Coral reefs benefit from reduced land-sea impacts under ocean warming.

Coral reef ecosystems are being fundamentally restructured by local human impacts and climate-driven marine heatwaves that trigger mass coral bleaching and mortality1. Reducing local impacts can increase reef resistance to and recovery from bleaching2. However, resource managers lack clear advice on targeted actions that best support coral reefs under climate change3 and sector-based governance means most land- and sea-based management efforts remain siloed4. Here we combine surveys of reef change with a unique 20-year time series of land-sea human impacts that encompassed an unprecedented marine heatwave in Hawai'i. Reefs with increased herbivorous fish populations and reduced land-based impacts, such as wastewater pollution and urban runoff, had positive coral cover trajectories predisturbance. These reefs also experienced a modest reduction in coral mortality following severe heat stress compared to reefs with reduced fish populations and enhanced land-based impacts. Scenario modelling indicated that simultaneously reducing land-sea human impacts results in a three- to sixfold greater probability of a reef having high reef-builder cover four years postdisturbance than if either occurred in isolation. International efforts to protect 30% of Earth's land and ocean ecosystems by 2030 are underway5. Our results reveal that integrated land-sea management could help achieve coastal ocean conservation goals and provide coral reefs with the best opportunity to persist in our changing climate.

Red-list status and extinction risk of the world's whales, dolphins, and porpoises.

To understand the scope and scale of the loss of biodiversity, tools are required that can be applied in a standardized manner to all species globally, spanning realms from land to the open ocean. We used data from the International Union for the Conservation of Nature Red List to provide a synthesis of the conservation status and extinction risk of cetaceans. One in 4 cetacean species (26% of 92 species) was threatened with extinction (i.e., critically endangered, endangered, or vulnerable) and 11% were near threatened. Ten percent of cetacean species were data deficient, and we predicted that 2-3 of these species may also be threatened. The proportion of threatened cetaceans has increased: 15% in 1991, 19% in 2008, and 26% in 2021. The assessed conservation status of 20% of species has worsened from 2008 to 2021, and only 3 moved into categories of lesser threat. Cetacean species with small geographic ranges were more likely to be listed as threatened than those with large ranges, and those that occur in freshwater (100% of species) and coastal (60% of species) habitats were under the greatest threat. Analysis of odontocete species distributions revealed a global hotspot of threatened small cetaceans in Southeast Asia, in an area encompassing the Coral Triangle and extending through nearshore waters of the Bay of Bengal, northern Australia, and Papua New Guinea and into the coastal waters of China. Improved management of fisheries to limit overfishing and reduce bycatch is urgently needed to avoid extinctions or further declines, especially in coastal areas of Asia, Africa, and South America.

Estado en la lista roja y riesgo de extinción de las ballenas, delfines y marsopas del mundo Resumen Para comprender el alcance y la escala de la pérdida de biodiversidad, se necesitan herramientas que puedan aplicarse de forma estandarizada a todas las especies a nivel mundial y que abarquen todos los ámbitos desde la tierra hasta el océano. Utilizamos datos de la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza para proporcionar una síntesis del estado de conservación y el riesgo de extinción de los cetáceos. Una de cada 4 especies de cetáceos (26% de 92 especies) se encuentra amenazada (es decir, en peligro crítico, en peligro o vulnerable) y el 11% de las especies está clasificado como casi amenazada. El 10% de las especies de cetáceos carecía de datos, por lo que predijimos que 2-3 de estas especies también podrían estar amenazadas. La proporción de cetáceos amenazados ha aumentado: 15% en 1991, 19% en 2008 y 26% en 2021. El estado de conservación evaluado del 20% de las especies ha empeorado de 2008 a 2021, pues sólo 3 pasaron a categorías de menor amenaza. Las especies de cetáceos con áreas de distribución geográficas pequeñas tenían más probabilidades de ser catalogadas como amenazadas que aquellas con áreas de distribución extensas, y aquellas que ocurren en hábitats de agua dulce (100% de las especies) y costeros (60% de las especies) eran las que se encontraban bajo mayor amenaza. La superposición de los mapas de distribución de las especies reveló la existencia de puntos calientes de pequeños cetáceos amenazados en el sudeste asiático y en una zona que abarca el Triángulo de Coral y se extiende por las aguas cercanas a la costa de la Bahía de Bengala, el norte de Australia, Papúa Nueva Guinea y las aguas costeras de China. Urge mejorar la gestión de las pesquerías para limitar la sobrepesca y reducir la captura accesoria con el fin de evitar extinciones o mayores descensos, especialmente en las zonas costeras de Asia, África y Sudamérica.

Adapting the WEPP Hillslope Model and the TLS Technology to Predict Unpaved Road Soil Erosion.

Unpaved road erosion have been recognized as important sediment sources in a watershed. To evaluate where and when road erosion occurs, the soil loss along road segments should be precisely predicted with process-based erosion models. Methods: The hillslope version of the Water Erosion Prediction Project (WEPP) was used to estimate soil loss from 20 typical road segments in the red soil region of South China. Terrestrial laser scanning (TLS)-measured soil losses were used to validate the model simulations. The results showed that the WEPP model could reasonably predict the total soil loss in relatively short (less than 100 m) and gentle (slope gradient lower than 10%) road segments. In contrast, soil loss would be underestimated for long or steep road segments. Detailed outputs along roads revealed that most of the peak soil loss rates were underestimated. It might due to the linear critical shear stress theory in the WEPP model. Additionally, the lack of upstream flow was found to be connected to the relatively low model efficiency. Nevertheless, the WEPP simulation could accurately fit erosion trend and predict the peak soil loss positions along road segments. Conclusions: The WEPP model could be adopted to evaluate the erosion risk of unpaved roads in the red soil region of South China.

A study on the marine ecological security assessment of Guangdong-Hong Kong-Macao Great Bay Area.

The construction of world-class Bay makes the marine ecology in Guangdong-Hong Kong-Macao Great Bay Area in risk. Based on the DPSIR index framework, Lotka-Volterra symbiosis model is applied to calculate symbiosis degree between coastal socio-economic system and marine ecosystem in 9 coastal cities. It is found that the marine ecological pressure in this area have not been reversed in recent 20 years. Most cities are in the stage that socio-economic development and marine ecological damage coexist. In Shenzhen, Guangzhou, Dongguan and Zhongshan, the damaged marine ecology has begun to restrain the further expansion of economy and society. The massive population agglomeration in Hong Kong, Macao and other places has caused serious marine ecological stress. It is urgent to improve the marine ecological security by cultivating ecological industrial system and industrial clusters, establishing a land-sea ecological restoration, promoting joint-protection and co-governance across different administrative regions.

Effects of human footprint and biophysical factors on the body-size structure of fished marine species.

Marine fisheries in coastal ecosystems in many areas of the world have historically removed large-bodied individuals, potentially impairing ecosystem functioning and the long-term sustainability of fish populations. Reporting on size-based indicators that link to food-web structure can contribute to ecosystem-based management, but the application of these indicators over large (cross-ecosystem) geographical scales has been limited to either fisheries-dependent catch data or diver-based methods restricted to shallow waters (<20 m) that can misrepresent the abundance of large-bodied fished species. We obtained data on the body-size structure of 82 recreationally or commercially targeted marine demersal teleosts from 2904 deployments of baited remote underwater stereo-video (stereo-BRUV). Sampling was at up to 50 m depth and covered approximately 10,000 km of the continental shelf of Australia. Seascape relief, water depth, and human gravity (i.e., a proxy of human impacts) were the strongest predictors of the probability of occurrence of large fishes and the abundance of fishes above the minimum legal size of capture. No-take marine reserves had a positive effect on the abundance of fishes above legal size, although the effect varied across species groups. In contrast, sublegal fishes were best predicted by gradients in sea surface temperature (mean and variance). In areas of low human impact, large fishes were about three times more likely to be encountered and fishes of legal size were approximately five times more abundant. For conspicuous species groups with contrasting habitat, environmental, and biogeographic affinities, abundance of legal-size fishes typically declined as human impact increased. Our large-scale quantitative analyses highlight the combined importance of seascape complexity, regions with low human footprint, and no-take marine reserves in protecting large-bodied fishes across a broad range of species and ecosystem configurations.

Las pesquerías marinas de los ecosistemas costeros en muchas áreas del mundo históricamente han removido a individuos de gran tamaño, potencialmente perjudicando el funcionamiento ambiental y la sostenibilidad a largo plazo de las poblaciones de peces. Los reportes sobre los indicadores basados en el tamaño que se vinculan con la estructura de la red alimenticia pueden contribuir al manejo basado en el ecosistema, aunque la aplicación de estos indicadores a grandes (inter-ecosistemas) escalas geográficas ha estado limitada a datos de captura dependientes de las pesquerías o métodos basados en el buceo restringidos a aguas someras (<20 m), lo cual puede representar erróneamente la abundancia de peces de gran tamaño capturados para la pesca. Obtuvimos los datos de la estructura del tamaño corporal de 82 teleósteos marinos demersales focalizados por razones recreativas o comerciales tomados de 2,904 despliegues de video estéreo subacuático remoto con cebo (stereo-BRUV, en inglés). El muestreo se realizó hasta los 50 metros de profundidad y abarcó aproximadamente 10,000 km del talud continental de Australia. El relieve marino, la profundidad del agua y la gravedad humana (es decir, un indicador de los impactos humanos) fueron los pronosticadores más sólidos de la probabilidad de incidencia de los peces de gran tamaño y de la abundancia de peces por encima del tamaño legal mínimo de captura. Las reservas marinas de protección total tienen un efecto positivo sobre la abundancia de los peces que están por encima del tamaño legal, aunque el efecto varió según el grupo de especies. Como contraste, los peces de tamaño sublegal fueron pronosticados de mejor manera usando gradientes de la temperatura de la superficie marina (media y varianza). En las áreas con un impacto humano reducido, los peces de gran tamaño corporal tenían hasta tres veces mayor probabilidad de aparecer y los peces de tamaño legal eran aproximadamente cinco veces más abundantes. Para los grupos de especies conspicuas con afinidades contrastantes de hábitat, ambiente y biogeografía, la abundancia de peces de tamaño legal normalmente declinó conforme aumentó el impacto humano. Nuestros análisis cuantitativos a gran escala resaltan la importancia conjunta que tienen la complejidad marina, las regiones con una huella humana reducida y las reservas marinas de protección total para la protección de los peces de gran tamaño corporal en una extensa gama de especies y configuraciones ecosistémicas. Efectos de la Huella Humana y los Factores Biofísicos sobre la Estructura del Tamaño Corporal de Especies Marinas Capturadas para la Pesca.

Environmental assessment, mechanical behavior, and chemical properties of self-compacting mortars (SCMs) with harbor dredged sediments to be used in construction.

Environmental and ecological issues have led to the development of new sustainable channels for the recovery of dredged sediments. One of the major difficulties of sediment valorization lies in particular in its very heterogeneous composition. For example, the presences of heavy metals and organic matter have a significant influence on the environmental impact of materials formulated with sediment. Some heavy metals such as antimony, mercury, lead, and cadmium in high concentrations are dangerous to the body. Trace metals trapped in sediments are transformed through complex biogeochemical processes. They subsequently associate with organic matter to form clay-humic groups that define the degree of sediment pollution. The Harbour Dredging Sediments (HDSs) used were classified as non-hazardous waste in accordance with Directive 12/12/14/EC. The purpose of this study is to evaluate the environmental impact of the use of HDS from active lagoon in the formulation of self-compacting concrete (SCC) with the objective of incorporating a high sediment content, obtaining materials with a low environmental impact and ensuring compressive strength of a C25/30 class concrete. Three HDSs are being studied that have a significant impact their difference by their fines content at 125 µm. Sediments recovered from the active lagooning process have not undergone any physical, chemical, or thermal treatment. The DMDA (Densified Mixture Design Algorithm) method is used to optimize the composition of "sediment" SSCs. The communication focuses on mortars equivalent to these "sediment" SCCs (SCMs). Sediment represents about 20% of the granular composition with a sediment-to-cement ratio of 80%. Compressive strengths are greater than 25 MPa and tensile strengths are in the range of 3 to 8 MPa at 28 days of curing. From an environmental point of view, all heavy metals are stabilized except nickel. In particular, there has been a considerable decrease in the levels of sulfate, total organic carbon, and chloride. The different SCMs are classified as inert, clinker hydration produces hydrates that capture and stabilize heavy metals in the cementitious matrix. The results obtained show that HDSs could be used as a secondary raw material in the formulation of self-compacting concretes.

Assessing the population-level conservation effects of marine protected areas.

Marine protected areas (MPAs) cover 3-7% of the world's ocean, and international organizations call for 30% coverage by 2030. Although numerous studies show that MPAs produce conservation benefits inside their borders, many MPAs are also justified on the grounds that they confer conservation benefits to the connected populations that span beyond their borders. A network of MPAs covering roughly 20% of the Channel Islands National Marine Sanctuary was established in 2003, with a goal of providing regional conservation and fishery benefits. We used a spatially explicit bioeconomic simulation model and a Bayesian difference-in-difference regression to examine the conditions under which MPAs can provide population-level conservation benefits inside and outside their borders and to assess evidence of those benefits in the Channel Islands. As of 2017, we estimated that biomass densities of targeted fin-fish had a median value 81% higher (90% credible interval: 23-148) inside the Channel Island MPAs than outside. However, we found no clear effect of these MPAs on mean total biomass densities at the population level: estimated median effect was -7% (90% credible interval: -31 to 23) from 2015 to 2017. Our simulation model showed that effect sizes of MPAs of <30% were likely to be difficult to detect (even when they were present); smaller effect sizes (which are likely to be common) were even harder to detect. Clearly, communicating expectations and uncertainties around MPAs is critical to ensuring that MPAs are effective. We provide a novel assessment of the population-level effects of a large MPA network across many different species of targeted fin-fish, and our results offer guidance for communities charged with monitoring and adapting MPAs.

Las áreas marinas protegidas (AMPs) cubren entre 3-7% de los océanos del planeta y las organizaciones internacionales piden una cobertura del 30% para el 2030. Aunque numerosos estudios muestran que las AMPs producen beneficios de conservación dentro de sus límites, muchas de estas áreas también están justificadas por otorgarles beneficios de conservación a las poblaciones conectadas que abarcan más allá de sus fronteras. Una red de AMPs que cubre aproximadamente el 20% del Santuario Marino Nacional de las Islas del Canal fue establecida en 2003 con el objetivo de proporcionar beneficios para la conservación y las pesquerías regionales. Usamos un modelo de simulación bioeconómica espacialmente explícito y una regresión bayesiana de diferencia-en-diferencia para examinar las condiciones bajo las que las AMPs pueden proporcionar beneficios de conservación a nivel poblacional dentro y fuera de sus límites y para evaluar las evidencias de esos beneficios en las Islas del Canal. Hasta el 2017, estimamos que la densidad de la biomasa de los peces focalizados tuvo un valor medio de 81% (90% intervalo creíble 23-148) dentro de las AMPs de las Islas del Canal que fuera de ellas. Sin embargo, no encontramos un efecto claro de estas AMPs sobre la densidad de biomasa total promedio a nivel poblacional; el efecto medio estimado fue de -7% (90% intervalo creíble -31 - 23) entre 2015 y 2017. Nuestro modelo de simulación mostró que los tamaños del efecto de las AMPs menores al 30% tenían mayor probabilidad de ser difíciles de detectar (incluso cuando estaban presentes); los tamaños de efecto más pequeños (que es probable que sean comunes) fueron incluso más difíciles de detectar. Claramente, es muy importante comunicar las expectativas e incertidumbres en torno a las AMPs para asegurar que éstas sean efectivas. Proporcionamos una evaluación novedosa de los efectos a nivel poblacional de una red extensa de AMPs para muchas especies de peces focalizados y nuestros resultados ofrecen una guía para las comunidades encargadas de monitorear y adaptar las AMPs.

Viability of the vaquita, Phocoena sinus (Cetacea: Phocoenidae) population, threatened by poaching of Totoaba macdonaldi (Perciformes: Sciaenidae) / Viabilidad de la población de vaquita marina, Phocoena sinus (Cetacea: Phocoenidae), amenazada por la pesca ilegal de Totoaba macdonaldi (Perciformes: Sciaenidae)

Abstract Introduction: Despite extensive science-based conservation policy recommendations, with fewer than 20 individuals remaining, the vaquita (Phocoena sinus) -endemic to the Gulf of California- is the world's most endangered marine mammal due to incidental catch in fishing nets and whether it can recover is unclear. Objective: Assess expectations for vaquita over the next two decades. Methods: We identified factors affecting the vaquita, constructed life tables, derived demographic parameters for different scenarios and conducted a population viability analysis using stochastic age-structured matrix Leslie models. Results: Analytical results indicate that the vaquita net growth rate is particularly sensitive to juvenile survival. We find that intensive, ongoing bycatch in gillnets used to poach totoaba (Totoaba macdonaldi) over the past decade brought the vaquita population to its current critically low size. Currently this seems to be exacerbated by demographic stochasticity and a potential Allee effect. Conclusions: If totoaba poaching is eliminated immediately, demographically, vaquita can recover; its long-term survival will depend on its uncertain genetic status, although a recent study found encouraging results in this regard.

Resumen Introducción: Pese a las acciones de conservación basadas en la ciencia y las políticas recomendadas, con menos de 20 individuos sobrevivientes, la vaquita (Phocoena sinus) -endémica del Golfo de California- es el mamífero marino más amenazado del mundo debido a su muerte incidental en redes de pesca; una pregunta relevante es si su población se puede recuperar. Objetivo: Evaluar las expectativas para la vaquita marina durante los próximos 20 años. Métodos: Identificamos los factores que afectan a la vaquita marina, construimos tablas de vida, derivamos parámetros demográficos para diferentes escenarios y realizamos un análisis de viabilidad poblacional utilizando matrices estocásticas de Leslie, estructuradas por edad. Resultados: La tasa de crecimiento neto de la vaquita es muy sensible a la supervivencia de los juveniles. Encontramos que la captura incidental intensiva y continua en redes de enmalle para la pesca furtiva de totoaba (Totoaba macdonaldi) durante la última década llevó a la población de vaquitas a su actual estado crítico. Esto parece agravarse por la estocasticidad demográfica y un potencial efecto Allee. Conclusiones: Si la pesca furtiva de totoaba se elimina de inmediato, demográficamente la vaquita puede recuperarse; su supervivencia a largo plazo dependerá de su incierto estatus genético, aunque los resultados de un estudio reciente son alentadores en este sentido.

Marine reserves, fisheries ban, and 20 years of positive change in a coral reef ecosystem.

By 2004, Belize was exhibiting classic fishing down of the food web. Groupers (Serranidae) and snappers (Lutjanidae) were scarce and fisheries turned to parrotfishes (Scarinae), leading to a 41% decline in their biomass. Several policies were enacted in 2009-2010, including a moratorium on fishing parrotfish and a new marine park with no-take areas. Using a 20-year time series on reef fish and benthos, we evaluated the impact of these policies approximately 10 years after their implementation. Establishment of the Southwater Caye Marine Reserve led to a recovery of snapper at 2 out of 3 sites, but there was no evidence of recovery outside the reserve. Snapper populations in an older reserve continued to increase, implying that at least 9 years is required for their recovery. Despite concerns over the feasibility of banning parrotfish harvest once it has become a dominant fin fishery, parrotfishes returned and exceeded biomass levels prior to the fishery. The majority of these changes involved an increase in parrotfish density; species composition and adult body size generally exhibited little change. Recovery occurred equally well in reserves and areas open to other forms of fishing, implying strong compliance. Temporal trends in parrotfish grazing intensity were strongly negatively associated with the cover of macroalgae, which by 2018 had fallen to the lowest levels observed since measurements began in 1998. Coral populations remained resilient and continued to exhibit periods of net recovery after disturbance. We found that a moratorium on parrotfish harvesting is feasible and appears to help constrain macroalgae, which can otherwise impede coral resilience.

Reservas Marinas, Vedas Pesqueras y 20 Años de Cambios Positivos en un Ecosistema de Arrecife de Coral Resumen Para el año 2004, Belice estaba exhibiendo la clásica pesca de los niveles más bajos de las cadenas alimenticias marinas. Los meros (Serranidae) y los pargos (Lutjanidae) eran escasos y las pesquerías comenzaron a consumir a los peces loro (Scarinae), lo que resultó en una declinación del 41% de su biomasa. Entre el 2009 y el 2010 se promulgaron varias políticas, incluyendo una moratoria para la pesca del pez loro y un nuevo parque marino con zonas de no consumo. Mediante una serie temporal de 20 años para los peces de arrecifes y el bentos, evaluamos el impacto de estas políticas aproximadamente diez años después de su implementación. La creación de la Reserva Marina del Cayo Southwater resultó en la recuperación del pargo en dos de tres sitios, pero no hubo evidencias de la recuperación fuera de la reserva. Las poblaciones de pargos en una reserva más vieja continuaron su incremento, lo que implica que se requieren al menos nueve años para su recuperación. A pesar de la preocupación por la viabilidad de la veda para el pez loro una vez que se haya convertido en una pesquería dominante, los peces loro regresaron al sitio de pesca y excedieron los niveles de biomasa previos a la pesquería. La mayoría de estos cambios involucró un incremento en la densidad de los peces loro; la composición de especies y la talla corporal adulta generalmente exhibieron pocos cambios. La recuperación ocurrió equitativamente bien en las reservas y en las áreas abiertas a otras formas de pesca, lo que implica un estricto cumplimiento de las restricciones. Las tendencias temporales en la intensidad de pastoreo de los peces loro estuvieron fuertemente asociadas de manera negativa con la cobertura de macroalgas, la cual para el 2018 había caído a los niveles más bajos observados desde que se comenzó a medir en 1998. Las poblaciones coralinas permanecieron resilientes y continuaron exhibiendo periodos de recuperación neta después de la perturbación. Descubrimos que una moratoria para la pesca de pez loro es viable y parece ayudar a restringir las macroalgas, las cuales de otra forma pueden impedir la resiliencia del coral.

Diversidad de los hábitats submareales de la Península de Santa Elena e Islas Murciélago, Pacífico Norte, Costa Rica

Introducción: Los hábitats costeros de todo el mundo están experimentando una presión cada vez mayor debido a la contaminación, el desarrollo costero, la pesca y el cambio climático. Identificar y registrar la biodiversidad costera es esencial para evaluar la salud, los cambios y el alcance de la pérdida de biodiversidad de los ecosistemas. Los hábitats costeros tropicales como los arrecifes de coral y los lechos de pastos marinos han sido el foco de investigación de los científicos durante las últimas décadas; sin embargo, se han descuidado otros ecosistemas, como los bosques de macroalgas, los fondos de sedimentos submareales (20-30 m de profundidad) y los arrecifes rocosos. Objetivo: Este trabajo reporta la biodiversidad marina asociada con arrecifes rocosos, arrecifes de coral, bosques de Sargazo y fondos submareales sedimentarios (20-30 m de profundidad), en un área tropical de afloramiento estacional (Península de Santa Elena, Bahía de Santa Elena e Islas Murciélago, Costa Rica). Métodos: Durante la Expedición Santa Elena (21 de abril-2 de mayo de 2018), se visitaron un total de 28 sitios para registrar la biodiversidad en cuatro hábitats diferentes (arrecifes rocosos y de coral, bosques de sargazo y fondos de sedimentos submareales), utilizando SCUBA, en muestreos sistemáticos, evaluaciones visuales y en algunos fondos de sedimentos se utilizó una draga de arrastre por 20 minutos. Resultados: Se identificaron un total de 254 taxones, siendo los peces óseos el grupo más diverso con 91 especies, seguido de los gasterópodos (25 spp.), las algas rojas (21 spp.) y los antozoos (19 spp.). Se reportan cuatro nuevos registros para el Pacífico continental de Costa Rica, incluida la subclase de una anémona tubícola (Ceriantharia). Conclusiones: Los resultados muestran que la península de Santa Elena, la bahía de Santa Elena y las islas Murciélago albergan hábitats poco comunes y no estudiados, como bosques del alga parda Sargassum, fondos de sedimentos, arrecifes construidos por el coral masivo Pavona gigantea, que es muy inusual, y comunidades de arrecifes rocosos dominadas por colonias calcáreas de poliquetos (Salmacina tribranchiata).

Introduction: Worldwide, coastal habitats are experiencing increasing pressure from pollution, coastal development, fisheries, and climate change. Identifying and recording coastal biodiversity is essential to assess ecosystem health, changes and the extent of biodiversity loss. Coastal tropical habitats such as coral reefs and seagrass beds have been the research focus for scientists during the last decades; however, other ecosystems have been neglected, such as macroalgae forests, subtidal (20-30 m deep) sedimentary bottoms, and rocky reefs. Objective: Our study reports the marine biodiversity associated with rocky reefs, coral reefs, Sargassum forests and sedimentary subtidal bottoms (20-30 m deep), in a tropical seasonal upwelling area (Santa Elena Peninsula, Santa Elena Bay, and Murciélago Islands, Costa Rica). Methods: During the 'Santa Elena Expedition' (April 21-May 2 2018), a total of 28 sites were visited in order to record the biodiversity across four different habitats (rocky and coral reefs, Sargassum forests, subtidal sedimentary bottoms), using SCUBA and both systematic surveys and visual assessments; in some sedimentary bottoms a 20-minute dredge tows were done. Results: A total of 254 taxa were identified, being bony fishes the most diverse group (91 species), followed by gastropods (25 spp.), red algae (21 spp.) and anthozoans (19 spp.). We report four new records for the Pacific mainland of Costa Rica, including the subclass of tube-dwelling sea anemone (Ceriantharia). Conclusions: Our results show that Santa Elena Peninsula, Santa Elena Bay, and Murciélago Islands harbor uncommon and unstudied habitats, such as Sargassum forests, sedimentary bottoms, reefs constructed by the stony coral Pavona gigantea -which is very unusual- and rocky reef communities dominated by calcareous colonies of polychaetes (Salmacina tribranchiata).

Área de conservación Guanacaste Echinoderms, North Pacific of Costa Rica / Equinodermos del Área de Conservación Guanacaste, Pacífico Norte de Costa Rica

Introduction: The study of the marine diversity of the North Pacific of Costa Rica began with isolated foreign expeditions in the 1930s and was systematically developed in the mid-1990s by the Center for Research in Marine Sciences and Limnology, Universidad de Costa Rica, as consequence there are now a total of 1 479 reported species in this region. Objective: Present an update to the echinoderm richness of the Guanacaste Conservation Area. Methods: We sampled 25 localities exhaustively and estimated similarity between sites based on the family richness and environmental heterogeneity. Results: We found 61 taxa, which represent 26 % of the echinoderm reported species for the country's Pacific coast. Of these, 43 species are new records for the Guanacaste Conservation Area, and seven for Costa Rica and Central American Pacific coasts. We found three morpho-species that do not match to available descriptions of the Eastern Tropical Pacific echinoderm species. We also found the holothuroid Epitomapta tabogae, and the ophiuroid Ophioplocus hancocki, previously thought endemic to Panama and the Galapagos Islands, respectively. The proximity of the sampled sites and the redundancy of certain families may explain why we did not find important differences among localities. Conclusions: The echinoderm richness of this conservation area is at least 20 % higher than previously reported, reaching similar levels to those in other high diversity sites of the Eastern Tropical Pacific.

Introducción: El estudio de la diversidad marina del Pacífico Norte de Costa Rica inició con expediciones extranjeras aisladas en la década de 1930, y fue desarrollado sistemáticamente a mediados de la década de 1990 por el Centro de Investigaciones en Ciencias del Mar y Limnología de la Universidad de Costa Rica, como consecuencia ahora se reporta un total de 1 479 especies en esta región. Objetivo: Presentar una actualización de la riqueza de equinodermos del Área de Conservación Guanacaste. Métodos: Realizamos muestreos exhaustivos en 25 localidades y estimamos la similitud entre sitios con base en la riqueaza de familias y la heterogeneidad ambiental. Resultados: Encontramos 61 taxa, que representan el 26% de las especies reportadas para la costa pacífica del país. De estas, 43 especies son nuevos registros para el Área de Conservación Guanacaste y siete para las costas de Costa Rica y el Pacífico centroamericano. Tres morfoespecies no coinciden con las descripciones disponibles para las especies del Pacífico Tropical Oriental. Por último, hallamos un ejemplar del holoturoideo Epitomapta tabogae y otro del ofiuroideo Ophioplocus hancocki, considerados endémicos para Panamá y las Islas Galápagos respectivamente. La proximidad entre los sitios muestreados y la redundancia de ciertas familias pueden explicar por qué no se encontraron diferencias entre las localidades. Conclusiones: La riqueza de equinodermos de esta área de conservación es al menos 20% mayor que la reportada anteriormente, alcanzando niveles similares a los de otros sitios de alta diversidad del Pacífico Tropical Oriental.

Effects of learning and adaptation on population viability.

Cultural adaptation is one means by which conservationists may help populations adapt to threats. A learned behavior may protect an individual from a threat, and the behavior can be transmitted horizontally (within generations) and vertically (between generations), rapidly conferring population-level protection. Although possible in theory, it remains unclear whether such manipulations work in a conservation setting; what conditions are required for them to work; and how they might affect the evolutionary process. We examined models in which a population can adapt through both genetic and cultural mechanisms. Our work was motivated by the invasion of highly toxic cane toads (Rhinella marina) across northern Australia and the resultant declines of endangered northern quolls (Dasyurus hallucatus), which attack and are fatally poisoned by the toxic toads. We examined whether a novel management strategy in which wild quolls are trained to avoid toads can reduce extinction probability. We used a simulation model tailored to quoll life history. Within simulations, individuals were trained and a continuous evolving trait determined innate tendency to attack toads. We applied this model in a population viability setting. The strategy reduced extinction probability only when heritability of innate aversion was low (<20%) and when trained mothers trained >70% of their young to avoid toads. When these conditions were met, genetic adaptation was slower, but rapid cultural adaptation kept the population extant while genetic adaptation was completed. To gain insight into the evolutionary dynamics (in which we saw a transitory peak in cultural adaptation over time), we also developed a simple analytical model of evolutionary dynamics. This model showed that the strength of natural selection declined as the cultural transmission rate increased and that adaptation proceeded only when the rate of cultural transmission was below a critical value determined by the relative levels of protection conferred by genetic versus cultural mechanisms. Together, our models showed that cultural adaptation can play a powerful role in preventing extinction, but that rates of cultural transmission need to be high for this to occur.

La adaptación cultural es un medio mediante el cual los conservacionistas pueden ayudar a las poblaciones a adaptarse a las amenazas. Un comportamiento aprendido puede proteger a un individuo de las amenazas y este comportamiento puede transmitirse horizontalmente (dentro de las generaciones) y verticalmente (entre generaciones), lo que otorga rápidamente una protección a nivel poblacional. Aunque esto es posible en teoría, aún no está claro si dichas manipulaciones funcionan dentro de un escenario de conservación; cuáles son las condiciones requeridas para que funcionen las manipulaciones; y cómo pueden afectar el proceso evolutivo. Examinamos modelos en los cuales una población puede adaptarse tanto con mecanismos genéticos como culturales. Nuestro trabajo estuvo motivado por la invasión de sapos altamente tóxicos (Rhinella marina) en todo el norte de Australia y las declinaciones resultantes de cuoles norteños (Dasyurus hallucatus), los cuales atacan y mueren envenenados por los sapos tóxicos. Analizamos si una estrategia de manejo novedoso en la cual los cuoles silvestres son entrenados para evitar a los sapos puede reducir la probabilidad de extinción. Usamos un modelo de simulación diseñado alrededor de la historia de vida de los cuoles. Dentro de las simulaciones, se entrenó a cuoles individuales y una característica en continua evolución determinó la tendencia innata para atacar a los sapos. Aplicamos este modelo en un escenario de viabilidad poblacional. La estrategia redujo la probabilidad de extinción sólo cuando la heredabilidad de la aversión innata fue baja (<20%) y cuando las madres entrenadas entrenaron a más del 70% de sus crías para evitar a los sapos. Cuando ambas condiciones fueron cumplidas, la adaptación genética fue más lenta pero la adaptación cultural rápida mantuvo a la población vigente mientras se completaba la adaptación genética. Para ganar conocimiento sobre las dinámicas evolutivas (en las cuales vimos un pico transitorio en la adaptación cultural a lo largo del tiempo) también desarrollamos un modelo analítico simple de las dinámicas evolutivas. Este modelo mostró que la fuerza de la selección natural declinó conforme incrementó la tasa de transmisión cultural y que la adaptación procedió solamente cuando la tasa de transmisión cultural estuvo por debajo de un valor crítico determinado por los niveles relativos de protección otorgados por los mecanismos genéticos contra los mecanismos evolutivos. En conjunto, nuestros modelos mostraron que la adaptación cultural puede jugar un papel importante en la prevención de la extinción, pero las tasas de transmisión cultural necesitan ser altas para que esto ocurra.

Gillnet illumination as an effective measure to reduce sea turtle bycatch.

The growing demand for fish around the world is an immediate threat to marine megafauna that are unintentionally captured in commercial and artisanal fishery operations. Bycatch mitigation strategies, such as turtle excluder devices, circle hooks, and net illumination, have successfully reduced this risk in some fisheries. We explored the effectiveness of gillnet illumination to reduce sea turtle captures in 2 artisanal fisheries (Mankoadze and Winneba, Ghana) under normal fishing conditions. We first quantified sea turtle bycatch in Ghana's artisanal gillnet fishery from 15 boats for 12 months. We then quantified catch of targeted species and sea turtle bycatch from 20 boats for 15 months (7427 net sets). For 10 of these boats, we placed a Centro Economy green light (1 LED) at each 10-m interval on the net. We also quantified target catch and sea turtle bycatch from 30 boats for 8 months (2250 net sets). In 15 of these boats, a Centro Deluxe green light (3 LEDs) was installed at 15-m intervals. Boats with economy lights and those with deluxe lights both exhibited an 81% decrease in sea turtle captures (W = 1, p < 0.001, n = 20; W = 215, p < 0.001, n = 30, respectively) compared with control boats without lights. Illuminated nets resulted in fewer turtle catches for leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), and green sea turtles (Chelonia mydas) (p < 0.05 for all species). Target catch (mass) (W = 53, p = 0.853 n = 20; W = 76, p = 0.449, n = 23) and value (W = 50, p = 1, n = 20; W = 69, p = 0.728, = 23) were not different across treatments. Our study affirms net illumination can reduce capture rates of 3 species of sea turtles, including the imperiled leatherback. Gear modification methods can successfully reduce bycatch if they are affordable and have broad applications for multiple species in different fisheries.

Iluminación de las Redes Agalleras como una Medida Efectiva para Reducir la Captura Incidental de Tortugas Marinas Resumen La creciente demanda de pescado en todo el mundo es una amenaza inmediata para la megafauna marina que es capturada accidentalmente durante las operaciones de pesca comercial y artesanal. Las estrategias de mitigación de la captura incidental como los dispositivos excluyentes de tortugas, los ganchos circulares y la iluminación de redes han reducido exitosamente este riesgo en algunas pesquerías. Exploramos la efectividad de la iluminación de las redes agalleras para reducir la captura de tortugas marinas en dos pesquerías artesanales (Mankoadze y Winneba, Ghana) bajo condiciones normales de pesca. Primero cuantificamos la captura incidental de tortugas marinas en la pesca artesanal con redes agalleras en Ghana a partir de 15 botes durante doce meses. Después cuantificamos la captura de especies focalizadas y la captura incidental de tortugas marinas a partir de 20 botes durante 15 meses (7,247 conjuntos de redes). En el caso de diez de estos botes, colocamos una luz verde Centro Economy (1 LED) en cada intervalo de 10 m en la red. También cuantificamos la captura focalizada y la captura incidental de tortugas marinas a partir de 30 botes durante 8 meses (2,250 conjuntos de redes). En 15 de estos botes se instaló una luz verde Centro Deluxe (3 LEDs) en cada intervalo de 15 metros. Los botes con las luces Economy y aquellos con las luces Deluxe exhibieron una disminución del 81% en la captura de tortugas marinas (W = 1, p < 0.001, n = 20; W = 215, p < 0.001, n = 30, respectivamente) en comparación con los botes control que no contaban con luces. Las redes iluminadas resultaron en una menor captura de tortugas laúd (Dermochelys coriacea), golfina (Lepidochelys olivacea) y verde (Chelonia mydas) (p < 0.05 para todas las especies). La captura focalizada (masa) (W = 53, p = 0.853 n = 20; W = 76, p = 0.449, n = 23) y el valor focalizado (W = 50, p = 1, n = 20; W = 69, p = 0.728, n = 23) no fueron diferentes entre los tratamientos. Nuestro estudio afirma que la iluminación de las redes puede reducir la tasa de captura de tres especies de tortuga marina, incluyendo a la tortuga laúd que se encuentra en grave peligro de extinción. Los métodos de modificación de equipamiento pueden reducir exitosamente la captura incidental si son asequibles y también tienen aplicaciones amplias para múltiples especies en diferentes industrias pesqueras.

Climate and land-use as the main drivers of recent environmental change in a mid-altitude mountain lake, Romanian Carpathians.

Recent decades have been marked by unprecendented environmental changes which threaten the integrity of freshwater systems and their ecological value. Although most of these changes can be attributed to human activities, disentagling natural and anthropogenic drivers remains a challenge. In this study, surface sediments from Lake Ighiel, a mid-altitude site in the Carpathian Mts (Romania) were investigated following high-resolution sedimentological, geochemical, environmental magnetic and diatom analyses supported by historical cartographic and documentary evidence. Our results suggest that between 1920 and 1960 the study area experienced no significant anthropogenic impact. An excellent correspondence is observed between lake proxy responses (e.g., growth of submerged macrophytes, high detrital input, shifts in diatom assemblages) and parameters tracking natural hydroclimate variability (e.g., temperature, NAO). This highlights a dominant natural hydroclimatic control on the lacustrine system. From 1960 however, the depositional regime shifted markedly from laminated to homogenous clays; since then geochemical and magnetic data document a trend of significant (and on-going) subsurface erosion across the catchment. This is paralleled by a shift in lake ecosystem conditions denoting a strong response to an intensified anthropogenic impact, mainly through forestry. An increase in detrital input and marked changes in the diatom community are observed over the last three decades, alongside accelerated sedimentation rates following enhanced grazing and deforestation in the catchment. Recent shifts in diatom assemblages may also reflect forcing from atmospheric nitrogen (N) deposition, a key recent drive of diatom community turnover in mountain lakes. In general, enhanced human pressure alongside intermittent hydroclimate forcing drastically altered the landscape around Lake Ighiel and thus, the sedimentation regime and the ecosystem's health. However, paleoenvironmental signals tracking natural hydroclimate variability are also clearly discernible in the proxy data. Our work illustrates the complex link between the drivers of catchment-scale impacts on one hand, and lake proxy responses on the other, highlighting the importance of an integrated historical and palaeolimnological approach to better assess lake system changes.

Improved estimates on global carbon stock and carbon pools in tidal wetlands.

Tidal wetlands are global hotspots of carbon storage but errors exist with current estimates on their carbon density due to the use of factors estimated from other habitats for converting loss-on-ignition (LOI) to organic carbon (OC); and the omission of certain significant carbon pools. Here we show that the widely used conversion factor (LOI/OC = 1.724) is significantly lower than our measurements for saltmarsh sediments (1.92 ± 0.01) and oversimplifies the polynomial relationship between sediment OC and LOI for mangrove forests. Global mangrove OC stock in the top-meter sediment reaches 1.93 Pg when corrected for this bias, and is 20% lower than the previous estimates. Ecosystem carbon stock (living and dead biomass, sediment OC and inorganic carbon) is estimated at 3.7-6.2 Pg. Mangrove deforestation leads to carbon emission rates at 23.5-38.7 Tg yr-1 after 2000. Mangrove sediment OC stock has previously been over-estimated while ecosystem carbon stock underestimated.

Effects of rainfall intensity, slope angle, and vegetation coverage on the erosion characteristics of Pisha sandstone slopes under simulated rainfall conditions.

The water loss and soil erosion in the Pisha sandstone region in the middle reaches of the Yellow River are extremely severe, leading to extremely harmful effects on the ecological environment and safety of the lower reaches. In this paper, the effects of the slope angle (20, 30, and 40°), rainfall intensity (20, 50, and 80 mm/h), and vegetation coverage (10, 30, and 50%) on the erosion characteristics of the Pisha sandstone slopes are studied using indoor-simulated rainfall tests. The results show that the infiltration into the Pisha sandstone is only 10~15%. It is found that rainfall intensity has the most significant effect on runoff, which gradually increases with increasing rainfall intensity. Vegetation significantly affects runoff reduction when the rainfall intensity is low (approximately 20 mm/h), but this effect decreases with increasing rainfall intensity. Rainfall intensity has an extremely significant effect (P < 0.01) on the sediment yield, followed by vegetation coverage, and slope angle. When the vegetation coverage is approximately 50%, the reduction in sediment yield reaches approximately 70%. Additionally, the sediment reduction benefit is more significant than the runoff reduction benefit. The presence of the eroded gullies on slopes with vegetation is less compared to that on the bare slopes. Therefore, relatively high vegetation coverage (≥ 50%) is required for soil and water conservation in Pisha sandstone area. The findings will provide some reference for Pisha sandstone conservation.

Climate vulnerability assessment for Pacific salmon and steelhead in the California Current Large Marine Ecosystem.

Major ecological realignments are already occurring in response to climate change. To be successful, conservation strategies now need to account for geographical patterns in traits sensitive to climate change, as well as climate threats to species-level diversity. As part of an effort to provide such information, we conducted a climate vulnerability assessment that included all anadromous Pacific salmon and steelhead (Oncorhynchus spp.) population units listed under the U.S. Endangered Species Act. Using an expert-based scoring system, we ranked 20 attributes for the 28 listed units and 5 additional units. Attributes captured biological sensitivity, or the strength of linkages between each listing unit and the present climate; climate exposure, or the magnitude of projected change in local environmental conditions; and adaptive capacity, or the ability to modify phenotypes to cope with new climatic conditions. Each listing unit was then assigned one of four vulnerability categories. Units ranked most vulnerable overall were Chinook (O. tshawytscha) in the California Central Valley, coho (O. kisutch) in California and southern Oregon, sockeye (O. nerka) in the Snake River Basin, and spring-run Chinook in the interior Columbia and Willamette River Basins. We identified units with similar vulnerability profiles using a hierarchical cluster analysis. Life history characteristics, especially freshwater and estuary residence times, interplayed with gradations in exposure from south to north and from coastal to interior regions to generate landscape-level patterns within each species. Nearly all listing units faced high exposures to projected increases in stream temperature, sea surface temperature, and ocean acidification, but other aspects of exposure peaked in particular regions. Anthropogenic factors, especially migration barriers, habitat degradation, and hatchery influence, have reduced the adaptive capacity of most steelhead and salmon populations. Enhancing adaptive capacity is essential to mitigate for the increasing threat of climate change. Collectively, these results provide a framework to support recovery planning that considers climate impacts on the majority of West Coast anadromous salmonids.

Recent trend reversal for declining European seagrass meadows.

Seagrass meadows, key ecosystems supporting fisheries, carbon sequestration and coastal protection, are globally threatened. In Europe, loss and recovery of seagrasses are reported, but the changes in extent and density at the continental scale remain unclear. Here we collate assessments of changes from 1869 to 2016 and show that 1/3 of European seagrass area was lost due to disease, deteriorated water quality, and coastal development, with losses peaking in the 1970s and 1980s. Since then, loss rates slowed down for most of the species and fast-growing species recovered in some locations, making the net rate of change in seagrass area experience a reversal in the 2000s, while density metrics improved or remained stable in most sites. Our results demonstrate that decline is not the generalised state among seagrasses nowadays in Europe, in contrast with global assessments, and that deceleration and reversal of declining trends is possible, expectingly bringing back the services they provide.