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Schoolchildren discover hotspots of floating plastic litter in rivers using a large-scale collaborative approach

Autores:

Kiessling, T., Knickmeier, K., Kruse, K., Gatta-Rosemary, M., Nauendorf, A., Brennecke, D., Thiel, L., Wichels, A., Parchmann, I., Körtzinger, A., Thiel, M.

Resumen:

Rivers are an important transport route of anthropogenic litter from inland sources toward the sea. A collaborative (i.e. citizen science) approach was used to evaluate the litter pollution of rivers in Germany: schoolchildren within the project “Plastic Pirates” investigated rivers across the entire country during the years 2016 and 2017 by surveying floating macrolitter at 282 sites and taking 164 meso−/microplastic samples (i.e. particles 24.99–5 mm, and 4.99–1 mm, respectively). Floating macrolitter was sighted at 54% of sampling sites and floating macrolitter quantities ranged from 0 to 8.25 items m−1 h−1 (average of 0.34 ± 0.89 litter items m−1 h−1). Floating meso−/microplastics were present at 57% of the sampling sites, and floating meso−/microplastic quantities ranged from 0 to 220 particles h−1 (average of 6.86 ± 24.11 items h−1). As only particles >1 mm were sampled and analyzed, the pollution of rivers in Germany by microplastics could be a much more prevalent problem, regardless of the size of the river. We identified six plastic pollution hotspots where 60% of all meso−/microplastics collected in the present study were found. These hotspots were located close to a plastic-producing industry site, a wastewater treatment plant, at and below weirs, or in residential areas. The composition of the particles at these hotspots indicates plastic producers and possibly the construction industry and wastewater treatment plants as point sources. An identification of litter hotspots would enable specific mitigation measures, adjusted to the respective source, and thereby could prevent the release of large quantities of small plastic particles in rivers. The adopted large-scale citizen science approach was especially suitable to detect pollution hotspots by sampling a variety of rivers, large and small, and enabled a national overview of litter pollution in German rivers.

Año: 2021

Palabras claves: Plastic litter; Floating macrolitter; Microplastics; Rivers; Citizen science

Referencia APA: Kiessling, T., Knickmeier, K., Kruse, K., Gatta-Rosemary, M., Nauendorf, A., Brennecke, D., Thiel, L., Wichels, A., Parchmann, I., Körtzinger, A., Thiel, M. 2021. Schoolchildren discover hotspots of floating plastic litter in rivers using a large-scale collaborative approach. Science of The Total Environment,V. 789,147849, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2021.147849.

COVID lessons from the global south – Face masks invading tourist beaches and recommendations for the outdoor seasons

Autores:

Thiel, M., de Veer, D., Espinoza-Fuenzalida, N.L., Espinoza, C., Gallardo, C., Hinojosa, I.A., Kiessling, T., Rojas, J., Sanchez, A., Sotomayor, F., Vasquez, N., Villablanca, R.

Resumen:

In response to the COVID-19 pandemic in 2020, Personal Protective Equipment (PPE) has been extensively used, and discarded PPE has been observed in many different environments, including on tourist beaches. Here we examined the distribution and densities of face masks on some of the main tourist beaches in Chile, and we monitored their daily accumulation rates on one beach in northern-central Chile. Face masks were found on beaches across the country with average densities of 0.006 ± 0.002 (mean ± se) face masks m−2, which are higher than densities reported on Peruvian beaches, but lower than those on some Kenyan beaches. Face masks were also found on more remote beaches and rocky shores in northern-central Chile. Daily accumulation rates on one tourist beach were low during austral fall/winter (0.2 face masks km−1 d−1), but were over ten times higher during austral summer (3.0 face masks km−1 d−1). These values are substantially higher than daily accumulation rates reported from urban streets, which is most likely due to the high densities of beach visitors during the summer tourist season. COVID-19 related infrastructure (signposts and PPE waste bins) was present on most beaches, but while signposts about personal protection were abundant, there were few signposts about littering, and only one of the 12 beaches sampled for COVID infrastructure had a signpost that offered recommendations about the proper disposal of used face masks. Specific waste bins for PPE waste were only available at three beaches. Based on these findings it is recommended to provide sufficient PPE-related signs and waste bins, establish general and strict waste disposal regulations, and to improve enforcement. Educational campaigns should aim at recommending proper use and disposal of face masks, litter prevention, reduction of single-use waste and enhanced pro-environmental behaviors.

Año: 2021

Palabras claves: COVID-19, Personal Protective Equipment (PPE), Littering, Beach pollution, Waste infrastructure, Waste management.

Referencia APA: Thiel, M., de Veer, D., Espinoza-Fuenzalida, N.L., Espinoza, C., Gallardo, C., Hinojosa, I.A., Kiessling, T., Rojas, J., Sanchez, A., Sotomayor, F., Vasquez, N., Villablanca, R. 2021. COVID lessons from the global south – Face masks invading tourist beaches and recommendations for the outdoor seasons. Science of The Total Environment, V. 786, 147486, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2021.147486.

The Effect of Hybridization between Natural and Cultivated Peruvian Scallop Argopecten purpuratus populations on Growth and Tolerance to Abiotic Stress

Autores:

Bavestrello-Riquelme, C., Rios, R.S., Farías, W.J., Cárcamo, C.B., Pérez, H., Brokordt, K.

Resumen:

Intraspecific hybridization has been a strategy used frequently in mollusc aquaculture to improve the performance of traits for productive interest. In this study, the effect of hybridization between a natural population (Arica = A) and a cultivated population (Coquimbo = C; without genetic management for more than 30 y) of the Peruvian scallop Argopecten purpuratus was evaluated to assess the effect of this strategy on the performance of the cultivated population in terms of growth, survival, and stress tolerance due to hypoxia and increased temperature. To this end, progenies from intrapopulation (C × C and A × A) and reciprocal hybrid (C × A and A × C) crosses were produced and were evaluated after 6 mo under sea cultivation and in a controlled environment. Stress responses were evaluated via metabolic rates and the transcriptional level of stress-associated genes [superoxide dismutase (SOD) and HSP70]. The results showed that CC and the reciprocal hybrids CA and AC had greater size and survival rates than AA; on the other hand, AA presented the highest metabolic rates when exposed to stress; and, in parallel, AA and both hybrids (CA and AC) presented greater antioxidant capacity (SOD) when exposed to hyperthermia. Therefore, growth and survival showed positive heterosis because the hybrids performed better in these traits than the parental mean. In addition, hybridization with the Arica population would allow the Coquimbo stock under cultivation to improve its resilience to temperature increases associated to oceanographic oscillations or to climate change.

Año: 2021

Palabras claves: Aquaculture, Argopecten purpuratus, growth, growth genes, hybrids, metabolic rates, Peruvian scallop, stress, stress genes

Referencia APA: Bavestrello-Riquelme, C., Rios, R.S., Farías, W.J., Cárcamo, C.B., Pérez, H., Brokordt, K. 2021. The Effect of Hybridization between Natural and Cultivated Peruvian Scallop Argopecten purpuratus populations on Growth and Tolerance to Abiotic Stress. Journal of Shellfish Research, 40(1), 9-18. https://doi.org/10.2983/035.040.0102

Global Plastic Pollution Observation System to Aid Policy

Autores:

Bank, M.S., Swarzenski, P.W., Duarte, C.M., Rillig, M.C., Koelmans, A.A., Metian, M., Wright, S., Provencher, J.F., Sanden, M., Jordaan, A., Wagner, M., Thiel, M, and Ok, Y.S.

Resumen:

Plastic pollution has become one of the most pressing environmental challenges and has received commensurate widespread attention. Although it is a top priority for policymakers and scientists alike, the knowledge required to guide decisions, implement mitigation actions, and assess their outcomes remains inadequate. We argue that an integrated, global monitoring system for plastic pollution is needed to provide comprehensive, harmonized data for environmental, societal, and economic assessments. The initial focus on marine ecosystems has been expanded here to include atmospheric transport and terrestrial and freshwater ecosystems. An earth-system-level plastic observation system is proposed as a hub for collecting and assessing the scale and impacts of plastic pollution across a wide array of particle sizes and ecosystems including air, land, water, and biota and to monitor progress toward ameliorating this problem. The proposed observation system strives to integrate new information and to identify pollution hotspots (i.e., production facilities, cities, roads, ports, etc.) and expands monitoring from marine environments to encompass all ecosystem types. Eventually, such a system will deliver knowledge to support public policy and corporate contributions to the relevant United Nations (UN) Sustainable Development Goals (SDGs).

Año: 2021

Palabras claves: Public policy monitoring reporting plastic waste pollution ecosystem.

Referencia APA: Bank, M.S., Swarzenski, P.W., Duarte, C.M., Rillig, M.C., Koelmans, A.A., Metian, M., Wright, S., Provencher, J.F., Sanden, M., Jordaan, A., Wagner, M., Thiel, M, and Ok, Y.S. 2021. Global Plastic Pollution Observation System to Aid Policy. Environmental Science & Technology, 55 (12), 7770-7775 DOI: 10.1021/acs.est.1c00818

Tracing trophic pathways through the marine ecosystem of Rapa Nui (Easter Island)

Autores:

Zapata‐Hernández, G., Sellanes, J., Letourneur, Y., Harrod, C., Morales, N.A., Plaza, P., Meerhoff, E., Yannicelli, B., Carrasco, S.A., Hinojosa, I., Gaymer, C.F.

Resumen:

The structure of food webs provides important insight into biodiversity, organic matter (OM) pathways, and ecosystem functioning.

Stable isotope analysis (δ13C and δ15N) was used to characterize the trophic structure and the main OM pathways supporting food webs in the Rapa Nui coastal marine ecosystem.

The trophic position of consumers and isotopic niche metrics were estimated for different assemblages (i.e. mesozooplankton, emergent zooplankton, reef invertebrates, reef fishes, pelagic fishes, and seabirds). Furthermore, the relative importance of different OM sources (i.e. macroalgae, zooxanthellate corals, and particulate OM [POM]) was assessed for heterotrophic consumers using Bayesian mixing model (MixSIAR).

Results show a clear pattern of 13C and 15N enrichment from small‐sized pelagic and benthic invertebrates, to reef and pelagic fishes, and seabirds. Most invertebrates were classified as primary consumers, reef fishes as secondary consumers and pelagic predators and seabirds as tertiary and quaternary consumers.

Isotopic niche metrics indicate a low trophic diversity for pelagic assemblages (mesozooplankton and pelagic fishes), in contrast to reef fauna (invertebrates and fishes), whose higher trophic diversity suggest the exploitation of a wider range of trophic resources. Overlapping of standard ellipses areas between reef invertebrates and reef fishes indicates that both assemblages could be sharing trophic resources.

Mixing models results indicate that POM is the main trophic pathway for mesozooplankton, macroalgae (Rhodophyta) for emergent zooplankton, and a mix of coral‐derived OM and Rhodophyta for coral reef assemblages such as macrobenthos and reef invertebrates. In contrast, POM contribution was notably more important for some pelagic fishes and seabirds from upper trophic levels.

This study provides key elements for conservation efforts on coral reefs, management planning and full‐implementation of the recently created Rapa Nui Multiple Use Marine Protected Area.

Año: 2021

Palabras claves: Coral reefs, cryptic fauna, food web, mixing models, organic matter fluxes, stable isotopes, subtropical South Pacific, trophic position, trophic structure.

Referencia APA: Zapata‐Hernández, G., Sellanes, J., Letourneur, Y., Harrod, C., Morales, N.A., Plaza, P., Meerhoff, E., Yannicelli, B., Carrasco, S.A., Hinojosa, I., Gaymer, C.F. (2021). Tracing trophic pathways through the marine ecosystem of Rapa Nui (Easter Island). Aquatic Conservation, Marine and Fresh Water Ecosystems, Special Issue, V. 32, Advances in Science for Ecology and Sustainable Management of Oceanic Islands. https://doi.org/10.1002/aqc.3500

The Humboldt Current Large Marine Ecosystem (HCLME), a Challenging Scenario for Modelers and Their Contribution for the Manager

Autores:

Chevallier A., Stotz W., Ramos M., Mendo J.

Resumen:

The Humboldt Current Large Marine Ecosystem (HCLME) is a salient feature of the southeastern Pacific, along the South American coast of Chile and Peru. It is associated with coastal upwelling which generates a very productive ecosystem. However, due to a variety of interconnected biophysical processes at diverse temporal and spatial scales, production varies greatly in time and space. The interplay of the biophysical environment, biological processes involving valuable resources on international markets, the socio-political context, and some management decisions, has shaped the daily life of the HCLME fisheries, marked by booms and busts, offering wealth for short periods of time, followed by collapses. These collapses are generally interpreted as the consequence of a lack of appropriate management, so that a variety of increasingly stricter regulations have been implemented. Nevertheless, this has not significantly reduced the temporal variability of the fisheries landings, which is broadly characterized by a peaks and troughs pattern. While the HCLME is one of the most productive marine ecosystems on Earth, along with a great biophysical and biological variability, it is also a huge but fragile exploited social-ecological system. Modelers can help to understand how to continuously adapt in order to deal with recurrent fisheries “crises,” which, as we are beginning to learn, may simply be an expression of the variability inherent in this complex system. Furthermore, it is essential to increase our capacity to adapt to the expected consequences of climate change.

Año: 2021

Palabras claves:

Referencia APA: Chevallier A., Stotz W., Ramos M., Mendo J. (2021). The Humboldt Current Large Marine Ecosystem (HCLME), a Challenging Scenario for Modelers and Their Contribution for the Manager. In: Ortiz M., Jordán F. (eds) Marine Coastal Ecosystems Modelling and Conservation. Springer, Cham. https://doi.org/10.1007/978-3-030-58211-1_2

Season-dependent effects of ocean warming on the physiological performance of a native and a non-native sea anemone

Autores:

Suárez, J., Hansen, M., Urtubia, U., Lenz, M., Valdivia, N., & Thiel, M.

Resumen:

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.

Año: 2020

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.

Autores:

Pizarro‐Koch, M., Pizarro, O., Dewitte, B., Montes, I., Ramos, M., Paulmier, A., & Garçon, V.

Resumen:

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.

Año: 2019

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

Autores:

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.

Resumen:

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.

Año: 2019

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.

Autores:

González, R., Brokordt, K., Rojas, R., & Schmitt, P.

Resumen:

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.

Año: 2020

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

Autores:

Winkler, F., Concha, M., & Concha, C.

Resumen:

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.

Año: 2019

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

Autores:

Tala, F., López, B., Velásquez, M., Jeldres, R., Macaya, E., & Mansilla, A., Ojeda, J., Thiel, M.

Resumen:

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.

Año: 2019

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