Coast Of Southern Chile Research Articles

Lightning in Western Patagonia

AbstractOn the basis of 8 years (2005–2012) of stroke data from the World Wide Lightning Location Network we describe the spatial distribution and temporal variability of lightning activity over Western Patagonia. This region extends from ~40°S to 55°S along the west coast of South America, is limited to the east by the austral Andes, and features a hyper‐humid, maritime climate. Stroke density exhibits a sharp maximum along the coast of southern Chile. Although precipitation there is largely produced by cold nimbostratus, days with more than one stroke occur up to a third of the time somewhere along the coastal strip. Disperse strokes are also observed off southern Chile. In contrast, strokes are virtually nonexistent over the austral Andes—where precipitation is maximum—and farther east over the dry lowlands of Argentina. Atmospheric reanalysis and satellite imagery are used to characterize the synoptic environment of lightning‐producing storms, exemplified by a case study and generalized by a compositing analysis. Lightning activity tends to occur when Western Patagonia is immersed in a pool of cold air behind a front that has reached the coast at ~40°S. Under these circumstances, midlevel cooling occurs before and is more prominent than near‐surface cooling, leading to a weakly unstable postfrontal condition. Forced uplift of the strong westerlies impinging on the coastal mountains can trigger convection and produces significant lightning activity in this zone. Farther offshore, large‐scale ascent near the cyclone's center may lift near‐surface air parcels, fostering shallow convection and dispersing lightning activity.

Health statistics aren't born in a cabbage patch: Jesuits, political arithmetic, stigmergy and oligopticons.

By analyzing the content and network of production of a map from 1751, created by the circular mission of the Jesuits in Chiloé (an archipelago located off the southern coast of Chile), that contains birth, death and population data, this article discusses the role that health statistics play historically, philosophically, technically and sociologically. In doing so, the article seeks to comprehend the genesis of a process of production of data and references in order to debate what health statistics are composed of, what ends they are used for, what their connection is to the formation of collectives and the differential conditions of possibility that exist for producing statistics. We attempt to develop hypotheses that demonstrate statistics as a hybrid articulation between diverse elements, epistemological, biopolitical, historical and philosophical in nature, with facets at once religious and demographic, ontological and ethnic, scientific and governmental.

Las estadísticas de salud no nacen de un repollo: jesuitas, aritméticas políticas, estigmergias y oligópticos

By analyzing the content and network of production of a map from 1751, created by the circular mission of the Jesuits in Chiloé (an archipelago located off the southern coast of Chile), that contains birth, death and population data, this article discusses the role that health statistics play historically, philosophically, technically and sociologically. In doing so, the article seeks to comprehend the genesis of a process of production of data and references in order to debate what health statistics are composed of, what ends they are used for, what their connection is to the formation of collectives and the differential conditions of possibility that exist for producing statistics. We attempt to develop hypotheses that demonstrate statistics as a hybrid articulation between diverse elements, epistemological, biopolitical, historical and philosophical in nature, with facets at once religious and demographic, ontological and ethnic, scientific and governmental.

Mythologizing Greed and Betrayal in the Strait of Magellan in Juan de Miramontes' Armas antárticas

AbstractTaking as a starting point Antonio Sánchez Jiménez's recent work on the myth of Jason in Lope de Vega's El Vellocino de Oro, this article examines the myths of Jason and Leander in Juan de Miramontes Zuázola's epic, Armas antárticas (1608-1609). After exploring the explicit allusions to the myths in the epic, I analyse an implicit reference to Leander in the portrayal of Tomé Hernández, the only survivor of the failed sixteenth-century Spanish settlements in the Strait of Magellan. As it turns out, Hernández was rescued by the English pirate, Thomas Cavendish. In evoking the myth of Leander on the southern coast of Chile, Armas antárticas recalls Alonso de Ercilla's self-description in La Araucana (1569, 78, 89) as analysed by Ricardo Padrón. However, I contend that the representation of Hernández is best understood in comparison to Juan Boscán's Leandro (1543), the fullest and most widely disseminated Spanish version of the tale in the sixteenth century. Appealing to the Leander myth allows Armas antárticas to turn away from a focus on the role of greed in colonization. Yet shadows of Jason still lurk behind the portrayal of Hernández, which raise other serious ethical questions for the Spanish Empire concerning piracy and loyalty as these play out in the Strait of Magellan. This essay shows that the poetic portrayal of Hernández and Cavendish ends up exhibiting the same ambiguities associated with piracy as analysed by Daniel Heller-Roazen.ResumenPartiendo del trabajo reciente de Antonio Sánchez Jiménez sobre el mito de Jasón y sus asociaciones con la codicia en El Vellocino de Oro de Lope de Vega, este artículo examina los mitos de Jasón y Leandro en la épica de Juan de Miramontes Zuázola, Armas antárticas (1608-1609). Después de explorar las alusiones explícitas a estos mitos en la épica, analizo una referencia implícita a Leandro en la representación de Tomé Hernández, el único sobreviviente de la fracasada colonia española en el estrecho de Magallanes del siglo XVI. Sucede que Hernández fue socorrido por el pirata inglés, Thomas Cavendish. Al evocar el mito de Leandro en la costa meridional de Chile, Armas antárticas también recuerda la autodescripción de Alonso de Ercilla en La Araucana (1569, 78, 89), según la lectura de Ricardo Padrón. Sin embargo, propongo que la descripción de Hernández se entiende mejor comparada con el Leandro (1543) de Juan Boscán, la más completa y más divulgada versión española del mito del siglo XVI. Recurrir al mito de Leandro le permite a Armas antárticas apartarse de un enfoque en el papel de la codicia en la colonización. Mas, la sombra de Jasón sigue tras la representación de Hernández, planteando así problemas éticos para el imperio español sobre la piratería y la lealtad como estos temas se plasman en el estrecho de Magallanes. Este ensayo demuestra que la representación de Hernández y Cavendish acaba por poner de manifiesto la misma ambigüedad asociada con la piratería como analizada por Daniel Heller-Roazen.

Codium bernabei sp. nov. (Bryopsidales, Chlorophyta), a coalescing green seaweed from the coast of Chile

González A.V., Chacana, M.E. and Silva P.C. 2012. Codium bernabei sp. nov. (Bryopsidales, Chlorophyta), a coalescing green seaweed from the coast of Chile. Phycologia 51: 666–671. DOI: 10.2216/12-025.1Many intertidal rocky habitats of the Chilean coast were dominated by the dark green thalli of a mat-forming Codium. This green seaweed was ecologically important because it formed a permanent belt by coalescence between conspecific thalli, and thus it affected substrate dominance and community structure. Six species of mat-forming Codium have been recorded in Chile; the adherent Codium in central and northern Chile has been recognized as C. dimorphum, a species first described from the Guaitecas Islands in southern Chile. We analyzed 320 Codium specimens collected from 11 sites spanning the entire Chilean coastline. Morphological and rbcL sequence data revealed the presence of two distinct species with non-overlapping geographical distributions. Codium dimorphum, which is characterized by dimorphic utricles (inner utricles having thin apical walls, and outer utricles having thick apical walls), was found to be restricted to the southern Chilean coast. Specimens from central and northern Chile with uniform utricles were described as a new species, C. bernabei.

Interactive effects of UV radiation and enhanced temperature on photosynthesis, phlorotannin induction and antioxidant activities of two sub-Antarctic brown algae

Lessonia nigrescens and Durvillaea antarctica, two large sub-Antarctic brown algae from the southern Chilean coast, were exposed to solar UV radiation in an outdoor system during a summer day (for 11 h) as well as to artificial UV radiation under controlled laboratory conditions at two temperatures (15 and 20 °C) for 72 h. Chlorophyll a fluorescence–based photoinhibition of photosynthesis was measured during the outdoor exposure, while electron transport rates, lipid peroxidation, antioxidant activity and content of phlorotannins were determined at different time intervals during the laboratory exposure. Under natural solar irradiances in summer, both species displayed well-developed dynamic photoinhibition: F v/F m values decreased by 70 % at noon coinciding with the levels of PAR >1,500 μmol m−2 s−1 and UV-B radiation >1 W m−2 and recovered substantially in the afternoon. In treatments including UV radiation, recovery in D. antarctica started already during the highest irradiances at noon. The results from laboratory exposures revealed that (a) elevated temperature of 20 °C exacerbated the detrimental effects of UV radiation on photochemical parameters (F v/F m and ETR); (b) peroxidative damage measured as MDA formation occurred rapidly and was strongly correlated with the decrease in F v/F m, especially at elevated temperature of 20 °C; (c) the antioxidant activity and increases in soluble phlorotannins were positively correlated mainly in response to UV radiation; (d) phlorotannins were rapidly induced but strongly impaired at 20 °C. In general, short-term (2–6 h) exposures to enhanced UV radiation and temperature were effective to activate the photochemical and biochemical defenses against oxidative stress, and they continued operative during 72 h, a time span clearly exceeding the tidal or diurnal period. Furthermore, when algae were exposed to dim light and control temperature of 15 °C for 6 h, F v/F m increased and lipid peroxidation decreased, indicating consistently that algae retained their ability for recovery. D. antarctica was the most sensitive species to elevated temperature for prolonged periods in the laboratory. Although no conclusive evidence for the effect of the buoyancy of fronds was found, the interspecific discrepancies in thermo-sensitivity in the UV responses found in this study are consistent with various ecological and biogeographical differences described for these species.

Waveform and Spectral Analyses of the 2011 Japan Tsunami Records on Tide Gauge and DART Stations Across the Pacific Ocean

We studied the 11 March 2011 Tohoku tsunami through analysis of the sea level records from 21 tide gauge and 16 DART (Deep-ocean Assessment and Reporting of Tsunamis) stations from across the Pacific Ocean. The extreme power of this trans-oceanic tsunami was indicated by the trough-to-crest heights of 3.03 m at Arena Cove on the western coast of the USA and 3.94 m at Coquimbo on the southern coast of Chile. The average value of the maximum amplitude was 163.9 cm for the examined tide gauge records. At many coastal tide gauge stations the largest wave arrived several hours after the first arrival of the tsunami wave, and the tsunami lasted for a long time with an average duration of 4 days. On the contrary, at most of the DART stations in the deep ocean, the first wave was the largest, the tsunami amplitudes were smaller with an average maximum of 51.2 cm, and the durations were shorter with an average of 2 days. The two dominant tsunami periods on the DART records were 37 and 67.4 min, which are possibly attributed to the width and length of the tsunami source fault, respectively. The dimensions of the tsunami source was estimated as 233 km × 424 km. Wavelet analyses of tide gauge and DART records showed that most of the tsunami energy was distributed at the wide period band of around 10–80 min during the first hour after the tsunami arrival, then it was concentrated in a relatively narrower band. The frequency-time plots showed the switches and lapses of tsunami energy at the 35- and 65-min period bands.

Metazoan parasite communities of rock cod Eleginops maclovinus along southern Chilean coast and their use as biological tags at a local spatial scale

The composition of the metazoan parasite fauna of the rock cod Eleginops maclovinus from three locations in southern Chile was compared to assess the local spatial variation of the community component of their parasitic faunas. A total of 13 108 metazoan parasites (5267 endoparasites and 7841 ectoparasites) belonging to 34 taxa were collected from 268 specimens of E. maclovinus between October 2008 and March 2009. The populations and community quantitative descriptors were estimated. Altogether, 97.4% of the fish were infected with at least one parasite taxon. The most prevalent species were Hypoechinorhynchus magellanicus (Acanthocephala), Caligus rogercresseyi, Lepeophtheirus mugiloides, Clavella adunca (Copepoda) and Similascarophis sp. (Nematoda). Five species are new records for this host: Argulus araucanus, Hirudinea gen. sp1., Hirudinea gen. sp2., Benedenia sp. and Camallanidae gen. sp. A linear discriminant analysis (LDA) showed that the metazoan parasite fauna of E. maclovinus varied qualitatively and quantitatively among three locations, with 89.7% of fish being correctly assigned to their respective locations. This suggested that parasites could be a reliable tool to discriminate individual fish from geographically close locations. There was a weak relationship between the parasite fauna and fish size and there were no accumulations of parasites in the host over time, which could be associated with ontogenetic changes of diet associated with habitat use.

Intraregional variation among Alexandrium catenella (Dinophyceae) strains from southern Chile: Morphological, toxicological and genetic diversity

Morphological, toxicological and phylogenetic analyses, using the partial LSU gene and internal spacer (ITS) regions of the rDNA gene, were combined to evaluate the intraregional diversity of Alexandrium catenella occurring along the southern coast of Chile. Twenty-two strains isolated from different localities along the wide area of distribution of the species (from 42°S to 55°S) were examined by these three approaches. Morphologically, although the strains showed diagnostic characters according to the species definition, variations in these traits within and between strains were also observed. The absence of an apical or posterior attachment pore, for instance, was observed mainly in old isolates. Indirect connection between the apical and 1′ plates, traits normally seen in other species of the same genus, was also noted in some strains. However, the lack of a ventral pore on the 1′ plate was one of the most distinctive characteristics present in all the Chilean strains. Toxicologically, the Chilean strains were characterized by the dominance of N-sulfocarbamate (C1,2) and gonyautoxins (GTX1–4), but also by the scarcity or absence of saxitoxin. Considering the dominance of these toxins in each strain, at least two distinctive toxin patterns were distinguished. Through rDNA sequence analysis, the Chilean strains were segregated as part of Clade I (North American) of the Alexandrium tamarense species complex. Nevertheless, significant genetic diversity was also observed among the Chilean strains, especially using ITS sequences. Through these three approaches, Chilean strains of A. catenella showed significant intraregional variability, which is appropriate for a native species. However, the distribution of its genetic diversity seems to be inconsistent with the apparent northward expansion observed along the west coast of South America.

(A3) Health Care Facilities Affected by the Earthquake in Chile

IntroductionOn February 27, 2010, a 8,8 MW earthquake struck the central and southern coast of Chile, that was followed by a tsunami that destroyed some cities such as Constitution, Ilaco, Talcahuando and Dichato. The national authorities reported 512 dead and 81,444 homes were affected. It was the one of the five most powerful earthquakes in the human modern history. The most affected regions were Maule (VII) and Bio (VIII).ResultsThe impact of the quake in the health sector was enormous especially on the health care infrastructure. The preliminary evaluations showed that 18 hospitals were out of service due severe structural and no-structural damages, interruption of the provision of water or because they were at risk to landslides. Another 31 hospitals had moderate damage. The Ministry of Health lost 4249 beds including 297 (7%) in critical care units. Twenty-two percent of the total number of beds and thirty-nine surgical facilities available in the affected regions were lost in a few minutes due to quake. At least eight hospitals should be reconstructed and other hospitals will need complex repair.ConclusionThe effect of the earthquake was significant on hospital services. It included damages to the infrastructure and the loss of furniture and biomedical equipment. The interruption of the cold chain caused loss of vaccines. National and foreign field hospitals, temporary facilities and the strengthening of the primary health care facilities had been important to assure the continuation of health care services. *Based on information from PAHO – Chile.

Endoparasite fauna of five Gadiformes fish species from the coast of Chile: host ecology versus phylogeny

The aims of the present study were to compare, using multivariate analyses, the degree of similarity of the endoparasite fauna of five fish species belonging to the order Gadiformes: Merluccius gayi, Merluccius australis, Macruronus magellanicus (Gadoidei) and Micromesistius australis and Nezumia pulchella (Macrouroidei), from the southern and central Chilean coast, and to evaluate whether the composition of the endoparasite fauna was determined by phylogenetic or ecological relationships. We employed our database of Merluccius australis, M. magellanicus and Micromesistius australis, which was complemented with published information for M. magellanicus, Merluccius australis, Micromesistius australis, M. gayi and N. pulchella. A higher number of endoparasite species was recorded for Merluccius australis, Micromesistius australis and M. magellanicus, namely Anisakis sp. and Hepatoxylon trichiuri, which is the most prevalent parasite among these hosts. Aporocotyle wilhelmi and Hysterothylacium sp. were detected only in M. gayi, whereas Lepidapedon sp. was found exclusively in N. pulchella. These results suggest that fish ecology rather than host phylogeny was the most important factor for the determination of similarity in parasite composition. This result could be explained by the similar trophic patterns of hosts and by the predominance of generalist larval species among these fish parasite communities.

Vagrant Antarctic fur seals, Arctocephalus gazella, in southern Chile

The Antarctic fur seal, Arctocephalus gazella, in the eastern South Pacific Ocean, first reported on Hoste Island, Cape Horn in 1973, and then on the Juan Fernandez Archipelago in 1982 and 1983, was recorded again in October and December 2009 on the southern coast of Chile. Three different individuals were seen simultaneously on a single day at Punta Dungenes, Magellan Strait, and a fourth individual was sighted at the northeastern coast of Almirantazgo Sound, Tierra del Fuego. These records represent the first sightings of live Arctocephalus gazella in southern Chile. Although it is difficult to establish both their origin and rationale for dispersion outside of their distribution range, the substantial breeding population recovery in South Georgia and food shortages during the breeding and post-breeding season are suggested as possible explanations.

Microhabitat segregation and physiological differences in two species of intertidal porcellanid crabs (Genus <i>Petrolisthes</i>) on the southern coast of Chile

Intertidal crustaceans have a high degree of physiological plasticity, which allows them to withstand periods of water emersion. In this study we examine the physiological constraints that determine the distribution and abundance of the intertidal porcellanid crabs Petrolisthes laevigatus and Petrolisthes violaceus . This study evaluates the distribution and abundance of the two species at different tidal heights, in relation to haemocyanin concentration and LDH activity, resistance to air desiccation, thermal tolerance, and resistance to hypoxic water. The results showed that Petrolisthes laevigatus was more abundant at the high tide level than Petrolisthes violaceus , which was more abundant at the low tide level. Petrolisthes laevigatus showed greater tolerance to high temperatures and lower tolerance to desiccation when exposed to air than P. violaceus , which was also more tolerant to hypoxia during prolonged exposure. No differences were found in haemocyanin concentration and LDH activity. These findings support the idea of an evolutionary gradient towards terrestrial adaptations. Of the two species, Petrolisthes laevigatus showed the most advanced physiological features for semi-terrestrial specialization.

Potential source regions of biogenic aerosol number concentration apportioning at King George Island, Antarctic Peninsula

AbstractNowadays it is well accepted that background aerosols in the boundary layer over remote oceans are of marine origin and not aged continental. Particularly in the Atlantic sector of the Southern Ocean at least four main important regions exhibit significant ocean primary productivity. They are the Bellingshausen–Amundsen Sea, the Weddell Sea, the southern Argentinean shelf and the southern Chilean coast. In this work, we have combined ground-based continuous atmospheric sampling of aerosol number concentration (ANC), over-sea dimethyl sulphide (DMS) measurements, chlorophyll a (chl a) concentration provided by Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite images, in situ meteorological data and monthly regional NCEP-NCAR re-analysis wind fields in order to investigate the relative contribution of each of the above regions to the apportionment of the ANC at King George Island (KGI), South Shetland Islands. Our results suggest that, at least during the period from September 1998–December 1999, the southern Argentinean shelf acted as the main contributor to the ANC measured in KGI.

Fishing yields and size structures of Patagonian toothfish (Dissostichus eleginoides) caught with pots and long-lines off far southern Chile

Herein, we compare information taken from the Patagonian toothfish ( Dissostichus eleginoides ) fishery operations carried out off the far southern coast of Chile (47°00’S-57°00’S) using pots (pots) and longlines. In January 2006 and from June to October 2006, 167 fishing hauls were done, 119 using long-lines and 48 using pots. The total Patagonian toothfish catch was 60.9 tons, of which 81.2% were caught with long-lines and 18.8% with pots. On average, 5,395 hooks and 147 pots were set per haul, with average yields of 0.08 kg hook -1 and 1.43 kg pot -1 . The average depth for setting the gear was 1,581 m (long-lines) and 1,318 m (pots). Significant differences were found between these two types of gear, as well as between the time of setting and the time of retrieval. Greater fishing yields were obtained from the long-line fishery operations, with significant differences between the gear types in terms of the catch per haul (kg haul -1 ) and the catch per length of the specimens retained (kg 1000 m -1 ). On average, the individuals caught with pots (110.8 cm total length) were larger than those caught with long-lines (105.1 cm total length). Nonetheless, no significant differences were recorded for the size structures. In terms of interactions with birds, during setting, no birds were observed at the trapping operations, whereas a few specimens (≤ 10 birds) were seen during only 2.5% of the long-line operations. During retrieval, birds were observed during 34.9% of the hauls with pots and 62.8% of the longline operations. The presence of mammals around the fishery operations during setting and retrieval was similar for both types of gear.

Palaeobiogeographical provenance, taphonomy, and mode of life of Aturia cubaensis (Cephalopoda, Nautiloidea) from Cainozoic deposits of Chile

The presence of Aturia cubaensis (Lea) is reported from several Cainozoic localities along the central and southern Chilean coast. The shells are very well preserved and the ultrastructure of the shell, especially of the siphuncular tube, of A. cubaensis is described and the function of the siphuncular tube discussed. A. cubaensis shows an interesting distributional pattern in Chile, becoming more frequent towards higher latitudes. It occurs in the Navidad, Ranquil, and Lacui formations of central and southern Chile and the Cameronian Stage of Tierra del Fuego, spanning a time of Eocene-Oligocene to latest Miocene, possibly even earliest Pliocene. Tierra del Fuego is the southernmost record of this species. The preservation of Aturia in all these localities is exceptionally good, no incrustation and microboring is observed in the shells. Post-mortem shell breakage is present, but usually the phramocone is not destroyed. These records contradict either the subtropical to tropical nature of the genus Aturia or existing climatic reconstructions for the southeastern Pacific during the middle to late Cainozoic. A number of southern South American names for nautiloids are synonymized with A. cubaensis: Nautilus maldonadi Philippi, Nautilus caroliameghinoi Ihering, Aturia ( Sphenaturia) brueggeni Ihering, Aturia ( Sphenaturia) felschi Ihering. Nautilus araucanus Philippi and Nautilus magellanicus Philippi are nomina nuda but presumably also synonyms of A. cubaensis.

Black-browed albatross foraging on jellyfish prey in the southeast Pacific coast, southern Chile

Direct observations on Black-browed albatross (BBA, Thalassarche melanophrys) feeding have been barely informed. An item considered scarce in the Diomedeidae diets is jellyfishes, due to the impossibility of recognizing them from bird regurgitates or their feces. By means of direct visual records, BBAs were seen capturing jellyfish in southern Chilean coasts (40°S). These birds used the surface seizing method over short periods (<13 s), feeding mainly on jellyfish umbrella. The prey corresponds to the family Ulmaridae, neritic cnidarians distributed in the Pacific and Atlantic Oceans. Difficulties arose when determining the identity of cnidarians to species level mainly due to the lack of reference material on Chile and few studies on this region. The present contribution helps to add to the few registers of the in situ feeding activity of BBAs in the waters of the southeast Pacific Ocean.

Chromosomal characteristics of the temperate notothenioid fish Eleginops maclovinus (Cuvier)

The Falkland’s mullet, Eleginops maclovinus, is the only modern representative of the Sub-Antarctic family Eleginopidae, suborder Notothenioidei. Based on specimens from the Falkland Islands/Islas Malvinas, the Magellan Straits, and the southern coast of Chile, we have established the specific karyotype by conventional cytogenetic methods and have mapped the chromosomal loci of the ribosomal genes by fluorescence in situ hybridization (FISH). With respect to the basal notothenioid family Bovichtidae and to the hypothetical basal condition of the suborder (diploid number = 48, fundamental number = 48), E. maclovinus displays a slightly derived karyotype (diploid number = 48, fundamental number = 54). In contrast to the bovichtids, the 45S and 5S ribosomal DNAs are co-localized to a single chromosome pair. Condensation of the ribosomal genes to a single locus is likely to represent an intermediate stage in the evolution of notothenioid karyology. Features unique to E. maclovinus (e.g., morphology of its large, rDNA-bearing chromosome pair) probably result from divergence during the long evolutionary isolation of the family.

Conceptual PHES-system models of the Aysén watershed and fjord (Southern Chile): Testing a brainstorming strategy

The use of brainstorming techniques for the generation of conceptual models, as the basis for the integrated management of physical–ecological–social systems (PHES-systems) is tested and discussed. The methodology is applied in the analysis of the Aysén fjord and watershed (Southern Chilean Coast). Results show that the proposed methods can be adequately used in management scenarios characterized by highly hierarchical, experts/non-experts membership.

Reproductive biology and population parameters of Petrolisthes laevigatus (Anomura: Porcellanidae) in southern Chile: consequences on recruitment

The present study describes the reproductive cycle and population structure of the intertidal crab Petrolisthes laevigatus, an abundant inhabitant of the upper rocky intertidal zone, as well as the relationship between seasonal patterns in the release of its planktonic larvae and recruiting. A total of 22900 individuals was collected along the coast of southern Chile between May 2001 and March 2003.The structure and density of the adult population (males and females) was relatively constant throughout the study period, although seasonal variations were observed in these two parameters of the benthic population (males, females, juveniles and megalopae), principally due to the incorporation of new individuals (recruitment) into the intertidal zone. Petrolisthes laevigatus presented a prolonged reproductive period. Females with initial eggs were present from the end of summer through to the middle of the following summer (11 months) and the breeding season lasted seven months (from August to February), as reflected in the six months of intertidal settlement (October–March).The interannual patterns and variations observed in the settlement along the southern Chilean coastline were related to the patterns in the abundance of potential released planktonic larvae. Petrolisthes laevigatus, unlike most temperate species, has a broad reproductive and settlement period in the south of Chile, which allows a highly stable structure and population abundance in this intertidal zone.