Time filter

Source Type

Dufault A.M.,Northridge | Cumbo V.R.,Northridge | Fan T.-Y.,National Museum of Marine Biology and Aquarium | Fan T.-Y.,National Dong Hwa University | Edmunds P.J.,Northridge
Proceedings of the Royal Society B: Biological Sciences | Year: 2012

Manipulative studies have demonstrated that ocean acidification (OA) is a threat to coral reefs, yet no experiments have employed diurnal variations in pCO2 that are ecologically relevant to many shallow reefs. Two experiments were conducted to test the response of coral recruits (less than 6 days old) to diurnally oscillating pCO2; one exposing recruits for 3 days to ambient (440 μatm), high (663 μatm) and diurnally oscillating pCO2 on a natural phase (420-596 μatm), and another exposing recruits for 6 days to ambient (456 μatm), high (837 μatm) and diurnally oscillating pCO2 on either a natural or a reverse phase (448-845 μatm). In experiment I, recruits exposed to natural-phased diurnally oscillating pCO2 grew 6-19% larger than those in ambient or high pCO2. In experiment II, recruits in both high and natural-phased diurnally oscillating pCO2 grew 16 per cent larger than those at ambient pCO2, and this was accompanied by 13-18% higher survivorship; the stimulatory effect on growth of oscillatory pCO2 was diminished by administering high pCO2 during the day (i.e. reverse-phased). These results demonstrate that coral recruits can benefit from ecologically relevant fluctuations in pCO2 and we hypothesize that the mechanism underlying this response is highly pCO2-mediated, night-time storage of dissolved inorganic carbon that fuels daytime calcification. © 2012 The Royal Society.

Cumbo V.R.,Northridge | Fan T.Y.,National Museum of Marine Biology and Aquarium | Fan T.Y.,National Dong Hwa University | Edmunds P.J.,Northridge
Journal of Experimental Marine Biology and Ecology | Year: 2013

Efforts to evaluate the response of coral larvae to global climate change (GCC) and ocean acidification (OA) typically employ short experiments of fixed length, yet it is unknown how the response is affected by exposure duration. In this study, we exposed larvae from the brooding coral Pocillopora damicornis to contrasts of temperature (24.00°C [ambient] versus 30.49°C) and pCO2 (49.4Pa versus 86.2Pa) for varying periods (1-5days) to test the hypothesis that exposure duration had no effect on larval response as assessed by protein content, respiration, Symbiodinium density, and survivorship; exposure times were ecologically relevant compared to representative pelagic larval durations (PLD) for corals. Larvae differed among days for all response variables, and the effects of the treatment were relatively consistent regardless of exposure duration for three of the four response variables. Protein content and Symbiodinium density were unaffected by temperature and pCO2, but respiration increased with temperature (but not pCO2) with the effect intensifying as incubations lengthened. Survival, however, differed significantly among treatments at the end of the study, and by the 5th day, 78% of the larvae were alive and swimming under ambient temperature and ambient pCO2, but only 55-59% were alive in the other treatments. These results demonstrate that the physiological effects of temperature and pCO2 on coral larvae can reliably be detected within days, but effects on survival require ≥5days to detect. The detection of time-dependent effects on larval survivorship suggests that the influence of GCC and OA will be stronger for corals having long PLDs. © 2012 Elsevier B.V.

Liu J.T.,National Sun Yat - sen University | Wang Y.H.,National Sun Yat - sen University | Lee I.-H.,National Museum of Marine Biology and Aquarium | Hsu R.T.,National Sun Yat - sen University
Marine Geology | Year: 2010

The benthic nepheloid layer (BNL) has been observed in the head region of the Gaoping/Kaoping Submarine Canyon (KPSC) throughout a year. The top of the BNL could be as high as 100 m above the canyon floor in which the suspended sediment concentration (SSC) could be as high as 30 mg/l. In the BNL, sand-sized particles comprise the largest size-class in the suspended sediment population. Based on three one-month time series observations near the canyon floor of along-canyon velocity, water temperature, and the volume concentration (VC) of clay, very-fine-to-medium silt, coarse silt and sand size-classes in 2000, 2002, and 2004, the BNL is strongly modulated by the tides at semidiurnal, diurnal, quarter, and sixth diurnal and spring-neap frequencies. In the course of a semidiurnal tidal cycle, the flood (up-canyon) current brings colder water from the seaward part of the canyon causing the SSC and the thickness of the BNL to increase. The SSC immediately near the canyon floor also increases in response to the maximum flood and ebb currents of the M2 tide. The tidal-to-total energy ratio (ER) of the along-canyon flow is between 70-80%, and between 50-80% among the suspended sediment of clay, very-fine-to-medium silt, coarse silt and sand size-classes. The M2 is the most important tidal constituent in the temporal variations of along-canyon flow, water temperature, and the VC of the four size-classes. The local phase differences between the forcing (velocity), and the responses (temperature and VC) at the M2 frequency show distinct phase-lock that suggests patterns of standing and progressive internal tides. Suspended sediments in the BNL also respond to the M2 forcing in a coherent fashion. Suspended sediment movements are strongly affected by nonlinear processes as indicated by the elevated values of the amplitude ratio of M4/M2 of the suspended sediment size-classes comparing to that of the flow. The cross-canyon geometry and the slope of the submarine canyon floor affect the propagation of the barotropic and internal tides, which in turn, affect the nonlinearity generation in the BNL. © 2010 Elsevier B.V. All rights reserved.

Lin C.,National Museum of Marine Biology and Aquarium | Lin C.,National Dong Hwa University | Tsai S.,MingDao University
Theriogenology | Year: 2012

Understanding chilling sensitivity and chilling injury of coral oocytes, in the presence and absence of a cryoprotectant, is important in developing cryopreservation protocols, as well as for short-term storage and transport (e.g., for species conservation). The objective of this study was to investigate the chilling sensitivity of hard coral (Echinopora spp.) oocytes and the effectiveness of methanol (as a cryoprotectant) in protecting these oocytes during short-term, low temperature preservation. Oocytes were exposed to 0.5, 1, or 2 m methanol at 5, 0, or -5 °C for 1, 2, 4, 6, 8, 16, or 32 h, and their quality determined based on adenosine triphosphate (ATP) content. Methanol at 0.5 m was the most effective means to reduce chilling-induced reduction in ATP concentrations. Coral oocytes can be stored at room temperature for 4 h in filtered nature seawater with no detrimental effect on oocyte quality; however, in the present study, oocyte survival was extended for 8 h by addition of methanol in low concentrations (0.5 or 1 m) at low temperatures (5 and 0 °C). These findings should enhance conservation efforts and facilitate low-temperature transport of endangered and threatened coral species. © 2012 Elsevier Inc.

Chen T.-H.,National Museum of Marine Biology and Aquarium | Chen T.-H.,National Dong Hwa University | Lin C.-Y.,National Pingtung University of Science and Technology | Tseng M.-C.,National Pingtung University of Science and Technology
Marine Pollution Bulletin | Year: 2011

In this study, zebrafish embryos were exposed to titanium dioxide nanoparticles (TiO2 NPs at 0.1, 0.5, 1, 5, 10mg/L or control) from fertilization to free swimming stage. Hatchability, survival, and malformation rate were not affected by TiO2 NPs at these exposure levels. However, larval swimming parameters, including average and maximum velocity and activity level were significantly affected by TiO2 NPs. Co-exposure to either the glutathione precursor, N-acetylcysteine (NAC), or the glutathione synthesis inhibitor, buthionine sulfoximine (BSO), did not significantly alter the behavioral effects resulting from TiO2 NPs, suggesting that other factor(s) besides oxidative stress may contribute to the behavioral toxicity of TiO2 NPs. Our study also demonstrated that the behavioral endpoints were more sensitive than the others (e.g., hatchability and survival) to detect toxicity of TiO2 NPs on developing fish. © 2011 Elsevier Ltd.

Edmunds P.J.,Northridge | Cumbo V.,Northridge | Fan T.-Y.,National Museum of Marine Biology and Aquarium | Fan T.-Y.,National Dong Hwa University
Journal of Experimental Biology | Year: 2011

This study describes the effects of temperature on the respiration of brooded larvae of scleractinian corals, and evaluates the implications of these effects relative to seawater temperature when peak larval release occurs. Respiration rates of larvae from Pocillopora damicornis, Seriatopora hystrix and Stylophora pistillata were quantified in darkness as oxygen uptake during 1-3h exposures to five temperatures between 26. 4 and 29. 6 C. To assess the biological significance of these experiments, the temperature of the seawater into which larvae of P. damicornis and S. hystrix were released was measured for 32-34 months over 5years between 2003 and 2008. Mean respiration varied from 0. 029 to 0. 116nmol O 2 larva -1 min -1, and was related parabolically to temperature with a positive threshold at 28. 0°C. The temperature coefficients (Q 10) for the ascending portion of these relationships (Q 10=15-76) indicate that the temperature dependency is stronger than can be explained by kinetics alone, and probably reflects behavioral and developmental effects. Larval release occurred year-round in synchrony with the lunar periodicity when seawater temperature ranged from 21. 8 to 30. 7°C, and more than half of the sampled larvae were released at 27. 5-28. 9°C. The coincidence on the temperature scale of peak larval release with the thermal threshold for respiration suggests that high metabolic rates have selective value for pelagic coral larvae. The large and rapid effects of temperature on larval respiration have implications for studies of the effects of climate change on coral reproduction, particularly when seawater temperature exceeds ∼28°C, when our results predict that larval respiration will be greatly reduced. © 2011. Published by The Company of Biologists Ltd.

Ho H.-C.,National Museum of Marine Biology and Aquarium | Shao K.-T.,Academia Sinica, Taiwan
Zootaxa | Year: 2010

Parapercis randalli sp. nov. is described on the basis of four specimens collected in southern Taiwan by angling at a depth of 5-150 m. It differs from its congeners in having five broad reddish brown saddles on the dorsal surface; both jaws and anterior portion of snout reddish orange; a yellow bar with red margin on cheek; a series of 8 red bars below body axis; configuration of spots on head, dorsal and caudal fins; and a combination of morphological characters: three pairs of canine teeth anteriorly in lower jaw; no palatine teeth; vomerine teeth stout, in a single curved row; lateral-line scales 53; margin of preopercle smooth; 4th dorsal spine longest; caudal fin slightly rounded on ventral half, truncate on dorsal half, with a prolonged upper lobe; appressed pelvic fin extends beyond anus. A total of 21 valid pinguipedid species are now recorded from Taiwanese waters. Copyright © 2010.

Chen T.-H.,National Museum of Marine Biology and Aquarium | Chen T.-H.,National Dong Hwa University | Wang Y.-H.,National Dong Hwa University | Wu Y.-H.,University of California at Davis
Aquatic Toxicology | Year: 2011

Ethanol and dimethylsulfoxide (DMSO) are commonly used as carrier solvents for lipophilic chemicals in aquatic toxicity bioassays. However, very little information has been reported on the behavioral effects of these solvents. In this study, we examined the effects of ethanol and DMSO on development and locomotor activity by a zebrafish embryo-larval bioassay. The zebrafish were exposed to different concentrations (control, 0.01, 0.1, and 1%) of ethanol or DMSO from blastula stage to 144. hour-post-fertilization (hpf). Hatchability, survival, and abnormalities were monitored every 12. h, and locomotor activity of the larvae was analyzed at 144. hpf. Hatchability was not affected by the ethanol or DMSO treatments. No effect on survival was observed except the 1% ethanol group suffered 89% mortality during 108-120. hpf. No developmental defects were observed in any of the solvents at the 0.01 and 0.1% concentrations, but significantly higher deformity rates occurred with 1% ethanol and DMSO groups. Hyperactivity and less tortuous swimming paths were observed in all ethanol and DMSO concentrations. Based on this study, we suggest that data of behavioral toxicity bioassays using ethanol or DMSO as carrier solvents should be interpreted cautiously, because the solvents at low concentrations could alter locomotor activity of larval zebrafish without causing any observable developmental defects. © 2011 Elsevier B.V.

Yau A.J.-Y.,University of California at Santa Barbara | Fan T.-Y.,National Museum of Marine Biology and Aquarium
Marine Biology | Year: 2012

Giant clams form a symbiosis with photosynthetic algae of the genus Symbiodinium that reside in clam mantle tissue. The allometry of symbiont photosynthetic performance was investigated as a mechanism for the increasing percentage of giant clam carbon respiratory requirements provided by symbionts as clam size increases. Chlorophyll fluorescence measurements of symbionts of the giant clam Tridacna maxima were measured during experiments conducted in September of 2009 using specimens 0.5-200 g tissue wet weight (3-25 cm long), collected from waters around southern Taiwan (N 21°36′, E 120°47′) from July to August of 2009. Light-dependent decreases in effective quantum yield ΔF/F m′) calculated as the noontime maximum excitation pressure over PSII (Q m), relative electron transport rates (rETR), and dark-adapted maximum quantum yield (F v/F m) all varied as a quadratic function of clam size. Both Q m and rETR increased as clam size increased up to ~10-50 g then decreased as clam size increased. F v/F m decreased as clam size increased up to ~5-50 g then increased as clam size increased. Chlorophyll fluorescence measurements of rETR were positively correlated with gross primary production measured during chamber incubations. Overall, symbionts of mid-sized clams ~5-50 g exhibited the highest light-dependent decreases in effective photosynthetic efficiencies, the highest relative electron transport rates, and the lowest maximum photosynthetic efficiencies, and symbiont photosynthetic performance is allometric with respect to host clam size. © 2011 Springer-Verlag.

Ko F.-C.,National Dong Hwa University | Chang C.-W.,National Dong Hwa University | Cheng J.-O.,National Museum of Marine Biology and Aquarium
Environmental Pollution | Year: 2014

Surface sediments and corals (Acropora sp. and Montipora sp.) from the coastline of Kenting were analyzed in 2009 and 2010 for content levels of polycyclic aromatic hydrocarbons (PAHs) using gas chromatography-mass spectrometry. The total PAH concentrations (t-PAH) in corasls (143-1715 ng g-1 dw) were significantly higher than in the ambient sediments (2-59 ng g-1 dw) indicating the bioaccumulation of PAHs in corals. The spatial and seasonal variation in PAH levels suggested that land-loaded contaminants may be the main source of PAHs in the Kenting coral reefs. Based on molecular indices, PAHs were substantially of petroleum origin. The major PAH components were phenanthrene, pyrene and fluorine, but PAH congeners in corals and sediments still have characteristic composition patterns which would be altered by the bio/accumulation mechanisms. Further study is essential to assess and understand the impacts of these chemicals on coral reefs.© 2013 Elsevier Ltd. All rights reserved.

Loading National Museum of Marine Biology and Aquarium collaborators
Loading National Museum of Marine Biology and Aquarium collaborators