Autor(es):
Mata, Leonardo Filipe Rodrigues da 
Data: 2008
Identificador Persistente: http://hdl.handle.net/10400.1/1707
Origem: Sapientia - Universidade do Algarve
Assunto(s): Aquacultura; Algas; Biofiltros; Asparagopsis
Descrição
Tese de dout., Ciências do Mar, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2008 The use of seaweed as biofilters of animal mariculture discharges has not been widely
adopted by the aquaculture industry. Research efforts should focus on the cultivation of
novel seaweed species with economic value so that nutrient biofiltration may be identified
by the aquaculture industry as a self sustainable, environmental friendly technology that
produces profitable biomass. The Asparagopsis spp. volatile halogenated compounds
(VHCs) are explored for cosmetics formulations and so the integrated aquaculture of
Asparagopsis species should be considered as an opportunity. In this thesis I aim to establish
the tank domestication of the tetrasporophyte phase of Asparagopsis species (A. armata and
A. taxiformis) and compare its nutrient biofiltration and biomass production performance
with the most successful seaweed biofilters, Ulva spp. By exploiting the physiological
responses of the species to different levels of the manageable resources in culture (light,
nitrogen and carbon) I aim to determine the cultivation conditions that maximize the TAN
removal from the effluents, the biomass production of the system and the internal levels of
VHCs.
The performances of Asparagopsis species in integrated aquaculture exceeded that of
the Ulva spp. In this integrated cultivation system, the optimal Asparagopsis spp. stocking
density (light) was 5 g fresh weight L-1 and the ideal supply rates of fish effluents to the
seaweed tanks was ~3 vol h-1. These conditions provided the the quantity of nutrients, but
especially CO2 to maximize the nutrients biofiltration, the biomass yield and the bromoform
(the major VHC in these species) internal levels. At CO2 limiting conditions for
photosynthesis non–structural carbohydrate pools are affected, decreasing both growth and
the production of carbon based secondary compounds. The continuously year round
cultivation of both Asparagopsis species in this system was not possible, because the tank
water temperature surpassed 27 and 29 ºC, lethal for the cultivation of A. armata and A.
taxiformis, respectively.
