Adaptive strategies of sponges to deoxygenated oceans
"Ocean deoxygenation is one of the major consequences of climate change. In coastal waters, this process can be exacerbated by eutrophication, which is contributing to an alarming increase in the so-called ‘dead zones’ globally. Despite its severity, the effect of reduced dissolved oxygen has only been studied for a very limited number of organisms, compared to other climate change impacts such as ocean acidification and warming. Here, we experimentally assessed the response of sponges to moderate[...]".
Source: Wiley Online Library
Authors: Valerio Micaroni et al.
High spatial resolution global ocean metagenomes from Bio-GO-SHIP repeat hydrography transects
"Detailed descriptions of microbial communities have lagged far behind physical and chemical measurements in the marine environment. Here, we present 971 globally distributed surface ocean metagenomes collected at high spatio-temporal resolution. Our low-cost metagenomic sequencing protocol produced 3.65 terabases of data, where the median number of base pairs per sample was 3.41 billion. The median distance between sampling stations was 26 km[...]"
Source: Scientific Data
Authors: Alyse A. Larkin et al
Ocean acidification may slow the pace of tropicalization of temperate fish communities
"Poleward range extensions by warm-adapted sea urchins are switching temperate marine ecosystems from kelp-dominated to barren-dominated systems that favour the establishment of range-extending tropical fishes. Yet, such tropicalization may be buffered by ocean acidification, which reduces urchin grazing performance and the urchin barrens that tropical range-extending fishes prefer. Using ecosystems experiencing natural warming and acidification, we show that ocean acidification could buffer warming-facilitated tropicalization by reducing urchin populations (by 87%) and inhibiting the formation of barrens. This buffering effect of CO2[...]"
Source: Nature Climate Change
Authors: Ericka O. C. Coni et al.
On the co‐evolution of surface oxygen levels and animals
"Few topics in geobiology have been as extensively debated as the role of Earth's oxygenation in controlling when and why animals emerged and diversified. All currently described animals require oxygen for at least a portion of their life cycle. Therefore, the transition to an oxygenated planet was a prerequisite for the emergence of animals. Yet, our understanding of Earth's oxygenation and the environmental requirements of animal habitability and ecological success is currently limited; estimates for the timing of the appearance of environments sufficiently oxygenated to support ecologically stable populations of animals span a wide range, from billions of years to only a few million years before animals appear in the fossil record. [...]"
Authors: Devon B. Cole et al.
Effects of hypoxia on the behavior and physiology of kelp forest fishes
"Forecasts from climate models and oceanographic observations indicate increasing deoxygenation in the global oceans and an elevated frequency and intensity of hypoxic events in the coastal zone, which have the potential to affect marine biodiversity and fisheries. Exposure to low dissolved oxygen (DO) conditions may have deleterious effects on early life stages in fishes. [...]"
Source: Global Change Biology
Authors: Evan G. Mattiasen et al.
A crisis in the water is decimating this once-booming fishing town
"TOMBWA, Angola — His ancestors were Portuguese colonialists who settled on this otherworldly stretch of coast, wedged between a vast desert and the southern Atlantic. They came looking for the one thing this barren region had in abundance: fish.
By the time Mario Carceija Santos was getting into the fishing business half a century later, in the 1990s, Angola had won independence and the town of Tombwa was thriving. There were 20 fish factories strung along the bay, a constellation of churches and schools, a cinema hall built in art deco, and, in the central plaza, massive drying racks for the tons upon tons of fish hauled out of the sea. [...]"
Source: The Washington Post
Powering Ocean Giants: The Energetics of Shark and Ray Megafauna
"Energetics studies have illuminated how animals partition energy among essential life processes and survive in extreme environments or with unusual lifestyles. There are few bioenergetics measurements for elasmobranch megafauna; the heaviest elasmobranch for which metabolic rate has been measured is only 47.7 kg, despite many weighing >1000 kg. Bioenergetics models of elasmobranch megafauna would answer fundamental ecological questions surrounding this important and vulnerable group, and enable an understanding of how they may respond to changing environmental conditions, such as ocean warming and deoxygenation. [...]"
Source: Trends in Ecology & Evolution
Authors: Christopher L. Lawson et al.
Vision is highly sensitive to oxygen availability in marine invertebrate larvae
"For many animals, evolution has selected for complex visual systems despite the high energetic demands associated with maintaining eyes and their processing structures. The metabolic demands of visual systems therefore make them highly sensitive to fluctuations in available oxygen. In the marine environment, oxygen changes over daily, seasonal, and inter-annual time scales and there are large gradients of oxygen with depth. [...]"
Source: Journal of Experimental Biology
Auhtors: Lillian R. McCormick, Lisa A. Levin and Nicholas W. Oesch
Oysters as sentinels of climate variability and climate change in coastal ecosystems
"Beyond key ecological services, marine resources are crucial for human food security and socio-economical sustainability. Among them, shellfish aquaculture and fishing are of primary importance but become more vulnerable under anthropogenic pressure, as evidenced by reported mass mortality events linked to global changes such as ocean warming and acidification, chemical contamination, and diseases. Understanding climate-related risks is a vital objective for conservation strategies, ecosystems management and human health. [...]"
Source: Environmental Research Letters
Authors: Yoann Thomas et al.
Decreased oxygen levels could present hidden threat to marine species
"Scientists have shown that creatures which develop in hypoxic (low oxygen) conditions in the marine environment could experience previously unseen hindered development, and become compromised as adults. [...]
The prevalence of hypoxic (low oxygen) areas in coastal waters is predicted to increase in the future, both in terms of their scale and duration. And while the adults of many estuarine invertebrates can cope with short periods of hypoxia, it has previously been unclear whether that ability is present if animals are bred and reared under chronic hypoxia.[...]"
Source: Sciencedaily.com (University of Plymouth)