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Jellyfish form spectacular blooms throughout the world's oceans. Jellyfish body plans are characterised by high water and low carbon contents which enables them to grow much larger than non-gelatinous animals of equivalent carbon content and to deviate from non-gelatinous pelagic animals when incorporated into allometric relationships. Jellyfish have, however, been argued to conform to allometric relationships when carbon content is used as the metric for comparison. Here we test the hypothesis that differences in allometric relationships for several key functional parameters remain for jellyfish even after their body sizes are scaled to their carbon content. Data on carbon and nitrogen contents, rates of respiration, excretion, growth, longevity and swimming velocity of jellyfish and other pelagic animals were assembled. Allometric relationships between each variable and the equivalent spherical diameters of jellyfish and other pelagic animals were compared before and after sizes of jellyfish were standardised for their carbon content. Before standardisation, the slopes of the allometric relationships for respiration, excretion and growth were the same for jellyfish and other pelagic taxa but the intercepts differed. After standardisation, slopes and intercepts for respiration were similar but excretion rates of jellyfish were 10× slower, and growth rates 2× faster than those of other pelagic animals. Longevity of jellyfish was independent of size. The slope of the allometric relationship of swimming velocity of jellyfish differed from that of other pelagic animals but because they are larger jellyfish operate at Reynolds numbers approximately 10× greater than those of other pelagic animals of comparable carbon content. We conclude that low carbon and high water contents alone do not explain the differences in the intercepts or slopes of the allometric relationships of jellyfish and other pelagic animals and that the evolutionary longevity of jellyfish and their propensity to form blooms is facilitated by their unique body plans.

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 58:141-151 (2010) - DOI: https://doi.org/10.3354/ame01368 Temperature and phosphorus regulating carbon flux through bacteria in a coastal marine system Emma S. Kritzberg1,2,*, Jesus M. Arrieta1, Carlos M. Duarte1 1IMEDEA, CSIC-Universitat Illes Balears, Miquel Marques 21, Esporles 07190, Spain 2Lund University, Department of Ecology/Limnology, Ecology Building, 223 62 Lund, Sweden *Email: Emma.Kritzberg@limnol.lu.se ABSTRACT: The aim of this study was to explore the variation and regulation of bacterial carbon processing at a coastal oligotrophic site of the Island of Majorca in the Mediterranean Sea. In situ bacterial production (BP), respiration (BR), growth efficiency, and carbon demand in relation to environmental parameters were studied over an annual cycle. In addition, the response of bacterial carbon processing to an experimental resource (phosphate) and temperature manipulations was tested. While concentrations of dissolved organic carbon (DOC) and phosphorus were fairly stable over the year, BP and BR varied 65-fold and 79-fold, respectively. Addition of phosphate stimulated both BP and BR during most of the year, suggesting that phosphorus limitation keeps a tight rein on bacterial DOC utilization. Both BP and BR responded positively to a 2°C experimental increase, but at higher temperature increases BP and BR leveled off or decreased. In situ BP and BR were positively related to temperature, suggesting that elevated water temperature would yield increased BP and BR. BR responded more strongly to temperature than BP, suggesting that increased temperature may result in a decrease in bacterial growth efficiency. KEY WORDS: Bacterial carbon processing · Bacterial growth efficiency · Temperature regulation · Resource regulation · Phosphorus limitation Full text in pdf format PreviousNextCite this article as: Kritzberg ES, Arrieta JM, Duarte CM (2010) Temperature and phosphorus regulating carbon flux through bacteria in a coastal marine system. Aquat Microb Ecol 58:141-151. https://doi.org/10.3354/ame01368 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 58, No. 2. Online publication date: January 07, 2010 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2010 Inter-Research.

Abstract The distribution of dissolved organic carbon (DOC) concentration across coastal waters was characterized based on the compilation of 3510 individual estimates of DOC in coastal waters worldwide. We estimated the DOC concentration in the coastal waters that directly exchange with open ocean waters in two different ways, as the DOC concentration at the edge of the shelf break and as the DOC concentration in coastal waters with salinity close to the average salinity in the open ocean. Using these estimates of DOC concentration in the coastal waters that directly exchange with open ocean waters, the mean DOC concentration in the open ocean and the estimated volume of water annually exchanged between coastal and open ocean, we estimated a median ± SE (and average ± SE) global DOC export from coastal to open ocean waters ranging from 4.4 ± 1.0 Pg C yr −1 to 27.0 ± 1.8 Pg C yr −1 (7.0 ± 5.8 Pg C yr −1 to 29.0 ± 8.0 Pg C yr −1 ) depending on the global hydrological exchange. These values correspond to a median and mean median (and average) range between 14.7 ± 3.3 to 90.0 ± 6.0 (23.3 ± 19.3 to 96.7 ± 26.7) Gg C yr −1 per km of shelf break, which is consistent with the range between 1.4 to 66.1 Gg C yr −1 per km of shelf break of available regional estimates of DOC export. The estimated global DOC export from coastal to open ocean waters is also consistent with independent estimates of the net metabolic balance of the coastal ocean. The DOC export from the coastal to the open ocean is likely to be a sizeable flux and is likely to be an important term in the carbon budget of the open ocean, potentially providing an important subsidy to support heterotrophic activity in the open ocean.

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 390:129-135 (2009) - DOI: https://doi.org/10.3354/meps08183 Genetic recolonization of mangrove: genetic diversity still increasing in the Mekong Delta 30 years after Agent Orange Sophie Arnaud-Haond1,2,*, Carlos M. Duarte3, Sara Teixeira1, Sonia Isabel Massa1, Jorge Terrados3, Nguyen Hong Tri4,5, Phan Nguyen Hong4,5, Ester A. Serrão1 1CCMAR - CIMAR, Center of Marine Sciences, Universidade do Algarve, Gambelas, 8005-139, Faro, Portugal 2IFREMER, Centre de Brest, BP70, 29280 Plouzané, France 3Instituto Mediterraneo de Estudios Avanzados, CSIC-Universitat de les Illes Balears, C/ Miquel Marques 21, 07190 Esporles, Mallorca, Spain 4Mangrove Ecosystem Research Division (MERD), Vietnam National University, N°7 Ngo 115 Nguyen Khuyen St, Van Mieu, Hanoi, Vietnam 5Present address: Center for Environmental Research and Education (CERE), Hanoi University of Education, 136 Xuan thuy, Quan Hoa, Cau Giay, Hanoi, Vietnam *Email: sarnaud@ifremer.fr ABSTRACT: The widespread use of Agent Orange (a mixture of phenoxyl herbicides) over Southern Vietnam by US Forces led to the decimation of mangrove forests in the Mekong Delta. Mangrove trees Avicennia alba were sampled across the Mekong Delta; their age was assessed using models based on internode growth and samples were genotyped for 6 microsatellite loci. The evolution of genetic diversity over time elapsed since local extinction was reconstructed and compared with the genetic diversity of an unaffected population from Thailand. The results show that genetic diversity of the A. alba population is still increasing in the Mekong Delta 3 decades after the end of the Vietnam War, but is reaching an asymptotic level that is comparable to the adjacent non-affected population of Thailand. This might be a sign of genetic recovery, but may also reveal a limitation, either of genetic enrichment due to current predominance of auto-recruitment or of demographic increase due to intraspecific competition in this pioneer species. In any case, these results, although encouraging, demonstrate that genetic recovery after complete or almost complete population depletion continues over a longer time-scale than apparent demographic recovery. KEY WORDS: Recolonization genetics · Genetic recovery · Demographic recovery · Local extinction · Mangrove · Deforestation · Agent Orange Full text in pdf format PreviousNextCite this article as: Arnaud-Haond S, Duarte CM, Teixeira S, Massa SI and others (2009) Genetic recolonization of mangrove: genetic diversity still increasing in the Mekong Delta 30 years after Agent Orange. Mar Ecol Prog Ser 390:129-135. https://doi.org/10.3354/meps08183 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 390. Online publication date: September 18, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.

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 124:215-225 (1995) - doi:10.3354/meps124215 Meadow maintenance, growth and productivity of a mixed Philippine seagrass bed Vermaat JE, Agawin NSR, Duarte CM, Fortes MD, Marbà N, Uri JS Leaf production, shoot demography and rhizome growth and branching were quantified for the common seagrass species in a mixed seagrass bed on the Bolinao reef flat (Luzon, The Philippines) to assess the contribution of these species to canopy maintenance, meadow biomass and productivity. We tested the hypothesis that seagrass growth rates correlated negatively with shoot size and age when compared across species, and found that shoot recruitment, leaf turnover and horizontal rhizome elongation and branching rates were lower for species with older and larger shoots. Median shoot ages for the short-lived species were generally less than a year; those for the longer-lived Enhalus acoroides (L. f.) Royle and Thalassia hemprichii (Ehrenb.) Aschers. were slightly more than 1.5 yr. The oldest E. acoroides had almost reached 10 yr. Generally, shoot mortality and recruitment balanced each other fairly well. The rhizomes of longer-lived E. acoroides and T. hemprichii elongated at rates of 5 and 21 cm yr-1, respectively, and those of the short-lived Syringodium isoetifolium (Aschers.) Dandy and Halophila ovalis (R. Br.) Hook f. at rates of 135 and 141 cm yr-1. Vertical shoot elongation ranged from 2 to 13 cm shoot-1 yr-1 and was not correlated with size or age. The meadow had a total biomass of 624 g dry wt (DW) m-2 (roots excluded), to which the larger and longer-lived species T. hemprichii and E. acoroides contributed substantially (52 and 37%, respectively). Leaf production dominated total annual productivity, constituting 91% of 2143 g DW m-2 yr-1 (roots excluded); this productivity was mainly due to T. hemprichii (74%), and not to the oldest and slowest-growing E. acoroides (10%). Tropical seagrasses . Shoot life spans . Recruitment and mortality . Pioneer vs climax species . Allometry Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 124. Publication date: August 10, 1995 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1995 Inter-Research.

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Aerial images of inner Kobbefjord (SW Greenland) were acquired on two occasions in 2018 (2018-09-07 15:06; 2018-09-07 16:00) representing different tidal levels and on one occasion in 2019 (2019-08-26). Images were acquired using a DJI Mavic Air drone. The imagery was acquired in connection with the “Greenland Ecosystem Monitoring Program” “Nuuk Basis” monitoring of marine flora (http://g-e-m.dk/). This drone survey was carried out with the primary goal of documenting and quantifying the area distribution of the tidal vegetation (dominated by the brown macroalga <em>Ascophyllum nodosum</em>) and shallow subtidal vegetation at the monitoring site. Images were processed using Agisoft Metashape Professional to produce high resolution orthomosaics from each UAV survey.

The role of saline lakes in CO 2 exchange with the atmosphere was evaluated on the basis of calculated partial pressure ( p CO 2 ) and CO 2 exchange rates with the atmosphere derived from a compilation of published data for 196 saline lakes around the world. The average surface water p CO 2 exceeded atmospheric p CO 2 by a factor of 5–8 times, indicative of a tendency for saline lakes to emit CO 2 to the atmosphere. Chemically enhanced emission, calculated from solute chemistry, pH, and wind speed, increased gas exchange an average of 2.3 times over that of freshwater lakes having equivalent p CO 2 . The globally distributed lakes emitted CO 2 at rates in excess of 80 mmol m −2 d −1 . The Caspian Sea was calculated to support alone a total CO 2 emission of 0.02 to 0.04 Gt C a −1 , with the total CO 2 emissions to the atmosphere from saline lakes calculated to be 0.11–0.15 Gt C a −1 . Consideration of CO 2 emissions from saline lakes raises the total CO 2 emissions to the atmosphere from all lakes to 0.28–0.32 Gt CO 2 . These results point to a significant role of saline lakes in global C cycling.