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First assessment of MODIS satellite ocean color products (OC3 and nFLH) in the inner Sea of Chiloé, northern Patagonia

Autores:

Lara, C., Saldías, G. S., Westberry, T. K., Behrenfeld, M. J., & Broitman, B. R.

Resumen:

The use of remote sensing has allowed enormous progress in our understanding of biophysical processes worldwide. Despite their importance, the use of satellite bio-optical products is still limited due to optical complexity. In this study we assess the performance of the Moderate Resolution Imaging Spectroradiometer algorithm for chlorophyll-a (MODIS-OC3) and of normalized Fluorescence Line Height (nFLH), in inner waters of northern Chilean Patagonia (41°-45ºS). Satellite data were evaluated using a compilation of in situ chlorophyll-a data collected by the CIMAR-FIORDOS program during 2003-2012.

During austral spring MODIS-OC3 showed a significant relationship with in situ measurements (R2 = 0.2, P = 0.03, F = 5.33) in comparison with winter when the relationship was non-significant. In contrast, nFLH explained a significant fraction of observed variance of Chl-a during austral winter (R2 = 0.54, P = <0.01, F = 10.68) and this relationship was not significant in spring. Our preliminary results offer an excellent chance to understand patterns of variability of the autotrophic biomass and physiological status in optically complex interior marine ecosystems.

Año: 2017

Palabras claves: Satellite validation, MODIS, fluorescence, chlorophyll-a, optical complex, northern Patagonia

Referencia APA: Lara, C., Saldías, G. S., Westberry, T. K., Behrenfeld, M. J., & Broitman, B. R. (2017). First assessment of MODIS satellite ocean color products (OC3 and nFLH) in the inner Sea of Chiloé, northern Patagonia. Latin American Journal of Aquatic Research, 45(4), 822-827. http://dx.doi.org/10.3856/vol45-issue4-fulltext-18

Seasonal variation in epifaunal communities associated with giant kelp (Macrocystis pyrifera) at an upwelling‐dominated site

Autores:

Winkler, N. S., Pérez‐Matus, A., Villena, Á. A., & Thiel, M.

Resumen:

Kelp forests are highly productive and species‐rich benthic ecosystems in temperate regions that provide biogenic habitat for numerous associated species. Diverse epifaunal communities inhabit kelp sporophytes and are subject to variations in the physical environment and to changes experienced by the kelp habitat itself. We assessed seasonal variations in epifaunal invertebrate communities inhabiting giant kelps, Macrocystis pyrifera, and their effects on this seaweed. Six seasonal samplings were conducted over a year at an upwelling‐dominated site in northern‐central Chile where physical conditions are known to fluctuate temporally. More than 30 taxa were identified, among which peracarid crustaceans stood out in both diversity and abundance. Species richness and abundance differed among sporophyte sections (holdfast and fronds) and throughout the year. The frond community was dominated by two grazers (the amphipod Peramphithoe femorata and the isopod Amphoroidea typa), while suspension feeders, grazers, and omnivores (the amphipod Aora typica, the isopod Limnoria quadripunctata, and polychaetes) dominated the holdfasts. Abundances of the dominant species fluctuated throughout the year but patterns of variation differed among species. The most abundant grazer (P. femorata) had highest densities in summer, while the less abundant grazer (A. typa) reached its peak densities in winter. Interestingly, the area of kelp damaged by grazers was highest in autumn and early winter, suggesting that grazing impacts accumulate during periods of low kelp growth, which can thus be considered as ‘vestiges of herbivory past.’ Among the factors determining the observed seasonal patterns, strong variability of environmental conditions, reproductive cycles of associated fauna, and predation by fishes vary in importance. Our results suggest that during spring and early summer, bottom‐up processes shape the community structure of organisms inhabiting large perennial seaweeds, whereas during late summer and autumn, top‐down processes are more important.

Año: 2017

Palabras claves: Associated epifauna, Kelp, Macrocystis pyrifera, Seasonal fluctuations, Temperate regions

Referencia APA: Winkler, N. S., Pérez‐Matus, A., Villena, Á. A., & Thiel, M. (2017). Seasonal variation in epifaunal communities associated with giant kelp (Macrocystis pyrifera) at an upwelling‐dominated site. Austral Ecology, 42(2), 132-144. http://dx.doi.org/10.1111/aec.12407

The variable routes of rafting: stranding dynamics of floating bull kelp Durvillea antartica (Fucales, Phaeophyceae) on beaches in the Pacific

Autores:

Lopez, B. A., Macaya, E. C., Tala, F., Tellier, F., & Thiel, M.

Resumen:

Dispersal on floating seaweeds depends on availability, viability, and trajectories of the rafts. In the southern hemisphere, the bull kelp Durvillaea antarctica is one of the most common floating seaweeds, but phylogeographic studies had shown low connectivity between populations from continental Chile, which could be due to limitations in local supply and dispersal of floating kelps. To test this hypothesis, the spatiotemporal dynamics of kelp strandings were examined in four biogeographic districts along the Chilean coast (28°–42°S). We determined the biomass and demography of stranded individuals on 33 beaches for three subsequent years (2013, 2014, 2015) to examine whether rafting is restricted to certain districts and seasons (winter or summer). Stranded kelps were found on all beaches. Most kelps had only one stipe (one individual), although we also frequently found coalesced holdfasts with mature males and females, which would facilitate successful rafting dispersal, gamete release, and reproduction upon arrival. High biomasses of stranded kelps occurred in the northern‐central (30°S–33°S) and southernmost districts (37°S–42°S), and lower biomasses in the northernmost (28°S–30°S) and southern‐central districts (33°S–37°S). The highest percentages and sizes of epibionts (Lepas spp.), indicative of prolonged floating periods, were found on stranded kelps in the northernmost and southernmost districts. Based on these results, we conclude that rafting dispersal can vary regionally, being more common in the northernmost and southernmost districts, depending on intrinsic (seaweed biology) and extrinsic factors (shore morphology and oceanography) that affect local supply of kelps and regional hydrodynamics.

Año: 2017

Palabras claves: Floating kelps, Marine biogeography, Rafting, Stalked barnacles, Strandings

Referencia APA: Lopez, B. A., Macaya, E. C., Tala, F., Tellier, F., & Thiel, M. (2017). The variable routes of rafting: stranding dynamics of floating bull kelp Durvillea antartica (Fucales, Phaeophyceae) on beaches in the Pacific. J. Phycol, 53, 70-84. http://dx.doi.org/10.1111/jpy.12479

Daily and seasonal changes of photobiological responses in floating bull kelp Durvillaea antarctica (Chamisso) Hariot (Fucales: Phaeophyceae)

Autores:

Tala, F., Penna-Díaz, M. A., Luna-Jorquera, G., Rothäusler, E., & Thiel, M.

Resumen:

Floating seaweeds are important dispersal vehicles, especially for organisms with limited movement capacities and for the seaweeds themselves. The persistence of floating seaweeds is determined by the balance between their acclimation potential and the environmental pressures at the sea surface. Solar radiation is the most important inducer of physiological stress, varying in intensity throughout the day and the year. Therefore photoinhibition and subsequent recovery can change depending on the daily radiation dose and season. The bull kelp Durvillaea antarctica is one of the most common floating seaweeds in the southern oceans, including New Zealand, Chile, and most subantarctic islands. Herein, daily cycles of maximum quantum yield (Fv/Fm), photoinhibition and recovery levels were examined in microcosm experiments with floating D. antarctica throughout the year, focusing on the blade side exposed to solar radiation (sunny vs shadow side). Also, the effect of simulated wave action (blade turnover) and ultraviolet radiation (UVR) on photoinhibition and recovery of Fv/Fm was evaluated. Significant differences in maximum quantum yield were observed between blade sides, with lowest values on the sun-exposed side, especially during noontime and spring/summer months. Phlorotannins and pigments were measured during seasons with the most intense solar radiation (late spring, early summer), when Fv/Fm values were lowest. Phlorotannin, but not pigment concentrations, differed between sunny (lower concentration) and shadow blade sides (higher concentration) and throughout the daily cycle. Both blade sides had similar photoinhibition and recovery levels when blades were constantly turned over. Absence of UVR favoured the recovery capacity of Fv/Fm in both blade sides, suggesting that the photorecovery potential of floating kelps depends on the environmental conditions that kelp rafts face at the sea surface (e.g. cloudy vs sunny days, intense seawater movement and splashing vs calm sea conditions). The results confirm that photobiological stress is more severe during summer and on continuously sun-exposed blade sides, thereby damaging the blades and suppressing the floating time of D. antarctica.

Año: 2017

Palabras claves: Durvillaea antarctica, Floating kelps, in vivo fluorescence, Photoinhibition, Recovery, Solar radiation

Referencia APA: Tala, F., Penna-Díaz, M. A., Luna-Jorquera, G., Rothäusler, E., & Thiel, M. (2017). Daily and seasonal changes of photobiological responses in floating bull kelp Durvillaea antarctica (Chamisso) Hariot (Fucales: Phaeophyceae). Phycologia, 56(3), 271-283. https://doi.org/10.2216/16-93.1

Temperate rocky subtidal reef community reveals human impacts across the entire food web

Autores:

Perez-Matus, A., Ospina-Alvarez, A., Camus, P. A., Carrasco, S. A., Fernandez, M., Gelcich, S., Godoy, N., Ojeda, F.P., Pardo, L.M., Rozbaczylo, N., Subida, M.D., Thiel, M., Wieters, E.A., & Navarrete, S.

Resumen:

Food webs as representations of who eats whom are at the core of community ecology. Incorporation of tools from network theory enables assessment of how complex systems respond to natural and human-induced stressors, revealing how harvesting may degrade the properties and resilience of food webs. We present a comprehensive, coastal marine food web that includes 147 taxa co-occurring on shallow subtidal reefs along the highly productive and exploited Humboldt Current System of central Chile. This food web has connectance of 0.06, link density of 1204 and mean chain length of 4.3. The fractions of intermediate (76%), omnivorous (49%) and cannibalistic (8%) nodes are slightly lower than those observed in other marine food webs. Of the 147 nodes, 34 are harvested. Links to harvested nodes represented 50 to 100% of all trophic links of non-harvested nodes, illustrating the great impact that fishery pressure can have on the food web. The food web was compartmentalized into 5 sub-webs with high representation of harvested taxa. This structure changes if the fishery node is removed. Similarity analyses identified groups of harvested species with non-harvested nodes, suggesting that these tropho-equivalents could be sentinel species for the community-wide impacts of coastal fisheries. We conclude that fishing effects can be transmitted throughout the food web, with no compartments completely unaffected by harvesting. It is urgent to establish monitoring programs for community-wide effects of fisheries and assess whether resilience of these highly productive subtidal food webs has already been compromised, thereby identifying essential nodes that require stronger fisheries regulation.

Año: 2017

Palabras claves: Network structure, Marine ecosystems, Fishery, Resilience, Chile

Referencia APA: Perez-Matus, A., Ospina-Alvarez, A., Camus, P. A., Carrasco, S. A., Fernandez, M., Gelcich, S., Godoy, N., Ojeda, F.P., Pardo, L.M., Rozbaczylo, N., Subida, M.D., Thiel, M., Wieters, E.A., & Navarrete, S. (2017). Temperate rocky subtidal reef community reveals human impacts across the entire food web. Marine Ecology Progress Series, 567, 1-16. https://doi.org/10.3354/meps12057

Who cares about dirty beaches? Evaluating environmental awareness and action on coastal litter in Chile

Autores:

Kiessling, T., Salas, S., Mutafoglu, K., & Thiel, M

Resumen:

Coastal litter is a source of environmental, economic and health-related problems in many parts of the world, but local responses are not necessarily related to the severity of the impacts. In particular, it is unclear how environmental perception of community members and government bodies relate to active engagement on coastal pollution. The present study analyses the coastal litter situation and evaluates the willingness of citizens to engage at four sites (three regions of mainland Chile, and Easter Island; henceforth Rapa Nui) that feature differences in culture, economy sectors and landscape characteristics. Data on coastal litter were obtained from citizen science campaigns and assessments of large litter accumulations on beaches and rocky shores. The willingness to engage was evaluated qualitatively, considering municipal planning documents and the perception of residents on coastal litter and general waste management. We found very large quantities of litter in northern Chile, posing a hazard to marine wildlife and human health, and moderate quantities in the other regions. The region with the most severe case of coastal pollution does not feature the highest engagement, possibly a result of underlying factors such as an unsustainable economy and few possibilities for the population to connect with the natural environment. On mainland Chile, municipal engagement is low to moderate while on Rapa Nui there exist integrated waste-management strategies that address coastal pollution. Inhabitants of Rapa Nui seem to have a better conduct in the coastal environment (picking up litter, littering less), and show more engagement in waste-reduction strategies (recycling, volunteering for beach clean-ups). We suggest that the unique cultural history of the island, a landscape that allows meaningful interaction with nature and an economy based on sustainable tourism and high international visibility facilitates engagement on environmental issues. We advise managers to consider respective underlying variables, to create environments that allow contact with nature (e.g. public access to parks), and to encourage bottom-up initiatives, preferably by local actors (e.g. by promoting already engaged individuals or organisations).

Año: 2017

Palabras claves: Marine litter, Willingness to engage, Socio-economic factors, Pro-environmental behaviour, Waste management

Referencia APA: Kiessling, T., Salas, S., Mutafoglu, K., & Thiel, M. (2017). Who cares about dirty beaches? Evaluating environmental awareness and action on coastal litter in Chile. Ocean & Coastal Management, 137, 82-95. https://doi.org/10.1016/j.ocecoaman.2016.11.029

Diversity of deep-sea fishes of the Easter Island Ecoregion

Autores:

Easton, E. E., Sellanes, J., Gaymer, C. F., Morales, N., Gorny, M., & Berkenpas, E.

Resumen:

The Easter Island Ecoregion is in the center of the South Pacific gyre and experiences ultra-oligotrophic conditions that could make it highly susceptible to global change and anthropogenic activities, so it is imperative that these regions are characterized and studied so that conservation and sustainable management strategies can be developed. From the few studies from the region, we know that the coastal areas are relatively depauperate and have relatively high rates of endemism. Here, we present a brief report from the first video observations from this region of the deep-dwelling fishes from ROV exploration of benthic communities from 157 to 281 m and baited drop-camera videos from 150 to 1850 m. We observed a total of 55 fish species from the ROV and Drop-Cam surveys; nine could not be assigned family level or lower, 26 were observed in the ROV surveys, 29 were observed in the Drop-Cam surveys, nine were observed with both survey methods, at least six species are potentially new to science, and nine species were observed at deeper depths than previously reported. These new reports may be indicative of the unique oceanographic conditions in the area and the relative isolation of the communities that have provided opportunity for the evolution of new species and favorable conditions for range expansion. In contrast, these new reports may be indicative of the severe undersampling in the south Pacific at mesopelagic depths. The prevalence of potentially new species suggests that the region likely harbors a wealth of undiscovered biodiversity.

Año: 2017

Palabras claves: MesophoticSqualus, Chromis, Tosanoides, Hydrolagus, Benthic ecology

Referencia APA: Easton, E. E., Sellanes, J., Gaymer, C. F., Morales, N., Gorny, M., & Berkenpas, E. (2017). Diversity of deep-sea fishes of the Easter Island Ecoregion. Deep Sea Research Part II: Topical Studies in Oceanography, 137, 78-88. https://doi.org/10.1016/j.dsr2.2016.12.006

Artificial defences in coastal marine ecosystems in Chile: Opportunities for spatial planning to mitigate habitat loss and alteration of the marine community structure

Autores:

Aguilera, M. A.

Resumen:

Many coastal habitats are actually replaced with hard infrastructures which alter the taxonomic/functional structure of natural ecosystems worldwide. Few information about habitat loss and species composition in South American coasts are available compared with other coasts. Here, I examine the distribution and identity of coastal artificial infrastructures, especially artificial breakwaters, present along the coast of Chile and the proportion of natural habitat loss derived from their construction. Differences in species taxonomic/functional composition in artificial breakwaters and natural habitats present in northern Chile are also examined. I also propose/discuss opportunities for coastal planning based on habitat rehabilitation and ecological engineering in Chile, which could guide future marine infrastructures construction. An important proportion of natural habitat has been replaced by artificial coastal defences along the coast of Chile, accounting for about 200 km of total coastal length. Given their specific uses and functions, artificial granite breakwaters are one of the most important coastal infrastructures present in Chile (62% of the total of artificial breakwaters present). Differences in taxonomic/functional structure between artificial breakwaters and natural adjacent habitats are significant, and appear related to contrasting spatial heterogeneity. Artificial infrastructures like granite breakwaters can facilitate presence of native and non-native species, which live in the marine-terrestrial interphase (crabs, rats). The present study highlights how the recent proliferation of coastal artificial infrastructures is replacing important natural habitats in Chile, and how the taxonomic/functional structure of coastal ecosystems can be negatively impacted. Furthermore, this study showed how artificial infrastructures can have direct consequences for human-health security and specific guidelines can be conducted to buffer impacts on ecosystem structure to match social livelihood and wellness.

Año: 2017

Palabras claves: Habitat loss, Coastal ecosystem, Functional structure, RehabilitationChile

Referencia APA: Aguilera, M. A. (2017). Artificial defences in coastal marine ecosystems in Chile: Opportunities for spatial planning to mitigate habitat loss and alteration of the marine community structure. Ecological Engineering. https://doi.org/10.1016/j.ecoleng.2017.04.021

Amberstripe scad Decapterus muroadsi (Carangidae) fish ingest blue microplastics resembling their copepod prey along the coast of Rapa Nui (Easter Island) in the South Pacific subtropical gyre

Autores:

Ory, N. C., Sobral, P., Ferreira, J. L., & Thiel, M.

Resumen:

An increasing number of studies have described the presence of microplastics (≤ 5 mm) in many different fish species, raising ecological concerns. The factors influencing the ingestion of microplastics by fish remain unclear despite their importance to a better understanding of the routes of microplastics through marine food webs. Here, we compare microplastics and planktonic organisms in surface waters and as food items of 20 Amberstripe scads (Decapterus muroadsi) captured along the coast of Rapa Nui (Easter Island) to assess the hypothesis that fish ingest microplastics resembling their natural prey. Sixteen (80%) of the scad had ingested one to five microplastics, mainly blue polyethylene fragments that were similar in colour and size to blue copepod species consumed by the same fish. These results suggest that planktivorous fish, as a consequence of their feeding behaviour as visual predators, are directly exposed to floating microplastics. This threat may be exacerbated in the clear oceanic waters of the subtropical gyres, where anthropogenic litter accumulates in great quantity. Our study highlights the menace of microplastic contamination on the integrity of fragile remote ecosystems and the urgent need for efficient plastic waste management.

Año: 2017

Palabras claves: Microplastic contamination, Rapa Nui (Easter Island), Planktivorous fish, South Pacific subtropical gyre, Copepod prey

Referencia APA: Ory, N. C., Sobral, P., Ferreira, J. L., & Thiel, M. (2017). Amberstripe scad Decapterus muroadsi (Carangidae) fish ingest blue microplastics resembling their copepod prey along the coast of Rapa Nui (Easter Island) in the South Pacific subtropical gyre. Science of The Total Environment, 586, 430-437. https://doi.org/10.1016/j.scitotenv.2017.01.175

Selective byssus attachment behavior of mytilid mussels from hard-and soft-bottom coastal systems

Autores:

Aguilera, M. A., Thiel, M., Ullrich, N., Luna-Jorquera, G., & Buschbaum, C

Resumen:

In both sedimentary and rocky coastal habitats, epibenthic mytilid mussels use byssal threads for attachment to the substratum and to form beds with high densities of individuals. Number and attachment strength of byssal threads can be adjusted according to external factors such as hydrodynamic forces or predators, but it is unknown whether mytilid mussels distinguish between substrata of different quality for byssus attachment in different habitat types. In field studies, we examined the attachment strength of the mussel Perumytilus purpuratus growing on Pacific hard- and soft-bottom shores in Chile and of the blue mussel Mytilus edulis from an Atlantic rocky shore in France and a sedimentary shore in the North Sea (Germany), respectively. In additional laboratory experiments, we studied mussel substratum selectivity of both bivalve species from soft and hard bottoms by offering living versus dead, barnacle-fouled vs. unfouled, and firmly attached vs. loose conspecifics. In the field, attachment strength of P. purpuratus on hard bottoms was substantially higher than on soft bottoms even though mussels produced more byssus in the latter habitat. In contrast, blue mussels M. edulis showed only a slightly reduced attachment strength on soft compared to hard bottoms. In the soft-bottom habitat, fouled individuals from the edge of a blue mussel bed were especially strongly attached. In the byssus attachment behavior experiments, P. purpuratus from both habitats showed a significant preference for living conspecifics and those from soft bottoms preferred firmly attached conspecifics. Blue mussels had no preference for particular conspecifics except those from soft-bottom habitats, which preferred fouled over clean mussels. In general, in the choice experiments hard-bottom M. edulis produced more byssus. Our results confirmed that mytilid mussels may show active substratum choice for byssus attachment, which depends on mussel species and habitat type. The results suggest that mussels are adapted to a particular habitat type, with P. purpuratus showing lower adaptation to soft-bottom areas while M. edulis shows successful strategies for both environments.

Año: 2017

Palabras claves: Attachment strength, Byssus production, Mytilid mussels, Selective behavior, Substratum choice

Referencia APA: Aguilera, M. A., Thiel, M., Ullrich, N., Luna-Jorquera, G., & Buschbaum, C. (2017). Selective byssus attachment behavior of mytilid mussels from hard-and soft-bottom coastal systems. Journal of Experimental Marine Biology and Ecology, 497, 61-70. https://doi.org/10.1016/j.jembe.2017.09.009

Phylogeography of two intertidal seaweeds, Gelidium lingulatum and G. rex (Rhodophyta: Gelidiales), along the South East Pacific: patterns explained by rafting dispersal?

Autores:

López, B. A., Tellier, F., Retamal-Alarcón, J. C., Pérez-Araneda, K., Fierro, A. O., Macaya, E. C., Tala, F., & Thiel, M.

Resumen:

Rafting on floating seaweeds facilitates dispersal of associated organisms, but there is little information on how rafting affects the genetic structure of epiphytic seaweeds. Previous studies indicate a high presence of seaweeds from the genus Gelidium attached to floating bull kelp Durvillaea antarctica (Chamisso) Hariot. Herein, we analyzed the phylogeographic patterns of Gelidium lingulatum (Kützing 1868) and G. rex (Santelices and Abbott 1985), species that are partially co-distributed along the Chilean coast (28°S–42°S). A total of 319 individuals from G. lingulatum and 179 from G. rex (20 and 11 benthic localities, respectively) were characterized using a mitochondrial marker (COI) and, for a subset, using a chloroplastic marker (rbcL). Gelidium lingulatum had higher genetic diversity, but its genetic structure did not follow a clear geographic pattern, while G. rex had less genetic diversity with a shallow genetic structure and a phylogeographic break coinciding with the phylogeographic discontinuity described for this region (29°S–33°S). In G. lingulatum, no isolation-by-distance was observed, in contrast to G. rex. The phylogeographic pattern of G. lingulatum could be explained mainly by rafting dispersal as an epiphyte of D. antarctica, although other mechanisms cannot be completely ruled out (e.g., human-mediated dispersal). The contrasting pattern observed in G. rex could be attributed to other factors such as intertidal distribution (i.e., G. rex occurs in the lower zone compared to G. lingulatum) or differential efficiency of recruitment after long-distance dispersal. This study indicates that rafting dispersal, in conjunction with the intertidal distribution, can modulate the phylogeographic patterns of seaweeds.

Año: 2017

Palabras claves:

Referencia APA: López, B. A., Tellier, F., Retamal-Alarcón, J. C., Pérez-Araneda, K., Fierro, A. O., Macaya, E. C., Tala, F., & Thiel, M. (2017). Phylogeography of two intertidal seaweeds, Gelidium lingulatum and G. rex (Rhodophyta: Gelidiales), along the South East Pacific: patterns explained by rafting dispersal?. Marine Biology, 164(9), 188. http://dx.doi.org/10.1007/s00227-017-3219-5

Gall-forming protistan parasites infect southern bull kelp across the Southern Ocean, with prevalence increasing to the south

Autores:

Blake, C., Thiel, M., López, B. A., & Fraser, C. I.

Resumen:

Protistan pathogens can have devastating effects on marine plants, yet the processes that affect their distributions and infection intensities are poorly understood. Species within the brown algal genus Durvillaea are major ecosystem engineers throughout the sub-Antarctic and cold-temperate Southern Hemisphere, and a newly described genus of protistan parasite, Maullinia, was recently found infecting D. antarctica in Chile. We set out to address 3 key questions. (1) Is there evidence for trans-oceanic dispersal of Maullinia? (2) Does Maullinia infect other Durvillaea species? (3) Does infection prevalence vary throughout the hosts’ ranges? We sampled Maullinia on Durvillaea populations along coasts in Chile (D. antarctica, from 32° to 42°S: 8 sites), Australia (D. potatorum and D. amatheiae, from 36° to 38°S: 5 sites) and sub-Antarctic Marion Island (46°53’47’’S, 37°43’32’’E). We used a genetic marker (18S rRNA) to verify the presence of Maullinia on Durvillaea at all sites and visual surveys of Maullinia galls to assess infection prevalence in Chile and Australia. We confirm that Maullinia infects Australian Durvillaea species, but our results indicate that each host species is parasitised by a different Maullinia lineage. Maullinia infection prevalence increased with latitude. Long- and short-distance dispersal events are inferred to have occurred based on genetic patterns. We conclude that Maullinia protists are broadly distributed and affect multiple host species, including at least 3 Durvillaea species (2 in Australia, and 1 in both Chile and Marion Island), and that environmental factors influence host susceptibility to infection.

Año: 2017

Palabras claves: Pathogen, Macroalgae, Host-specificity, Intertidal, Dispersal, Durvillaea, Maullinia

Referencia APA: Blake, C., Thiel, M., López, B. A., & Fraser, C. I. (2017). Gall-forming protistan parasites infect southern bull kelp across the Southern Ocean, with prevalence increasing to the south. Marine Ecology Progress Series, 583, 95-106. https://doi.org/10.3354/meps12346