In order to understand the effects of deoxygenating oceans on their inhabitants, we need accurate assessments of the animals’ oxygen consumption rates and their ability to regulate their metabolism under the conditions where they normally live. While an abundance of metabolic rate data for many meso- and bathypelagic species is available in the literature, these determinations were made...
Vision is an essential and metabolically demanding (oxygen intensive) process for both vertebrates and invertebrates; in the marine environment this is true for active arthropods, cephalopods, and fish that possess complex eyes and ‘fast vision’ (high temporal resolution). Oxygen loss in the ocean, termed ocean deoxygenation, is occurring as a result of ocean warming effects on solubility and...
This paper examines variations in gender-specific body growth, morphology and reproduction of the bearded goby (Sufflogobius bibarbatus) across the Namibian shelf. The results indicate a spatial variation in the size composition, condition factor and maturation of gobies across the shelf area. Low oxygen (<0.5 ml O2/L ) did not hinder reproduction in the bearded goby and off Walvis Bay,...
The ancient shelf upwelling system of the northern Benguela off Namibia has long operated under hypoxic pressure, likely close to biological tipping points, balancing always the abundance of particulate food against oxygen limitation and hydrogen sulphide toxification. The shelf sediments off Namibia are some of the most unusual and extreme marine habitats, containing high hydrogen sulphide...
Northern shrimp (Pandalus borealis) of the Estuary and Gulf of St. Lawrence (EGSL) typically inhabit waters deeper than 175 m and face chronic hypoxia (dissolved oxygen [DO] levels of 18–40% sat.). Hypoxia is typically accompanied by high PCO~2~ values and low pH. For instance, the pH of the deep waters of the EGSL are currently below 7.75. However, most studies of hypoxia tolerance have...
Understanding physiological mechanisms of Chilean scallop to the multiple-stressor scenario of upwelling by using an experimental integrative approach
Laura Ramajo1,2,3, Araceli Rodríguez-Romero4, Yolanda Núñez5, Carolina Fernández1,2, Paz Caballero1, María Valladares6, Paul Watt6, Manuel Núñez6, María José Poupin1, Bernardo Broitman2,6, Marco Lardies1,2
Presenting author
1Faculty of...
Oxygen supply to the sites of cellular respiration requires a partial pressure (PO2) gradient from the environment to the mitochondria to drive diffusion. In surface waters of the ocean, as in air, the PO2 drops from 21 kPa in ambient water to less than 1 kPa at the mitochondria. In some marine environments, such as mesopelagic oxygen minimum zones (OMZ), the PO2 in the ambient water is less...
The Baltic Sea is characterized by low salinity and pronounced fluctuations in pCO2, pO2 and temperature. On-line monitoring of pCO2 in 2014 in Kiel Fjord demonstrated occurrence of peak values of >2,000 µatm in summer and autumn and average values >700 µatm due to extensive wind driven upwelling of hypoxic - hypercapnic water masses. We assessed the impacts of elevated temperature (ambient...
Population responses to global change are driven by multiple factors interacting with each other and with intraspecific diversity. Correlations between responses to different drivers can alter selective outcomes dramatically. In three near-natural experiments, we explored response correlations of genetically different full-sibling families of seaweed germlings towards four global change...
Climate change is impacting marine ecosystems worldwide through a suite of associated stressors, including ocean acidification, warming, and hypoxia. However, our current understanding of the effects of climate change are primarily confined to single species, single stressor studies. To gain a broader understanding of its impacts at the community level, it is critical to examine interactions...
O2 depletion in marine ecosystems often occurs concomitantly with elevated pCO2. On a global scale, this coupling is attributed to the concurrent processes of ocean acidification and reduced O2 solubility as a by-product of rising ocean temperatures and enhanced stratification of the deep-sea. On a more local-scale, however, this inherent link is driven mostly by metabolic processes; where...
Man-induced global climate changes are leading to severe modifications on the ocean’s physicochemistry, with far-reaching consequences for marine life. While CO2 emissions are warming and acidifying seawater masses, oxygen content is diminishing due to decreased oxygen-solubility, increased stratification, augmented microbial respiration, and other abiotic/biotic processes. Following...
As the global climate adjusts to anthropogenic high levels of CO2, marine organisms have to cope with multiple changing environmental stressors that influence their performance. Marine metazoan hard limits to temperature and chronic anoxia have long been known. However, interactions between stressors, such as synergies between temperature and both low oxygen levels and acidification, have...