Some species of macroalgae continue to live for extended periods of time after detachment and may even maintain reproductive structures, yet very little is known about this process. Here, we describe the presence of sporophylls (with sporogenous tissues) on floating kelp rafts of Macrocystis spp. along the coast of Chile. Surveys were conducted at nine sites (18-501 S) during austral summer 2002, and floating kelp rafts were seen and collected at seven of these nine sites (between 22 and 501 S). Fifteen (26.8%) of the 56 samples had sporophylls, indicating maintenance of sporophylls after detachment. Some of the kelp sporophytes with reproductive blades showed signs of having been afloat for long periods (indicated by the large size of attached stalked barnacles). Additionally, experiments showed that floating kelps released viable zoospores. To understand the reproductive dynamics of floating kelps, we compared these results with information from attached populations of Macrocystis spp. at nearby coastal sites. In general, attached kelp had higher proportions of sporophylls than floating rafts, suggesting that detachment may negatively affect reproductive status. Nevertheless, floating kelps remained functionally reproductive, suggesting that zoospores may be dispersed via floating rafts. Published reports on other macroalgae indicate that some species (Lessoniaceae, Fucaceae, and Sargassaceae) are fertile and probably release zoospores or zygotes while floating or drifting in ocean currents. Because dispersal distances achieved by spores of most macroalgae are relatively short, release of spores from floating algae may be an alternative mechanism of long-distance dispersal.

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Aim The abundant-centre hypothesis (ACH) is based on the assumption that physiological constraints limit populations at the edges of their distributional range, yet the geographical variation of physiological performance or life-history traits has rarely been examined. Here we examine the applicability of the ACH in a marine system by testing whether physiological predictions are reflected in large-scale variations of life-history traits.Location The Chilean coast (18°-42°S), encompassing more than 2500 km along the Pacific coast of South America.Methods Five porcelain crab species (Petrolisthes granulosus, Petrolisthes laevigatus, Petrolisthes tuberculatus, Petrolisthes violaceus and Allopetrolisthes angulosus) were sampled on intertidal boulder beaches at 13 sampling sites. For each species and site we evaluated: (1) relative abundance (density), (2) maximum size, (3) size at maturity, (4) sex ratio, (5) proportion of ovigerous females, and (6) presence of recruits. The shape of the spatial distribution of each trait was evaluated statistically against the prediction of four hypothetical models (normal, ramped-south, ramped-north and abundant-edge). ResultsThe relative abundance and life-history traits showed different spatial patterns among species. Relative abundance (across sites) was fitted by a normal model in only two species. No model fitted the spatial variation in body size and size at first maturity, which showed a slight but monotonic poleward increase in all species. Sex ratio showed a prominent hump-shaped pattern, with females prevailing in the centre of the ranges and males dominating towards the range boundaries; this pattern was statistically significant in three of the five studied species. The proportion of ovigerous females showed no clear latitudinal trends, and mature individuals were observed across most of the geographical range of the species. However, recruits tended to be absent towards the southern (poleward) boundaries of the distribution. Main conclusionsThe ACH does not apply to all species equally. The link between abundance and life-history traits is complex and variable among the porcelain crab species studied. Overall, the observed patterns were consistent with the idea that equatorward boundaries might be controlled by physiological restrictions mainly affecting adult survival, whereas poleward boundaries might be shaped by limitations in reproductive output and larval survival. Our results underline the importance of incorporating ecological, physiological and life-history studies in future tests of the ACH.

Many littoral caprellid species have a very ample distribution, some having been reported from all over the world. The cosmopolitan distribution of many littoral caprellid species might be facilitated by the fact that they are often associated with fouling communities on floating objects, which have a high potential of far-range dispersal. This dispersal potential may also have implications for the distribution of caprellids on local and regional scales. Herein we examined the distribution of littoral caprellid species on two spatial scales, local (tens of kilometers) and regional (hundreds of kilometers) along the Pacific coast of continental Chile. On the local scale, we studied the caprellid fauna in different habitats (intertidal boulders, subtidal algal and seagrass beds, fouling community on buoys and ropes); on the regional scale we focused only on caprellids associated with the fouling community on buoys and ropes. We found a total of six caprellid species, some of which were very abundant both on the local as well as on the regional scale. On the local scale we found a difference between the three studied habitat types with respect to the assemblage of caprellid species, some of which were found in more than one habitat. The highest species richness and abundance of caprellids was found in the fouling community associated with anchored buoys and ropes. On the regional scale we found very high numbers of caprellids in the fouling community of the northern region (n of 30° S), and decreasing abundances and species richness in the central region (30-37° S). No caprellids were found in the southern region of the study area (37-42° S). This pattern coincides with the global distribution of littoral caprellid species, which are most abundant and diverse at low latitudes but occur in low abundances and low diversity at high latitudes. Detached buoys that were found a few km off the coast harbored similar caprellid assemblages (including ovigerous females) as anchored buoys, suggesting that buoys and other floating substrata (litter, macroalgae) may facilitate dispersal of caprellids (and other epibiota) along the Pacific coast of Chile. Since artificial and natural floating substrata are also abundant at high latitudes it is inferred that the low diversity of littoral caprellids at high latitudes is not due to lack of dispersal vectors, but rather of other factors.Key words: Crustacea, Amphipoda, Caprellidea, Chile, biogeography. RESUMENMuchas especies de caprélidos del litoral presentan una amplia distribución, algunas han sido citadas a lo largo de todo el mundo. La distribución cosmopolita de muchas especies de caprélidos podría deberse al hecho de que se asocian frecuentemente a las comunidades "fouling" en objetos flotantes, que presentan una capacidad importante de dispersión a largas distancias. Esta capacidad de dispersión puede tener implicaciones en la distribución de caprélidos a escala local y regional. En este estudio, nosotros examinamos la distribución de las especies de caprélidos litor...

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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.

The majority of zoogeographic studies along the Chilean Pacific coast have focused on benthic organisms and oceanographic conditions are considered the main factors influencing their distributions. Herein we examined the geographic distribution of pelagic barnacles of the family Lepadidae collected from floating macroalgae at seven sampling areas between 23 and 50° S. Four species were encountered and they are briefly described herein. The most abundant northern species was Lepas anatifera, and it diminished in abundance towards the south (33° S). Moreover, this species was not found in waters with a sea surface temperature (SST) of less than ~18 ºC. Lepas australis, primarily a circumpolar West Wind Drift species, diminished in abundance towards the north (33° S). This species was restricted to waters of < 18 ºC SST. A third species, L. pectinata, was encountered throughout almost the entire study area, but it was most abundant between 29 and 33° S. The fourth species, Dosima fascicularis, was only found at two sampling areas, namely at 27° S and 33° S, and this is the first record of this species from the central coast of Chile. The distributional pattern of the pelagic barnacles found herein corresponds to the three main zoogeographic regions as revealed by the majority of previous studies based on littoral organisms: the northern Peru-Chilean Province, the southern Magellanic Province, and the central Chilean Transition Zone where the two provinces overlap. Even though the present study only considers four species of pelagic barnacles, the results support the hypotheses on the importance of oceanographic conditions (in particular SST) in determining the zoogeographic patterns along the south east Pacific coast of Chile.Key words: zoogeography, Lepas, oceanography, pelagic, Cirripedia. RESUMENLa mayoría de los estudios de zoogeografía a lo largo de la costa chilena del Pacífico sur este se han enfocado en organismos bentónicos y las condiciones oceanográficas se sugieren como factores principales que modulan su distribución. Aquí examinamos la distribución geográfica de especies de cirripedios pelágicos de la familia Lepadidae, asociadas a macroalgas flotando a la deriva, en siete áreas de muestreo entre los 23 y 50º S. Se encontraron cuatro especies de cirripedios lepádidos y cada una se describe brevemente. La especie del norte más abundantes fue Lepas anatifera y disminuye su abundancia hacia el sur (33º S). Además, esta especie no se encontró en temperatura superficial del mar (SST) inferior a ~18 ºC. Lepas australis, que posee una distribución circumpolar, atenúa su abundancia hacia el norte (33º S). Esta especie se restringe a SST < 18 ºC. La tercera especie, L. pectinata se extiende en la mayor parte del área de estudio, pero posee su mayor abundancia relativa en el área central, entre 29 y 33º S. La cuarta especie, Dosima fascicularis, solo se encontró en dos lugares de muestreo, en 27 y 33º S, y es el primer registro para la costa central de Chile. El patrón de distribución de estas especies ...