scholarly journals Warming has a greater effect than elevated CO 2 on predator–prey interactions in coral reef fish

2017 ◽  
Vol 284 (1857) ◽  
pp. 20170784 ◽  
Author(s):  
Bridie J. M. Allan ◽  
Paolo Domenici ◽  
Sue Ann Watson ◽  
Philip L. Munday ◽  
Mark I. McCormick
Keyword(s):  
High Temperature ◽  
Coral Reef ◽  
High Temperatures ◽  
Swimming Performance ◽  
Reef Fishes ◽  
Independent Effect ◽  
Combined Effects ◽  
Ecological Processes ◽  
Predator Prey ◽  
Short Term Exposure

Ocean acidification and warming, driven by anthropogenic CO 2 emissions, are considered to be among the greatest threats facing marine organisms. While each stressor in isolation has been studied extensively, there has been less focus on their combined effects, which could impact key ecological processes. We tested the independent and combined effects of short-term exposure to elevated CO 2 and temperature on the predator–prey interactions of a common pair of coral reef fishes ( Pomacentrus wardi and its predator, Pseudochromis fuscus ). We found that predator success increased following independent exposure to high temperature and elevated CO 2 . Overall, high temperature had an overwhelming effect on the escape behaviour of the prey compared with the combined exposure to elevated CO 2 and high temperature or the independent effect of elevated CO 2 . Exposure to high temperatures led to an increase in attack and predation rates. By contrast, we observed little influence of elevated CO 2 on the behaviour of the predator, suggesting that the attack behaviour of P. fuscus was robust to this environmental change. This is the first study to address how the kinematics and swimming performance at the basis of predator–prey interactions may change in response to concurrent exposure to elevated CO 2 and high temperatures and represents an important step to forecasting the responses of interacting species to climate change.

scholarly journals Effect of elevated CO 2 and small boat noise on the kinematics of predator–prey interactions

2018 ◽  
Vol 285 (1875) ◽  
pp. 20172650 ◽  
Author(s):  
Mark I. McCormick ◽  
Sue-Ann Watson ◽  
Stephen D. Simpson ◽  
Bridie J. M. Allan
Keyword(s):  
Community Dynamics ◽  
Reef Fishes ◽  
Combined Effects ◽  
Predator Prey ◽  
Predator Attack ◽  
Perception Of Threat ◽  
Short Term Exposure ◽  
Multiplicative Effect ◽  
Key Drivers ◽  
Successful Capture

Oceans of the future are predicted to be more acidic and noisier, particularly along the productive coastal fringe. This study examined the independent and combined effects of short-term exposure to elevated CO 2 and boat noise on the predator–prey interactions of a pair of common coral reef fishes ( Pomacentrus wardi and its predator, Pseudochromis fuscus ). Successful capture of prey by predators was the same regardless of whether the pairs had been exposed to ambient control conditions, the addition of either playback of boat noise, elevated CO 2 (925 µatm) or both stressors simultaneously. The kinematics of the interaction were the same for all stressor combinations and differed from the controls. The effects of CO 2 or boat noise were the same, suggesting that their effects were substitutive in this situation. Prey reduced their perception of threat under both stressors individually and when combined, and this coincided with reduced predator attack distances and attack speeds. The lack of an additive or multiplicative effect when both stressors co-occurred was notable given the different mechanisms involved in sensory disruptions and highlights the importance of determining the combined effects of key drivers to aid in predicting community dynamics under future environmental scenarios.

Suspended sediment alters predator–prey interactions between two coral reef fishes

Coral Reefs ◽  
2012 ◽  
Vol 32 (2) ◽  
pp. 369-374 ◽  
Author(s):  
A. S. Wenger ◽  
M. I. McCormick ◽  
I. M. McLeod ◽  
G. P. Jones
Keyword(s):  
Coral Reef ◽  
Suspended Sediment ◽  
Reef Fishes ◽  
Coral Reef Fishes ◽  
Predator Prey

scholarly journals Effects of wave-driven water flow on the fast-start escape response of juvenile coral reef damselfishes

2021 ◽  
Author(s):  
Dominique Roche
Keyword(s):  
Coral Reef ◽  
Water Flow ◽  
Escape Response ◽  
Swimming Performance ◽  
Reef Fishes ◽  
Body Depth ◽  
Spatial And Temporal Scales ◽  
Juvenile Coral ◽  
Fast Start ◽  
Escape Responses

Fish often evade predators with a fast-start escape response. Studies typically examine this behaviour in still water despite water motion being an inherent feature of aquatic ecosystems. In shallow habitats, waves create complex flows that likely influence escape performance, particularly in small fishes with low absolute swimming speeds relative to environmental flows. I examined how wave-driven water flow affects the behaviour and kinematics of escape responses in juveniles of three coral reef damselfishes (Pomacentridae) with different body morphologies. Tropical damselfishes have similar fin and body shapes during early development with the exception of body depth, a trait deemed important for postural control and stability. Wave-driven flow increased response latency in two of the three species tested: fish with a fusiform body responded 2.4 times slower in wave-driven flow than in still water, whereas this difference was less pronounced in fish with an intermediate body depth (1.9 times slower response), and absent in fish with a laterally compressed body. The effect of wave-driven flow on swimming performance (cumulative escape distance and turning rate) was variable and depended on the timing and trajectory of escape responses in relation to the wave phase. Given intense predation pressure on juvenile coral reef fishes during settlement, interspecific differences in how wave-driven flow affects their ability to escape predators could influence the distribution and abundance of species across spatial and temporal scales.

scholarly journals Sediment suppresses herbivory across a coral reef depth gradient

2012 ◽  
Vol 8 (6) ◽  
pp. 1016-1018 ◽  
Author(s):  
Christopher H. R. Goatley ◽  
David R. Bellwood
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Reef Fishes ◽  
Reef Crest ◽  
Depth Gradient ◽  
Ecological Processes ◽  
Natural Sediment ◽  
Fish Feeding ◽  
Sediment Loads

Sediments are a ubiquitous feature of all coral reefs, yet our understanding of how they affect complex ecological processes on coral reefs is limited. Sediment in algal turfs has been shown to suppress herbivory by coral reef fishes on high-sediment, low-herbivory reef flats. Here, we investigate the role of sediment in suppressing herbivory across a depth gradient (reef base, crest and flat) by observing fish feeding following benthic sediment reductions. We found that sediment suppresses herbivory across all reef zones. Even slight reductions on the reef crest, which has 35 times less sediment than the reef flat, resulted in over 1800 more herbivore bites (h −1 m −2 ). The Acanthuridae (surgeonfishes) were responsible for over 80 per cent of all bites observed, and on the reef crest and flat took over 1500 more bites (h −1 m −2 ) when sediment load was reduced. These findings highlight the role of natural sediment loads in shaping coral reef herbivory and suggest that changes in benthic sediment loads could directly impair reef resilience.

scholarly journals Effects of wave-driven water flow on the fast-start escape response of juvenile coral reef damselfishes

2021 ◽  
Vol 224 (6) ◽  
pp. jeb234351 ◽  
Author(s):  
Dominique G. Roche
Keyword(s):  
Coral Reef ◽  
Water Flow ◽  
Escape Response ◽  
Swimming Performance ◽  
Reef Fishes ◽  
Body Depth ◽  
Spatial And Temporal Scales ◽  
Juvenile Coral ◽  
Fast Start ◽  
Escape Responses

ABSTRACTFish often evade predators with a fast-start escape response. Studies typically examine this behaviour in still water despite water motion being an inherent feature of aquatic ecosystems. In shallow habitats, waves create complex flows that likely influence escape performance, particularly in small fishes with low absolute swimming speeds relative to environmental flows. I examined how wave-driven water flow affects the behaviour and kinematics of escape responses in juveniles of three coral reef damselfishes (Pomacentridae) with different body morphologies. Tropical damselfishes have similar fin and body shapes during early development, with the exception of body depth, a trait deemed important for postural control and stability. Wave-driven flow increased response latency in two of the three species tested: fish with a fusiform body responded 2.9 times slower in wave-driven flow than in still water, whereas this difference was less pronounced in fish with an intermediate body depth (1.9 times slower response) and absent in fish with a laterally compressed body. The effect of wave-driven flow on swimming performance (cumulative escape distance and turning rate) was variable and depended on the timing and trajectory of escape responses in relation to the wave phase. Given intense predation pressure on juvenile coral reef fishes during settlement, interspecific differences in how wave-driven flow affects their ability to escape predators could influence the distribution and abundance of species across spatial and temporal scales.

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

NICROFER 5520 Co

Alloy Digest ◽  
1995 ◽  
Vol 44 (3) ◽  
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Creep Properties ◽  
Nickel Chromium ◽  
Temperature Performance

Abstract NICROFER 5520 Co is a nickel-chromium-cobalt-molybdenum alloy with excellent strength and creep properties up to high temperatures. Due to its balanced chemical composition the alloy shows outstanding resistance to high temperature corrosion in the form of oxidation and carburization. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-480. Producer or source: VDM Technologies Corporation.

CARLSON ALLOY C601

Alloy Digest ◽  
1994 ◽  
Vol 43 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
High Temperatures ◽  
Stress Corrosion Cracking ◽  
Heat Treating ◽  
Resistance To Stress ◽  
Extended Exposure ◽  
Sulfur Containing

Abstract Carlson Alloy C601 is characterized by high tensile, yield and creep-rupture strengths for high temperature service. The alloy is not embrittled by extended exposure to high temperatures and has excellent resistance to stress-corrosion cracking, to carburizing, nitriding and sulfur containing environments. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on forming, heat treating, machining, and joining. Filing Code: Ni-458. Producer or source: G.O. Carlson Inc.

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