aula 1/2 Flashcards
o que define/ caract de IMTA
Implies more than one trophic level
Sp interaction needed
Basic ecosystem functions need to be guaranteed
o Consumers
o Producers
o Detritivores
There is always 1 main sp and the entire system is based around it (usually the organisms that is more economically valuable)
Important to keep in mind when setting up an aquaculture business:
Sea or fresh water
Local: inland, off shore, estuaries …
Market value or client goal
Species
Efficiency
chinese aquaculture system
Usage of carps – fresh water fish - in rice fields
qual + facil: aquacultura em agua doce ou salgada
doce
larvae development is + simple
somethimes there is direct development
what are the functions of fish in the rice fields
their waste fertilizes the rice plants (stimulates N)
control pests from rice while feeding
also feed on plankton that can grow due to unused fertilizer
rice plant functions
filter ammonia and nitrates
environment stimulation (ex: hiding places)= - stress
use the unconsumed fish feed
why does the rice field with the carps work so well
these interactions create + feedback loops that promote each other
why added ducks
both animals created enough waste to effectively fertilize the rice field (the rice was the important product in this system)
a duckweed e plantas de arroz competem?
nao
as weeds são flutuantes e o arroz está no solo
what is aquaponia
hydropnia + aquacultura
hidroponia é?
platar plantas em apenas agua X solo
gasta - agua e há + controlo dos nutrientes
sistemas acoplados
= aquaponia sistema fechado
sistema fechado
how many trophic levels should exist in a IMTA? 2, 3, 4…
No universal answer/ formula
varies and depends
inicially better to have less levels = + control
most important process in aquaponics
Mineralization
what is mineralization
FORMS AMMONIA? or from amonia?
breakdown of organic solid waste into biologically available nutrients
organic matter are decomposed or oxidized into easily available forms to plants.
what does mineralization depend on
pH and temperature
forma mais e menos toxica de N
NH3 (amoniaco) > amonia >nitritos > nitratos
o que povoca o amoniaco nos peixes
epitelios branquiais espessos = dificulta trocas gasosas
nitritos são toxicos se sim como?
sim mas em elevadas concentrações
ligam-se à heamoglob = X transpote o2
why we dont use much the closed system aquaponia
pH baixo para crescimento das plantas mas alto para peixes
problemas = tudo comprometido (ex: denças, parasitas, susbt toxicas, insetissidas…)
sempre necessario corrigir nutrientes (peixes e plantas têm necessidades mt distintas)
porque trocar ar dos peixes e plantas
o2 das plantas para peixes
co2 peixes para plantas
