台湾海峡离岛工业区海域浮游生物丰度之长期变化

本研究利用1993-2010年在云林县台西乡沿岸的8个站位所进行的一年四季近岸10 m及离岸20 m水深的浮游生物调查资料及同步的水质资料, 分析了发电厂建成后对浮游生物的影响。本海域18年内浮游生物各类群丰度/密度的各季节平均值, 皆以第四季(10-12月)为最低, 而各个类群的最高平均值出现的季别并不一致。其中浮游动物出现于第一和第二季(1-6月), 浮游植物和虾、蟹幼体在第二季(4-6月), 而鱼卵和仔鱼则是在第一至第三季(1-9月)。自2000年第三季起, 测线5的测站经常有pH值低于7.8的情形。当该海域水体测得pH值低于7.8时, 浮游动物(75±69 ind./m³)﹑浮游植物((1.60±2.28)×10³ cell/L)﹑虾幼体(2.4±5.8 ind./m³)﹑蟹幼体(1.9±5.0 ind./m³)及鱼卵(0.88±1.10 ind./m³)和仔鱼(0.16±0.32 ind./m³)的丰度/密度值皆偏低, 仅为历年总平均值的1/2。据此建议将发电厂排入海洋之水体pH值控制在7.8以上, 以降低对浮游生物多样性及丰度的冲击。     

Future warming and acidification effects on anti‐fouling and anti‐herbivory traits of the brown alga Fucus vesiculosus (Phaeophyceae)

Human‐induced ocean warming and acidification have received increasing attention over the past decade and are considered to have substantial consequences for a broad range of marine species and their interactions. Understanding how these interactions shift in response to climate change is particularly important with regard to foundation species, such as the brown alga Fucus vesiculosus. This macroalga represents the dominant habitat former on coastal rocky substrata of the Baltic Sea, fulfilling functions essential for the entire benthic community. Its ability to withstand extensive fouling and herbivory regulates the associated community and ecosystem dynamics. This study tested the interactive effects of future warming, acidification, and seasonality on the interactions of a marine macroalga with potential foulers and consumers. F. vesiculosus rockweeds were exposed to different combinations of conditions predicted regionally for the year 2100 (+?5°C, +?700 μatm CO₂) using multifactorial long‐term experiments in novel outdoor benthic mesocosms (“Benthocosms”) over 9–12‐week periods in four seasons. Possible shifts in the macroalgal susceptibility to fouling and consumption were tested using consecutive bioassays. Algal susceptibility to fouling and grazing varied substantially among seasons and between treatments. In all seasons, warming predominantly affected anti‐fouling and anti‐herbivory interactions while acidification had a subtle nonsignificant influence. Interestingly, anti‐microfouling activity was highest during winter under warming, while anti‐macrofouling and anti‐herbivory activities were highest in the summer under warming. These contrasting findings indicate that seasonal changes in anti‐fouling and anti‐herbivory traits may interact with ocean warming in altering F. vesiculosus community composition in the future.     

The most primitive metazoan animals,the placozoans,show high sensitivity to increasing ocean temperatures and acidities

The increase in atmospheric carbon dioxide (CO₂) leads to rising temperatures and acidification in the oceans, which directly or indirectly affects all marine organisms, from bacteria to animals. We here ask whether the simplest—and possibly also the oldest—metazoan animals, the placozoans, are particularly sensitive to ocean warming and acidification. Placozoans are found in all warm and temperate oceans and are soft‐bodied, microscopic invertebrates lacking any calcified structures, organs, or symmetry. We here show that placozoans respond highly sensitive to temperature and acidity stress. The data reveal differential responses in different placozoan lineages and encourage efforts to develop placozoans as a potential biomarker system.     

Questa (Annelida, Polychaeta, Orbiniidae) from Pacific regions — new species and reassessment of the genus Periquesta

On the basis of new material from various Pacific regions we critically evaluate the characters for the taxonomy of the genus Questa and the former Questidae, a taxon now concluded to be a lineage within the family Orbiniidae. Two new species, Questa retrospermatica sp. n. from Hawaii (with similar forms also from New Caledonia and China), and Questa fijiensis sp. n. from Fiji, are described, and the morphological character patterns and phylogeny of the genus are revisited on the basis of a cladistic analysis. The finding of Hawaiian material of a new species, Levinsenia hawaiiensis sp. n., similar to Periquesta canariensis Brito & Nunez, 2002 (=Levinsenia canariensis comb. n.), challenges the view that Periquesta Brito & Nunez, 2002 is closely related to Questa; rather, it belongs to Paraonidae as a junior synonym of Levinsenia Mesnil, 1897.     

Diversity of deep-water cetaceans in relation to temperature: implications for ocean warming

Understanding the effects of natural environmental variation on biodiversity can help predict response to future anthropogenic change. Here we analyse a large, long-term data set of sightings of deep-water cetaceans from the Atlantic, Pacific and Indian Oceans. Seasonal and geographic changes in the diversity of these genera are well predicted by a convex function of sea-surface temperature peaking at c. 21 degrees C. Thus, diversity is highest at intermediate latitudes - an emerging general pattern for the pelagic ocean. When applied to a range of Intergovernmental Panel on Climate Change global change scenarios, the predicted response is a decline of cetacean diversity across the tropics and increases at higher latitudes. This suggests that deep-water oceanic communities that dominate > 60% of the planet's surface may reorganize in response to ocean warming, with low-latitude losses of diversity and resilience.     

Comparative oogenesis in cardinal fishes (Apogonidae,Perciformes), with special focus on the adaptive structures of the egg envelopes

The present study compares gonad structure and oogenesis in 30 species of cardinal fish (Apogonidae) from the Indo-Pacific region. In all of the species studied the ovaries are bilobed, with each lobe possessing ovigerous lamellae whose numbers and dimensions increase concomitantly with growth of the fish and reproductive stage, and correlate with the total dimensions of the particular species. In species of the genus Siphamia, the ovarian lobes are associated with a fat body that is not found in species of the other genera studied. Some of the species studied (Siphamia spp.; Archamia spp.) demonstrate group-synchronized maturation of eggs, possibly with only one spawn per reproduction season. However, most of the Apogon spp., and other genera, have unsynchronized cycles, a characteristic of multiple spawners. The various stages of previtellogenic and vitellogenic development are similar in the different species, but differ in timing and dimensions of the oocytes around which the morphogenesis of the egg envelope (chorion) and follicle begins. Differentiation of the egg envelope and follicle cells parallels the vitellogenic stages of egg development. The number of eggs was found to correlate positively with the length of the body and ovary of the fish, whereas egg diameter was found to correlate negatively with body length. The surface of the egg envelope bears ridges that form patterns of various types, whose structures and dimensions seem to be species-specific, and which in most species converge upon the single micropyle on the animal pole. The exposed ridge mazes include a special fibrous web that anchors in the micropyle. The production and importance of these ridges, as well as the correlations between egg numbers per spawn, egg dimensions, and the oral dimensions of the paternal male, are discussed.     

Impact of intentionally injected carbon dioxide hydrate on deep-sea benthic foraminiferal survival

Sequestration of carbon dioxide (CO₂) in the ocean is being considered as a feasible mechanism to mitigate the alarming rate in its atmospheric rise. Little is known, however, about how the resulting hypercapnia and ocean acidification may affect marine fauna. In an effort to understand better the protistan reaction to such an environmental perturbation, the survivorship of benthic foraminifera, which is a prevalent group of protists, was studied in response to deep-sea CO₂ release. The survival response of calcareous, agglutinated, and thecate foraminifera was determined in two experiments at ∼3.1 and 3.3 km water depth in Monterey Bay (California, USA). Approximately 5 weeks after initial seafloor CO₂ release, in situ incubations of the live–dead indicator CellTracker Green were executed within seafloor-emplaced pushcores. Experimental treatments included direct exposure to CO₂ hydrate, two levels of lesser exposure adjacent to CO₂ hydrate, and controls, which were far removed from the CO₂ hydrate release. Results indicate that survivorship rates of agglutinated and thecate foraminifera were not significantly impacted by direct exposure but the survivorship of calcareous foraminifera was significantly lower in direct exposure treatments compared with controls. Observations suggest that, if large scale CO₂ sequestration is enacted on the deep-sea floor, survival of two major groups of this prevalent protistan taxon will likely not be severely impacted, while calcareous foraminifera will face considerable challenges to maintain their benthic populations in areas directly exposed to CO₂ hydrate.     

The effect of ocean acidification and temperature on the fertilization and embryonic development of the Sydney rock oyster Saccostrea glomerata (Gould 1850)

This study investigated the synergistic effects of ocean acidification (caused by elevations in the partial pressure of carbon dioxide pCO₂) and temperature on the fertilization and embryonic development of the economically and ecologically important Sydney rock oyster, Saccostrea glomerata (Gould 1850). As pCO₂ increased, fertilization significantly decreased. The temperature of 26 °C was the optimum temperature for fertilization, as temperature increased and decreased from this optimum, fertilization decreased. There was also an effect of pCO₂ and temperature on embryonic development. Generally as pCO₂ increased, the percentage and size of D‐veligers decreased and the percentage of D‐veligers that were abnormal increased. The optimum temperature was 26 °C and embryonic development decreased at temperatures that were above and below this temperature. Abnormality of D‐veligers was greatest at 1000 ppm and 18 and 30 °C (≥90%) and least at 375 ppm and 26 °C (≤4%). Finally prolonged exposure of elevated pCO₂ and temperature across early developmental stages led to fewer D‐veligers, more abnormality and smaller sizes in elevated CO₂ environments and may lead to lethal effects at suboptimal temperatures. Embryos that were exposed to the pCO₂ and temperature treatments for fertilization and embryonic development had fewer D‐veligers, greater percentage of abnormality and reduced size than embryos that were exposed to the treatments for embryonic development only. Further at the elevated temperature of 30 °C and 750–1000 ppm, there was no embryonic development. The results of this study suggest that predicted changes in ocean acidification and temperature over the next century may have severe implications for the distribution and abundance of S. glomerata as well as possible implications for the reproduction and development of other marine invertebrates.     

Clues to the location of the spawning area and larval migration characteristics of Anguilla mossambica as inferred from otolith microstructural analyses

The spawning area location and the larval migration characteristics of Anguilla mossambica were studied through the examination of early life-history traits (ELHT) inferred from otolith microstructural analyses of 122 glass A. mossambica collected along the eastern coast of Madagascar, in the south-western Indian Ocean. Backcalculated hatching dates of leptocephali that recruited between November 2005 and February 2006 suggested that spawning was continuous from June to November 2005, although individual migration duration periods were variable. Larvae that exhibited the highest daily otolith growth rates had the shortest leptocephalus durations and total length ( L _T) at recruitment, possibly because they reached the competence to metamorphose more rapidly and to recruit to fresh waters. Migration durations and L _T increased from north to south on the Malagasy eastern coast, supporting earlier suggestions that A. mossambica spawns north-east of Madagascar, west of the Mascarene Ridge in the Indian Ocean.