Invasion risk associated with invertebrates and their dormant stages in ships entering Canadian ports

The shipping industry has been a leading mechanism for introducing nonindigenous species (NIS) into aquatic ecosystems. Two different ballast water regulations, mid-ocean exchange (MOE) and saltwater flushing, were implemented as management practices to reduce the likelihood of new biological invasions in the Pacific, Great Lakes and Atlantic regions of Canada. There has, however, been no formal assessment of the efficacy of these regulations on invertebrates and their dormant eggs transported in the ballast sediment of ships, and current invasion risk posed by these taxa to different regions of Canada. To determine the potential risk of invasion associated with this vector after the implementation of ballast water regulations, I collected sediment samples from 135 ships entering the Pacific, Great Lakes and Atlantic ports and measured density and diversity of invertebrates as well as viability of their dormant eggs. To accurately identify dormant eggs I tested the application of DNA barcoding using mitochondrial cytochrome c oxidase subunit I and 16S rDNA. Further, I explored survival of invertebrate dormant eggs in collected ballast sediment over a one year period to determine if they accumulate inside of ballast tanks. Subsequently, to test efficacy of saltwater flushing, I compared the results of samples I collected in the Great Lakes with the results of similar samples collected prior to the implementation of saltwater flushing regulations, and to test efficacy of MOE I compared voyages with MOE vs. voyages without MOE. Finally, I compared vector strength in different regions in Canada. Overall results show DNA barcoding to be a rapid and accurate approach to identification of invertebrate dormant eggs, and the results indicate possible accumulation of dormant eggs of onychopods and bryozoans inside ballast tanks. This comparative analysis suggests that vector strength varies among different regions in Canada with the Atlantic region being under the highest risk. The two ballast management regulations differently influence the probability of introductions of NIS via dormant eggs. Finally, the amount of sediment is the single, most important factor for management of invertebrates and their dormant eggs in ballast sediment and should be treated beyond current ballast management regulations

Imposto de renda na fonte

Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à lei de Direitos Autorais, não disponibilizamos a obra na íntegra. STJ00078077 336.215(81) Y73ir 9.ed

Where do the most successful invaders come from?

Dr. Elizabeta Briski has founded a research group at GEOMAR with a Sofia Kovalevskaya Award of the Humboldt Foundation 5th August 2014/Kiel. The Croatian/Canadian biologist Dr. Elizabeta Briski studies the question whether species from certain regions have inherent advantages over other species in colonizing new ecosystems. For her research she has been awarded with the Sofja Kovalevskaja Award of the Alexander von Humboldt Foundation. The award is endowed with 1.6 million euro. With the funding Dr. Briski will set up a junior research group at GEOMAR Helmholtz Centre for Ocean Research Kiel

An overview of recent research in marine biological invasions

The Topical Collection on Invasive Species includes 50 articles addressing many tenets of marine invasion ecology. The collection covers important topics relating to propagule pressure associated with transport vectors, species characteristics, attributes of recipient ecosystems, invasion genetics, biotic interactions, testing of invasion hypotheses, invasion dynamics and spread, and impacts of nonindigenous species. This article summarizes some of the collection’s highlights

The Beauty Myth

https://digitalcommons.chapman.edu/feminist_zines/1064/thumbnail.jp

State of the art of nuclear transfer technologies for assisting mammalian reproduction

The transfer of nuclear genomic DNA from a cell to a previously enucleated oocyte or zygote constitutes one of the main tools for studying epigenetic reprogramming, nucleus–cytoplasm compatibility, pluripotency state, and for genetic preservation or edition in animals. More than 50 years ago, the first experiences in nuclear transfer began to reveal that factors stored in the cytoplasm of oocytes could reprogram the nucleus of another cell and support the development of an embryo with new genetic information. Furthermore, when the nuclear donor cell is an oocyte, egg, or a zygote, the implementation of these technologies acquires clinical relevance for patients with repeated failures in ART associated with poor oocyte quality or mitochondrial dysfunctions. This review describes the current state, scope, and future perspectives of nuclear transfer techniques currently available for assisting mammal reproduction.Fil: Gambini, Andres. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of Queensland; AustraliaFil: Briski, Olinda. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Canel, Natalia Gabriela. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Are juveniles as tolerant to salinity stress as adults? A case study of Northern European, Ponto‐Caspian and North American species

Aim: Global biodiversity and ecosystems are highly impacted by anthropogenic activities, such as climate change and introduction of non-indigenous species. As numerous species from the Ponto-Caspian region have established in the North and Baltic Seas, as well as in the Laurentian Great Lakes, there have been large number of studies examining environmental tolerance of these species to determine their future potential to spread. However, many of those studies were conducted only on adult stages, while neglecting the possibility that early life history stages might not be equally resilient. Location: Northern European, Ponto-Caspian and North American regions. Methods: To determine whether juveniles would demonstrate the same environmental tolerance as their parents, we examined the salinity tolerance of adults and juveniles of one Northern European (Gammarus salinus), one Ponto-Caspian (Pontogammarus maeoticus) and one North American species (Gammarus tigrinus). Additionally, we compared our study to that of Paiva et al. (Global Change Biology, 24, 2018, 2708), who tested the salinity tolerance of the same species using only adults. Results: Our study determined that both adults and juveniles of all three species tolerated wide ranges of salinity, with juveniles of G. salinus tolerating only slightly narrower salinity range than their parents, while those of P. maeoticus and G. tigrinus much narrower range. Additionally, we determined better survival and higher growth rates of juveniles of G. salinus in higher salinities and better survival of P. maeoticus in lower salinities. Main conclusions: Based on juvenile salinity tolerance, our study further supported findings of Paiva et al. (2018), where Northern European species may be adapted to marine, while Ponto-Caspian to lower saline and freshwater environments. The North American species is probably adapted to intermediate salinities. As juveniles do not tolerate the same salinity stress as adults, we emphasize the importance of testing all life history stages when predicting species resilience to environmental stressors

Invertebrates and their dormant eggs transported in ballast sediments of ships arriving to the Canadian coasts and the Laurentian Great Lakes

The most effective strategy for managing nonindigenous species (NIS) is through prevention of their transport via regulation of introduction vectors. We sampled 135 ships arriving to three different regions of Canada to assess abundance and species richness of invertebrates and their dormant eggs transported in ballast sediments. By sampling ships that followed particular pathways, we were able to compare vector strength to different regions, the invasion risk of transoceanic vs. coastal vessels, and the effect of midocean exchange, length of voyage, and amount of sediment on the richness and abundance of species inside ballast tanks. Although standardized ballast management regulations have been implemented across Canada, the resulting invasion risk is not uniform across regions. Ships arriving to the Atlantic region carried a greater sediment load with correspondingly higher abundance and species richness than those arriving to the Pacific and Great Lakes regions. Abundance and species richness of invertebrates and their dormant eggs associated with transoceanic ships did not differ from that of ships operating along coastal areas of North America. Similarly, midocean exchange did not reduce either abundance or species richness of invertebrate dormant eggs in ships. Finally, the length of voyage did not influence taxonomic composition or abundance of invertebrate dormant eggs but was directly related to survival of active macroinvertebrates. Ballast sediments could introduce new NIS to some regions of Canada despite requirements to manage ships' ballast by midocean exchange. Minimizing sediment accumulation may be the only effective management option for this vector

Examination of a high resolution laser optical plankton counter and FlowCAM for measuring plankton concentration and size

Highlights: • A High Resolution-LOPC and a FlowCAM were evaluated for ballast water monitoring. • Both instruments underestimated density compared to microscopy. • Size measurements can be affected by organism orientation and complex morphology. • Both tools might be particularly useful when working with a known community. Abstract: Many commercial ships will soon begin to use treatment systems to manage their ballast water and reduce the global transfer of harmful aquatic organisms and pathogens in accordance with upcoming International Maritime Organization regulations. As a result, rapid and accurate automated methods will be needed to monitoring compliance of ships' ballast water. We examined two automated particle counters for monitoring organisms ≥ 50 μm in minimum dimension: a High Resolution Laser Optical Plankton Counter (HR-LOPC), and a Flow Cytometer with digital imaging Microscope (FlowCAM), in comparison to traditional (manual) microscopy considering plankton concentration, size frequency distributions and particle size measurements. The automated tools tended to underestimate particle concentration compared to standard microscopy, but gave similar results in terms of relative abundance of individual taxa. For most taxa, particle size measurements generated by FlowCAM ABD (Area Based Diameter) were more similar to microscope measurements than were those by FlowCAM ESD (Equivalent Spherical Diameter), though there was a mismatch in size estimates for some organisms between the FlowCAM ABD and microscope due to orientation and complex morphology. When a single problematic taxon is very abundant, the resulting size frequency distribution curves can become skewed, as was observed with Asterionella in this study. In particular, special consideration is needed when utilizing automated tools to analyse samples containing colonial species. Re-analysis of the size frequency distributions with the removal of Asterionella from FlowCAM and microscope data resulted in more similar curves across methods with FlowCAM ABD having the best fit compared to the microscope, although microscope concentration estimates were still significantly higher than estimates from the other methods. The results of our study indicate that both automated tools can generate frequency distributions of particles that might be particularly useful if correction factors can be developed for known differences in well-studied aquatic ecosystems