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MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 421:117-130 (2011) - DOI: https://doi.org/10.3354/meps08879 Evolutionary history of the seagrass genus Posidonia Tânia Aires1, Núria Marbà2, Regina L. Cunha1, Gary A. Kendrick3, Diana I. Walker3, Ester A. Serrão1, Carlos M. Duarte2, Sophie Arnaud-Haond1,4,* 1CCMAR-CIMAR, Center for Marine Sciences, University of Algarve, Gambelas, 8005-139 Faro, Portugal 2Department of Global Change Research, IMEDEA (CSIC-UIB) Institut Mediterráni d’Estudis Avançats, Miquel Marques 21, 07190 Esporles, Mallorca, Spain 3School of Plant Biology, The University of Western Australia, Crawley 6009, Australia 4IFREMER- Technopole de Brest-Iroise, BP 70, 29280 Plouzané, France *Corresponding author. Email: sophie.arnaud@ifremer.fr ABSTRACT: Seagrasses are the structural species of one of the most important coastal ecosystems worldwide and support high levels of biodiversity and biomass production. Posidonia is one of the most ancient seagrass genera and displays a contrasting disjunct biogeographic pattern. It contains one single species in the Northern Hemisphere, P. oceanica, which is endemic to the Mediterranean Sea, and has up to 8 recognized taxa in the Southern Hemisphere, which in Australia are divided into 2 complexes, P. ostenfeldii and P. australis. A phylogeny based on a nuclear marker (rRNA-ITS) revealed an ancient split between the northern (i.e. Mediterranean) and southern (i.e. Australian) taxa, followed by a separation of the 2 recognized Australian complexes. However, the species belonging to the P. ostenfeldii complex were indistinguishable, suggesting an ecotypic origin or a recent speciation. Therefore, among the 7 morphologically described Australian species only 4 species lineages can be discriminated. The organelle markers nad7 intron, trnL–F and matK/trnK intron were not informative for reconstructing the phylogeny of this genus, and the mitochondrial markers exhibited a strikingly slow evolutionary rate relative to other genome regions. KEY WORDS: Posidonia · Phylogeny · Low evolutionary rates · Ancient diversification Full text in pdf format PreviousNextCite this article as: Aires T, Marbà N, Cunha RL, Kendrick GA and others (2011) Evolutionary history of the seagrass genus Posidonia. Mar Ecol Prog Ser 421:117-130. https://doi.org/10.3354/meps08879 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 421. Online publication date: January 17, 2011 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2011 Inter-Research.

Abstract Vegetated coastal ecosystems along the Red Sea and Arabian Gulf coasts of Saudi Arabia thrive in an extremely arid and oligotrophic environment, with high seawater temperatures and salinity. Mangrove, seagrass and saltmarsh ecosystems have been shown to act as efficient sinks of sediment organic carbon, earning these vegetated ecosystems the moniker ‘blue carbon’ ecosystems. However, their role as nitrogen and phosphorus (N and P) sinks remains poorly understood. In this study, we examine the capacity of blue carbon ecosystems to trap and store nitrogen and phosphorous in their sediments in the central Red Sea and Arabian Gulf. We estimated the N and P stocks (in 0.2 m thick-sediments) and accumulation rates (for the last century based on 210 Pb and for the last millennia based on 14 C) in mangrove, seagrass and saltmarsh sediments from eight locations along the coast of Saudi Arabia (81 cores in total). The N and P stocks contained in the top 20 cm sediments ranged from 61 g N m −2 in Red Sea seagrass to 265 g N m −2 in the Gulf saltmarshes and from 70 g P m −2 in Red Sea seagrass meadows and mangroves to 58 g P m −2 in the Gulf saltmarshes. The short-term N and P accumulation rates ranged from 0.09 mg N cm −2 yr −1 in Red Sea seagrass to 0.38 mg N cm −2 yr −1 in Gulf mangrove, and from 0.027 mg P cm −2 yr −1 in the Gulf seagrass to 0.092 mg P cm −2 yr −1 in Red Sea mangroves. Short-term N and P accumulation rates were up to 10-fold higher than long-term accumulation rates, highlighting increasing sequestration of N and P over the past century, likely due to anthropogenic activities such as coastal development and wastewater inputs.

Northern elephant seals engage in large-scale foraging migrations traveling up to 15,000 Km over 8 months in the northeast Pacific. While traditionally considered solitary migrants, we demonstrate here that female seals migrate in a surprisingly coherent manner, for individual northern elephant seals traveling in over such a large region of the ocean. Animal movement remained coherent, in terms of the direction of individual swimming relative to group movement, throughout much of their migrations. Movement coherence remained well above the value expected if the movement was independent until the migrating seals were further than 1,000 Km from the colony, beyond which movement coherence declined. Migrating seals presented regional aggregations consisting of female seals traveling within the center of the aggregation, closely following the main migration pathway, with individuals isolated on the extremes of the aggregation. These formations were preserved in the out-and-return migration trips. Animals at the edges of the group show an absence of correlation in their movement with the rest of animals. The observed movements exhibited a lag in the group movement patterns that was greater for female animals > 1,000 Km apart. A model that reproduced movement based on the average individual movement properties failed to reproduce the observed movement patterns. In turn, when a parameter was introduced that reflected group behavior, the resulting modelled movement conformed to the observed patterns, thereby demonstrating the presence of coherent, or synchronized, movement. Whereas the duration of female migration is ultimately constrained by reproductive biology, the coherent movement may involve both endogenous and exogenous cues determining the timing of the initiation of return across 25 million Km 2 in the northeast Pacific.

Phytoplankton contribute half of the primary production in the biosphere and are the major source of energy for the Arctic Ocean ecosystem. While primary production measurements are therefore fundamental to our understanding of marine biogeochemical cycling, the extent to which current methods provide a definitive estimate of this process remains uncertain given differences in their underlying approaches and assumptions. This is especially the case in the Arctic Ocean, a region of the planet undergoing rapid evolution as a result of climate change, yet where primary production measurements are sparse. In this study, we compared three common methods for estimating primary production in the European Arctic Ocean: 1) production of 18O-labeled oxygen (GPP-18O), 2) changes in dissolved oxygen (GPP-DO) and 3) incorporation rates of 14C-labelled carbon into particulate organic carbon (14C-POC) and into total organic carbon (14C-TOC, the sum of dissolved and particulate organic carbon). Results show that primary production rates derived using oxygen methods showed good agreement across season and were strongly positively correlated. While also strongly correlated, higher scatter associated with seasonal changes was observed between 14C-POC and 14C-TOC. The 14C-TOC-derived rates were, on average, approximately 50 % of the oxygen-based estimates. However, the relationship between these estimates changed seasonally. In May, during a spring bloom of Phaeocystis sp., 14C-TOC was 52 % and 50 % of GPP-DO and GPP-18O respectively, while in August, during post-bloom conditions dominated by flagellates, 14C-TOC was 125 % of GPP-DO and 14C-TOC was 175 % of GPP-18O. Varying relationship between C and O rates may be the result of varying importance of respiration, where C-based rates estimate Net Primary Production (NPP) and O-based rates estimate Gross Primary Production (GPP).However, uncertainty remains in this comparison, given differing assumptions of the methods and the photosynthetic quotients.The median O:C ratio of 4.75 in May is within the range of that observed for other regions of the world's ocean. However, the median O:C ratio for August is < 1, lower than in any other reported region. Our results suggest further research is needed to estimate O:C in Arctic waters, and at different times of the seasonal cycle.

Abstract Aim Dispersal and environmental gradients shape marine microbial communities, yet the relative importance of these factors across taxa with distinct sizes and dispersal capacity in different ocean layers is unknown. Here, we report a comparative analysis of surface and deep ocean microbial beta diversity and examine how these patterns are tied to oceanic distance and environmental gradients. Location Tropical and subtropical oceans (30°N–40°S). Time period 2010–2011. Major taxa studied Prokaryotes and picoeukaryotes (eukaryotes between 0.2 and 3 μm). Methods Beta diversity was calculated from metabarcoding data on prokaryotic and picoeukaryotic microbes collected during the Malaspina expedition across the tropical and subtropical oceans. Mantel correlations were used to determine the relative contribution of environment and oceanic distance driving community beta diversity. Results Mean community similarity across all sites for prokaryotes was 38.9% in the surface and 51.4% in the deep ocean, compared to mean similarity of 25.8 and 12.1% in the surface and deep ocean, respectively, for picoeukaryotes. Higher dispersal rates and smaller body sizes of prokaryotes relative to picoeukaryotes likely contributed to the significantly higher community similarity for prokaryotes compared with picoeukaryotes. The ecological mechanisms determining the biogeography of microbes varied across depth. In the surface ocean, the environmental differences in space were a more important factor driving microbial distribution compared with the oceanic distance, defined as the shortest path between two sites avoiding land. In the deep ocean, picoeukaryote communities were slightly more structured by the oceanic distance, while prokaryotes were shaped by the combined action of oceanic distance and environmental filtering. Main conclusions Horizontal gradients in microbial community assembly differed across ocean depths, as did mechanisms shaping them. In the deep ocean, the oceanic distance and environment played significant roles driving microbial spatial distribution, while in the surface the influence of the environment was stronger than oceanic distance.

Abstract Animal-attached devices have transformed our understanding of vertebrate ecology. However, to be acceptable, researchers must minimize tag-related harm. The long-standing recommendation that tag masses should not exceed 3% of the animal’s body mass ignores tag forces generated by movement. We used collar-attached accelerometers on four free-ranging carnivores, spanning two orders of magnitude in mass, to reveal that during movement, forces exerted by ‘3%’ tags were generally equivalent to 4-19% of the animals’ masses, with a record of 54% in a hunting cheetah. Controlled studies on domestic dogs revealed how the tag forces are dictated by animal gait and speed but appear largely invariant of body mass. This fundamentally changes how acceptable tag mass limits should be determined, requiring cognizance of animal athleticism. One Sentence Summary There can be no universal rule for collar-tag masses as a percentage of carrier mass since tag forces depend on lifestyle.

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 553:93-109 (2016) - DOI: https://doi.org/10.3354/meps11764 Plasticity and trade-offs in physiological traits of intertidal mussels subjected to freshwater-induced environmental variation Laura Ramajo1,2,3, Luis Prado2, Alejandro B. Rodriguez-Navarro4, Marco A. Lardies3, Carlos M. Duarte1,5, Nelson A. Lagos2,* 1Global Change Department, Instituto Mediterráneo de Estudios Avanzados (IMEDEA, CSIC-UIB), C/ Miquel Marqués 21, 07190 Esporles (Mallorca), Spain 2Centro de Investigación e Innovación para el Cambio Climático (CiiCC), Universidad Santo Tomás, Avda. Ejército 146, 8370003 Santiago, Chile 3Facultad de Artes Liberales & Ingeniería y Ciencias, Universidad Adolfo Ibañez, Avda. Diagonal Las Torres 2640, Peñalolén, 7941169 Santiago, Chile 4Departamento de Mineralogía y Petrología, Universidad de Granada, Avda. Campus de Fuentenueva s/n, 18002 Granada, Spain 5King Abdullah University of Science and Technology (KAUST), Red Sea Research Center (RSRC), Thuwal 23955-6900, Saudi Arabia *Corresponding author: nlagoss@ust.cl ABSTRACT: Environmental gradients play an important role in shaping geographic variability in coastal marine populations. Thus, the ability of organisms to cope with these changes will depend on their potential to acclimatize, or adapt, to these new environmental conditions. We investigated the spatial variability in biological responses shown by Perumytilus purpuratus mussels collected from 2 intertidal areas experiencing contrasting freshwater input influences (river-influenced vs. marine conditions). To highlight the role of plasticity and adaptive potential in biological responses, we performed a reciprocal-transplant experiment and measured relevant phenotypic traits including mortality, growth, calcification, metabolism, and chemical composition of the shell periostracum. We determined that mussels exposed to river-influenced conditions had increased metabolic rates and reduced growth rates, as compared to mussels experiencing marine conditions (p < 0.05). While the energy investment strategies of the 2 local populations resulted in similar net calcification rates, these rates decreased significantly when mussels were transplanted to the river-influenced site. Stressful conditions at the river-influenced site were evidenced by decreased survivorship across treatments. Freshwater inputs modify the organic composition of the shell periostracum through a significant reduction in polysaccharides. Although our field experiment did not identify specific environmental factors underlying these contrasting phenotypic changes, the results imply that plasticity plays a strong role when P. purpuratus is exposed to some combination of natural (e.g. salinity) and anthropogenic influences (e.g. pollution), and that the lack of exposure to freshwater may promote less tolerant mussels with greater potential for local adaptation. KEY WORDS: Calcification · Shell periostracum · Metabolism · Local adaptation · Central Chile · Perumytilus purpuratus Full text in pdf format Supplementary material PreviousNextCite this article as: Ramajo L, Prado L, Rodriguez-Navarro AB, Lardies MA, Duarte CM, Lagos NA (2016) Plasticity and trade-offs in physiological traits of intertidal mussels subjected to freshwater-induced environmental variation. Mar Ecol Prog Ser 553:93-109. https://doi.org/10.3354/meps11764 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 553. Online publication date: July 14, 2016 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2016 Inter-Research.

Abstract Predictors for the ecological effects of non‐native species are lacking, even though such knowledge is fundamental to manage non‐native species and mitigate their impacts. Current theories suggest that the ecological effects of non‐native species may be related to other concomitant anthropogenic stressors, but this has not been tested at a global scale. We combine an exhaustive meta‐analysis of the ecological effects of marine non‐native species with human footprint proxies to determine whether the ecological changes due to non‐native species are modulated by co‐occurring anthropogenic impacts. We found that non‐native species had greater negative effects on native biodiversity where human population was high and caused reductions in individual performance where cumulative human impacts were large. On this basis we identified several marine ecoregions where non‐native species may have the greatest ecological effects, including areas in the Mediterranean Sea and along the northwest coast of the United States. In conclusion, our global assessment suggests coexisting anthropogenic impacts can intensify the ecological effects of non‐native species.