monitoring_systems:watercolumn-seafloor Flashcards
what are the effects of finfish aquauculture on the ecosystem?
local and water column effects:
- water discharge rich in POM DOM, DIM
- artificial reef (biofouling)
wider ecological effects:
- fish diseases
- parasites
- genetic interaction
macroecological effects:
fish feed production (sources and tranport)
why are surface currents important ?
- brings fresh water to the fish
- adds oxygen
- removes particles and dissolved waster compounds
why are spreading currents important?
- reduce sedimentation right beellow the farem
- spreading particles
whay are bottom currensts improtant?
- increases semidnet turnover
- prevenst deoxygenation of the sediment
what happens with Dissolved organice nutrienst (phosphat/ammonimu) from AQC?
immediately consumd by primary producers
what happens with Particulate organic nitrogen and phophorous from AQC?
larger particles consumed by fish/sink down
smaller articles suspended in water column–> consumed by filter feeders and bacteria
what happens with DON and DOP ?
- sink down /consumed by bacteria
what is the dilution effect?
difficult to document spread of inorganic nutrients
–> cause they are immendiately taken up by phytoplankton
what is the most important directive related to marine AQC management?
WFD
water framework directive
what does the WFD say about human activity in nature ?
all human acitivity in nature represnts a potential pressure on the aquatic ecosystem
how are aquaculture sited regulated?
what is the reugaltion based on?
in norway
based on
1.EGS and EGO (environmental quality objectives)
- localization of farms
- biomass regulation (carrying capacity)
- feed reguation
- standards used for regulatory control (food quality standards/environmental standards)
what is the carrying capacity in norway?
200 000 fish /sea cage
hat are the 3 monitoring programms used in marine AQC?
- monitoring of envronmental effects
- monitoring of food quality
- monitoring of water quality ((inorganic)nitrogen and phosphorus)
what are the 2 monitoring ways?
- self-monitoring
2. authority monitoring
what is the name for the norwegian standard for monitoring environmental, benthic impact impact from mariculture?
NS-9410
what are the three types of survey that are included in NS-9410?
- feasibility study
- B investigations
- C investigations
the zone which is impacteted by an AQC site is divided into 2 zone.
which?
how are these zones affected by the AQC site?
- zone under the farm = 0-30 m from the sea cage
- -> excess feed and faces –> strong effect - transitional zone = 30-500 m from the sea cage
- -> sedimentation of smaller particles (water currents)
- ->small effect
which investigations are done in which zone?
transitional zone = c-investigations
zone under the farm =
B and C investigations
what is the feasibility (machbarkeit) investigation?
definition
=environmental documentation that describes the area around the AQC site.
when is a feasibility investigation required?
- applying for new establishemnt of a site
- applying for substantial expansion of already existing sites
what is included in feasibility investsigatio
- B and modfied C investigation
- map
- current measuremnets
- hydrological data
definition of B investigation.
=trend monitoring/analyis of the bottom conditions under a fish farm performed by an authorized company
what does b investigation includes?
- chemical investigation (pH, redox potential) (–> quantitativ)
- senory investigation (–> qualitativ)
- qualitative fauna investigation (presence/abscene of animals) (–> qualitativ)
where is B investigation done?- at the site or in the lab?
directly at the AQC site!
by whom is B-investigtaion carried out?
by autorized companies
what determines the frequency of B investigations?
the status of the location
- the worse the status the more regular are the B investigations
waht are the states that a farm is characterized druing B- investiagtio ?
state1. very good
state2. good
state3. bad
state4. very bad
how frequent is the B -investagtion carried out at an AQC with 1.vergy good and 2.good status and
- very good: at next maximum lood
2. good: before next production cycle start and at next maximum load
what does maximum load mean?
=75-90% of the total feed in a production cycle is given to the farm
what happens when an AQC site become the state 4
authorities will carry out action plans
the B-investigation works with average values ( different cage values –> all into one farm value)
true or false?
true
B investagtions are more expensive than c investigations.
true or false?
false
defin. C investigation
=survey of the bottom conditions from the fish farm (local) and the regional impact zone.
-gives DETAILED information
what does c investiagtion include?
- bottom fauna (qualitative and quantitaive)
- chemical parameters (P, C, Zn, Cu)
- sediment grain size distribution (proprtion of clay, silt, gravel, sand )
- sensory analyses
- oxygen content (of water masses)
what is when the bottom under a farm is not soft –< rocky.
what impact has that on the investiagtion?
B investigation made for soft bottom (sediment anlysis etc)
–> include new monitoring methods
e.h. scanning of the seafloor,
comparing to situation befor AQC
what are new monitoring methods ideas? instead of the “grab-method”
- genetic characterizatin of benthic population
- hyperspectral imaging
who sets the monitoring of food quality?
the EU
monitoring regualtions are the same in every country in europe?
false
at what frequency are c-investigations done?
usually every third prodcution cycle–> every 6 years
what has been developed in monitoring in AQC sites in malta of bluefin tuna and sea bass /seabream
- uneaten food index (quantify uneaten food under the cages)
- seabed and seagrass states
