Non-indigenous species and their realized niche in tidepools along the South-East Pacific coast.

Non-indigenous species (NIS) have the potential to colonize and become established in a wide range of coastal habitats. Species with broad environmental tolerances can quickly adapt to local conditions and expand their niches along environmental gradients, and even colonize habitats with extreme abiotic conditions. Here we report and document the distribution of eight marine NIS (four seaweed and four invertebrate species) found in tidepools along a 3000 km latitudinal gradient along the Pacific coast of Chile (18.4°S to 41.9°S). The seaweed NIS Codium fragile, Capreolia implexa, Schottera nicaeensis and Mastocarpus latissimus were mostly distributed towards high latitudes (i.e., more southerly locations), where temperatures in tidepools were low. The invertebrate NIS Anemonia alicemartinae, Ciona robusta, Bugula neritina and Bugulina flabellata were more common towards low latitudes, where high temperatures were registered in the tidepools. Across the intertidal gradient, seaweed NIS were mostly found in pools in the mid and low intertidal zone, while invertebrate NIS occurred mostly in pools from the mid and upper intertidal zones. The realized niche spaces of NIS (based on the Outlying Mean Index, OMI) in the study area were mainly influenced by environmental conditions of temperature and salinity (along the latitudinal and intertidal gradients), while other tidepool characteristics (depth, surface area, exposition, and complexity) only had minor effects. Five of the eight NIS exhibited a realized niche space coinciding with the average tidepool environmental conditions, while marginal niches were occupied by species with affinities for specific temperatures and salinities along the latitudinal and intertidal gradients. Our results indicate that physiological tolerances to environmental factors play a fundamental role in the distribution of seaweed and invertebrate NIS in tidepools along the Chilean coast. This study confirms that tidepools offer suitable conditions for some seaweed and invertebrate NIS, potentially facilitating their invasion into new natural habitats.

Daily accumulation rates of floating debris and attached biota on continental and oceanic island shores in the SE Pacific: testing predictions based on global models.

Background: Long-distance rafting on anthropogenic marine debris (AMD) is thought to have a significant impact on global marine biogeography and the dispersal of non-indigenous species. Therefore, early identification of arrival sites of AMD and its epibionts is crucial for the prioritization of preventive measures. As accumulation patterns along global coastlines are largely unstudied, we tested if existing oceanographic models and knowledge about upstream sources of litter and epibionts can be used as a simple and cost-efficient approach for predicting probable arrival sites of AMD-rafting biota in coastal zones. Methods: Using the Southeast Pacific as a model system, we studied daily accumulation rates, composition, and minimum floating times of AMD with and without epibionts on seven sandy beaches, covering the oceanic environment (Rapa Nui/Easter Island) and three regions (south, centre, north) along the Chilean continental coast, over a minimum of 10 consecutive days, and we contrast our results with predictions from published models. Results: Total AMD accumulation rates varied from 56 ± 36 (mean ± standard deviation) to 388 ± 433 items km-1 d-1 and differed strongly between regions, in accordance with local geomorphology and socioeconomic conditions (presence of larger cities and rivers upstream, main economic activities, etc.). Daily accumulation of items with pelagic epibionts (indicators of a pelagic trajectory) ranged from 46 ± 29 (Rapa Nui) to 0.0 items km-1 d-1 (northern continental region). Minimum floating times of rafts, as estimated from the size of pelagic epibionts, were longest in the South Pacific Subtropical Gyre's (SPSG) centre region, followed by the high-latitude continental region under the influence of the onshore West Wind Drift, and decreased along the continental alongshore upwelling current, towards lower latitudes. Apart from pelagic rafters, a wide range of benthic epibionts, including invasive and cryptogenic species, was found on rafts at the continental beaches. Similarly, we present another record of local benthic corals Pocillopora sp., on Rapa Nui rafts. Discussion: Our results agree with the predictions made by recent models based on the prevailing wind and surface current regimes, with high frequencies of long-distance rafting in the oceanic SPSG centre and very low frequencies along the continental coast. These findings confirm the suitability of such models in predicting arrival hotspots of AMD and rafting species. Moreover, storm surges as well as site-related factors seem to influence AMD arrival patterns along the Chilean continental coast and might cause the observed high variability between sampling sites and days. Our results highlight the possible importance of rafting as a vector of along-shore dispersal and range expansions along the SE Pacific continental coast and add to the discussion about its role in benthic species dispersal between South Pacific oceanic islands.

Mountain streams flushing litter to the sea - Andean rivers as conduits for plastic pollution.

Rivers polluted by anthropogenic litter are major transport routes of litter from inland to the coastal zone and the ocean. However, litter studies have primarily focused on marine environments, and the litter dynamics in rivers are still poorly understood. Herein, we explored the abundances, composition and sources of litter at the riversides and in surface waters of mountain rivers from continental Chile in two different years. Additionally, we evaluated whether different temporal, geographic, topographic, hydrologic or anthropogenic factors influence the abundances of litter. Anthropogenic litter was prevalent in Chilean rivers, both at the riversides and in surface waters. Average abundances of riverside litter, floating macrolitter, and small floating plastics were 1.8 items m-2, 10.1 items h-1 and 5.8 items h-1, respectively, and abundances were generally higher in northern Chile. Plastics dominated in all compartments, comprising 29% of riverside litter and more than 70% of small floating litter, but other litter categories were also present at riversides. Sources of litter in Chilean rivers were mostly local, such as recreational visitors, residents, and illegal dumping, and there were no clear effects of the different tested factors on the abundances of litter. Litter densities in surface waters were low compared to those in lowland slow-flowing rivers in other countries, suggesting that retention of litter is limited in the highly dynamic and rapidly flushing mountain rivers, and thus most litter (primarily plastics) is transported directly to the sea. The results suggest that to adequately address this problem in Chile, prevention measures should be aimed at the identified local sources, by means of education, public policies, legislation, and enforcement.

A desert in the ocean - Depauperate fouling communities on marine litter in the hyper-oligotrophic South Pacific Subtropical Gyre.

The hyper-oligotrophic waters of the South Pacific Subtropical Gyre (SPSG) and the productive coastal Humboldt Current System (HCS) constitute an extreme nutrient gradient in the eastern South Pacific Ocean. Rich and dense fouling communities are known from floating objects in the HCS, but they have not been studied in the SPSG and it is not known which factors are influencing their richness and abundance. Here we present the first extensive study of rafting by marine invertebrates on floating anthropogenic debris in the eastern SPSG. We compared the effect of 9 raft-related categorical predictors on epibiont richness and fouling cover. Raft complexity was the most important predictor of richness. Fouling was dominated by thin crusts and biofilms, with more advanced communities only observed on few items. Fouling cover could not be predicted by any of the categorical factors tested. However, when tested as continuous predictors, raft volume and surface area were significantly correlated with both cover and richness. The most frequently encountered epibionts were common pelagic rafters, particularly Lepas spp., Planes spp., and Jellyella spp. Low fouling cover suggests that the SPSG's hyper-oligotrophic conditions strongly limit fouling growth, while the low frequency of coastal taxa points to the HCS/SPSG nutrient gradient acting as a filter for such organisms.

Travelling light: Fouling biota on macroplastics arriving on beaches of remote Rapa Nui (Easter Island) in the South Pacific Subtropical Gyre.

Marine anthropogenic debris was sampled from two beaches on the remote South Pacific island Rapa Nui (Easter Island). Abundance, composition, and the attached fouling assemblages on stranded litter were analysed. Most litter (n = 172 items found) was composed of plastic material, and 34% of all litter items were fouled. The main fouling species was the encrusting bryozoan Jellyella eburnea. Transporting vectors were exclusively made from plastics and were mainly small items and fragments, probably stemming from the South Pacific Subtropical Gyre. We present the first report of Planes major, Halobates sericeus, and Pocillopora sp. on anthropogenic litter in the South Pacific.

Dispersal of alien invasive species on anthropogenic litter from European mariculture areas.

The importance of mariculture areas for the dispersal of alien invasive species (AIS) on artificial floating items has recently been highlighted as a priority research need. Here we present the results of surveys in two important European shellfish culture areas that release rafting AIS, the Venetian lagoon and the Portuguese Algarve region. We found eight aquaculture-related non-native, invasive species attached to anthropogenic litter items mostly related to aquaculture: Amphibalanus amphitrite, Austrominius modestus, Balanus trigonus, Hesperibalanus fallax, Hydroides elegans, Hydroides sanctaecrucis, and Magallana angulata. These species are well-adapted to rafting on artificial surfaces and have a high potential to disperse via this vector. This is the first record of the notorious nuisance species H. sanctaecrucis both in the Mediterranean and Eastern Atlantic, as well as on floating litter. We also present the first records of M. angulata, H. sanctaecrucis, Sabellaria alveolata, Mytilus edulis and Chthamalus montagui on stranded anthropogenic litter.

Anthropogenic marine litter composition in coastal areas may be a predictor of potentially invasive rafting fauna.

Anthropogenic plastic pollution is a global problem. In the marine environment, one of its less studied effects is the transport of attached biota, which might lead to introductions of non-native species in new areas or aid in habitat expansions of invasive species. The goal of the present work was to assess if the material composition of beached anthropogenic litter is indicative of the rafting fauna in a coastal area and could thus be used as a simple and cost-efficient tool for risk assessment in the future. Beached anthropogenic litter and attached biota along the 200 km coastline of Asturias, central Bay of Biscay, Spain, were analysed. The macrobiotic community attached to fouled litter items was identified using genetic barcoding combined with visual taxonomic analysis, and compared between hard plastics, foams, other plastics and non-plastic items. On the other hand, the material composition of beached litter was analysed in a standardized area on each beach. From these two datasets, the expected frequency of several rafting taxa was calculated for the coastal area and compared to the actually observed frequencies. The results showed that plastics were the most abundant type of beached litter. Litter accumulation was likely driven by coastal sources (industry, ports) and river/sewage inputs and transported by near-shore currents. Rafting vectors were almost exclusively made up of plastics and could mainly be attributed to fishing activity and leisure/ household. We identified a variety of rafting biota, including species of goose barnacles, acorn barnacles, bivalves, gastropods, polychaetes and bryozoan, and hydrozoan colonies attached to stranded litter. Several of these species were non-native and invasive, such as the giant Pacific oyster (Crassostrea gigas) and the Australian barnacle (Austrominius modestus). The composition of attached fauna varied strongly between litter items of different materials. Plastics, except for foam, had a much more diverse attached community than non-plastic materials. The predicted frequency of several taxa attached to beached litter significantly correlated with the actually observed frequencies. Therefore we suggest that the composition of stranded litter on a beach or an area could allow for predictions about the corresponding attached biotic community, including invasive species.

Marine litter as a vector for non-native species: What we need to know.

Plastic debris and other floating materials endanger severely marine ecosystems. When they carry attached biota they can be a cause of biological invasions whose extent and intensity is not known yet. This article focuses on knowledge gaps and research priorities needed for, first, understanding and then preventing dispersal of alien invasive species attached to marine litter.

Expression of recombinant green fluorescent protein in Bacillus methanolicus.

Microbial biocatalysts are used in a wide range of industries to produce large scale quantities of proteins, amino acids, and commodity chemicals. While the majority of these processes use glucose or other low-cost sugars as the substrate, Bacillus methanolicus is one example of a biocatalyst that has shown sustained growth on methanol as a carbon source at elevated temperature (50-53°C optimum) resulting in reduced feed and utility costs. Specifically, the complete chemical process enabled by this approach takes methane from natural gas, and following a low-cost conversion to methanol, can be used for the production of high value products. In this study, production of recombinant green fluorescent protein (GFPuv) by B. methanolicus is explored. A plasmid was constructed that incorporates the methanol dehydrogenase (mdh) promoter of B. methanolicus MGA3 together with the GFPuv gene. The plasmid, pNW33N, was shown to be effective for expression in other Bacillus strains, although not previously in B. methanolicus. A published electroporation protocol for transformation of B. methanolicus was modified to result in expression of GFP using plasmid pNW33N-mdh-GFPuv (pNmG). Transformation was confirmed by both agarose gel electrophoresis and by observation of green fluorescence under UV light exposure. The mass yield of cells and protein were measured in shake flask experiments. The optimum concentration of methanol for protein production was found to be at 200 mM. Higher concentrations than 200 mM resulted in slightly higher biomass production but lower amounts of recombinant protein.

Teaching phagocytosis using flow cytometry.

Investigative microbiology on protists in a basic teaching laboratory environment is limited by student skill level, ease of microbial culture and manipulation, instrumentation, and time. The flow cytometer is gaining use as a mainstream instrument in research and clinical laboratories, but has had minimal application in teaching laboratories. Although the cost of a flow cytometer is currently prohibitive for many microbiology teaching environments and the number of trained instructors and teaching materials is limited, in many ways the flow cytometer is an ideal instrument for teaching basic microbiology. We report here on a laboratory module to study phagocytosis in Tetrahymena sp. using flow cytometry in a basic microbiology teaching laboratory. Students and instructors found the flow cytometry data analysis program, Paint-AGate(PRO-TM), to be very intuitive and easy to learn within a short period of time. Assessment of student learning about Tetrahymena sp., phagocytosis, flow cytometry, and investigative microbiology using an inquiry-based format demonstrated an overall positive response from students.