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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluation of the growth of seaweed Gracilaria birdiae (Gracilariales, Rhodophyta) grown in long-line structure / AvaliaÃÃo do crescimento da alga marinha gracilaria birdiae (gracilariales, rhodophyta), cultivada em estrutura de long-line

Francisco Carlos Lima Lelis 30 August 2006 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A presente dissertaÃÃo analisa o efeito da luminosidade no crescimento da alga marinha Gracilaria birdiae atravÃs da taxa de crescimento especÃfico (TCE) e aumento de biomassa em diferentes profundidades. Foi utilizada estrutura do tipo long-line com corda principal medindo 25m e 10 cordas secundÃrias de 2,5m instalaÃÃo a 200m da costa com profundidade entre 5 e 6 m (marà seca). Foram fixadas 12 mudas por corda secundÃria com espaÃamento de 20cm compondo 12 linhas de profundidade. Com 30 dias realizou-se a pesagem de todas as mudas da estrutura identificadas por corda secundÃria e linha de profundidade. Com 60 e 90 dias a pesagem foi apenas nas linhas de profundidade que apresentavam mudas em melhores condiÃÃes fÃsicas. Nas profundidades testadas de 0,2 a 2,4m, observou-se um melhor desempenho do crescimento como tambÃm melhor aparÃncia e condiÃÃo fÃsica das mudas fixadas de 0,2 a 1,2m, enquanto as fixadas entre 1,4 a 1,8m ou tiveram crescimento inferior ou praticamente nÃo cresceram, e as fixadas no limite inferior entre 2,0 e 2,4m verificou-se atrofiamento das mudas. Os pesos mÃdios obtidos apresentaram diferenÃa estatÃstica significativa (F = 187,104; p = 0,05). A TCE demonstrou correlaÃÃo negativa com a profundidade (r = - 0,95; p = 0,05; n = 120). Nas profundidades mais prÃximas da superfÃcie de 0,2 a 0,6m favoreceram o crescimento das algas alcanÃando pesos de 167,5 a 147,0g e TCE de 2,92 e 2,69% dia-1, entre 0,8 a 1,2m pesos de 139,0 a 124,0g e TCE de 2,29 a 1,90% dia-1, e a partir de 1,4m atà 2,4m pesos de 94,5 a 59,5g e TCE de 0,9 a 0,53% dia-1. A reduÃÃo nos pesos abaixo de 1,2m foi bastante acentuada evidenciando que as algas tiveram detrimento em seu crescimento com a reduÃÃo da intensidade luminosidade apresentando atrofiamento de algumas mudas fixadas nas extremidades das cordas. Os parÃmetros da Ãgua na Ãrea do cultivo temperatura, salinidade e grau de transparÃncia da Ãgua apresentaram mÃdias de 29,6  2,41 ÂC, 35,6  1,49 â e 1,20  0,76 m. No final do perÃodo experimental (90 dias) as mudas atingiram peso final de 937,0g, ideal para colheita. Para Gracilaria birdiae, a luminosidade foi o fator ambiental que afetou efetivamente sua TCE e produÃÃo de biomassa, apresentando nas condiÃÃes do cultivo, crescimento satisfatÃrio atà a profundidade de 1,2m onde as mudas atingiram peso mÃdio de 124,0  9,94 g e TCE de 1,90 %dia-1. / To present dissertation it analyzes the effect of the brightness in the growth of the alga sea Gracilaria birdiae through the rate of specific growth (TCE) and biomass increase in different depths. A structure of the type long-line was used with main rope measuring 25m and 10 sec ondary strings of 2,5m installation to 200m of the coast with depth between 5m and 6m (tide evaporates). 12 seedlings were fastened by secondary rope with spacing of 20cm composing 12 depth lines. With 30 days it accomplished the measure of the weights of the seedlings of the structure identified by secondary rope and depth line. With 60 and 90 days the measure of the weights was just in the depth lines that presented seedlings in better physical conditions. In the tested depths from 0,2 to 2,4m, it was observed a better acting of the growth as well as better appearance and physical condition of the fastened seedlings from 0,2m to 1,2m, while fastened them from 1,4m to 1,8m or they had inferior growth or practically they didn't grow , and fastened them in the inferior limit from 2,0 to 2,4m reduced growth of the seedlings it was verified. The obtained medium weights presented significant statistical difference (F = 187,104; p = 0,05). TCE demonstrated negative correlation with the dept h (r = - 0,95; p = 0,05; n = 120). In the closest depths of the surface from 0,2 to 0,6m favored the growth of the algae reaching weights from 167,5 to 147,0g and TCE 2,92 and 2,69% day-1, among 0,8m to 1,2m weights from 139,0 to 124,0g and TCE fr om 2,29 to 1,90% day-1, and starting from 1,4m until 2,4m weights from 94,5 to 59,5g and TCE 0,9 to 0,53% day-1. The reduction in the weights below 1,2 m was quite accentuated evidencing that the algae had detriment in your growth with the reduction of the intensity brightness presenting reduced growth of some you change fastened in the extremities of the strings. The parameters of the water in the area of the cultivation temperature, salinity and degree of transparency of the water presented averages of 29,6  2,41ÂC, 35,6  1,49â and 1,20  0,76m. In the end of the experimental period (90 days) the seedlings reached final weight of 937,0g, ideal for crop. For Gracilaria birdiae, the brightness was the environmental factor that it affected your TCE and biomass production indeed, presenting in the conditions of the cultivation, satisfactory growth until the depth of 1,2m where the seedlings reached weight of 124,0  9,94 g and TCE of 1,90 %dia-1.

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