Transcript EU Mediterranean Acoustic Survey on Small Pelagic MEDIAS

EU MEDIterranean Acoustic
Survey on
Small Pelagics
“MEDIAS”
GFCM, ISMIR, September 2008
Current status (E.U. states)
In the Mediterranean 5 direct surveys on small pelagic fish are regularly
held at least during the last decade.
Iberian coast (IEO)
Gulf of Lions (IFREMER)
Adriatic Sea (ISMAR) & Slovenia
Sicilian channel & Malta (IAMC)
Aegean Sea (HCMR)
ECOMED
PELMED
ANCHOVY
ANCHOVY
These surveys mainly target on anchovy and sardine
Cover the major stocks of these species in the
Mediterranean European Union waters
In the new DCR all EU acoustic surveys will be funded.
A workshop took place in Athens between 25 and 26
/2/2008. During this meeting a common protocol for all the
EU Mediterranean acoustic surveys has been adopted
In the framework of DCR this Pan-Mediterranean acoustic
survey will be coordinated by a steering committee which
has been approved by RCM Med
Name
Athanassios Machias
Marianna Giannoulaki
Bernard Liorzou
Jacques Masse
Mark Dimech
Tomaz Modic
Andrea De Felice
Iole Leonori
Angelo Bonanno
Dolores Onate
Magdalena Iglesias
Antonio Cervantes
Stylianos Somarakis
Country
Greece HCMR
Greece HCMR
France IFREMER
France IFREMER
Malta MCFS
Slovenia FRIS
Italy
CNR-ISMAR
Italy
CNR-ISMAR
Italy
CNR- IAMC
Spain
IEO
Spain
IEO
EC–DG Fish and Maritime Affairs
Facilitator of the WG on Small
pelagics (GFCM)
Echo sounder parameters
Echo sounder
Frequency for assessment (kHz)
Complementary frequencies (kHz)
Pulse duration (ms)
Beam Angle
Ping rate
Calibration (No per survey)
Threshold for acquisition (dB)
Threshold for assessment (dB)
Survey design
Split beam
38
120, 200 depending on availability.
1 ms
Should be reported
Maximum depending on depth
A calibration report should be given (Annex III)
One calibration per survey
-80
-70 to -60 (reported)
Perpendicular to the coastline/bathymetry, otherwise depending on topography
The survey design should be reported.
Inter-transect distance (NM)
Max <=12 NM.
Day time.
Time of day for acoustic sampling
Otherwise, in cases of time limitation and if echo allocation into species does not depend on school shape
identification (in this case justification of the accuracy of results will be presented)
EDSU (nm)
1 NM
Distance from the coast according to the Bottom depth (min, At least 20 m bottom depth, minimum 10 m of echo-sampling.
m)
Echo sounding depth (min, m)
Depending on the draught of RV. Should be reported
Echo sounding depth (max, m) recording.
200 m
Vessel speed
8-10 knots
Software for analysis
Movies and/or Echoview
File format
*.hac
Inter - transect
Acoustic energy in the inter-transect track will not be taken into account
Applied TS (dB)
Keep historical TS equations.
Echo trace classification based on echogram visual scrutinisation
Echo partitioning into species
Direct allocation and
allocation on account of representative fishing station
Transects design
Abundance estimates
Abundance indices estimated
Maps and charts
Common database
Total fish NASC per EDSU
Target Species NASC per EDSU
Biomass per EDSU per target species
Numbers per EDSU per target species
Number/age/Target species
Biomass/age/Target species
Point maps of total fish NASC
Point maps of target species in NASC/mile; biomass / mile.
Catch compositions of the hauls, pie-charts indicating biomass per species
Issues of common database will be established by the participants
Discussed the possibility to collaborate with the Atlantic survey
Fish sampling
Target species
Other species
Fishing gear
Duration of haul
Vessel speed during fishing
Sampling intensity, no of hauls
Anchovy, Sardine
Biological data for all species in the pelagic community: Length-Weight relationships; Length distribution.
Pelagic trawl,
Codend and trawl characteristics should be reported.
Max Codend mesh size = 24 mm (side of mesh = 12 mm).
Minimum 30 min for unknown echoes
3.5 – 4.5 knots
The total number of hauls has to be adequate to
ensure identification of echo traces
obtain length structure of the population
obtain species composition
get biological samples
Biological and oceanographic parameters
Length
Age readings, ALK
Length - Weight
Oceanographic. Parameter (CTD)
All species: Total length (TL), Length frequency distribution (0.5 cm)
Sardine, Anchovy: Mean TL at age
Sample sizes according to the new DCR.
All pelagic species
Minimum 3 CTD per transect or grid of stations with density adequate to describe the oceanography of the area.
Minimum variables: T, S
In the framework of the DCR at least one meeting will be
held every year
During these meetings the MEDIAS survey will be further
harmonized.