Oxygen- and capacity-limited thermal tolerance: blurring ecology and physiology

No abstract available

A review of the toxicology of oil in vertebrates : what we have learned following the Deepwater Horizon oil spill

This research was made possible by a grant from The Gulf of Mexico Research Initiative. This publication is UMCES contribution No. 6045 and Ref. No. [UMCES] CBL 2022-008. This is National Marine Mammal Foundation Contribution #314 to peer-reviewed scientific literature.In the wake of the Deepwater Horizon (DWH) oil spill, a number of government agencies, academic institutions, consultants, and nonprofit organizations conducted lab- and field-based research to understand the toxic effects of the oil. Lab testing was performed with a variety of fish, birds, turtles, and vertebrate cell lines (as well as invertebrates); field biologists conducted observations on fish, birds, turtles, and marine mammals; and epidemiologists carried out observational studies in humans. Eight years after the spill, scientists and resource managers held a workshop to summarize the similarities and differences in the effects of DWH oil on vertebrate taxa and to identify remaining gaps in our understanding of oil toxicity in wildlife and humans, building upon the cross-taxonomic synthesis initiated during the Natural Resource Damage Assessment. Across the studies, consistency was found in the types of toxic response observed in the different organisms. Impairment of stress responses and adrenal gland function, cardiotoxicity, immune system dysfunction, disruption of blood cells and their function, effects on locomotion, and oxidative damage were observed across taxa. This consistency suggests conservation in the mechanisms of action and disease pathogenesis. From a toxicological perspective, a logical progression of impacts was noted: from molecular and cellular effects that manifest as organ dysfunction, to systemic effects that compromise fitness, growth, reproductive potential, and survival. From a clinical perspective, adverse health effects from DWH oil spill exposure formed a suite of signs/symptomatic responses that at the highest doses/concentrations resulted in multi-organ system failure.Publisher PDFPeer reviewe

Near-future CO2 levels impair the olfactory system of a marine fish

This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this recordData availability: All raw sequence data are accessible at the NCBI Sequence Read Archive through accession number SRP097118. Water chemistry, behaviour and electrophysiology data are available through Pangaea (https://doi.pangaea.de/10.1594/PANGAEA.884674).Survival of marine fishes that are exposed to elevated near-future CO2levels is threatened by their altered responses to sensory cues. Here we demonstrate a physiological and molecular mechanism in the olfactory system that helps to explain altered behaviour under elevated CO2. We combine electrophysiology measurements and transcriptomics with behavioural experiments to investigate how elevated CO2affects the olfactory system of European sea bass (Dicentrarchus labrax). When exposed to elevated CO2(approximately 1,000 µatm), fish must be up to 42% closer to an odour source for detection, compared with current CO2levels (around 400 µatm), decreasing their chances of detecting food or predators. Compromised olfaction correlated with the suppression of the transcription of genes involved in synaptic strength, cell excitability and wiring of the olfactory system in response to sustained exposure to elevated CO2levels. Our findings complement the previously proposed impairment of γ-aminobutyric acid receptors, and indicate that both the olfactory system and central brain function are compromised by elevated CO2levels.This study was supported by grants from Association of European Marine Biology Laboratories (227799), the Natural Environment Research Council (R.W.W.; NE/H017402/1), the Biotechnology and Biological Sciences Research Council (R.W.W.; BB/D005108/1), Fundação para a Ciência e Tecnologia (Portuguese Science Ministry) (UID/Multi/04326/2013) and a Royal Society Newton International Fellowship to C.S.P. C.S.P. is also a beneficiary of a Starting Grant from AXA

Regulation of apical [H.sup.+]-ATPase activity and intestinal HC[O.sub.3.sup.-] secretion in marine fish osmoregulation.(Author abstract)

The absorption of [Cl.sup.-] and water from ingested seawater in the marine fish intestine is accomplished partly through [Cl.sup.-]/HC[O.sub.3.sup.-] exchange. Recently, a [H.sup.+] pump (vacuolar-type [H.sup.+]-ATPase) was found to secrete acid into the intestinal lumen, and it may serve to titrate luminal HC[O.sub.3.sup.-] and facilitate further [Cl.sup.-]/HC[O.sub.3.sup.-] exchange, especially in the posterior intestine, where adverse concentration gradients could limit [Cl.sup.-]/HC[O.sub.3.sup.-] exchange. The [H.sup.+] pump is expressed in all intestinal segments and in gill tissue of gulf toadfish (Opsanus beta) maintained in natural seawater. After acute transfer of toadfish to 60 ppt salinity, [H.sup.+] pump expression increased 20-fold in the posterior intestine. In agreement with these observations was a fourfold-increased [H.sup.+]-ATPase activity in the posterior intestine of animals acclimated to 60 ppt salinity. Interestingly, [Na.sup.+]-[K.sup.+]-ATPase activity was elevated in the anterior intestine and gill, but not in the posterior intestine. Apical acid secretion by isolated intestinal tissue mounted in Ussing chambers fitted with pH-stat titration systems increased after acclimation to hypersalinity in the anterior and posterior intestine, titrating >20% of secreted bicarbonate. In addition, net base secretion increased in hypersalinity-acclimated fish and was ~70% dependent on serosal HC[O.sub.3.sup.-]. Protein localization by immunohistochemistry confirmed the presence of the vacuolar-type [H.sup.+]-ATPase in the apical region of intestinal enterocytes. These results show that the [H.sup.+] pump, especially in the posterior intestine, plays an important role in hypersaline osmoregulation and that it likely has significant effects on HC[O.sub.3.sup.-] accumulation in the intestinal lumen and, therefore, the continued absorption of [Cl.sup.-] and water. water absorption; posterior intestine; pH-stat titration; salinity; ion transport doi: 10.1152/ajpregu.00059.2011.Academi

Regulation of apical H +

The absorption of [Cl.sup.-] and water from ingested seawater in the marine fish intestine is accomplished partly through [Cl.sup.-]/HC[O.sub.3.sup.-] exchange. Recently, a [H.sup.+] pump (vacuolar-type [H.sup.+]-ATPase) was found to secrete acid into the intestinal lumen, and it may serve to titrate luminal HC[O.sub.3.sup.-] and facilitate further [Cl.sup.-]/HC[O.sub.3.sup.-] exchange, especially in the posterior intestine, where adverse concentration gradients could limit [Cl.sup.-]/HC[O.sub.3.sup.-] exchange. The [H.sup.+] pump is expressed in all intestinal segments and in gill tissue of gulf toadfish (Opsanus beta) maintained in natural seawater. After acute transfer of toadfish to 60 ppt salinity, [H.sup.+] pump expression increased 20-fold in the posterior intestine. In agreement with these observations was a fourfold-increased [H.sup.+]-ATPase activity in the posterior intestine of animals acclimated to 60 ppt salinity. Interestingly, [Na.sup.+]-[K.sup.+]-ATPase activity was elevated in the anterior intestine and gill, but not in the posterior intestine. Apical acid secretion by isolated intestinal tissue mounted in Ussing chambers fitted with pH-stat titration systems increased after acclimation to hypersalinity in the anterior and posterior intestine, titrating >20% of secreted bicarbonate. In addition, net base secretion increased in hypersalinity-acclimated fish and was ~70% dependent on serosal HC[O.sub.3.sup.-]. Protein localization by immunohistochemistry confirmed the presence of the vacuolar-type [H.sup.+]-ATPase in the apical region of intestinal enterocytes. These results show that the [H.sup.+] pump, especially in the posterior intestine, plays an important role in hypersaline osmoregulation and that it likely has significant effects on HC[O.sub.3.sup.-] accumulation in the intestinal lumen and, therefore, the continued absorption of [Cl.sup.-] and water. water absorption; posterior intestine; pH-stat titration; salinity; ion transport doi: 10.1152/ajpregu.00059.2011.Academi