), aunque la distribución espacial de este no es coincidente con las mayores abundancias de centolla. Se determinó que el efecto de la pesca con trampas sobre una de las especies más abundantes (langostino) así como sobre aquellas que presentan un rol ecológico relevante en el sistema (ejemplo esponjas y tunicados) es muy bajo, ya que existió una clara diferenciación entre la fauna macrobentónica con potencial de ser capturada y la efectivamente retenida en las trampas.

Se presenta el primer listado de grupos de invertebrados bentónicos del sistema lagunar de Mandinga (SLM). Se realizaron siete colectas en temporadas de secas de 2008 a 2015 y una en temporada lluviosa de 2015. Los organismos endobénticos se colectaron con una draga y los organismos epibénticos, con una red tipo Renfro y chinchorro. Todos los organismos se identificaron hasta el nivel permisible. El listado está conformado por un total de 43 grupos zoológicos, distribuidos en ocho filos, siete clases, nueve órdenes, 16 familias y tres tipos de larvas. Los grupos Decapoda (10), Gastropoda (8), Amphipoda (4), Bivalvia (3), Tanaidacea (3) e Isopoda (3), fueron los más diversos, seguidos en menor medida por los grupos que se determinaron a niveles superiores a Familia (12). La diversidad de grupos es similar a la de otros sistemas costeros veracruzanos, donde los órdenes Decapoda, Amphipoda y Tanaidacea fueron los más diversos, seguidos por Isopoda. Los resultados de la presente investigación, representan un aporte importante para el conocimiento de la diversidad del sistema estudiado y de la distribución de los grupos en Veracruz y golfo de México.

El río Chico, ubicado en el centro de Santa Cruz, recorre 600 km desde sus nacientes hasta su desembocadura. En su tramo medio, se encuentra la localidad de Gobernador Gregores (48°45'3"S, 70°14'54"O), que ejerce su influencia sobre el río a través de las actividades agropecuarias y el vertido de efluentes urbanos. Con el objetivo de conocer el grado de impacto sobre la calidad del agua del río, se realizó un análisis de la comunidad de macroinvertebrados bentónicos y se calculó el índice Biotic Monitoring Patagonian Streams (BMPS). En marzo de 2017, se efectuó un primer relevamiento en seis estaciones de muestreo dispuestas en un diseño de gradiente de impacto, con dos estaciones control aguas arriba de la localidad y cuatro estaciones aguas abajo. En cada estación se tomaron muestras de agua para análisis fisicoquímicos, se registraron datos ambientales mediante sonda multiparamétrica y se recolectaron cuatro muestras de macrobentos utilizando una red Surber con malla de 0,5 mm de abertura. Los organismos recolectados fueron identificados y contabilizados bajo microscopios estereoscópico y óptico. Para cada muestra se calculó el número de taxones (S), la abundancia total (N), la diversidad (H’) y la equitatividad (J); los datos de abundancia se analizaron utilizando estadística multivariada. Se identificaron 25 taxones, siendo los mejor representados los oligoquetos Naididae, los hirudíneos, los moluscos Chilinidae y Lymnaeidae, y los insectos Chironomidae, Baetidae y Glossosomatidae. En las estaciones ubicadas aguas abajo más cercanas a la localidad, la comunidad se encontró dominada ampliamente por oligoquetos y quironómidos, y presentó los valores más bajos de S, H’ y J. Los valores de BMPS en esas estaciones indicaron la existencia de aguas contaminadas a fuertemente contaminadas. En las estaciones control y las más alejadas aguas abajo, los valores de S, H’ y J aumentaron significativamente y el índice BMPS indicó mejores condiciones en la calidad ambiental del río.

In autumn 2020, a large mucilaginous outbreak was recorded in the entire Sea of Marmara and lasted until summer 2021. Mucilaginous aggregates in the water column and the impacts on gorgonians were qualitatively monitored at Prince Islands. Suspending and drifting mucilaginous aggregates in several forms and sizes were present from April to July 2021. All four main gorgonian species present in the area were observed to be covered with mucilage; some colonies were still healthy, some showed total mortality, while others had partial mortality. The population of the red gorgonian Paramuricea clavata was already severely declined in the area and might be expected to be the worst impacted. Gorgonian populations in the area could potentially recover but the recurring nature of mucilage outbreaks might prevent a recovery by rejuvenation as mucilage deposition mainly impact young colonies. Considering with accelerating climate-driven changes, mucilage outbreaks would probably recur in this semi-enclosed sea with clearly altered environmental conditions. The ecological status is clearly alarming and effective measures need to be taken urgently to prevent the formation of another large-scale and long-lasting mucilage event. The implementation of the recent Action Plan for the conservation of the Sea of Marmara could highly improve the conditions if genuinely applied throughout the basin. [ABSTRACT FROM AUTHOR]

Introduction: Benthos is an efficient indicator of environmental disturbances, biodiversity and trophic dynamics. In Cuba, benthic mollusks have been reported as the main food for the lobster Panulirus argus. Objectives: To estimate spatiotemporal variations in the soft-bottom benthic community of the Gulf of Batabanó, and to infer, with emphasis on mollusks, the effect of such variations on the availability of food for spiny lobsters. Methods: A historical analysis of the variations in the density and biomass of megazoobenthos (organisms = 4 mm) and particularly of megazoobenthic mollusks was carried out, taking as a reference the studies published in 1990 (with samples from 1983) and recent data (2007-2018) recorded on site using comparable methodologies based on sediment drags. Abundance was given as density (ind/m2) and biomass in g/m2. Results: It was found that both the density and the biomass were significantly higher at the end of the last century and show a tendency to gradually decrease towards recent times. Regarding the values reported in 1983, the density of organisms showed a decrease of 73%, however, the biomass experienced an even greater decrease (86%). The areas with the highest density and biomass, both benthos and mollusks, have varied from 1983 and are currently located towards the center of the gulf. Despite this, bivalves continue to be better represented than gastropods. In general, mollusks showed a significant decrease (55% and 88% respectively). Conclusions: The deterioration of the benthic community in the fishing areas of the Gulf of Batabanó was corroborated and it was demonstrated, based on megazoobenthos, that malacofauna can be used as a reliable indicator of the general parameters of the softbottom benthic community. The availability of food for lobsters have decreased 55.6% compared to 1983. This could help to explain the current changes in the abundance, distribution and nutritional condition of lobsters, which could also be related to the recent megazoobenthos variations. [ABSTRACT FROM AUTHOR]

Introduction: Information on the number of flatfish species and their depth distributions is scarce for the Eastern Tropical Pacific. Historical data is important to evaluate changes in ecosystems due to local, regional and global stressors. Objective: To provide information on the presence, depth distributions and lengths of flatfish species collected by trawl nets. Methods: Fish studies were conducted by trawling at four sites along the Pacific coast of Costa Rica by the survey vessels Skimmer (1979-1980), Nishin Maru (1987-1988) and Victor Hensen (1993-1994). The published lists of species were consulted, museum specimens were accessed, and an updated list of flatfish species assembled. Results: A total of 36 species were found over a depth range of 8-359 m. The family Paralichthyidae included 13 species followed by the Cynoglossidae with 12 species, Achiridae with six and Bothidae with five. Thirty-five species were collected at depths from 10-235 m in the Gulf of Nicoya and Golfo Dulce. Monolene asadeae was collected offshore at a depth range of 254-359 m. The Gulf of Nicoya estuary yielded 27 species during the Skimmer expedition over a depth range of 8-60 m, while 31 species were found during the V. Hensen survey at depths from 10-228 m. The V. Hensen survey in Golfo Dulce (20-235 m) collected 19 species, and 17 species in Coronado Bay (21-187 m). Off the Nicoya Peninsula (56-359 m) 13 species were collected by the Nishin Maru shrimp trawler. A total of 21 species (58%) were found at depths greater than 100 m which were probably exposed to low oxygen concentrations. During the V. Hensen survey Symphurus chabanaudi and S. elongatus were collected more frequently in the Gulf of Nicoya, while S. leei was collected more frequently in Golfo Dulce. Cluster analyses based on presence-absence data for the Gulf of Nicoya and Golfo Dulce revealed low station similarity indicating possible habitat partitioning among species. The size (Total length) of 33 species measured from both the Gulf of Nicoya and Golfo Dulce ranged from 8 cm (Syacium cf longidorsale, Trinectes xanthurus) to 50 cm (S. ovale). Only 12 species were found with lengths over 20 cm. Data on flatfish landings by the semi-industrial fishing fleet for the period 2000-2016 indicates that this group represents less than 1% of the total landings (shrimp and bycatch), with a minimum of 365 kg in 2001 and a maximum of 13 414 kg in 2013. Conclusions: The number of flatfish species of the Pacific coast of Costa Rica appears relatively high but comparable to the numbers found in other tropical regions. A reduced fishing impact on the populations together with this updated list of flatfish provide a good baseline for a new survey of fish populations. Both are important for a future updating of the trophic models available the Gulf of Nicoya and Golfo and their use as tools for better management of the ecosystems. [ABSTRACT FROM AUTHOR]

As part of a biodiversity study on intertidal invertebrates, several sea anemones from the west coast of the Baja California Peninsula were collected in June 2016. The taxonomic features of four specimens agree well with those of the species Anthopleura radians, a recently described sea anemone from northern Chile. This study is the first published report on this species outside the range of distribution documented in the original description, including new images of A. radians' external and internal features and complete characterization of their cnidae. Differences between A. radians from other species of the genus reported from the eastern Pacific are also discussed. [ABSTRACT FROM AUTHOR]

Con la finalidad de determinar la estructura numérica de la comunidad de insectos acuáticos derivantes y compararla con la estructura de la comunidad bentónica de insectos, en un tramo del río Santa María, se seleccionaron dos estaciones de muestreo, en las que se recolectaron insectos acuáticos derivantes y bentónicos. El índice de similitud de Jaccard mostró un valor de similitud entre la fracción de insectos acuáticos derivantes y bentónicos, en el tramo estudiado de IJ= 75 %. Esto indica que la mayor parte de los taxones se desplazan en la deriva y que la estructura numérica de la fracción derivante de los insectos acuáticos no es más que el reflejo de la estructura numérica de la comunidad bentónica de insectos acuáticos, lo que hace de la deriva, un fenómeno dependiente de la densidad.

Se analiza la presencia de metales pesados en tejidos de organismos provenientes del sector aledaño a Isla Rocuant, Bahía Concepción. Los organismos estudiados fueron los bivalvos bentónicos Tagelus dombeii (“navajuela”), Mulinia edulis (“taquilla”), las macroalgas Gracilaria chilensis (“pelillo”) y Rhodymenia sp (“rodymenia”) y el pez Stromateus stellatus (“pampanito”). Los metales analizados en sus tejidos fueron Cd, Fe, Hg, Pb y Zn para los cuales no existen registros previos en la localidad. La obtención de las muestras fue realizada por medio de buceo “hooka” para los organismos bentónicos, mientras que los peces fueron capturados mediante redes de pesca. En general, los metales encontrados presentan concentraciones comparables con los valores reportados en la literatura para las misma especies, pero en otras localidades, por lo que reflejan una condición natural, indicando además que los niveles de Cd, Hg y Pb en los moluscos bivalvos se encuentran bajo los niveles de aceptación para productos de exportación. Se destaca además que en el caso del Pb, este se encuentra bajo los niveles de detección analíticas en todos los organismos, al igual que el Cd en el pez S. stellatus y el alga G. chilensis. Otra diferencia que resalta corresponde a la presencia de Fe en Rhodymenia sp. que presenta el mayor valor absoluto de todo el estudio.

Diatoms are useful ecological indicators because they are found in abundance in most lotic ecosystems. The use of diatoms as indicators of the quality of river waters is widely accepted based on the fact that all diatom species have optima with respect to their tolerance for environmental conditions such as nutrients, organic pollution, pH, etc. Moreover diatoms are indicators of pollution in short term compared with other groups eg. macroinvertebrates. The rivers and streams of the Pampean plain, in Buenos Aires Province, are subjected to different human impacts. The most important stresses on rivers and streams in the Pampean plain are organic enrichments (discharge of insufficiently treated sewage), nutrients, heavy metals, pathogenic agents, pesticides, herbicides and physical changes produced by dredging and canalisation. The bottom substrate is mostly composed of slime-clay with low proportions of gravel and sand; in consequence, the epipelon is the most represented benthic community and suitable for biomonitoring purposes because it allows for comparing similar substrates along the rivers and streams. The aim of this study is to summarise the most common methodologies used in biomonitoring with diatoms and the application of biotic indices (diversity and pollution indices) in the evaluation of water quality of rivers and streams from the Pampean plain.

The use of chironomids as indicator organisms of the water quality and in the classification of the different aquatic environments demonstrated mainly along the history of Limnology in the Northern Hemisphere was pointed out. The temporal- spatial distribution of Chironomidae in the Limay River (Patagonia) and in the Grande River (San Luis) as part of the studies carried out until present to characterize different running waters were commented. The growing interest for the studies of environmental impact in our country, using the benthic macroinvertebrates, and among them the chironomids, was analyzed through out a monitoring study carried out in the Matanza - Riachuelo basin by the application of the IMRP biotic index with the purpose to evaluate the biological status of these area. The analysis of the pupal exuviae from the drift of flowing waters besides their taxonomical value in biodiversity progress and their use in pollution assessments, starting from the knowledge of the tolerant and non tolerant species to the contamination, was suggested for the region.

L’estudi d’indrets pristins és de gran importància per conèixer els oceans tal com eren sense l’impacte de l’ésser humà. Per efecte de les condicions ambientals extremes, la llunyania dels altres continents i per la seva profunditat, a causa del pes del gel continental, la plataforma continental antàrtica ofereix una gran oportunitat per a entendre millor com seria un ecosistema pristí. A més d’una elevada biodiversitat, els organismes bentònics antàrtics presenten pautes de distribució espacial i demogràfica diferents de les comunitats de les plataformes continentals d’altres mars i oceans del món. Això fa que les comunitats bentòniques antàrtiques s’assemblin més del que es podria pensar a aquelles comunitats del planeta amb la més alta biodiversitat coneguda.

The number of marine protected areas (MPAs) has increased dramatically in the last decade and poses a major logistic challenge for conservation practitioners in terms of spatial extent and the multiplicity of habitats and biotopes that now require assessment. Photographic assessment by autonomous underwater vehicle (AUV) enables the consistent description of multiple habitats, in our case including mosaics of rock and sediment. As a case study, we used this method to survey the Greater Haig Fras marine conservation zone (Celtic Sea, northeast Atlantic). We distinguished 7 biotopes, detected statistically significant variations in standing stocks, species density, species diversity, and faunal composition, and identified significant indicator species for each habitat. Our results demonstrate that AUV‐based photography can produce robust data for ecological research and practical marine conservation. Standardizing to a minimum number of individuals per sampling unit, rather than to a fixed seafloor area, may be a valuable means of defining an ecologically appropriate sampling unit. Although composite sampling represents a change in standard practice, other users should consider the potential benefits of this approach in conservation studies. It is broadly applicable in the marine environment and has been successfully implemented in deep‐sea conservation and environmental impact studies. Without a cost‐effective method, applicable across habitats, it will be difficult to further a coherent classification of biotopes or to routinely assess their conservation status in the rapidly expanding global extent of MPAs. Article impact statement: AUVs offer a solution to monitoring challenges posed by the mixed habitats and growing spatial extent of marine protected areas globally. [ABSTRACT FROM AUTHOR]

Introduction: Since the middle of the XXth century the Gulf of Nicoya estuary (10o N & 85o W) has been the main source of numerous fishing resources, such as mollusks, crustaceans, and fish. The estuary is presently under the increasing impact of local, regional and global stressors. The expeditions on board the Skimmer (1979-1980) and Victor Hensen (1993-1994) research vessels provided multidisciplinary data on the estuary in support of management policies. However, updated information is still needed. Objectives: To update the published lists of fish species from both expeditions and make suggestions for new research areas for future evaluations of the ecosystem. Methods: The fish collections by the Skimmer covered a depth range of 10 to 50 m using an otter trawl net, and those aboard the Victor Hensen were made between 10 to 228 m depth using otter and beam trawl nets. The identification of most of the fish species and the measurement of its lenghts were made on board of both vessels. The species names were updated based on recent literature and the web page World Register of Marine Species (WORMS). The list of species identified in recent years based on voucher specimens from the estuary and deposited in the Ichthyology Collection of the Museum of Zoology, University of Costa Rica, was also included. Results: The total number of identified species from both vessels is 268. A new species of Pontinus is under description. Of the total, 19 are cartilaginous fishes and 249 are bony fishes. The Sciaenidae and the flatfishes were represented by 31 and 32 species, respectivley. The flatfish genus Symphurus was the most diverse, with 11 species. Eighteen species were identified after the publication of the original lists. Eight species were described based on specimens collected during the expeditions: Gymnothorax phalarus, Notarius biffi, N. cookei, Ophicthus mecoptera, O. melope, Sphoeroides rosenblatti, Trinectes xanthurus and Urotrygon cimar. The five longer specimens collected by both vessels, were: the longtail sting ray Hypanus longus (117 cm), the pike conger Cynoponticus coniceps (103 cm), the brown sea catfish Sciades dowii (87 cm), the electric ray Narcine brancroftii (80 cm), and the queen corvina Cynoscion albus (75 cm). Conclusions: In view of the increasing number of users of the estuarine resources, it is urgent a multidisciplinary evaluation of the ecosystem in support of new management policies. The expected results may facilitate updating the Gulf of Nicoya Trophic Model, a management tool available for the estuary since 1998 and based mainly on information gathered during both expeditions. Ecosystem stressors, such as the extraction of resources, the input of pollutants and its possible link to endocrine disruption, as well as the presence of natural barriers such as hypoxia at deeper waters at the mouth of the estuary must be taken into account in a future evaluation. [ABSTRACT FROM AUTHOR]

Em ecossistemas lóticos é comum a formação de diferentes mesohabitats intercalados ao longo do rio, como poções, corredeiras e rápidos, frequentemente acompanhados de alterações na estrutura da fauna bentônica associada. No trabalho analisamos a fauna de invertebrados bentônicos em rápidos e corredeiras de um trecho de serra do Rio Capivara (Bacia do Médio Rio Tietê). A análise das características ambientais e a coleta da fauna foram realizadas em três corredeiras e três rápidos, em um mês da estação chuvosa (cinco réplicas de cada). Os mesohabitats se diferenciaram quanto ao maior porcentual de blocos nos rápidos e maiores valores de profundidade, correnteza e porcentual de matacões nas corredeiras. Do total de 57 Unidades Taxonômicas Operacionais (UTO's) amostradas, 75% foram comuns aos dois mesohabitats (Similaridade de Morisita = 0,86). Quando analisado o porcentual de abundância, a similaridade espacial se manteve e dois grupos se sobressaíram em abundância: Hexapoda (>80%, sendo a maioria Ephemeroptera, Diptera e Trichoptera) e Annelida (10%). As análises exploratórias (cluster e NMDS) também apontaram para uma elevada similaridade espacial, porém os resultados da Análise de Similaridade (ANOSIM) indicaram uma diferença significativa entre os mesohabitats (p

La conservación de los arrecifes coralinos radica en el manejo adecuado de estos ecosistemas marinos, sin embargo es necesario dotar de información biológica para saber que se debe proteger, por lo tanto, disponer con descripciones de las comunidades coralinas contribuye en gran medida a formular estrategias de manejo eficaces. Bajo este contexto se describe la distribución de los hábitats bentónicos dominantes de la planicie del arrecife Enmedio. Durante el periodo noviembre 2014-abril 2016 se recabaron datos geográficos de los componentes bentónicos de la llanura arrecifal mediante buceo libre, esencialmente la información espacial se obtuvo a partir de registros fotográficos utilizando una cámara digital con receptor de posicionamiento global (GPS), con los datos recabados se generó un mapa temático mediante el método kriging simple. Las descripciones de los hábitats arrecifales se complementó con base al número de ensamblajes de especies principalmente de macroinvertebrados bentónicos y peces. Básicamente se diferencian ocho hábitats bentónicos en la planicie del arrecife Enmedio, fundamentalmente están constituidos por las especies Acropora palmata, Millepora alcicornis, Orbicella annularis, Pseudodiploria clivosa, Porites furcata, Palythoa caribaeorum, Eunicea flexuosa y por dos fondos bentónicos: cresta arrecifal y escombros. Los hábitats bentónicos: O. annularis y de A. palmata presentaron un mayor número de especies asociadas, mismas que comparten mayor semejanza en el ensamblaje de especies en comparación al resto de los componentes bentónicos. La distribución que manifiestan los componentes bentónicos con respecto a la cresta arrecifal es parecido al de otras regiones del Atlántico. ABSTRACT The conservation of the coral reefs lies in the proper management of these marine ecosystems, however it is necessary to provide biological information to know what we must protect. Therefore, in order to formulate effective management strategies, descriptions of coral communities are needed. Under this context, the distribution of dominant benthic habitats of the Enmedio reef’s plateau is described. Geographical data of benthic components in the reef lagoon were recorded by free diving during the November 2014-April 2016 period. The spatial information was obtained essentially from photographic records using a digital camera with a receiver using global positioning system (GPS). A thematic map was generated with the data obtained through the simple kriging method. The descriptions of the reef landscapes were complemented by a number of species assemblage, consisting mainly of the benthic macroinvertebrates and fish. Eight benthic habitats in the plain of the Enmedio reef are differentiated and represented mainly by the species Acropora palmata, Millepora alcicornis, Orbicella annularis, Pseudodiploria clivosa, Porites furcata, Palythoa caribaeorum, Eunicea flexuosa and two benthic funds: reef crest and debris. The areas of O. annularis and A. palmata are the most important reef landscapes because these species concentrated a greater number of associated species. These zones subsequently share greater similarity in the assemblage of species compared to other benthic components. The distribution of the benthic components is similar to other regions of the Atlantic.

El bentos, epifiton, seston, las algas filamentosas libres y las plantas acuáticas proporcionan recursos alimenticios y refugio al resto de los niveles tróficos del arroyo. Aquí estudiamos el efecto de una sequía sobre su biomasa y composición elemental en el arroyo Pampeano La Choza, comparando el año 2007, con ~1200 mm anual, y el año 2008, con ~600mm anual (40% menos que el histórico). Considerando que su abundancia dependería principalmente de la transferencia de masa en la capa límite a bajas velocidades y de la deriva aguas abajo, postulamos (H1) que un año seco genera condiciones desfavorables para las plantas acuáticas y el seston, y favorables para las algas filamentosas epifíticas, bentónicas y de matas libres en un arroyo Pampeano. Como son arroyos ricos en nutrientes, postulamos también (H2) que no hay cambios interanuales apreciables en sus composiciones elementales. Los bajos caudales del 2008 determinaron una mayor conductividad, pH y luz disponible, sin cambios apreciables en las típicas altas concentraciones de nutrientes. La sequía produjo bajos caudales y velocidades, con un detrimento de la cantidad de plantas acuáticas (2±0.3 g/m2) y seston (20±8 g/m2), apoyando la H1. La biomasa de las algas filamentosas perifíticas no se incrementó, al contrario de la H1, y las filamentosas libres crecieron apreciablemente a partir de la primavera, apoyando parcialmente la H1. Los resultados de la composición elemental apoyaron la H2, siendo en el caso del seston y del perifiton muy variable. El impacto de un año de sequía sobre la Pampa Ondulada provocaría la reducción de la biomasa de plantas y seston, favoreciendo el incremento de la biomasa de algas filamentosas libres de los arroyos y, consecuentemente, afectaría a los animales que se alimentan y refugian en ellos.

In Colombia, livestock activity is of great importance for the rural economy and the country's food supply. In order to measure the impact of cattle raising and riparian corridors on the composition and diversity of benthic macroinvertebrates in Andean microbasins, nine headwater streams were selected in the municipality of Villamaría (Caldas, Colombia), five of them with riparian corridors and four without protection. During July 2013, macroinvertebrate samples were collected using D-net and Surber nets, and each streams was characterized according to water quality, channel metrics and habitat quality score. In total 98 934 individuals were collected, distributed in nine classes, 17 orders, 56 families and 92 genera. Veneroidea was the most abundant order followed by Trichoptera, Diptera, Tubificida and Ephemeroptera. Coleoptera was the richest order with 28 genera, followed by Diptera with 18, Trichoptera with 11, Ephemeroptera with 10 and Odonata with 8. Streams with riparian corridors were deeper, had higher proportion of coarse substrates and Habitat Quality Score and presented higher genus diversity than those unprotected (P < 0.05). The genera Ferrisia, Eurygerris, Heleobia and Pisidium; total nitrogen, ammonia nitrogen and silt proportion on the streambed were correlated with unprotected streams, whilst the genus Rhagovelia, the subfamily Chironominae, the Habitat Quality Score and the proportion of coarse substrates were correlated with streams with riparian corridors. This information confirms that riparian corridors help reducing the negative impact generated by cattle ranching practices and improve the provision of environmental services, and therefore it is recommended to maintain or restore the strip of riparian vegetation to protect the streams in cattle ranching landscapes. [ABSTRACT FROM AUTHOR]

A total of 298 species of polychaetes have been recorded from Colombia. However, only the family Protodrilidae has been reported from the marine interstitial realm. We here aim at identifying the interstitial annelids inhabiting the sandy beaches in Santa Marta region to the most accurate taxonomic level based on light microscopy examinations. Our samples, collected from the intertidal zone at three touristic beaches in the department of Magdalena (Santa Marta Bay, Rodadero Bay, and Taganga Bay), yielded a total of 83 specimens, which we assigned to five families, ten genera and nine species. From those, two families, eight genera, and the species Hesionides gohari, Neogyptis mediterranea, Neopetitia amphophthalma, Westheidesyllis gesae, and Syllis beneliahuae represent new records for the Colombian fauna. This survey should be considered as a first step towards a complete knowledge of the Colombian diversity of interstitial annelids, and our results significantly contribute to fill the gap of our current knowledge, suggesting a high diversity of species comparable to this in better-known areas of the Caribbean and the Atlantic coasts of Brazil. A brief diagnosis, comments on distribution and ecology, and remarks are provided for each record, in order to facilitate the re-identification of the species. [ABSTRACT FROM AUTHOR]

Four hundred-thirty six polychaetes collected in soft bottoms from the Gulf of Venezuela were examined. Samples were taken from ninety stations, between 2008 and 2012. Thirhteen species were identified, belonging to four families from Eunicida: Eunicidae (6 spp.), Onuphidae (5 spp.), Lumbrineridae (1 sp.) and Oenonidae (1 sp.). Seven of these species are new records for Venezuela. These results increase the knowledge about marine biodiversity from the continental shelf in Venezuela and the southern Caribbean Sea. [ABSTRACT FROM AUTHOR]

La zona litoral rocosa esta entre los ambientes físicamente más extremos de la tierra. Los organismos que allí habitan son azotados alternadamente por factores físico-químicos y biológicos. Debido a la gran importan- cia ecológica que poseen estos ambientes, se estudió la diversidad, abundancia y distribución de la macrofauna bentónica del litoral rocoso, en la costa norte del estado Sucre, Venezuela. Se realizaron muestreos bimensuales, durante un año. La recolecta del material biológico se realizó de forma manual, dentro de una cuadrícula de 0.25m², en la zona litoral (supra, medio e infralitoral). Los organismos fueron preservados en formalina al 10% para su posterior identificación y análisis (parámetros ecológi- cos y prueba Kruskal-Wallis a la abundancia y diversidad). Se obtuvieron un total 19 020 organismos (86spp.), en 8 filos, 45 familias y 47 géneros. Los moluscos fueron los más abundantes y diversos (58 spp.), seguido de los artró- podos (12spp.), anélidos (7spp.), equinodermos (5spp.), y cnidarios, sipuncúlidos, nemertínidos y urocordados (1sp.). Los resultados encontrados, coincidieron con el esquema universal de zonación de Stephenson & Stephenson (1949). Las localidades de Río Caribe y Boca de Río presentaron los valores más altos de los parámetros ecológicos y Playa Grande los más bajos. Estadísticamente se observaron diferencias en la abundancia y diversidad de la macrofauna, entre las tres zonas. La poca información de la composición y distribución macrobentónica del litoral rocoso, impide una mejor comparación, no obstante los resultados contri- buyen al conocimiento de la biodiversidad marina en esta región venezolana.

La elaboración de listas de los diferentes grupos zoológicos posee gran valor, ya que constituyen la base para futuros estudios zoogeográficos y ecológicos. Tales listas tienen especial importancia en los países de esta parte del Pacífico, donde son muy escasas. En nuestro medio se han realizado algunos avances de este tipo con respecto a los moluscos y crustáceos, pero ninguno con respecto a poliquetos, que conjuntamente con los anteriores, constituyen los grupos más importantes del ecosistema marino.

Se evaluó mensualmente los cambios y la magnitud del impacto de "El Niño" (EN), sobre el mecanismo del asentamiento larval de algunos invertebrados marinos bentónicos, en sustratos artificiales filamentosos (fibra nylon), entre enero 1996 y julio 1998, en una estación fija, a 10m de profundidad, situada en el lado oriental de la Isla Independencia, en Bahía Independencia, Durante 1996, en la fase fría "La Niña" (LN), el número de especies presentó un pico en abril y la densidad en junio. En la fase cálida EN 199798, la densidad total y el número de especies, presentaron un primer pico en marzo de 1997, luego, un segundo pico, en febrero y julio de 1998, respectivamente. Un primer grupo de especies que intensificó su asentamiento durante la fase fría LN 1996, estuvo constituido por el bivalvo Hiatella solida, el turbelario Notoplana sp. y el gastrópodo Caecum chilense. El segundo grupo intensificó su asentamiento en la etapa temprana de la fase cálida EN 1997-98, Y lo formaron el braquiópodo Discinisca lamel/osa, el equinodermo Ophíactís kr6yerí y bivalvos de la Familia Mytllidae, Un tercer grupo, mostró una intensificación del asentamiento larval, en la etapa tardía de la fase cálida EN 1997-98, a inicios de 1998, y fue formado por el bivalvo Argopecten purpuratus y un gastrópodo turriforme. La aparición de larvas recién asentadas de especies tropicales, como el bivalvo Ptería stema y el gastrópodo Epitoníum sp., tuvo lugar en la etapa tardía de la fase cálida EN 1997-98.

Tropical Eastern Pacific island streams (TEPis) differ from other neotropical streams in their rainy climate, mixed sedimentary-volcanic geology and faunal composition. Yet, their relationships between environmental characteristics and stream biota remain unexplored. We analyzed the environmental subject at three spatial scales using a fully nested sampling design (6 streams, 2 reaches within each stream, 2 habitats within each reach, and 4 replicates per habitat) on Gorgona Island (Colombia). Sampling was carried out in two months with contrasting rainfall during early 2009. We studied the spatial variation of assemblage composition and density along with 27 independent variables within two contrasting rainfall conditions. Five stream-scale variables, two reach-scale variables, and five habitat-scale variables were selected using a Canonical Correspondence Analysis (CCA). A partial CCA showed that the total variance explained was 13.98%, while stream- and habitat-scale variables explained the highest proportion of the variance (5.74 and 5.01%, respectively). Dissolved oxygen (as affected by rainfall), high-density use zone (a management category), and sedimentary geology were the best descriptors of insect assemblages. The two latter descriptors affected fine-scale variables such as total benthic organic matter and gravel substratum, respectively. A Nested ANOVA showed significant differences in total density and richness among streams and habitats, and significant differences between the two sampling months regardless of the spatial scale. The evenness showed a significant stream- and habitat-dependent temporal variability. These results suggested that rainfall regime in Gorgona Island might be a driver of insect assemblage dynamics mediated by water chemistry and substratum properties. Spatial assemblage variability here is greater within habitats (among samples), and a minor fraction occurs at habitat- and stream-scales, while no longitudinal pattern was observed probably due to the short courses. Temporal variability should be further studied relative to rainfall and discharge regimes. Rev. Biol. Trop. 62 (Suppl. 1): 65-83. Epub 2014 February 01.

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Thirty waterbodies on the Transmexican Volcanic Belt were studied using standardized methods, covering an altitudinal gradient from 737 to 4283 masl and different climatic types. Waterbodies of tree different origins were included: tectonic (4), volcanic (11 craters or maars and 7 volcanic dams) and reservoirs (8). Reservoirs and tectonic lakes were mostly shallow (< 6 m) while volcanic lakes were the deepest (> 25 m). Most were freshwater bodies with alkaline waters (pH > 7.5) dominated by [Ca2+] or [Na+] and [HCO3 -]. Subsaline (6) and hyposaline (2) lakes were dominated by [Cl-] - [HCO3 -] and [Na+]. In thirteen lakes, nutrient levels could be limiting primary productivity, mostly P, but also N and Si. Half of the lakes (16) were eutrophic or hypertrophic and most of these were also shallow (< 8 m) and correlated with warm, moist conditions. Ninety-seven taxa of aquatic organisms (phytoplankton, and surface sediment diatoms, testate amoebae, cladoceran and ostracodes) were reported, which could potentially be used as bioindicators. Principal component analysis (PCA) showed that temperature and precipitation were the main environmental gradients related to the lakes' limnological characteristics: colder climates related with lowest TDS (< 100 mg/L); dry climates with subsaline and hyposaline lakes, and warm-moist climates with eutrophic and hypertrophic lakes. Through the Procrustes technique we obtained indications that general geographic variables were important for some of the lakes, whereas the local factors were significant for others. It is through the knowledge of the basic limnology and biodiversity of Mexican lakes that more complex or detailed studies can be proposed leading to a better understanding, management, and conservation of water resources. [ABSTRACT FROM AUTHOR]

In this study, fifteen species of benthic polychaetes associated with soft bottoms of the Gulf of Venezuela are taxonomically analyzed. The material was collected in ninety stations between 2009-2012. A total of 421 specimens were examined, among which 13 species of wandering polychaetes belonging to eight families were identified. Among the species identified Paranaitis polynoides, Phyllodocidae, and Aglauphamus verrilli, Nephtyidae, constitute new records for Venezuela. These results increase knowledge about marine biodiversity in the Venezuelan continental shelf. [ABSTRACT FROM AUTHOR]