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1.
Sci Total Environ ; 901: 166430, 2023 Nov 25.
Article in English | MEDLINE | ID: mdl-37607626

ABSTRACT

Climate change is thought to influence the composition of atmospheric air, but little is known about the direct relationship between these variables, especially in a hot tropical climate like that of Malaysia. This work summarizes and analyzes the climate state and air quality of Peninsular Malaysia based on selected ground-based observations of the temperature, precipitation, relative humidity, wind speed, wind direction and concentrations of PM10, O3, CO, NO2, and SO2 over the last 20 years (2000-2019). The relationship between the climate state and air quality is analyzed using the Pearson correlation and canonical correlation analysis (CCA) methods is employed to predict the degree of change in the future air quality under different warming scenarios. It is found that the Peninsular Malaysia mainly experienced strong precipitation in the central and mountainous regions, while air pollutants are primarily concentrated in densely populated areas. Throughout the period of study (interannual, monthly, and diurnal time series analyses), Peninsular Malaysia became warmer and drier, with a significant increase in temperature (+4.2 %), decrease in the relative humidity (-4.5 %), and greater fluctuation in precipitation amount. The pollution conditions have worsened; there has been an increase in the PM10 (+16.4 %), O3 (+39.5 %), and NO2 (+2.1 %) concentration over the last 20 years. However, the amount of SO2 (-53.6 %) and CO (-20.6 %) decreased significantly. The analysis of the monthly variation shows a strong bimodality of the PM10 and O3 concentrations that corresponds to the monsoon transition. Intensive diurnal fluctuations and correlations are observed for all the variables in this study. According to the CCA, the air quality factors are strongly correlated with meteorological factors; in particular, the CO, O3, and PM10 concentrations interact strongly with the air temperature. These findings show that the future air quality in Peninsular Malaysia has high possibility to deteriorate under warming condition.

2.
PeerJ ; 10: e13929, 2022.
Article in English | MEDLINE | ID: mdl-36164604

ABSTRACT

Octocorals possess sclerites, small elements comprised of calcium carbonate (CaCO3) that are important diagnostic characters in octocoral taxonomy. Among octocorals, sea pens comprise a unique order (Pennatulacea) that live in a wide range of depths. Habitat depth is considered to be important in the diversification of octocoral species, but a lack of information on sea pens has limited studies on their adaptation and evolution across depth. Here, we aimed to reveal trends of adaptation and evolution of sclerite shapes in sea pens with regards to habitat depth via phylogenetic analyses and ancestral reconstruction analyses. Colony form of sea pens is suggested to have undergone convergent evolution and the loss of axis has occurred independently across the evolution of sea pens. Divergences of sea pen taxa and of sclerite forms are suggested to depend on habitat depths. In addition, their sclerite forms may be related to evolutionary history of the sclerite and the surrounding chemical environment as well as water temperature. Three-flanged sclerites may possess the tolerance towards the environment of the deep sea, while plate sclerites are suggested to be adapted towards shallower waters, and have evolved independently multiple times. The common ancestor form of sea pens was predicted to be deep-sea and similar to family Pseudumbellulidae in form, possessing sclerites intermediate in form to those of alcyonaceans and modern sea pens such as spindles, rods with spines, and three-flanged sclerites with serrated edges sclerites, as well as having an axis and bilateral traits.


Subject(s)
Anthozoa , Animals , Phylogeny , Ecosystem , Adaptation, Physiological , Acclimatization
3.
Mar Environ Res ; 170: 105445, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34392055

ABSTRACT

Offshore Onna Village, Okinawa Island, Japan, there is a large and densely covered coral assemblage of free-living mushroom corals (Scleractinia: Fungiidae) on a reef slope at depths from 20 m to 32 m, covering an area of approximately 350 × 40 m2. From previous research, it is known that migration distances of mushroom corals may depend on coral shapes, coral sizes, substrate, and bottom inclination. However, until now there have been no published examples of regular Fungiidae movement and behavior from typhoon-exposed coastlines, such as those in the western Pacific Ocean. Our surveys across three years offshore Onna Village show that mushroom corals always move in down-slope direction from shallow to deeper reef zones. The results indicated that mushroom corals migrated faster in autumn than in other seasons, and that oval-elongate fungiids, and particularly those with a smooth underside, migrated more quickly than species with other shapes. Surprisingly, we observed a negative relationship between the presence of typhoons and migration rates. We also observed active migration by fungiid individuals to escape situations in which they were threatened to become overgrown by Acropora corals, or when they needed to escape from burial underneath coral debris.


Subject(s)
Anthozoa , Cyclonic Storms , Animals , Coral Reefs , Ecosystem , Humans , Japan
4.
PeerJ ; 7: e6532, 2019.
Article in English | MEDLINE | ID: mdl-31011490

ABSTRACT

Marine biodiversity and derived ecosystem services are critical to the healthy functioning of marine ecosystems, and to human economic and societal well-being. Thus, an understanding of marine biodiversity in different ecosystems is necessary for their conservation and management. Coral reefs in particular are noted for their high levels of biodiversity, and among the world's coral reefs, the subtropical Ryukyu Islands (RYS; also known as the Nansei Islands) in Japan have been shown to harbor very high levels of marine biodiversity. This study provides an overview of the state of marine biodiversity research in the RYS. First, we examined the amount of English language scientific literature in the Web of Science (WoS; 1995-2017) on six selected representative taxa spanning protists to vertebrates across six geographic sub-regions in the RYS. Our results show clear taxonomic and sub-region bias, with research on Pisces, Cnidaria, and Crustacea to be much more common than on Dinoflagellata, Echinodermata, and Mollusca. Such research was more commonly conducted in sub-regions with larger human populations (Okinawa, Yaeyama). Additional analyses with the Ocean Biogeographic Information System (OBIS) records show that within sub-regions, records are concentrated in areas directly around marine research stations and institutes (if present), further showing geographical bias within sub-regions. While not surprising, the results indicate a need to address 'understudied' taxa in 'understudied sub-regions' (Tokara, Miyako, Yakutane, Amami Oshima), particularly sub-regions away from marine research stations. Second, we compared the numbers of English language scientific papers on eight ecological topics for the RYS with numbers from selected major coral reef regions of the world; the Caribbean (CAR), Great Barrier Reef (GBR), and the Red Sea (RES). As expected, the numbers for all topics in the RYS were well below numbers from all other regions, yet within this disparity, research in the RYS on 'marine protected areas' and 'herbivory' was an order of magnitude lower than numbers in other regions. Additionally, while manuscript numbers on the RYS have increased from 1995 to 2016, the rate of increase (4.0 times) was seen to be lower than those in the CAR, RES, and GBR (4.6-8.4 times). Coral reefs in the RYS feature high levels of both endemism and anthropogenic threats, and subsequently they contain a concentration of some of the world's most critically endangered marine species. To protect these threatened species and coral reef ecosystems, more data are needed to fill the research gaps identified in this study.

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