15 results
 Pacific Data Hub

Declining health of scleractinian corals in response to deteriorating environmental conditions is widely acknowledged, however links between physiological and functional genomic responses of corals are less well understood. Here we explore growth and the expression of 20 target genes with putative roles in metabolism and calcification in the branching coral, Acropora millepora, in two separate experiments: 1) elevated pCO2 (464, 822, 1187 and 1638 $μ$atm) and ambient temperature (27 °C), and 2) elevated pCO2 (490 and 822 $μ$atm) and temperature (28 and 31 °C).

 Pacific Data Hub

Production of CO2-tolerant microalgae have received much attention as well as physicochemical fixation of CO2 in industrial flue gas. Although many microalgae that are tolerant to high levels of CO2 have been found and evaluated, the CO2 concentration for their good growth is generally lower than their maximum tolerable CO2 level. In the present study, we attempted to isolate microalgae capable of growing in high levels of CO2 (high-level-CO2-preferring microalgae, HCP-microalgae). We used a CO2-permeable polystyrene bottle for the enrichment of HCP-microalgae in environmental samples.

 Pacific Data Hub

Ocean acidification (OA) is predicted to have widespread implications for marine organisms, yet the capacity for species to acclimate or adapt over this century remains unknown. Recent transgenerational studies have shown that for some marine species, exposure of adults to OA can facilitate positive carryover effects to their larval and juvenile offspring that help them to survive in acidifying oceanic conditions. But whether these positive carryover effects can persist into adulthood or the next generation is unknown.

 Pacific Data Hub

To test the effects of chronic stress caused by CO2-driven decreases in pH (NBS scale) on molluscs, juvenile Pacific abalone (Haliotis discus hannai), an economically important gastropod, were cultured at pH 8.1 (control), pH 7.9 or 7.7 for 3 months. Eroded shell surfaces, reduced growth rates, and altered biochemical composition and energy metabolism were found in abalone cultured in acidified conditions.

 Pacific Data Hub

Excavating sponges are prominent bioeroders on coral reefs that in comparison to other benthic organisms may suffer less or may even benefit from warmer, more acidic and more eutrophic waters. Here, the photosymbiotic excavating sponge Cliona orientalis from the Great Barrier Reef was subjected to a prolonged simulation of both global and local environmental change: future seawater temperature, partial pressure of carbon dioxide (as for 2100 summer conditions under "business-as-usual" emissions), and diet supplementation with particulate organics.

 Pacific Data Hub

Anthropogenic carbon dioxide (CO2) emissions simultaneously increase ocean temperatures and reduce ocean surface pH, a process termed ocean acidification (OA). OA is expected to negatively affect the growth and physiology of many calcified organisms, but the response of non-calcified (fleshy) organisms is less well understood. Rising temperatures and pCO2 can enhance photosynthetic rates (within tolerance limits). Therefore, warming may interact with OA to alter biological responses of macroalgae in complicated ways.

 Pacific Data Hub

Alterations in predation pressure can have large effects on trophically-structured systems. Modification of predator behaviour via ocean warming has been assessed by laboratory experimentation and metabolic theory. However, the influence of ocean acidification with ocean warming remains largely unexplored for mesopredators, including experimental assessments that incorporate key components of the assemblages in which animals naturally live.

 Pacific Data Hub

The present study was performed to evaluate the effects of CO2- or HCl-induced seawater acidification (pH 7.7 or 7.1; control: pH 8.1) on haemocytes of Mytilus edulis, and the changes in the structure and immune function were investigated during a 21-day experiment. The results demonstrated that seawater acidification had little effect on the cellular mortality and granulocyte proportion but damaged the granulocyte ultrastructure. Phagocytosis of haemocytes was also significantly inhibited in a clearly concentration-dependent manner, demonstrating that the immune function was affected.

 Pacific Data Hub

The CO2-boosted trophic transfer from primary producers to herbivores has been increasingly discovered at natural CO2 vents and in laboratory experiments. Despite the emerging knowledge of this boosting effect, we do not know the extent to which it may be enhanced or dampened by ocean warming. We investigated whether ocean acidification and warming enhance the nutritional quality (C:N ratio) and energy content of turf algae, which is speculated to drive higher feeding rate, greater energy budget and eventually faster growth of herbivores.

 Pacific Data Hub

Ocean acidification (OA), the process by which increasing atmospheric CO2 is absorbed by the ocean, lowering the pH of surface waters, has been shown to affect many marine organisms negatively. It has been suggested that organisms from regions with naturally low pH waters, such as upwelling areas, could serve as models for future effects of OA and may be adapted to increased pCO2 levels. In this study, we examined the effects of OA on yellowfin tuna, a highly pelagic species that spawns in the eastern tropical Pacific, an area that includes regions of strong upwelling events.

 Pacific Data Hub

During mariculture period, maricultured macroalga Gracilaria lemaneiformis experienced seasonal temperature changes. In this study, we examine the effects of predicted ocean acidification on carbon and nitrogen accumulation and amino acids (AA) contents in G. lemaneiformis under different temperature levels. The results showed that G. lemaneiformis exhibited higher growth rates under high temperature conditions than under low temperature conditions, regardless of CO2 levels. Moreover, compared with low temperature, the culture conditions of high temperature enhanced N accumulation in G.

 Pacific Data Hub

Ocean acidification driven by rising levels of CO2 impairs calcification, threatening coral reef growth. Predicting how corals respond to CO2 requires a better understanding of how calcification is controlled. Here we show how spatial variations in the pH of the internal calcifying fluid (pHcf) in coral (Stylophora pistillata) colonies correlates with differential sensitivity of calcification to acidification. Coral apexes had the highest pHcf and experienced the smallest changes in pHcf in response to acidification.

 Pacific Data Hub

Ulva spp., an increasingly important food, are the dominant species of the large-scale green tides. In this study, both the growth and the physiological responses of the Ulva prolifera were studied after cultured in three different light and dark regimes (12:12, 14:10 and 16:8-h light/dark) in combination with current (420 $μ$atm; LC) and increased (1000 $μ$atm; HC) levels of atmospheric CO2. Grown rate of U.

 Pacific Data Hub

As global ocean change progresses, reef-building corals and their early life history stages will rely on physiological plasticity to tolerate new environmental conditions. Larvae from brooding coral species contain algal symbionts upon release, which assist with the energy requirements of dispersal and metamorphosis. Global ocean change threatens the success of larval dispersal and settlement by challenging the performance of the larvae and of the symbiosis.

 Pacific Data Hub

The physiological response to individual and combined stressors of elevated temperature and pCO2 were measured over a 24-day period in four Pacific corals and their respective symbionts (Acropora millepora/Symbiodinium C21a, Pocillopora damicornis/Symbiodinium C1c-d-t, Montipora monasteriata/Symbiodinium C15, and Turbinaria reniformis/Symbiodinium trenchii). Multivariate analyses indicated that elevated temperature played a greater role in altering physiological response, with the greatest degree of change occurring within M. monasteriata and T. reniformis.