112 results
 Pacific Data Hub

The economy and population in Taiwan grew rapidly in the 20th century, during which time little attention was paid to marine environmental protection. Discharges of heavy metals, BOD, COD, organic/inorganic nitrogen, and phosphorous have, as a result, caused environmental problems. Besides pollutants brought by long-range transport such as dust storms, haze, and water-borne radiation, locally sourced pollutants were transported to the coastal area by small mountain rivers on the narrow island.

 Pacific Data Hub

Hemocytes play important roles in the innate immune response and biomineralization of bivalve mollusks. However, the hemocytes in pearl oysters are poorly understood. In the present study, we investigated the morphology and classification of hemocytes in the pearl oyster, P. fucata. Three types of hemocytes were successfully obtained by light microscopy, electron microscopy and flow cytometry methods: small hyalinocytes, large hyalinocytes and granulocytes. The small hyalinocytes are the major hemocyte population.

 Pacific Data Hub

Possible future changes of ambient shipping noise at 0.1-1 kHz in the North Pacific caused by changing seawater chemistry conditions are analyzed with a simplified propagation model. Probable decreases of pH would cause meaningful reduction of the sound absorption coefficient in near-surface ocean water for these frequencies. The results show that a few decibels of increase may occur in 100 years in some very quiet areas very far from noise sources, with small effects closer to noise sources.

 Pacific Data Hub

The 3-day diurnal dynamics of carbonate system and related parameters on Luhuitou fringing reef of Sanya Bay-adjacent to the South China Sea (SCS) were observed in December of 2009 (early winter), April (spring), July (summer) and November (late-autumn) of 2010. The Luhuitou fringing reef ecosystem was generally dominated by macro and planktonic algae throughout the year except by coralline algae in winter. The system parameters showed distinct diurnal trends in the four seasons.

 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

This modeling study investigates the impacts of increasing atmospheric CO2 concentration on acidification in the East Sea. A historical simulation for the past three decades (1980 to 2010) was performed using the Hadley Centre Global Environmental Model (version 2), a coupled climate model with atmospheric, terrestrial and ocean cycles. As the atmospheric CO2 concentration increased, acidification progressed in the surface waters of the marginal sea. The acidification was similar in magnitude to observations and models of acidification in the global ocean.

 Pacific Data Hub

Ocean acidification (OA) is likely to have an effect on the fertilizing potential of desert dust in high-nutrient, low-chlorophyll oceanic regions, either by modifying iron (Fe) speciation and bioavailability or by altering phytoplankton Fe requirements and acquisition. To address this issue, short incubations (4 days) of northeast subarctic Pacific waters enriched with either FeSO4 or dust and set at pH 8.0 (in situ) and 7.8 were conducted in August 2010.

 Pacific Data Hub

Oceanic uptake of anthropogenic carbon dioxide results in a decrease in seawater pH, a process known as “ocean acidification”. The pearl oyster Pinctada fucata, the noble scallop Chlamys nobilis, and the green-lipped mussel Perna viridis are species of economic and ecological importance along the southern coast of China. We evaluated the effects of seawater acidification on clearance, respiration, and excretion rates in these three species. The ammals were reared in seawater at pH 8.1 (control), 7.7, or 7.4. The clearance rate was highest at pH 7.7 for P. fucata and at pH 8.1 for C.

 Pacific Data Hub

Ulva is the dominant genus in the green tide events and is considered to have efficient CO2 concentrating mechanisms (CCMs). However, little is understood regarding the impacts of ocean acidification on the CCMs of Ulva and the consequences of thalli's acclimation to ocean acidification in terms of responding to environmental factors. Here, we grew a cosmopolitan green alga, Ulva linza at ambient (LC) and elevated (HC) CO2 levels and investigated the alteration of CCMs in U. linza grown at HC and its responses to the changed seawater carbon chemistry and light intensity.

 Pacific Data Hub

Elevated pCO2 threatens coral reefs through impaired calcification. However, the extent to which elevated pCO2 affects the distribution of the pelagic larvae of scleractinian corals, and how this may be interpreted in the context of ocean acidification (OA), remains unknown. We tested the hypothesis that elevated pCO2 affects one aspect of the behavior (i.e., motility) of brooded larvae from Pocillopora damicornis in Okinawa (Japan), and used UV-transparent tubes that were 68-cm long (45 mm ID) to incubate larvae on a shallow fringing reef.

 Pacific Data Hub

Eastern boundary upwelling systems (EBUS) are naturally more acidic than most of the rest of the surface ocean. Observations of EBUS already show pH values and saturation states with regard to the carbonate mineral aragonite that are as low as those expected for most open ocean waters several decades from now. Thus, as atmospheric CO2 increases further, EBUS are prone to widespread and persistent undersaturation with regard to aragonite, making them especially sensitive to ocean acidification.

 Pacific Data Hub

The impact that ocean acidification (OA) could generate in the fisheries of Isostichopus badionotus at the north of the Yucatan Peninsulta, Mexico, was analysed by reducing the value of a parameter of the Beverton-Holt recruitment function, in accordance with the acidification scenarios of the Intergovermental Panel Panel on Climate Change (IPCC). The behaviour of the stock and the resulting fishery were analysed in a bioeconomic model structured by age, taking into account different market prices and fishing efforts.

 Pacific Data Hub

There is increasing concern about the effects of ocean acidification on marine biogeochemical and ecological processes and the organisms that drive them, including marine bacteria. Here, we examine the effects of elevated CO2 on the bacterioplankton community during a mesocosm experiment using an artificial phytoplankton community in subtropical, eutrophic coastal waters of Xiamen, southern China.

 Pacific Data Hub

Several studies have demonstrated that shellfish calcification rate has been impacted by ocean acidification. However, the carbonate system variables responsible for regulating calcification rate are controversial. To distinguish the key variables, we manipulated a seawater carbonate system by regulating seawater pH and dissolved inorganic carbon (DIC). Calcification rates of juvenile blue mussel (Mytilus edulis) and Zhikong scallop (Chlamys farreri) were measured in different carbonate systems.

 Pacific Data Hub

Rising anthropogenic CO2 in the atmosphere is accompanied by an increase in oceanic CO2 and a concomitant decline in seawater pH (ref. 1). This phenomenon, known as ocean acidification (OA), has been experimentally shown to impact the biology and ecology of numerous animals and plants, most notably those that precipitate calcium carbonate skeletons, such as reef-building corals. Volcanically acidified water at Maug, Commonwealth of the Northern Mariana Islands (CNMI) is equivalent to near-future predictions for what coral reef ecosystems will experience worldwide due to OA.

 Pacific Data Hub

Cryptic colouration in crustaceans, important for both camouflage and visual communication, is achieved through physiological and morphological mechanisms that are sensitive to changes in environmental conditions. Consequently, ocean warming and ocean acidification can affect crustaceans' biophotonic appearance and exoskeleton composition in ways that might disrupt colouration and transparency.

 Pacific Data Hub

Shoaling of the saturation horizon for aragonite in the California Current System has been well-documented; however, these reports are based primarily on surveys conducted in waters off the continental shelf. Here we characterize, for the first time, regional spatial and seasonal patterns in aragonite saturation state ($Ømega$arag) in the shallow, nearshore waters of the southern California continental shelf through a series of synoptic surveys. Spectrophotometric pH and total alkalinity samples were collected quarterly from 72 sites along the shelf for two years.

 Pacific Data Hub

The marine life of Canada's Pacific marine ecosystems, adjacent to the province of British Columbia, may be relatively responsive to rapid oceanographic and environmental change associated with global climate change due to uniquely evolved plasticities and resiliencies as well as particular sensitivities and vulnerabilities, given this dynamic and highly textured natural setting.

 Pacific Data Hub

Increasing atmospheric CO2 concentrations are causing decreased pH over vast expanses of the ocean. This decreasing pH may alter biogeochemical cycling of carbon and nitrogen via the microbial process of nitrification, a key process that couples these cycles in the ocean, but which is often sensitive to acidic conditions. Recent reports have indicated a decrease in oceanic nitrification rates under experimentally lowered pH. How the composition and abundance of ammonia-oxidizing bacteria (AOB) and archaea (AOA) assemblages respond to decreasing oceanic pH is unknown.

 Pacific Data Hub

Increasing global concentrations of atmospheric CO2 are predicted to decrease ocean pH, with potentially severe impacts on marine food webs, but empirical data documenting ocean pH over time are limited. In a high-resolution dataset spanning 8 years, pH at a north-temperate coastal site declined with increasing atmospheric CO2 levels and varied substantially in response to biological processes and physical conditions that fluctuate over multiple time scales.