scholarly journals Distribution and Flora of Seaweed Beds in the Coastal Waters of China

2021 ◽  
Vol 13 (6) ◽  
pp. 3009
Author(s):  
Xunmeng Li ◽  
Kai Wang ◽  
Shouyu Zhang ◽  
Meiping Feng
Keyword(s):  
Water Temperature ◽  
Environmental Sustainability ◽  
Coastal Waters ◽  
Dominant Species ◽  
Coastal Ecosystem ◽  
Warm Water ◽  
Water Types ◽  
Development And Utilization ◽  
The Mean ◽  
Seaweed Bed

Seaweed plays an important role in energy production in marine, coastal, and island ecosystems. The protection of seaweed beds is a key point for coastal ecosystem health, but the community characteristics, dominant species, and distribution of seaweed beds in the coastal waters of China are still unknown. Dividing seaweed beds based on their ecological function is also required for coastal ecosystem conservation, marine development, and utilization. We conducted ecological surveys on various types of ecosystems at approximately 50 sites dedicated to the conservation of seaweed bed biodiversity in China from 2018 to 2019. These seaweed beds were classified into different flora by water temperature and the attributes of the dominant species. The study showed that Sargassum dominated the coast of China. The coverage of the genus Undaria and the genus Laminaria in the coastal waters of Liaoning and Shandong was high and gradually decreased from Zhejiang to the south. The mean biomass of the seaweed beds along the coast of China was 7.29 kg/m2, and the mean coverage was 41.25%. The height and fresh weight of the dominant species gradually decreased with the decreasing latitude. The seaweed beds were distributed from the shallow water zone to the profundal zone along the coast from north to south, and the bathymetry of seaweed beds in Hainan was below 6 m. Based on the water temperature, the attributes of the seaweed beds, the temperature attributes of the dominant species, and the seaweed’s distribution, the seaweed beds in China can be specifically divided into temperate warm water types, subtropical warm water types, and tropical warm water types. This study is relevant to the development of regulations and directives to ensure biodiversity conservation and environmental sustainability.

Incubation Temperature Influences the Duration of Egg Hatching and Early Development in the Boreal Digging Frog, Kaloula Borealis

2020 ◽  
Vol 3 (1) ◽  
pp. ACCEPTED
Author(s):  
Rho-Jeong Rae
Keyword(s):  
Water Temperature ◽  
Early Life ◽  
Rainy Season ◽  
Incubation Temperature ◽  
Life Stages ◽  
Early Life Stages ◽  
Egg Hatching ◽  
Significant Difference ◽  
The Mean ◽  
Hatching Rates

This study investigated the boreal digging frog, Kaloula borealis, to determine the egg hatching period and whether the hatching period is affected by incubation temperature. The results of this study showed that all the eggs hatched within 48 h after spawning, with 28.1% (±10.8, n=52) hatching within 24 h and 99.9% (±0.23, n=49) within 48 h after spawning. A significant difference was noted in the mean hatching proportion of tadpoles at different water temperatures. The mean hatching rates between 15 and 24 h after spawning was higher at a water temperature of 21.1 (±0.2) °C than at 24.1 (±0.2) °C. These results suggest that incubation temperature affected the early life stages of the boreal digging frog, since they spawn in ponds or puddles that form during the rainy season.

scholarly journals The features of the coastal fronts in the Eastern Guangdong coastal waters during the downwelling-favorable wind period

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chaoyu Yang ◽  
Haibin Ye
Keyword(s):  
Coastal Waters ◽  
Meteorological Data ◽  
Pearson Correlation ◽  
Ocean Model ◽  
Ekman Pumping ◽  
Zonal Distribution ◽  
Factors Affecting ◽  
China Sea ◽  
Hybrid Coordinate Ocean Model ◽  
The Mean

AbstractA coastal front was detected in the eastern Guangdong (EGD) coastal waters during a downwelling-favorable wind period by using the diffuse attenuation coefficient at 490 nm (Kd(490)). Long-term satellite data, meteorological data and hydrographic data collected from 2003 to 2017 were jointly utilized to analyze the environmental factors affecting coastal fronts. The intensities of the coastal fronts were found to be associated with the downwelling intensity. The monthly mean Kd(490) anomalies in shallow coastal waters less than 25 m deep along the EGD coast and the monthly mean Ekman pumping velocities retrieved by the ERA5 dataset were negatively correlated, with a Pearson correlation of − 0.71. The fronts started in October, became weaker and gradually disappeared after January, extending southwestward from the southeastern coast of Guangdong Province to the Wanshan Archipelago in the South China Sea (SCS). The cross-frontal differences in the mean Kd(490) values could reach 3.7 m−1. Noticeable peaks were found in the meridional distribution of the mean Kd(490) values at 22.5°N and 22.2°N and in the zonal distribution of the mean Kd(490) values at 114.7°E and 114.4°E. The peaks tended to narrow as the latitude increased. The average coastal surface currents obtained from the global Hybrid Coordinate Ocean Model (HYCOM) showed that waters with high nutrient and sediment contents in the Fujian and Zhejiang coastal areas in the southern part of the East China Sea could flow into the SCS. The directions and lengths of the fronts were found to be associated with the flow advection.

scholarly journals Faecal bacteria in Perna perna (Linnaeus, 1758) (Mollusca: Bivalvia) for biomonitoring coastal waters and seafood quality

2010 ◽  
Vol 58 (spe3) ◽  
pp. 29-35 ◽  
Author(s):  
Diego Igawa Martinez ◽  
Ana Júlia Fernandes Cardoso de Oliveira
Keyword(s):  
Coastal Waters ◽  
Microbiological Quality ◽  
Perna Perna ◽  
Clearance Rates ◽  
Bacterial Concentration ◽  
Allometric Relations ◽  
The Mean ◽  
Negative Impacts ◽  
Faecal Bacteria

Urban development in coastal areas is intense and leads to the increase of sewage outfall and other negative impacts as consequences. Thus, stringent regulations establishing limits to the microbiological contamination of water and seafood are needed. The objective of this study is to evaluate the usefulness of Enterococci and Thermotolerant Coliform densities in the flesh of mussels Perna perna as an alternative tool for monitoring the microbiological quality of coastal waters. The study also considers allometric relations applied to clearance rates to understand rates of bacterial concentration. Bacterial loads obtained in mussels' flesh were from 50 to 4,300 times greater than in the water sampled in the vicinity of the mussels and some were considered inappropriate for consumption even when the water presented no restrictions. The mean clearance rate obtained for Enterococci retention was 317.7 ml h-1 and this rate (CR) is related to the mussels' size (L) by the equation CR = 28.3229L1.6421. The results showed that bacterial densities in the mussels' tissues may reflect chronic contamination of the environment and that clearance rates are important for taking the best decision in situations where, for example, it is desired to introduce mussels for aquaculture and the evaluation of the water concerned is required.

Light, Nutrients, and Water Temperature as Determinants of Phytoplankton Production in Two Saline, Prairie Lakes with High Sulphate Concentrations

1992 ◽  
Vol 49 (11) ◽  
pp. 2281-2290 ◽  
Author(s):  
Richard D. Robarts ◽  
Marlene S. Evans ◽  
Michael T. Arts
Keyword(s):  
Water Temperature ◽  
Photosynthetic Capacity ◽  
Chlorophyll Concentration ◽  
Euphotic Zone ◽  
Dominant Factor ◽  
Phytoplankton Production ◽  
Dissolved Phosphorus ◽  
Prairie Lakes ◽  
The Mean ◽  
Algal Productivity

Our data support empirical models indicating that algal productivity is low relative to total phosphorus (TP) levels in prairie lakes with high sulphate concentrations. Mean chlorophyll accounted for 91.1% of the variance in euphotic zone primary production (ΣA) in Humboldt Lake (total dissolved solids (TDS) = 3.3 g∙L−1; Zmax = 6 m), while TP, total dissolved phosphorus, and water temperature accounted for 82.7% of ΣA variance in Redberry Lake (TDS = 20.9 g∙L−1; Zmax = 17 m). The relative importance of these variables to ΣA resulted from biological, chemical, and physical differences of these lakes. Light usually penetrated to the bottom of Redberry Lake due to a mean euphotic zone (Zeu) chlorophyll of 1.7 mg∙m−3, while Humboldt Lake's mean Zeu was 3.4 m with a mean chlorophyll concentration of 62.6 mg∙m−3. Chlorophyll was the dominant factor correlated with light penetration in Humboldt Lake (r2 = 0.65) but not in Redberry Lake. Photosynthetic capacity was correlated (r2 = 0.72) with water temperature only in Redberry Lake. The mean ΣA was 57.1 and 230.2 mg C∙m−2∙h−1 for Redberry and Humboldt lakes, respectively.

scholarly journals Reproductive Biology of Round Sardinella (Sardinella Aurita) (Valenciennes, 1847) in Senegalese Coastal Waters

2018 ◽  
Vol 9 (1) ◽  
pp. 31
Author(s):  
Ismaïla NDIAYE ◽  
Alassane SARR ◽  
Alioune FAYE ◽  
Modou THIAW ◽  
Malick DIOUF ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Coastal Waters ◽  
Sexual Maturity ◽  
Reproductive Parameters ◽  
Monthly Variation ◽  
Relative Fecundity ◽  
The Mean ◽  
Sardinella Aurita ◽  
Somatic Index

In this study, a total of 1068 specimens Sardinella aurita of which 553 females and 515 males were examined. The objectif of this study was to determine the reproductive parameters of Sardinella aurita. The sex ratio was significantly in favor of females (55%). The size at first sexual maturity was estimated at 18.9 cm for females and 18.0 cm for males. The monthly variation of sexual maturity stages and gonado-somatic index (GSI) allowed to locate the reproduction periods from February to June and from September to December. The mean absolute fecundity was estimated at 110.794 ± 7582 oocytes whereas relative fecundity was about 422 ± 26 oocytes per gram of female.

Studies of sound transmission fluctuations in shallow coastal waters

1969 ◽  
Vol 265 (1169) ◽  
pp. 567-606 ◽  
Keyword(s):  
Interference Pattern ◽  
Coastal Waters ◽  
Water Structure ◽  
Acoustic Measurements ◽  
Phase Fluctuations ◽  
Wave Effects ◽  
Tidal Changes ◽  
Streaming Velocity ◽  
The Mean ◽  
Shallow Coastal Waters

The propagation and fluctuation of sound have been studied in shallow coastal waters off the British Isles. The environment and the special environmental measurements are described. Acoustic measurements were made for various ranges between about 2 and 137 km, with bottom-laid transducers. Frequencies used were mainly 1, 2 and 3 kHz, most often transmitted continuously but sometimes pulsed. The investigations have extended over several years, and amplitude and phase fluctuations have been found with periods ranging from a year to less than a second. The nine fluctuation mechanisms which have been identified may be summarized as: ( a ) seasonal in amplitude, (seasonal in phase, ( c ) attenuation due to fish which sometimes causes a greatly reduced amplitude at night when the shoals break up, ( d ) storm effects, (e) tidal changes in depth which sweep an interference pattern past the receiver, ( f ) tidal changes in the shear flow or the water structure which also affect the interference pattern, ( g ) phase effects due to tidal changes in the mean streaming velocity, ( h ) fluctuations of a minutes period, some due to fish, ( i ) surface wave effects, which depend critically on the position in the tidal interference cycle. The above nine effects are really all subjects in their own right, and here large advances are described for seven of them. Most of the effects are both new and important, to be measured in many tens of decibels and in hundreds of phase cycles, but perhaps special attention should be drawn to the significance of the work on fish.

scholarly journals Study of the thermal regime of a reservoir on the Qinghai-Tibetan Plateau, China

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243198
Author(s):  
Yanjing Yang ◽  
Yun Deng ◽  
Youcai Tuo ◽  
Jia Li ◽  
Tianfu He ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Diurnal Variation ◽  
Water Temperature ◽  
Water Column ◽  
Temperature Structure ◽  
Observation Data ◽  
The Mean ◽  
Low Altitude ◽  
Mean Variance ◽  
Whole Water

The Qinghai-Tibetan Plateau region has unique meteorological characteristics, with low air temperature, low air pressure, low humidity, little precipitation, and strong diurnal variation. A two-dimensional hydrodynamic CE-QUAL-W2 model was configured for the Pangduo Reservoir to better understand the thermal structure and diurnal variation inside the reservoir under the local climate and hydrological conditions on the Qinghai-Tibetan Plateau. Observation data were used to verify the model, and the results showed that the average error of the 6 profile measured monthly from August to December 2016 was 0.1°C, and the root-mean-square error (RMSE) was 0.173°C. The water temperature from August 2016 to September 2017 was simulated by inputting measured data as model inputs. The results revealed that the reservoir of the Qinghai-Tibetan Plateau was a typical dimictic reservoir and the water mixed vertically at the end of March and the end of October. During the heating period, thermal stratification occurred, with strong diurnal variation in the epilimnion. The mean variance of the diurnal water temperature was 0.10 within a 5 m water depth but 0.04 in the whole water column. The mixing mode of inflow changed from undercurrent, horizontal-invaded flow and surface layer flow in one day. In winter, the diurnal variation was weak due to the thermal protection of the ice cover, while the mean variance of diurnal water temperature was 0.00 within both 5 m and the whole water column. Compared to reservoirs in areas with low altitude but the same latitude, significant differences occurred between the temperature structure of the low-altitude reservoir and the Pangduo Reservoir (P<0.01). The Pangduo Reservoir presented a shorter stratification period and weaker stratification stability, and the annual average SI value was 26.4 kg/m2, which was only 7.5% that of the low-altitude reservoir. The seasonal changes in the net heat flux received by the surface layers determined the seasonal cycle of stratification and mixing in reservoirs. This study provided a scientific understanding of the thermal changes in stratified reservoirs under the special geographical and meteorological conditions on the Qinghai-Tibetan Plateau. Moreover, this model can serve as a reference for adaptive management of similar dimictic reservoirs in cold and high-altitude areas.

scholarly journals Morphology and ecology of Thalassiosira Cleve (Bacillariophyta) species rarely recorded in Brazilian coastal waters

2009 ◽  
Vol 69 (4) ◽  
pp. 1059-1071 ◽  
Author(s):  
M. Garcia ◽  
C. Odebrecht
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Water Temperature ◽  
Wide Temperature Range ◽  
Coastal Waters ◽  
Light Microscope ◽  
Temperature Range ◽  
The World ◽  
First Time ◽  
Scanning Electron

The detailed description of rarely recorded Thalassiosira species in Brazil is presented with light microscope (LM) and scanning electron microscope (SEM) illustrations. A total of 78 phytoplankton net samples (20 µm) collected between the years 2000 and 2006 in coastal waters of southern Brazilian, Cassino Beach and the estuary of Lagoa dos Patos, were studied in cleaned material using the Axiovert Zeiss LM and Jeol 6060 SEM. Water temperature and salinity of samples and six species are presented: Thalassiosira endoseriata, T. hendeyi, T. lundiana, T. minuscula, T. oceanica and T. wongii. Two species, Thalassiosira hendeyi and T. endoseriata were the most common being observed in all seasons at Cassino Beach in a wide temperature range (10-26 ºC), while only sporadically in the estuary of Lagoa dos Patos. Thalassiosira endoseriata, T. lundiana, T. oceanica and T. wongii are for the first time reported in Brazilian coastal waters. The latter two species, rarely recorded in the world, are fully illustrated based on Brazilian material.

Shark Nursery Grounds of the Gulf of Mexico and the East Coast Waters of the United States

2007 ◽  
Keyword(s):  
Water Temperature ◽  
Coastal Waters ◽  
Fork Length ◽  
The United States ◽  
Nursery Habitat ◽  
Tiger Shark ◽  
Carcharhinus Plumbeus ◽  
Species Area ◽  
Catch Rates ◽  
Mustelus Canis

<em>Abstract.</em>—To identify and characterize shark nursery habitat in the coastal waters of Massachusetts, longline and shark angler surveys were conducted from 1989 to 2002 in the neritic waters of Nantucket Sound, Massachusetts. Additional samples and information were opportunistically collected from recreational and commercial fishermen, as well as published sources. A total of 123 longline sets of 5,591 hooks caught 372 sharks consisting of 344 (92.5%) smooth dogfish <em>Mustelus canis</em>, 23 (6.2%) sandbar sharks <em>Carcharhinus plumbeus</em>, and 5 (1.3%) dusky sharks <em>C. obscurus</em>. The sharks were taken during the period of 16 June–24 September in water temperature and depth ranges of 16.0–27.2°C and 1.2–27.1 m, respectively. Longline catch rates (number of sharks per longline set) were stratified by species, area, month, year, water temperature, and depth. Angler surveys reported the capture of 294 sharks, including sandbar sharks (72%) and smooth dogfish (28%). Data from 540 neonatal and adult smooth dogfish ranging 27.5–121.0 cm fork length (FL) support the conclusion that the neritic waters of southern Massachusetts serve as primary nursery habitat for this species. Size and sex data from 235 juvenile sandbar sharks ranging 61.0–157.0 cm FL indicate that this region provides secondary nursery habitat for this species. Opportunistic samples of juvenile sand tiger <em>Carcharias taurus</em>, white shark <em>Carcharodon carcharias</em>, basking shark <em>Cetorhinus maximus</em>, and tiger shark <em>Galeocerdo cuvier </em>provide evidence that these species utilize Massachusetts coastal waters for secondary nursery habitat.

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