Trabajo presentado en la NetSci Conference, celebrada online del 17 al 25 de septiembre de 2020.
Rising ocean temperatures are constraining the availability of dissolved oxygen and simultaneously increasing the respiratory oxygen requirements of marine organisms. This is particularly relevant for tropical corals, as periods of anomalously high temperature destabilize the symbiosis between corals and Symbiodiniaceae, resulting in coral bleaching. These observations point towards a possible role of mismatched rates of photosynthetic oxygen production and consumption in contributing to the breakdown of the holobiont under heat stress. Here we use a global dataset comprising experimentally derived relationships between coral metabolic rates and temperature to investigate this hypothesis. Across all available relationships, we calculated and analysed the activation energy (E), optimum temperature (T<sub>opt</sub>) of respiration, net productivity, gross productivity and where possible, P: R ratio. Despite known variations in the thermal tolerances among corals in our database, we resolved composite thermal performance curves for scleractinian corals and provide insight into differences between tropical and temperate corals and among selected genera. We show that after the theoretical T<sub>opt</sub> is exceeded, photosynthesis declines at a faster rate than respiration. At temperatures exceeding the theoretical T<sub>opt</sub> for net productivity, this metabolic mismatch could possibly contribute to the destabilization of the coral-symbiont association. Specifically, we postulate that a lack of symbiont oxygen production and heightened holobiont respiratory demand at peak temperatures represents a burden on the oxygen budget of the holobiont.
Abstract. The metabolism of the Arctic Ocean is marked by extremely pronounced seasonality and spatial heterogeneity associated with light conditions, ice cover, water masses and nutrient availability. Here we report the marine planktonic metabolic rates (net community production, gross primary production and community respiration) along three different seasons of the year, for a total of eight cruises along the western sector of the European Arctic (Fram Strait – Svalbard region) in the Arctic Ocean margin: one at the end of 2006 (fall/winter), two in 2007 (early spring and summer), two in 2008 (early spring and summer), one in 2009 (late spring–early summer), one in 2010 (spring) and one in 2011 (spring). The results show that the metabolism of the western sector of the European Arctic varies throughout the year, depending mostly on the stage of bloom and water temperature. Here we report metabolic rates for the different periods, including the spring bloom, summer and the dark period, increasing considerably the empirical basis of metabolic rates in the Arctic Ocean, and especially in the European Arctic corridor. Additionally, a rough annual metabolic estimate for this area of the Arctic Ocean was calculated, resulting in a net community production of 108 g C m−2 yr−1.
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 290:291-296 (2005) - doi:10.3354/meps290291 Clonality in seagrasses, emergent properties and seagrass landscapes Gary A. Kendrick1,*, Carlos M. Duarte2, Núria Marbà2 1School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia2Instituto Mediterraneo de Estudios Avanzados, (IMEDEA, CSIC-UIB), Miquel Marques 21, 07190 Esporles Islas Baleares, Spain *Email: garyk@cyllene.uwa.edu.au ABSTRACT: Seagrasses are clonal monocots that dominate shallow subtidal coastal and estuarine environments worldwide. They are important for their relatively high productivity and their role in coastal sediment stabilization, as habitat and food for invertebrates, fishes, turtles, dugongs and manatees, and as a source for detrital food webs. Seagrasses grow through the iteration of a vegetative ramet, consisting of leaves capable of photosynthesizing attached to a shoot, a portion of rhizome and associated roots. Seagrass research has in the past focused on either the study of growth of the ramet or changes of seagrass distributions over 1000s of ha to 1000s of km2. There has been little attempt to link these scales. Interestingly, growth and space occupation of both measured and modelled patches of seagrasses have been found to be faster than predicted from the growth and iteration, through branching, of ramets. Similarly, predicted radial spread of patches does not agree with observed changes in the distribution of seagrasses in shallow subtidal landscapes. This review assesses the links between growth of ramets and patches of seagrasses and the spread, infilling and distribution of seagrasses in shallow subtidal landscapes. We explore the potential that accelerated growth of patches and seagrass landscapes are an emergent property of ramet growth. KEY WORDS: Seagrasses · Clonal growth · Ramets · Patch dynamics · Emergence · Subtidal landscapes Full text in pdf format PreviousExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 290. Online publication date: April 13, 2005 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2005 Inter-Research.
Abstract Automated positioning devices can generate large datasets with information on the movement of humans, animals and objects, revealing patterns of movement, hot spots and overlaps among others. However, in the case of Automated Information Systems (AIS), attached to vessels, observed strange behaviors in the tracking datasets may come from intentional manipulation of the electronic devices. Thus, the analysis of anomalies can provide valuable information on suspicious behavior. Here, we analyze anomalies of fishing vessel trajectories obtained with the Automatic Identification System. The map of silent anomalies, those that occur when positioning data are absent for more than 24 hours, shows that they are most likely to occur closer to land, with 87.1% of anomalies observed within 100 km of the coast. This behavior suggests the potential of identifying silence anomalies as a proxy for illegal activities. With the increasing availability of high-resolution positioning of vessels and the development of powerful statistical analytical tools, we provide hints on the automatic detection of illegal activities that may help optimize the management of fishing resources.
1. The hypothesis that herbivory pressure (defined as the per cent of the photosynthetic tissue biomass and production consumed daily by herbivores) increases with increasing plant growth rate was tested. The basis for the test was a compilation of 56 published reports on biomass, production and herbivory, from a wide range of aquatic and terrestrial plant communities. 2. Herbivory was independent of ecosystem primary production and the fraction of plant production and biomass daily consumed by herbivores increased as the 0.6 and 1.6 power of plant turnover rate, respectively. 3. These results suggest that the tendency of fast-growing plants to support lower biomass of photosynthetic tissues than slow-growing ones can be accounted for by the tendency of herbivore control of plant biomass and production to increase with increasing plant growth rate
During the course of a survey into the distribution and growth of the fan mussels Pinna nobilis and Pinna rudis from the coastal waters of the Spanish Mediterranean the presence within the mussels of Pontonia pinnophylax has been recorded. Pontonia pinnophylax typically occurred in adult pairs, but occasionally solitary male individuals were found. The width of the cephalothorax is greater in females than males, whereas the chelae of the second periopods, which are unequal, are larger in males. There is a general relationship between the size of P. pinnophylax and its pinnid host; the largest individuals were found in the largest Pinna and vice versa.
