Green Tide Algae Research Articles

<i>Ulva prolifera</i> Monitoring Study in the Yellow Sea from Multi-Temporal Remote Sensing Images

Multi-temporal Moderate resolution Imaging Spectroradiometer (MODIS) remote sensing images were used to monitor the massive blooms of floating green tide algae Ulva prolifera in the midwest of Yellow Sea (YS). In addition, from the marine environment elements of sea surface temperature (SST) and sea surface wind field, the growth and drift characteristic of U. Prolifera were studied based on MODIS thermal infrared channel SST data and Windsat wind field data. In May 2014, U. Prolifera accumulation areas were first found in central YS north of Subei Bank. With summer arrival, seawater temperature of ocean surface gradually increased in YS, It provided a more suitable environment for the growth of U. Prolifera. Due to the prevailing northerly winds in central and western YS, U. Prolifera advected to the coastal waters of Shandong Peninsula, and spread to the northeastward. In late June, it had a massive bloom and reached the maximum coverage in the northern YS. The U. Prolifera drift characteristic was confirmed by the analysis on SST and sea surface wind field, and the result shows that under the environment of suitable sea surface temperature, the driving force of the prevailing sea surface wind field might be the main reason of YS U. Prolifera bloom occurrence.

Fatty acid and elemental composition of littoral “green tide” algae from the Gulf of Finland, the Baltic Sea

Coastal eutrophication leads to a shift in primary producer communities from perennial species to ephemeral fast-growingspeciesofmacroalgae,whichisknownas"green tides" phenomenon. In brackish water habitats of the Baltic Sea,theopportunisticgreenalgae,Cladophoraglomerataand Ulva intestinalis, replaced the brown alga Fucus vesiculosus, while in freshwater estuarine parts they replaced epilithic microalgae. We studied Baltic populations of the macroalgae, C. glomerata and U. intestinalis, and epilithic and epiphytic microalgae, with respect to their nutritive quality, such as content of essential polyunsaturated fatty acids (PUFAs) and elemental composition. Fatty acid profiles of the two macroalgae were significantly different, including levels of essential PUFAs. We found a relatively high content of eicosapentaenoic acid (EPA; 20:5n�3) in C. glomerata bio- mass (4.14 mg g �1 C), whereas U. intestinalis had a lower value (0.45 mg g �1 C). Comparison with literature data showed that C. glomerata appeared to be a more valuable food for potential invertebrate consumers in respect to EPA content and stoichiometric C/P ratio than perennial F. vesiculosus and U. intestinalis. Thus, replacement of F.vesiculosusand epilithicmicroalgaebyC. glomeratawould not decrease the potential nutritive value of coastal algal communities for invertebrates. In turn, if U. intestinalis dom- inate in algal community, the nutritive value of primary pro- ducers in coastal zone would decrease. However, in following works, other important indicators of nutritive value, such as sterols and amino acids, should be included in the estimations of green tide algae species.

Growth characteristics and reproductive capability of green tide algae in Rudong coast, China

Since 2007, green tides have occurred along the coast of the Yellow Sea, China. The green tide extended to 50,000 km2 (floating area) within 2–3 months and the calculated covering area was about 400 km2 in 2010. These facts implied that the growth and reproduction of the dominant species Ulva prolifera were stimulated. We observed that 1 cm2 blades (single layer) released 2.84–6.62 × 106 spores or 1.14–2.65 × 107 gametes and that 91.6–96.4 % of them germinated into younger seedlings. This means that, in theory, 1 g (fresh weight) of blades was able to produce about 2.8 × 108–2.7 × 109 new younger seedlings. From 2009 to 2011, the growth rate of green tide algae was measured in situ in enclosure experiments in Rudong coast, Jiangsu Province and the growth curve of the algae was divided into four phases: lag phase, accelerated phase, stationary phase, and decline phase. Usually, the average daily specific relative growth rate was about 23.2–23.6 % d−1 for a whole growth period, and it reached up to 56.2 % d−1 in the accelerated phase. Correspondingly, the morphology of green tide algae in enclosures also showed periodic variation as follows: blades presented new filamentous branches from old thallus in the lag phase, longer filamentous branches in the accelerated phase, tubular and cystic blades in the stationary phase, and folded blades in the decline stage. Those studies may be useful for understanding the green tide blooming mechanism.

Nutrition analysis and food safety evaluation of green tide algae in 2010

Successive green tides that happened in South Yellow Sea in recent years have caused widespread concern.In order to provide the basis for making integrated use of green tide algae,and according to national standards,this study analyzed basic nutrients,chlorophyll,amino acids,mineral elements and heavy metals of green algae collected from Jiangsu and Shandong in 2010.The results indicated that:carbohydrates were the main nutritional components of these green tide algae,accounting for 35.82%-52.43%;the crude protein contents varied greatly,from 31.04% to 12.11%;the fat contents were low and all less than 1%;there was a significant difference in the contents of chlorophyll,the contents decreased significantly when the collection dates delayed;the amino acid contents were high and the percent age of essential amino acids was up to 37.45%,the flavor amino acids aspartic acid,glutamic acid,glycine and alanine were considerably high;these algae contained abundant mineral elements,the contents of Ca,Fe,Zn were distinctly high,but the heavy metals Pb,Hg and Cd were all lower than the limited requirements in national standards.The composition of attached samples did not change significantly.

Future CO2-Induced Ocean Acidification Mediates the Physiological Performance of a Green Tide Alga

The oceans take up more than 1 million tons of CO2 from the air per hour, about one-quarter of the anthropogenically released amount, leading to disrupted seawater chemistry due to increasing CO2 emissions. Based on the fossil fuel-intensive CO2 emission scenario (A1F1; [Houghton et al., 2001][1]),

Seasonal growth dynamics and resilience of the green tide alga Cladophora coelothrix in high-nutrient tropical aquaculture

Two distinct climatic seasons in the tropics generate extreme environmental fluctua- tions in land-based aquaculture and corresponding challenges for integrated aquaculture. Here we assessed the influence of environmental and culture variables on productivity of Cladophora coelothrix at multiple scales, firstly in an operational settlement pond and subsequently in labora- tory and flow-through mesocosm experiments. Classification and regression tree (CART) analyses were used to partition the influence of key variables on growth. In situ productivity correlated pri- marily with nitrogen concentration, position in the pond and stocking density, with a lesser influ- ence of salinity, temperature and the ratio of nitrate-nitrogen (NO3 � -N) and total ammonium nitro- gen (TAN). We subsequently evaluated the resilience of C. coelothrix in laboratory and mesocosm environments by manipulating salinity, temperature and nutrients across a broader range of val- ues derived from a year-long survey of the settlement pond. Here temperature had the greatest influence on growth, followed by nitrogen concentration and salinity. Growth rates of C. coelothrix were high, irrespective of season, except at the extremes of each season, for example, at the lowest annual temperature and with the combination of high temperature and low salinity. Growth was also limited by ~20% when NO3 � -N and TAN were available simultaneously. The use of CART analyses for both in situ and controlled environment data provided a formal dissection of the relative contribution of each environmental variable to growth, demonstrating the year-round potential for bioremediation and identifying the critical combinations of environmental variables for management of this system.

Algal biochar – production and properties

This study presents baseline data on the physiochemical properties and potential uses of macroalgal (seaweed) biochar produced by pyrolysis of eight species of green tide algae sourced from fresh, brackish and marine environments. All of the biochars produced are comparatively low in carbon content, surface area and cation exchange capacity, but high in pH, ash, nitrogen and extractable inorganic nutrients including P, K, Ca and Mg. The biochars are more similar in characteristics to those produced from poultry litter relative to those derived from ligno-cellulosic feedstocks. This means that, like poultry litter biochar, macroalgal biochar has properties that provide direct nutrient benefits to soils and thereby to crop productivity, and will be particularly useful for application on acidic soils. However, macroalgal biochars are volumetrically less able to provide the carbon sequestration benefits of the high carbon ligno-cellulosic biochars.

A Review on the Ecological Dynamics Studies of Green Tide in China

In this paper,the recent progress on the ecological behaviors of green tide,including its life history and the factors,such as temperature,salinity,light and nutrients,which determine the growth and the survival of green tide algae,was reviewed.The intention is to outline a vision as to where these studies are going,describe the recent advances,identify gaps and weaknesses in the field,and discuss how they might be applied to develop a system of coupled physical-biological models.The coupled model would contribute to a more extensive,longer term,research effort involving monitoring and intensive field data collection,experimental study and conceptual development,and be a tool for the management of marine environment.

The green tide threat in the UK — a brief overview with particular reference to Langstone Harbour, south coast of England and the Ythan Estuary, east coast of Scotland

Summary World-wide, our coastal waters have been subject to an increased nutrient input since the latter part of the nineteenth century. This has led to the eutrophication or ‘nutrient pollution’ of many coastal sites, including Langstone Harbour and the Ythan Estuary here in the UK. Eutrophication at these and, indeed, at other nutrient enriched sites is evident by the appearance of large blooms of fast-growing opportunistic macroalgae. Blooms of macroscopic species of green algae (Chlorophyta: Ulvophyceae) are particularly common and the phenomenon is often referred to as the occurrence of green tides. Green tides may have a dramatic environmental impact, causing much damage to the local ecosystem. Numerous strategies have hence been employed in order to combat the problem, but to date there has been limited success. For this reason, current research in the UK is aimed at increasing our knowledge of green tide algae in terms of their ecophysiology, whilst further investigation of the nutrient pathways and fluxes within specific ecosystems has been deemed necessary. It is anticipated that this ‘backto basics’ approach will ultimately contribute to the development of new, successful eutrophication management strategies.