scholarly journals CO2-driven decrease in pH disrupts olfactory behaviour and increases individual variation in deep-sea hermit crabs

2015 ◽  
Vol 73 (3) ◽  
pp. 613-619 ◽  
Author(s):  
Tae Won Kim ◽  
Josi Taylor ◽  
Chris Lovera ◽  
James P. Barry
Keyword(s):  
Ocean Acidification ◽  
Individual Variation ◽  
Deep Sea ◽  
Phenotypic Diversity ◽  
Hermit Crabs ◽  
Prey Detection ◽  
Stable Conditions ◽  
Living Species ◽  
Metabolic Performance ◽  
Olfactory Behaviour

Abstract Deep-sea species are generally thought to be less tolerant of environmental variation than shallow-living species due to the relatively stable conditions in deep waters for most parameters (e.g. temperature, salinity, oxygen, and pH). To explore the potential for deep-sea hermit crabs (Pagurus tanneri) to acclimate to future ocean acidification, we compared their olfactory and metabolic performance under ambient (pH ∼7.6) and expected future (pH ∼7.1) conditions. After exposure to reduced pH waters, metabolic rates of hermit crabs increased transiently and olfactory behaviour was impaired, including antennular flicking and prey detection. Crabs exposed to low pH treatments exhibited higher individual variation for both the speed of antennular flicking and speed of prey detection, than observed in the control pH treatment, suggesting that phenotypic diversity could promote adaptation to future ocean acidification.

scholarly journals Ocean Acidification Amplifies the Olfactory Response to 2-Phenylethylamine: Altered Cue Reception as a Mechanistic Pathway?

2021 ◽  
Author(s):  
Paula Schirrmacher ◽  
Christina C. Roggatz ◽  
David M. Benoit ◽  
Jörg D. Hardege
Keyword(s):  
Climate Change ◽  
Ocean Acidification ◽  
Hermit Crabs ◽  
Ecological Interactions ◽  
Ecological Processes ◽  
Mechanistic Pathway ◽  
Sea Lampreys ◽  
Pagurus Bernhardus ◽  
Decreasing Ph ◽  
The Impact

AbstractWith carbon dioxide (CO2) levels rising dramatically, climate change threatens marine environments. Due to increasing CO2 concentrations in the ocean, pH levels are expected to drop by 0.4 units by the end of the century. There is an urgent need to understand the impact of ocean acidification on chemical-ecological processes. To date, the extent and mechanisms by which the decreasing ocean pH influences chemical communication are unclear. Combining behaviour assays with computational chemistry, we explore the function of the predator related cue 2-phenylethylamine (PEA) for hermit crabs (Pagurus bernhardus) in current and end-of-the-century oceanic pH. Living in intertidal environments, hermit crabs face large pH fluctuations in their current habitat in addition to climate-change related ocean acidification. We demonstrate that the dietary predator cue PEA for mammals and sea lampreys is an attractant for hermit crabs, with the potency of the cue increasing with decreasing pH levels. In order to explain this increased potency, we assess changes to PEA’s conformational and charge-related properties as one potential mechanistic pathway. Using quantum chemical calculations validated by NMR spectroscopy, we characterise the different protonation states of PEA in water. We show how protonation of PEA could affect receptor-ligand binding, using a possible model receptor for PEA (human TAAR1). Investigating potential mechanisms of pH-dependent effects on olfactory perception of PEA and the respective behavioural response, our study advances the understanding of how ocean acidification interferes with the sense of smell and thereby might impact essential ecological interactions in marine ecosystems.

scholarly journals Rapid ocean acidification and protracted Earth system recovery followed the end-Cretaceous Chicxulub impact

2019 ◽  
Vol 116 (45) ◽  
pp. 22500-22504 ◽  
Author(s):  
Michael J. Henehan ◽  
Andy Ridgwell ◽  
Ellen Thomas ◽  
Shuang Zhang ◽  
Laia Alegret ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Ocean Acidification ◽  
Carbon Isotope ◽  
Primary Productivity ◽  
Deep Sea ◽  
Mass Extinction ◽  
System Modeling ◽  
Earth System ◽  
Ph Gradients ◽  
Chicxulub Impact

Mass extinction at the Cretaceous–Paleogene (K-Pg) boundary coincides with the Chicxulub bolide impact and also falls within the broader time frame of Deccan trap emplacement. Critically, though, empirical evidence as to how either of these factors could have driven observed extinction patterns and carbon cycle perturbations is still lacking. Here, using boron isotopes in foraminifera, we document a geologically rapid surface-ocean pH drop following the Chicxulub impact, supporting impact-induced ocean acidification as a mechanism for ecological collapse in the marine realm. Subsequently, surface water pH rebounded sharply with the extinction of marine calcifiers and the associated imbalance in the global carbon cycle. Our reconstructed water-column pH gradients, combined with Earth system modeling, indicate that a partial ∼50% reduction in global marine primary productivity is sufficient to explain observed marine carbon isotope patterns at the K-Pg, due to the underlying action of the solubility pump. While primary productivity recovered within a few tens of thousands of years, inefficiency in carbon export to the deep sea lasted much longer. This phased recovery scenario reconciles competing hypotheses previously put forward to explain the K-Pg carbon isotope records, and explains both spatially variable patterns of change in marine productivity across the event and a lack of extinction at the deep sea floor. In sum, we provide insights into the drivers of the last mass extinction, the recovery of marine carbon cycling in a postextinction world, and the way in which marine life imprints its isotopic signal onto the geological record.

scholarly journals Mobile Elements in Ray-Finned Fish Genomes

Life ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 221 ◽  
Author(s):  
Federica Carducci ◽  
Marco Barucca ◽  
Adriana Canapa ◽  
Elisa Carotti ◽  
Maria Assunta Biscotti
Keyword(s):  
Deep Sea ◽  
Genetic Resource ◽  
Phenotypic Diversity ◽  
Mountain Streams ◽  
High Mountain ◽  
Model Group ◽  
Biological Interest ◽  
Wide Range ◽  
Molecular Bases

Ray-finned fishes (Actinopterygii) are a very diverse group of vertebrates, encompassing species adapted to live in freshwater and marine environments, from the deep sea to high mountain streams. Genome sequencing offers a genetic resource for investigating the molecular bases of this phenotypic diversity and these adaptations to various habitats. The wide range of genome sizes observed in fishes is due to the role of transposable elements (TEs), which are powerful drivers of species diversity. Analyses performed to date provide evidence that class II DNA transposons are the most abundant component in most fish genomes and that compared to other vertebrate genomes, many TE superfamilies are present in actinopterygians. Moreover, specific TEs have been reported in ray-finned fishes as a possible result of an intricate relationship between TE evolution and the environment. The data summarized here underline the biological interest in Actinopterygii as a model group to investigate the mechanisms responsible for the high biodiversity observed in this taxon.

Ocean acidification affects predator avoidance behaviour but not prey detection in the early ontogeny of a keystone species

2014 ◽  
Vol 502 ◽  
pp. 157-167 ◽  
Author(s):  
PH Manríquez ◽  
ME Jara ◽  
ML Mardones ◽  
R Torres ◽  
JM Navarro ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Predator Avoidance ◽  
Keystone Species ◽  
Early Ontogeny ◽  
Avoidance Behaviour ◽  
Prey Detection

scholarly journals Plastic proteans: reduced predictability in the face of predation risk in hermit crabs

2013 ◽  
Vol 9 (5) ◽  
pp. 20130592 ◽  
Author(s):  
Mark Briffa
Keyword(s):  
Individual Variation ◽  
Startle Response ◽  
Response Duration ◽  
Hermit Crabs ◽  
Residual Variance ◽  
Predation Threat ◽  
Mean Response Time ◽  
The Face ◽  
Predator Cue ◽  
Multiple Levels

Variation in behaviour occurs at multiple levels, including between individuals (personality) and between situations (plasticity). Behaviour also varies within individuals, and intra-individual variation (IIV) in behaviour describes within-individual residual variance in behaviour that remains after the effects of obvious external and internal influences on behaviour have been accounted for. IIV thus describes how predictable an individual's behaviour is. Differences in predictability, between individuals and between situations, might be biologically significant. For example, behaving unpredictably under predation threat might reduce the chance of capture. Here, we investigated the duration of startle responses in hermit crabs, in the presence and absence of a predator cue. Individuals differed in startle response duration (personality) and while individuals also varied in their sensitivity to risk, mean response time was greater in the presence of a predator (plasticity). Moreover, IIV was greater in the presence of a predator, providing some of the first evidence that the facultative injection of unpredictability into behaviour might represent a strategy for dealing with risk.

scholarly journals Corals and Carbon: The physiological response of a protected deep-sea coral (Solenosmilia variabilis) to ocean acidification

2021 ◽  
Author(s):  
◽  
Malindi Gammon
Keyword(s):  
Treatment Group ◽  
Ocean Acidification ◽  
Deep Sea ◽  
Exposure Period ◽  
Interactive Effects ◽  
Tissue Loss ◽  
Control Group ◽  
Respiration Rates ◽  
Deep Sea Corals

<p>Calcifying corals provide important habitat complexity in the deep-sea and are consistently associated with a biodiversity of fish and other invertebrates. Little is understood about how deep-sea corals may respond to predicted scenarios of ocean acidification (OA), but any predicted changes will have wider impacts on the ecosystem.   Colonies of Solenosmilia variabilis, a species of deep-sea coral found in the waters surrounding New Zealand, were collected during a cruise in March 2014 from the Louisville Seamount chain. Over 12-months, coral samples were maintained in temperature controlled (~3.5°C) continuous flow-through tanks. A control group of coral colonies was held in seawater with pH 7.88 and a treatment group in pH 7.65. These two pH levels were designed to reflect current pH conditions and end-of-century conditions, respectively. In addition to investigating changes in growth and morphology, measurements of respiration and intracellular pH (pHi) were taken after a mid-term (6 months for respiration; 9 months for pHi) and long-term (12 months for both respiration and pHi) exposure period. An established method used in measuring the pHi of shallow water corals was adapted for use with deep-sea corals for the first time. pHi was independent from the seawater treatment and ranged from 7.67 – 8.30. Respiration rate was not influenced by the reduced seawater pH tested here. Respiration rates were highly variable, ranging from 0.065 to 1.756 μg O2 g-1 protein h-1 and pHi ranged from 7.67 – 8.30. Yearly growth rates were also variable, ranging from 0.53 to 3.068 mm year-1, and again showed no detectable difference between the treatment and control colonies. However, a loss in the colouration of coral skeletons was observed in the treatment group and was attributed to a loss of tissue. This could indicate a reallocation of energy, allowing for the maintenance of those other physiological parameters measured here (e.g. growth and respiration rates). If this is indeed occurring, it would be consistent with the idea of phenotypic plasticity, where corals can alternate between soft-bodied and fossilizing forms, allowing them to survive past periods of environmental stress.   This research is an important first step towards understanding the sensitivity of deep-sea corals to OA and the potential for acclimation, and suggests that in many respects, S. variabilis might not be susceptible to end-of-century projections of OA. Nevertheless, the observed tissue loss is interesting and warrants further investigation to assess its long-term implications. Furthermore, the impacts of greater levels of OA, and the interactive effects of other ecological parameters such as food availability, need to be tested.</p>

scholarly journals Projected pH reductions by 2100 might put deep North Atlantic biodiversity at risk

2014 ◽  
Vol 11 (6) ◽  
pp. 8607-8634 ◽  
Author(s):  
M. Gehlen ◽  
R. Séférian ◽  
D. O. B. Jones ◽  
T. Roy ◽  
R. Roth ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
North Atlantic ◽  
Deep Sea ◽  
Biological Diversity ◽  
Management Strategies ◽  
Co2 Concentration ◽  
Convention On Biological Diversity ◽  
Resource Exploitation ◽  
Atlantic Sector ◽  
The Impact

Abstract. This study aims at evaluating the potential for impacts of ocean acidification on North Atlantic deep-sea ecosystems in response to IPCC AR5 Representative Concentration Pathways (RCP). Deep-sea biota is likely highly vulnerable to changes in seawater chemistry and sensitive to moderate excursions in pH. Here we show, from seven fully-coupled Earth system models, that for three out of four RCPs over 17% of the seafloor area below 500 m depth in the North Atlantic sector will experience pH reductions exceeding −0.2 units by 2100. Increased stratification in response to climate change partially alleviates the impact of ocean acidification on deep benthic environment. We report major potential consequences of pH reductions for deep-sea biodiversity hotspots, such as seamounts and canyons. By 2100 and under the high CO2 scenario RCP8.5 pH reductions exceeding −0.2, (respectively −0.3) units are projected in close to 23% (~ 15%) of North Atlantic deep-sea canyons and ~ 8% (3%) of seamounts – including seamounts proposed as sites of marine protected areas. The spatial pattern of impacts reflects the depth of the pH perturbation and does not scale linearly with atmospheric CO2 concentration. Impacts may cause negative changes of the same magnitude or exceeding the current target of 10% of preservation of marine biomes set by the convention on biological diversity implying that ocean acidification may offset benefits from conservation/management strategies relying on the regulation of resource exploitation.

scholarly journals Observations of deep-sea fishes and mobile scavengers from the abyssal DISCOL experimental mining area

2019 ◽  
Vol 16 (16) ◽  
pp. 3133-3146 ◽  
Author(s):  
Jeffrey C. Drazen ◽  
Astrid B. Leitner ◽  
Sage Morningstar ◽  
Yann Marcon ◽  
Jens Greinert ◽  
...  
Keyword(s):  
Deep Sea ◽  
Fish Community ◽  
Population Level ◽  
Mining Area ◽  
Hermit Crabs ◽  
Fish Density ◽  
Environmental Drivers ◽  
Large Contribution ◽  
Ecosystem Responses ◽  
Polymetallic Nodule

Abstract. Industrial interest in deep-sea mineral extraction began decades ago, and today it is at an all-time high, accelerated by global demand for metals. Several seafloor ecosystem disturbance experiments began in the 1970s, including the Disturbance and Recolonization experiment (DISCOL) conducted in the Peru Basin in 1989. A large seafloor disturbance was created by repeatedly ploughing the seafloor over an area of ∼10.8 km2. Though a number of studies in abyssal mining regions have evaluated megafaunal biodiversity and ecosystem responses, few have included quantitative and detailed data on fishes or scavengers despite their ecological importance as top predators. We used towed camera transects (1989–1996, 2015) and baited camera data (1989–1992) to evaluate the fish community at the DISCOL site. The abyssal fish community included 16 taxa and was dominated by Ipnops meadi. Fish density was lower in ploughed habitat at 6 months and 3 years following disturbance but thereafter increased over time. Twenty-six years after disturbance there were no differences in overall total fish densities between reference and experimental areas, but the dominant fish, I. meadi, still exhibited much lower densities in ploughed habitat, likely avoiding these areas and suggesting that the fish community remains affected after decades. At the scale of industrial mining, these results could translate to population-level effects. The scavenging community was dominated by eelpouts (Pachycara spp.), hermit crabs (Probeebei mirabilis) and shrimp. The large contribution of hermit crabs appears to be unique amongst abyssal scavenger studies worldwide. The abyssal fish community at DISCOL was similar to that in the more northerly Clarion–Clipperton Zone (CCZ), though some species have only been observed at DISCOL thus far. Also, further species-level identifications are required to refine this assessment. Additional studies across the polymetallic nodule provinces of the Pacific are required to further evaluate the environmental drivers of fish density, diversity and species biogeographies. This information will be important for the development of appropriate management plans aimed at minimizing human impact from deep-sea mining.

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