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1. Ballast water has been identified as a leading vector for introduction of non-indigenous species (NIS). Recently, the International Maritime Organization (IMO) implemented management standards – D-2 – where all large, commercial ships trading internationally are required to adopt an approved treatment system using technologies such as ultraviolet radiation or chlorination. However, current management regulations are based only on the total abundance of viable taxa transported (i.e., total propagule pressure), largely ignoring species richness (i.e., colonization pressure).2. To determine the efficacy of chlorine treatment in reducing invasion risks and changes in transported biological communities inside ballast tanks, we used DNA metabarcoding-based approaches to estimate colonization pressure (here, the number of species/Operational Taxonomic Units (OTUs) introduced) and relative propagule pressure (relative abundance of each species/OTU) of zooplankton communities in control and chlorine treated tanks during four transatlantic voyages. 3. Our study demonstrated that transport itself did not significantly reduce colonization pressure of zooplankton species, nor did chlorine treatment. Chlorine treatment altered community structure by reducing relative propagule pressure of some taxa such as Mollusca and Rotifera, while increasing relative propagule pressure of some Oligohymenophorea and Copepoda species.4. Synthesis and applications. Chlorine treatment may not reduce invasion risks as much as previously thought. Reduction in total propagule pressure does not mean reduction in abundance of all species equally. While some taxa might experience drastically reduced abundance, others might not change at all or increase due to hatching from dormant stages initiated by chlorine exposure. Therefore, management strategies should consider changes in total propagule pressure and colonization pressure when forecasting risk of new invasions. We therefore recommend adopting new approaches, such as DNA metabarcoding-based methods, to assess the whole biodiversity discharged from ballast water. As species responses to chlorine treatment are variable and affected by concentration, we also recommend a combination of different technologies to reduce introduction risks of aquatic organisms. Supplement to: Lin, Yaping; Zhan, Aibin; Hernandez, Marco R; Paolucci, Esteban; MacIsaac, Hugh J; Briski, Elizabeta (2020): Can chlorination of ballast water reduce biological invasions? Journal of Applied Ecology, 57(2), 331-343 The zip file includes:1. raw_data_clean.fasta: Raw sequence reads of zooplankton in ballast water samples2. raw_data.fasta: OTU representative sequences3. OTU_table.xlsx: OTU table

The main petroleum product transported through pipelines in Canada is diluted bitumen (dilbit), a semi-liquid form of heavy crude oil mixed with natural gas condensates to facilitate transport. The weathering, fate, behaviour, and environmental effects of dilbit are crucial to consider when responding to a spill, however few environmental studies on dilbit have been completed. Here we report on 11-day long experimental spills of dilbit (Cold Lake Winter Blend) in outdoor micro-cosms meant to simulate a low-energy aquatic system containing natural lake water and sedi-ments treated with a low (1:8,000 oil:water) and high (1:800 oil:water) volume of dilbit. In the first 24 hours of the experiment, volatile hydrocarbons quickly evaporated from the dilbit, result-ing in increased dilbit density and viscosity. These changes in dilbit’s physical and chemical properties ultimately led to its submergence after 8 days. We also detected rapid accumulation of polycyclic aromatic compounds in the water column of the treated-microcosms following the spills. Our study provides new information on the environmental fate and behaviour of dilbit in a freshwater environment that will be critical to environmental risk assessments of proposed pipe-line projects. In particular, our study demonstrates the propensity for dilbit to sink under ambient environmental conditions in fresh waters typical of many boreal lakes.

We compared Centroid Moment Tensors (CMTs), calculated for large (Mw >5), shallow (<30 km) seismic events to the orientations of seafloor lineaments (n = 4000) mapped throughout the Lau Basin, in the SW Pacific. Ship-based multibeam was combined with vertical gravity gradient data to provide comprehensive coverage to create the lineament map. By comparing the possible focal planes of the CMTs to the orientations of the lineaments, the most likely fault plane solutions were selected, thus classifying the faults and establishing the nature of the highly variable stress regimes in the basin. We resolved the strike, dip and dip direction of 308 faults, and classified 258 additional structures by fault type. The majority of the table was data downloaded from the Global Centroid Moment Tensor (GCMT) database (www.globalcmt.org: accessed October 2018). For more details about the column headers consult the GCMT database website. New data from this study include the latitude and longitude error estimates (in meters), the classified faults (column: 'fault_type'), and the stress domain (column: 'stress_domain'), allocated to each of the classified faults.

Fuerteventura detrital zircon geochemistry, U-Pb age and Hf/O isotopic compositions

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We produced carbon and nitrogen isoscapes across the entire Southern Ocean (>40°S) using surface particulate organic matter isotope data, collected over the past 50 years. We used Integrated Nested Laplace Approximation -based approaches to predict mean annual isoscapes and four seasonal isoscapes using a suite of environmental data as predictor variables.