Ученые записки Латвийского государственного университета. Том 259. Система языка

The Australian spotted scyphomedusa Phyllorhiza punctata was recorded for the first time in Tunisian waters in August 2012, in the lagoon of Bizerte (Tunisia). Metaephyrae and juveniles occurred simultaneously in August 2012. The occurrence of adult medusae was detected from September to November 2012, and from August to October 2013. This is the second record of a reproducing population of P. punctata in the Mediterranean Sea. The low abundance of mesozooplankton in summer and autumn 2012 coincides temporally with the highest density of P. punctata recorded in the lagoon, suggesting that predation by this alien jellyfish may have been a limiting factor for the mesozooplankton abundance on site

La emergencia de China y su impacto en las relaciones comerciales entre Argentina y Brasil

i bien la expansión de las relaciones económicas entre China y los países de América Latina puede ofrecer oportunidades en el corto plazo, como se aprecia en las exporta- ciones de productos primarios, y la evolución favorable de los términos de intercambio, también plantea desafíos para el largo plazo que de no ser correctamente enfrentados, pueden dar lugar a procesos que aumenten su vulnerabilidad externa estructural. En este trabajo se analizan aquellos efectos que repercuten en forma directa e indirecta en los países de la región que más comercian con China y, particularmente, a Argentina y su relación con Brasil

Occurrence of epibenthic dinoflagellates in relation to biotic substrates and to environmental factors in Southern Mediterranean (Bizerte Bay and Lagoon, Tunisia): An emphasis on the harmful Ostreopsis spp., Prorocentrum lima and Coolia monotis

Harmful events associated with epibenthic dinoflagellates, have been reported more frequently over the last decades. Occurrence of potentially toxic benthic dinoflagellates, on the leaves of two magnoliophytes (Cymodocea nodosa and Zostera noltei) and thalli of the macroalgae (Ulva rigida), was monitored over one year (From May 2015 to April 2016) in the Bizerte Bay and Lagoon (North of Tunisia, Southern Mediterranean Sea). The investigated lagoon is known to be highly anthropized. This is the first report on the seasonal distribution of epibenthic dinoflagellates hosted by natural substrates, from two contrasted, adjacent coastal Mediterranean ecosystems. The environmental factors promoting the development of the harmful epibenthic dinoflagellates Ostreopsis spp., Prorocentrum lima and Coolia monotis were investigated. The highest cell densities were reached by Ostreopsis spp. (1.9 × 103 cells g−1 FW, in October 2015), P. lima (1.6 × 103 cells g−1 FW, in June 2015) and C. monotis (1.1 × 103 cells g−1 FW, in May 2015). C. nodosa and Z. noltei were the most favorable host macrophytes for C. monotis (in station L2) and Ostreopsis spp. (in station L3), respectively. Positive correlations were recorded between Ostreopsis spp. and temperature. Densities of the epibenthic dinoflagellates varied according to the collection site, and a great disparity was observed between the Bay and the Lagoon. Maximum concentrations were recorded on C. nodosa leaves from the Bizerte Bay, while low epiphytic cell abundances were associated with macrophytes sampled from the Bizerte Lagoon. The observed differences in dinoflagellate abundances between the two ecosystems (Bay-Lagoon) seemed not related to the nutrients, but rather to the poor environmental conditions in the lagoon.This work was supported by the LAGUNOTOX project funded byFondation TOTAL. Thanks to the IRD (Institut de Recherche pour leDéveloppement) and to the LMI COSYS-Med (Laboratoire MixteInternational Contaminants et Ecosystèmes Marins SudMéditerranéens) for funding Hela Ben Gharbia’s Ph.D. We would alsolike to thank the Tunisian National Institute of Agronomy for providingall necessary means forfield trips, and Zeineb Hentati for her help during sampling. Many thanks to Dr. Dorra Ben Gharbia for English improvement and to both anonymous reviewers for their precious help[CG] Appendix AScopu