scholarly journals VARIACIÓN ESPACIO-TEMPORAL DE LA BIOMASA DEL ALGA CAULERPA SERTULARIOIDES EN POBLACIONES NATURALES Y EN CONDICIONES DE CULTIVO EN ESTANQUES DE CAMARÓN EN LA BAHÍA DE TUMACO, PACÍFICO COLOMBIANO

2016 ◽  
Vol 43 (1) ◽  
Author(s):  
Hernel Marín Salgado ◽  
Enrique Javier Peña Salamanca
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Algal Biomass ◽  
Algal Species ◽  
Natural Populations ◽  
Ammonia Nitrogen ◽  
Shrimp Ponds ◽  
Relative Growth ◽  
Culture Techniques ◽  
The Impact

The biomass of natural populations and biomass under cultured conditions in shrimp ponds of the green alga Caulerpa sertularioides (Chlorophyta, Bryopsidales) was evaluated during March-December 2010 and January- June 2011. The algal biomass in the estuary was collected monthly at low tide using 625 cm2 quadrants. Water quality variables, such as dissolved oxygen, salinity, temperature, Secchi disk, NO3 -, NH3 and PO4 3-, were taken simultaneously with algal samples. Algal biomass was taken to the lab to remove debris. Afterward, wet and dry weights were obtained to get final biomass. Relative growth rate (RGR% d-1) in ponds as well as physicochemical variables was evaluated weekly. Growth rates of plants registered a mean of 1.69 % day-1 (± 0.97). There were no significant differences (p = 0.315) in terms of biomass of C. sertularioides between Natal and Pajal creeks, showing averages between 4.09 and 4.67 g cm-2. Algal biomass showed significant differences between seasons (p = 0.000039), with highest values recorded between July and September. Salinity in Natal creek showed a direct relationship with seasonal variation of algal biomass (p = 0.019), with highest values of biomass in July-September related to higher levels of salinity in the study area. In contrast, salinity values and algal biomass in Pajal creek did not show significant relationship (p = 0.97). Nitrates, ammonia nitrogen, and orthophosphate were not significant with respect to changes in algal biomass (p = 0.93; p = 0.33; p = 0.55, respectively). Significant differences (p = 0.0021) between biomass of natural populations and algal biomass in shrimp ponds were reported, with higher values in cultured conditions, being those three times the biomass of natural creeks. Values of algal biomass from natural creeks suggested the importance of perform culture techniques, since natural populations would not sustain a commercial exploitation of this species. This study reports the first data of growth of a potential algal species and it is necessary to develop additional experiments to assess the impact of additional environmental factors on the relative growth rate.

A Discussion on the Influence Mechanism of Iron to Algal Blooms in Natural Raw Water

2013 ◽  
Vol 726-731 ◽  
pp. 2084-2091
Author(s):  
Jie Deng ◽  
Guang Xiao Kou ◽  
Jia Quan Wu
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Algal Blooms ◽  
Algal Biomass ◽  
Nitrogen And Phosphorus ◽  
Relative Growth ◽  
Influence Mechanism ◽  
Fe Content ◽  
Orthogonal Tests ◽  
Peak Value

Through designing orthogonal tests, the influence mechanism of iron to the growth of fresh water algae was studied. The results indicated that the initial Fe concentration of 0.3mg/L or above can lead to high algae relative growth rate while the initial Fe concentration under 0.3mg/L can only generate low algae relative growth rate. The consumption of iron in Group LNLP under low initial Fe concentration and Group HNHP under high initial Fe concentration was in synchronism with the consumption of nitrogen and phosphorus. However, in Group HNHP under low initial Fe concentration and Group LNLP under high initial Fe concentration the concentration of iron decreased with the increase of algal biomass before reaching the peak value of algal biomass and it increased after reaching the peak value in contrary. Among all those 25 groups the order of the peak value of algal biomass from big to small is as follows:All-rich Group>Nitrogen-lacked Group>Phosphorus-lacked Group>Iron-lacked Group>All-lacked Group. The lack of Fe content will restrain the growth of algae. In certain concentration rage algal biomass increased with the increasing of Fe content while Fe content will restrain the growth of algae in contrary if beyond the concentration rage.

scholarly journals Impact of Information and Communication Technologies on Research and Development: A Case of University of the Punjab-Pakistan

2014 ◽  
Vol 15 ◽  
pp. 47-53 ◽  
Author(s):  
Nosheen Fatima Warriach ◽  
Muzamil Tahira
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Information And Communication Technologies ◽  
Research Productivity ◽  
Doubling Time ◽  
Research Output ◽  
Communication Technologies ◽  
Relative Growth ◽  
Information And Communication ◽  
The Impact

This study explores the research trends at Pakistani universities by highlighting the use of Information and Communication Technologies (ICTs) in the research process and its productivity. It also investigates the impact of Higher Education Commission (HEC) initiatives for research output in Pakistani universities in general and PU, in particular. It explores the essential ICT skills to increase research productivity as perceived by researchers from the Faculty of Social and Behavioral Sciences through structured interviews. An analysis of HEC of Pakistan and PU websites is carried out. The statistics of these websites shows that there is an increase in the number of research articles and PhDs produced every year. Data show that the respondents are not fully utilizing the pricey electronic sources provided by the HEC, yet there is a yearly increase in a number of PhDs produced and published research. The relative growth rate of research productivity and doubling time were not constant. It is also observed that doubling time has increased while the relative growth rate is going to decrease.

Growth relationships in silver maple seedlings fumigated with O3 and SO2

1983 ◽  
Vol 13 (2) ◽  
pp. 298-302 ◽  
Author(s):  
K. F. Jensen
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Growth Analysis ◽  
Dry Weight ◽  
Ozone Treatment ◽  
Dry Matter Accumulation ◽  
Relative Growth ◽  
Silver Maple ◽  
The Impact

Growth analysis was used to measure the impact of low levels of ozone, alone and with sulfur dioxide, on the growth of silver maple (Acersaccharinum L.) seedlings. The seedlings were fumigated for up to 60 consecutive days with cither 0.05, 0.1, or 0.2 ppm ozone, alone and with 0.1 ppm SO2 for 12 h per day. Dry weight and leaf area development curves were calculated from data collected at 10-day intervals throughout the study. Growth analysis variables were calculated from these curves. Three variables, relative growth rate, relative leaf area growth rate, and relative leaf weight growth rate, were reduced by 0.2 ppm ozone and decreased even further when 0.1 ppm SO2 was applied. Neither the 0.05 nor 0.1 ppm ozone treatment decreased the relative growth rate of the silver maple seedlings. Even small differences in growth rate may produce large differences in dry matter accumulation over a growing season.

scholarly journals Growth of Gracilaria under Different Planting Distances in Pond

2009 ◽  
Vol 8 (2) ◽  
pp. 157
Author(s):  
. Sunarto
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Shrimp Ponds ◽  
Relative Growth ◽  
Improve Production ◽  
Length Increment ◽  
Planting Distance ◽  
Thallus Length ◽  
Production Target

<p>The use of non-productive shrimp ponds for cultivation of <em>Gracilaria</em> is one of the strategies that can be performed to achieve production target of seaweed. This study was conducted to determine the influence of different planting distances on growth of <em>Gracilaria</em> cultivated in pond. <em>Gracilaria</em> was separately planted in distant of 20x20 cm; 25x25 cm; 30x30 cm and 35x35 cm in pond for 45 days cultivation.  Relative growth rate and thallus length increment were measured to obtain an optimal planting distance. The results of study showed that 25x25 cm planting distance resulted in a higher relative growth rate (137.8%) and increment of thallus length (15.3%) compared with other treatments.  Thus, cultivation of <em>Gracilaria</em> in an unproductive pond with 25x25 cm planting distance may improve production.</p> <p>Keywords : non-productive ponds, planting distance, <em>Gracilaria</em></p> <p> </p> <p>ABSTRAK</p> <p>Pemanfaatan tambak udang yang tidak produktif untuk budidaya <em>Gracilaria</em> merupakan salah satu strategi yang dapat dilakukan untuk mencapai target produksi rumpul laut. Penelitian ini dilakukan untuk mengetahui pengaruh jarak tanam yang berbeda terhadap pertumbuhan <em>Gracilaria</em> di tambak.  Gracilaria ditanam terpisah dengan jarak 20x20 cm; 25x25 cm; 30x30 cm dan 35x35 cm di tambak selama 45 hari pemeliharaan.  Pertumbuhan relatif dan panjang thalus diukur untuk memperoleh jarak tanam yang optimal.  Hasil penelitian menunjukkan bahwa jarak tanam 25x25 cm memberikan pertumbuhan relatif (137.8%) dan pertambahan panjang thalus (15.3%) tertinggi dibandingkan dengan perlakuan lainnya. Dengan demikian, budidaya <em>Gracilaria</em> di tambak tidak produktif dengan jarak tanam 25x25 xm diduga sangat membantu untuk mencapai target produksi rumput laut.</p> <p>Kata kunci : tambak non-produktif, jarak tanam, Gracilaria</p>

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