Season-dependent effects of ocean warming on the physiological performance of a native and a non-native sea anemone
Suárez, J., Hansen, M., Urtubia, U., Lenz, M., Valdivia, N., & Thiel, M.
The effects of ocean warming on the physiological performance of marine organisms have been widely studied. However, few studies have considered the relevance of seasonal acclimation to elevated temperatures and whether native and non-native species have similar tolerances to warming. We tested the hypotheses that the susceptibility to warming in two species of sea anemones from temperate latitudes is (i) higher in winter than in summer, and (ii) higher in the native than in the non-native species. Seasonal variability in the upper thermal tolerance limit of Anthothoe chilensis (native) and Anemonia alicemartinae (non-native) individuals from the northern-central coast of Chile was assessed in laboratory experiments during the austral winter 2015 and summer 2016. In line with our predictions, seawater warming (up to 16 °C above natural levels) significantly suppressed individual performance proxies such as survival and asexual reproduction (longitudinal fission) in the native species, but not in the non-native species. However, asexual reproduction in the non-native sea anemone was rare across warming treatments, and the native species showed a stronger capacity to detach from the substratum under adverse thermal conditions. Negative effects of warming on survival and fission were evident only in winter, when asexual reproduction is more intense in these taxa. Finally, water temperatures of 30 °C or more were lethal for both native and non-native sea anemones. These results show that the non-native species may have a broader thermal tolerance (in terms of survival) than the native taxonomically related species, but the latter displays behavioral adaptations to avoid adverse conditions of high temperatures. We suggest that knowledge about life history traits related to seasonal variations in water temperature and the invasion status of a species can help to predict its performance in a warming ocean.
Palabras claves: Ocean warming, Thermal tolerance, Seasonality, Anthothoe chilensis, Anemonia alicemartinae
Referencia APA: Suárez, J., Hansen, M., Urtubia, U., Lenz, M., Valdivia, N., & Thiel, M. (2020). Season-dependent effects of ocean warming on the physiological performance of a native and a non-native sea anemone. Journal Of Experimental Marine Biology And Ecology, 522, 151229. doi: 10.1016/j.jembe.2019.151229
Seasonal variability of the southern tip of the Oxygen Minimum Zone in the eastern South Pacific (30°-38°S): A modeling study.
Pizarro‐Koch, M., Pizarro, O., Dewitte, B., Montes, I., Ramos, M., Paulmier, A., & Garçon, V.
We investigate the seasonal variability of the southern tip (30°–38°S) of the eastern South Pacific oxygen minimum zone (OMZ) based on a high horizontal resolution (1/12°) regional coupled physical‐biogeochemical model simulation. The simulation is validated by available in situ observations and the OMZ seasonal variability is documented. The model OMZ, bounded by the contour of 45 μM, occupies a large volume (4.5x104 km3) during the beginning of austral winter and a minimum (3.5x104 km3) at the end of spring, just 1 and 2 months after the southward transport of the Peru‐Chile Undercurrent (PCUC) is maximum and minimum, respectively. We showed that the PCUC significantly impacts the alongshore advection of dissolved oxygen (DO) modulating the OMZ seasonal variability. However, zonal transport of DO by meridionally alternating zonal jets and mesoscale eddy fluxes play also a major role in the seasonal and spatial variability of the OMZ. Consistently, a DO budget analysis reveals a significant contribution of advection terms to the rate of change of DO and the prominence of mesoscale variability within the seasonal cycle of these terms. Biogeochemical processes and horizontal and vertical mixing, associated with subgrid scale processes, play only a secondary role in the OMZ seasonal cycle. Overall, our study illustrates the interplay of mean and (mesoscale) eddy‐induced transports of DO in shaping the OMZ and its seasonal cycle off Central Chile.
Palabras claves: Oxygen minimum zone, Eddy fluxes, Peru‐Chile Undercurrent, Oxygen budget, Eastern South Pacific
Referencia APA: Pizarro‐Koch, M., Pizarro, O., Dewitte, B., Montes, I., Ramos, M., Paulmier, A., & Garçon, V. (2019). Seasonal Variability of the Southern Tip of the Oxygen Minimum Zone in the Eastern South Pacific (30°‐38°S): A Modeling Study. Journal Of Geophysical Research: Oceans, 124(12), 8574-8604. doi: 10.1029/2019jc015201
The rise and demise of plastic shopping bags in Chile – Broad and informal coalition supporting ban as a first step to reduce single-use plastics
Amenábar Cristi, M., Holzapfel, C., Nehls, M., De Veer, D., Gonzalez, C., & Holtmann, G., Honorato-Zimmer, D., Kiessling, T., Leyton Munoz, A., Narvaez Reyes, S., Nunez, P., Sepulveda, J.M., Vásquez, N., Thiel, M.
Single-use plastic bags (SUPBs) were introduced to society as a way to facilitate our daily lives, but due to their low post-use value they are found as litter in many different environments, from urban to rural and remote, natural environments. Given the increasing awareness about environmental litter, many communities have banned SUPBs in the recent past. Here we explore an emerging economy to document the rise and demise of SUPBs in society. Through a review of scientific and grey literature (including governmental documents and media coverage) we reconstruct the timeline of SUPBs in Chile, including the development of the plastic industry and retail business within Chile, the introduction, spread and finally the demise of SUPBs. Focused on the demise phase, we document the creation and succession of municipal ordinances to reduce SUPBs in local commerce, and the development of a national law to regulate the use of SUPBs. In order to document the involvement of the general public during the demise phase, we also examined current behavior and behavioral intentions of people in (i) a local project introducing reusable cloth bags to reduce the use of SUPBs, and (ii) a consumer survey about public perception of SUPBs and their use. Plastic bags were introduced in Chile in the 1970s, then spread with the emergence of supermarkets and retail stores in the 1980s and 1990s, and were widely used in commerce by the turn of the century. During the first decade of the 21st century the first scientific studies reported large amounts of plastic litter and high proportions of single-use plastics in coastal environments, public awareness grew, and numerous initiatives aiming to reduce consumption and littering of plastics developed. The first municipal ban of SUPBs in 2013 was emulated during the following five years by 62 other Chilean municipalities and in 2018 translated into a national law, which was highly approved and supported by the population. We conclude that the ban of SUBPs in Chile was facilitated by a broad concern among the general public, which led to a bottom-up movement culminating in the national government taking stakes in the issue. Finally, we argue that this can only be a first step that must be followed by further actions to abolish single-use products in order to effectively protect the environment and in particular the world's oceans.
Palabras claves: Marine litter, Willingness to engage, Socio-economic factors, Pro-environmental behavior, Waste management.
Referencia APA: Amenábar Cristi, M., Holzapfel, C., Nehls, M., De Veer, D., Gonzalez, C., & Holtmann, G., Honorato-Zimmer, D., Kiessling, T., Leyton Munoz, A., Narvaez Reyes, S., Nunez, P., Sepulveda, J.M., Vásquez, N., Thiel, M. (2019). The rise and demise of plastic shopping bags in Chile – Broad and informal coalition supporting ban as a first step to reduce single-use plastics. Ocean & Coastal Management, 105079. doi: 10.1016/j.ocecoaman.2019.105079
Molecular characterization and expression patterns of two LPS binding /bactericidal permeability-increasing proteins (LBP/BPIs) from the scallop Argopecten purpuratus.
González, R., Brokordt, K., Rojas, R., & Schmitt, P.
Lipopolysaccharide-binding proteins (LBPs) and bactericidal permeability-increasing proteins (BPIs) are effec-
tors of the innate immune response which act in a coordinated manner to bind and neutralize the LPS present in
Gram negative bacteria. The structural organization that confers the function of LBPs and BPIs is very similar,
however, they are antagonistic to each other. In this work, we characterized two LBP/BPIs from the scallop
Argopecten purpuratus, namely ApLBP/BPI1 and ApLBP/BPI2. The molecular and phylogenetic analyses of
ApLBP/BPIs indicated that both isoforms display classic characteristics of LBP/BPIs from other invertebrates.
Additionally, ApLBP/BPIs are constitutively expressed in scallop tissues and their transcript expression is up-
regulated in hemocytes and gills in response to an immune challenge. However, some structural characteristics
of functional importance for the biological activity of these molecules, such as the net charge differ substantially
between ApLBP/BPI1 and ApLBP/BPI2. Furthermore, each isoform displays a specific profile of basal expression
among different tissues, as well as specific patterns of expression during the activation of the immune response.
Results suggest that functional specialization of ApLBP/BPIs might happen, with potential role as LBP or BPI in
this species of scallop. Further research on the biological activities of ApLBP/BPIs are necessary to elucidate their
participation in the scallop immune response.
Palabras claves: Innate immunity, Antimicrobial effectors, Mollusks, Scallops, Aquaculture
Referencia APA: González, R., Brokordt, K., Rojas, R., & Schmitt, P. (2020). Molecular characterization and expression patterns of two LPS binding /bactericidal permeability-increasing proteins (LBP/BPIs) from the scallop Argopecten purpuratus. Fish & Shellfish Immunology, 97, 12-17. doi: 10.1016/j.fsi.2019.12.032
Modeling the reproductive impact of aquaculture-produced sexually fertile triploids on conspecific diploid populations
Winkler, F., Concha, M., & Concha, C.
The use of artificially produced triploid (3n) organisms has been proposed as a strategy to produce total or partial sterility in a number of species in order to prevent the potential negative effects of escapees on the genetic structure and integrity of wild conspecific populations or to avoid having alien species become feral in a new environment. When infertility is incomplete, triploid organisms are able to produce gametes that compete with those produced by wild diploid populations or crops that share the same habitat during reproductive periods, which may adversely affect the reproductive success of the wild population. In the present study, a model was developed in order to estimate the effects of the production of gametes by triploid organisms on the reproductive efficiency of a sympatric diploid population of the same species. The chance of the production of balanced gametes by triploids rapidly reduced with the increase of haploid number of the species. It was concluded that, in most aquatic species, this effect depends on the relative contribution of gametes derived from triploid individuals ( pet), which is determined by the proportion of triploids in the population and their relative fecundity relative to normal diploids. The variation of the reproductive efficiency in a mixed population of diploids and triploids will be directly proportional to pet if only one sex is fertile in triploids but will have a logarithmic relationship if both sexes are fertile.
Palabras claves: Triploids, Risk assessment, Reproductive success, Sterility, Chromosome manipulation, Fecundity
Referencia APA: Winkler, F., Concha, M., & Concha, C. (2019). Modeling the reproductive impact of aquaculture-produced sexually fertile triploids on conspecific diploid populations. Aquaculture Environment Interactions, 11, 205-211. doi: 10.3354/aei00308
Long-term persistence of the floating bull kelp Durvillaea antarctica from the South-East Pacific: Potential contribution to local and transoceanic connectivity
Tala, F., López, B., Velásquez, M., Jeldres, R., Macaya, E., & Mansilla, A., Ojeda, J., Thiel, M.
Current knowledge about the performance of floating seaweeds as dispersal vectors comes mostly from mid latitudes (30°–40°), but phylogeographic studies suggest that long-distance dispersal (LDD) is more common at high latitudes (50°–60°). To test this hypothesis, long-term field experiments with floating southern bull kelp Durvillaea antarctica were conducted along a latitudinal gradient (30°S, 37°S and 54°S) in austral winter and summer. Floating time exceeded 200d in winter at the high latitudes but in summer it dropped to 90d, being still higher than at low latitudes (<45d). Biomass variations were due to loss of buoyant fronds. Reproductive activity diminished during long floating times. Physiological changes included mainly a reduction in photosynthetic (Fv/Fm and pigments) rather than in defence variables (phlorotannins and antioxidant activity). The observed long floating persistence and long-term acclimation responses at 54°S support the hypothesis of LDD by kelp rafts at high latitudes.
Palabras claves: Chile, Durvillaea antarctica, Floating persistence, Rafting, Dispersal, Floating seaweeds, Temperature
Referencia APA: Tala, F., López, B., Velásquez, M., Jeldres, R., Macaya, E., & Mansilla, A., Ojeda, J., Thiel, M. (2019). Long-term persistence of the floating bull kelp Durvillaea antarctica from the South-East Pacific: Potential contribution to local and transoceanic connectivity. Marine Environmental Research, 149, 67-79. doi: 10.1016/j.marenvres.2019.05.013
How Does the Diversity of Divers Affect the Design of Citizen Science Projects?
Hermoso, M., Martin, V., Stotz, W., Gelcich, S., & Thiel, M.
Divers have widely participated in citizen science (CS) projects and are one of the main groups of marine citizen scientists. However, there is little knowledge about profiles of, and incentives for potential divers to join CS projects. To date, most studies have focused on the SCUBA diving industry; nevertheless, there is a diversity of divers, not all using SCUBA, who engage in different activities during their dives. Differences in diver profiles could affect their willingness and ability to contribute to CS. In this study, we compare the diving profile, interests, preferences and motivations to participate in CS of five diver types (artisanal fishermen, recreational divers, instructors, scientific divers, and others). All divers have strong interests in participating in CS projects, with no major differences among diver types. In general, they are interested in a wide variety of themes related to CS but they prefer simple sampling protocols. Divers are motivated to participate in CS to learn about the sea and contribute to science. Some important differences among diver types were found, with artisanal fishermen having significantly more dive experience than other diver types, but less free time during their dives and limited access to some communication channels and technologies. These characteristics make them ideal partners to contribute their local ecological knowledge (LEK) to local CS projects. In contrast, recreational divers have the least experience but most free time during their dives and good access to cameras and communications channels, making them suitable partners for large-scale CS projects that do not require a high level of species knowledge. Instructors and scientific divers are well-placed to coordinate and supervise CS activities. The results confirm that divers are not all alike and specific considerations have to be taken into account to improve the contribution of each diver type to CS. The findings provide essential information for the design of different types of CS projects. By considering the relevant incentives and opportunities for diverse diver groups, marine CS projects will make efficient gains in volunteer recruitment, retention, and collaborative generation of knowledge about the marine environment.
Palabras claves: Participatory science, subtidal, SCUBA, fishermen, recreational divers.
Referencia APA: Hermoso, M., Martin, V., Stotz, W., Gelcich, S., & Thiel, M. (2019). How Does the Diversity of Divers Affect the Design of Citizen Science Projects?. Frontiers In Marine Science, 6. doi: 10.3389/fmars.2019.00239
Uncovering population structure in the Humboldt penguin (Spheniscus humboldti) along the Pacific coast at South America
Dantas, G., Oliveira, L., Santos, A., Flores, M., Melo, D., Simeone, A., González-Acuña, D., Luna-Jorquera, G., Le Bohec, C., Valdés-Velásquez, A., Cardeña, M., Morgante, J.S., Vianna, J.A.
The upwelling hypothesis has been proposed to explain reduced or lack of population structure in seabird species specialized in food resources available at cold-water upwellings. However, population genetic structure may be challenging to detect in species with large population sizes, since variation in allele frequencies are more robust under genetic drift. High gene flow among populations, that can be constant or pulses of migration in a short period, may also decrease power of algorithms to detect genetic structure. Penguin species usually have large population sizes, high migratory ability but philopatric behavior, and recent investigations debate the existence of subtle population structure for some species not detected before. Previous study on Humboldt penguins found lack of population genetic structure for colonies of Punta San Juan and from South Chile. Here, we used mtDNA and nuclear markers (10 microsatellites and RAG1 intron) to evaluate population structure for 11 main breeding colonies of Humboldt penguins, covering the whole spatial distribution of this species. Although mtDNA failed to detect population structure, microsatellite loci and nuclear intron detected population structure along its latitudinal distribution. Microsatellite showed significant Rst values between most of pairwise locations (44 of 56 locations, Rst = 0.003 to 0.081) and 86% of individuals were assigned to their sampled colony, suggesting philopatry. STRUCTURE detected three main genetic clusters according to geographical locations: i) Peru; ii) North of Chile; and iii) Central-South of Chile. The Humboldt penguin shows signal population expansion after the Last Glacial Maximum (LGM), suggesting that the genetic structure of the species is a result of population dynamics and foraging colder water upwelling that favor gene flow and phylopatric rate. Our findings thus highlight that variable markers and wide sampling along the species distribution are crucial to better understand genetic population structure in animals with high dispersal ability.
Palabras claves: Penguins, Population genetics, Animal sociality, Chile (country), Gene flow, Islands, Seabirds, Haplotypes
Referencia APA: Dantas, G., Oliveira, L., Santos, A., Flores, M., Melo, D., Simeone, A., González-Acuña, D., Luna-Jorquera, G., Le Bohec, C., Valdés-Velásquez, A., Cardeña, M., Morgante, J.S., Vianna, J.A. (2019). Uncovering population structure in the Humboldt penguin (Spheniscus humboldti) along the Pacific coast at South America. PLOS ONE, 14(5), e0215293. doi: 10.1371/journal.pone.0215293
Unexpected population fragmentation in an endangered seabird: the case of the Peruvian diving-petrel
Cristofari, R., Plaza, P., Fernández, C., Trucchi, E., Gouin, N., Le Bohec, C., Zavalaga, C., Alfaro-Shigueto, J., Luna-Jorquera, G.
In less than one century, the once-abundant Peruvian diving petrel has become the first endangered seabird of the Humboldt Current System (HCS). This small endemic petrel of the South American Pacific coast is now an important indicator of ongoing habitat loss and of the success of local conservation policies in the HCS - an ecoregion designated as a priority for the conservation of global biodiversity. Yet so far, poorly understood life history traits such as philopatry or dispersal ability may strongly influence the species’ response to ecosystem changes, but also our capacity to assess and interpret this response. To address this question, we explore the range-wide population structure of the Peruvian diving petrel, and show that this small seabird exhibits extreme philopatric behavior at the island level. Mitochondrial DNA sequences and genome-wide SNP data reveal significant isolation and low migration at very short distances, and provide strong evidence for questioning the alleged recovery in the Peruvian and Chilean populations of this species. Importantly, the full demographic independence between colonies makes local population rescue through migration unlikely. As a consequence, the Peruvian diving petrel appears to be particularly vulnerable to ongoing anthropogenic pressure. By excluding immigration as a major factor of demographic recovery, our results highlight the unambiguously positive impact of local conservation measures on breeding populations; yet at the same time they also cast doubt on alleged range-wide positive population trends. Overall, the protection of independent breeding colonies, and not only of the species as a whole, remains a major element in the conservation strategy for endemic seabirds. Finally, we underline the importance of considering the philopatric behavior and demographic independence of breeding populations, even at very fine spatial scales, in spatial planning for marine coastal areas.
Referencia APA: Cristofari, R., Plaza, P., Fernández, C., Trucchi, E., Gouin, N., Le Bohec, C., Zavalaga, C., Alfaro-Shigueto, J., Luna-Jorquera, G. (2019). Unexpected population fragmentation in an endangered seabird: the case of the Peruvian diving-petrel. Scientific Reports, 9(1). doi: 10.1038/s41598-019-38682-9
Similarity in predator-specific anti-predator behavior in ecologically distinct limpet species, Scurria viridula (Lottiidae) and Fissurella latimarginata (Fissurellidae)
Aguilera, M., Weiß, M., & Thiel, M.
Many marine gastropods show species-specific behavioral responses to different predators, but less is known about the mechanisms influencing differences or similarities in specific responses. Herein, we examined whether two limpet species, Scurria viridula (Lamarck, 1819) and Fissurella latimarginata (Sowerby, 1835), show species- and size-specific similarities or differences in their reaction to predatory seastars and crabs. Both S. viridula and F. latimarginata reacted to their main seastar predators with escape responses. In contrast, both limpets did not flee from common crab predators, but, instead, fastened to the rock. All tested size classes of both limpet species reacted in a similar way, escaping from seastars, but clamping onto the rock in response to crabs. Limpets could reach velocities sufficient to outrun their specific seastar predators, but they were not fast enough to escape crabs. Experiments with limpets of different shell conditions (with and without shell damage) indicated that F. latimarginata with a damaged shell showed “accommodation movements” (slow movements away from stimulus) in response to predatory crabs. In contrast, intact F. latimarginata and all S. viridula (intact and damaged) clamped the shell down to the substratum. The response details suggest that the keyhole limpet F. latimarginata is more sensitive to predators (faster reaction time, longer escape distances, and higher proportion of reacting individuals) than S. viridula, possibly because the morphology of F. latimarginata (the relationship of its shell size and structure to its total body size) makes this species more vulnerable to predation. Our study suggests that chemically mediated effects of seastar and crab predators result in contrasting behavioral responses of both limpet species, independent of their habitat and morphology. Despite the different characteristics of the limpet species and the identity of predators, the limpets react in comparable ways to similar predator types.
Referencia APA: Aguilera, M., Weiß, M., & Thiel, M. (2019). Similarity in predator-specific anti-predator behavior in ecologically distinct limpet species, Scurria viridula (Lottiidae) and Fissurella latimarginata (Fissurellidae). Marine Biology, 166(4). doi: 10.1007/s00227-019-3485-5
Aves marinas varadas en la bahía de Coquimbo, norte de Chile: ¿Qué especies y cuántas mueren?
Portflitt Toro, M., Miranda Urbina, D., & Luna Jorquera, G.
El monitoreo de las aves varadas en las playas puede proporcionar información sobre sus causas de muerte, tales como la captura incidental en actividades de pesca o derrames de petróleo. Durante un año fue monitoreada mensualmente la Bahía de Coquimbo, norte de Chile para cuantificar el número de aves marinas varadas. Se encontraron 395 aves marinas muertas de las cuales 382 fueron identificadas y agrupadas en 21 especies. Las especies más abundantes fueron los piqueros con 115 individuos (30%), el cormorán guanay con 83 individuos (22%) y la gaviota dominicana con 65 individuos (17%). Las especies más abundantes y frecuentes fueron las que anidan en el Sistema Costero de Coquimbo. La mortalidad afecta principalmente a las aves marinas que se alimentan de la anchoveta, que es el principal recurso objetivo de la pesca con redes de cerco. Se sugiere que la mortalidad incidental causada por la pesca es crónica y relativamente constante durante el año. Se requiere un programa de monitoreo a largo plazo para mejorar la estimación de la mortalidad y los factores que influyen en la interacción de las aves marinas con las artes de pesca.
Monitoring of seabirds stranded on beaches can provide information about their causes of death, such as bycatch in fishing activities or oil spills. During a year we monthly monitored the Coquimbo Bay, north Chile, to quantify the number of seabirds and species stranded. We found 395 dead seabirds, of which 382 were identified and grouped into 21 species. The most abundant were the Peruvian booby with 115 individuals (30%), the Guanay cormorant with 83 individuals (22%) and the Kelp gull with 65 individuals (17%). The most abundant and frequent species were those nesting in the Coastal System of Coquimbo. Mortality mainly affected seabirds that feed on anchoveta, which is the main target resource of purse seine fishing. We suggest that the incidental mortality caused by fishing is chronic and relatively constant during the year. A long-term monitoring program is needed to better estimate the mortality and the factors that influence the interaction of seabirds with fishing gears.
Palabras claves: Strandings; seabirds; Suliformes; Coastal System of Coquimbo; Chile
Referencia APA: Portflitt Toro, M., Miranda Urbina, D., & Luna Jorquera, G. (2018). Aves marinas varadas en la bahía de Coquimbo, norte de Chile: ¿Qué especies y cuántas mueren?. Retrieved 24 July 2019, from Rev. biol. mar. oceanogr. vol.53 no.2, http://dx.doi.org/10.22370/rbmo.2018.53.2.1292
Struggling with social-ecological mismatches in marine management and conservation at Easter Island
Aburto, J., & Gaymer, C.
In Easter Island, most of fisheries regulations are top-down implemented by the central fisheries authority located ~4000 km eastwards. This could generate problems in regulations compliance, given the cultural differences between the western worldview and Polynesian culture of Easter Island. A total of 18 issues that must be considered previously to an intervention in the island were identified. Four of them scored the highest difference between Rapanui and public services representatives. Among them, “Integrating traditions and culture” had a little priority for the public services representatives, but was the most important for the Rapanui. According to the public services representatives in Easter Island and local fishermen, there is a little compliance with regulations related to fisheries and, due to cultural aspects, it is not possible to enforce regulations and apply sanctions. The low compliance with fisheries regulations is due to the lack of representativeness of regulations. Interventions in the island are based on western worldview that does not fit with social and ecological domains of social-ecological system. A flexible governance system, based on decision making at local level in line with local tradition is needed to navigate to a resource management and conservation in Easter Island.
Referencia APA: Aburto, J., & Gaymer, C. (2018). Struggling with social-ecological mismatches in marine management and conservation at Easter Island. Marine Policy, 92, 21-29. doi: 10.1016/j.marpol.2018.01.012