Page 1 CONSULTANCY AND RESEARCH IN AQUACULTURE AND THE AQUATIC ENVIRONMENT A Company in the...

CONSULTANCY AND RESEARCH IN AQUACULTURE AND THE AQUATIC ENVIRONMENT

A Company in the NIVA-group

Methodology for Environmental monitoring of aquaculture

Environmental monitoring and modelling

What information do we need?

Physical parametersChemical parametersBiological parametersDetailed survey of production in the area (area of pens and annual production)

Historical data Collecting new data

Predictive modelling of the areas

Environmental data

Survey for mapping the environmental condition

Weather datawind direction, speed, temperature

Bathymetry of the areaSea map information

New mapping

Tidal range and current speed, direction and dispersion

Temperature, turbidity, salinity, oxygen, chlorophyll profile through the water column

Water chemistry

Sediment analysis (biological and chemical)

Equipment required

2 Grab – freshwater Ekman grab and modified marine Van Veen grab

2 Sieve for the sieving the sediment samples

4 standard current meters – current and temp

2 enhanced current meters – current, temp, conductivity, oxygen, turbidity, depth

CTD probe – conductivity, temperature, depth, chlorophyll, oxygen, turbidity

2 handheld Garmin GPS

2 handheld echo sounders

Garmin GPS and echo sounder

2 portable computers

Total value of US$ 100,000

Bathymetry

• The bathymetry is done by using a Garmin echo-sounder which contains a GPS and a chart plotter (GPSmap 178C sounder)

• GPS store the tracks automatically tagged with the date and time of creation, as well as water temperature and depth

• It can be set up on a small boat

• It usually takes a full day to complete depending on the size of the area surveyed

Bathymetry

Bathymetry and sediment type surveys (results)

V esse l track2 0 0 m

Bathymetry survey (results)

-1 0 0

-9 0

-8 0

-7 0

-6 0

-5 0

-4 0

-3 0

-2 0

-1 0

0

D ep th (m )

D ep th (m ) an d cage p osition s2 0 0 m

Current meter deployments

These measurements are made to measure the general hydrodynamic conditions at each site. The main factors of interest are:• the distribution of the currents and the extremes

measured at the site

• how current speed and direction are affected by wind conditions

• the use of these measurements in modelling the dispersion of wastes from the cages

• Two of the current meters have sensor that are measuring turbidity, conductivity, depth, oxygen

Current meters deployment

Current meter deployment

•A typical mooring•current meters placed at 5m and 10m depths for areas with 20m deep•at 3.5 and 7.5m depths for areas 15m deep•Set up are often modified for site specific conditions•Deployed for 24 hours to one month

Equipment – Current meter

Downloading and processing data

Current meter deployments (results)

The plots show current speed and direction for a site measured over a one month period at the surface

0

10

20

30

40

17

-Se

p

18

-Se

p

19

-Se

p

20

-Se

p

21

-Se

p

22

-Se

p

23

-Se

p

24

-Se

p

25

-Se

p

26

-Se

p

27

-Se

p

28

-Se

p

29

-Se

p

30

-Se

p

1-O

ct

2-O

ct

3-O

ct

4-O

ct

5-O

ct

6-O

ct

7-O

ct

8-O

ct

9-O

ct

10

-Oct

11

-Oct

12

-Oct

13

-Oct

14

-Oct

15

-Oct

16

-OctSp

ee

d c

m s

ec

-1

0

90

180

270

360

17

-Se

p

18

-Se

p

19

-Se

p

20

-Se

p

21

-Se

p

22

-Se

p

23

-Se

p

24

-Se

p

25

-Se

p

26

-Se

p

27

-Se

p

28

-Se

p

29

-Se

p

30

-Se

p

1-O

ct

2-O

ct

3-O

ct

4-O

ct

5-O

ct

6-O

ct

7-O

ct

8-O

ct

9-O

ct

10

-Oct

11

-Oct

12

-Oct

13

-Oct

14

-Oct

15

-Oct

16

-OctDir

ec

tio

n °

ma

g

MHM LAMLASH CURRENT SPEED AND DIRECTION, SURFACE METER, 1345Z 17 SEP 1997 TO 1040Z 15 OCT 1997

Plots from the current meters at different depths. Analysis will also give the current speed and direction distribution

[0,3) [3,6) [6,9) [9,12) [12,15) [15,18) [18,21) [21,24) [24,27) [27,30) [30,33) [33,36) 360

100

200

300

400

500

600

700

800

900F

RE

QU

EN

CY

CURRENT SPEED (cm s-1)

MHM CAIRIDH CURRENT SPEED HISTOGRAM SURFACE METER, 1354Z 16 DEC 1998 TO 1204Z 4 JAN 1999

[0,1

5)

[15,3

0)

[30,4

5)

[45,6

0)

[60,7

5)

[75,9

0)

[90,1

05)

[105,1

20)

[120,1

35)

[135,1

50)

[150,1

65)

[165,1

80)

[180,1

95)

[195,2

10)

[210,2

25)

[225,2

40)

[240,2

55)

[255,2

70)

[270,2

85)

[285,3

00)

[300,3

15)

[315,3

30)

[330,3

45)

[345,3

60)

0

50

100

150

200

250

300

350

400

450

FR

EQ

UE

NC

Y

CURRENT DIRECT (° mag)

MHM CAIRIDH CURRENT DIRECTION HISTOGRAM, SURFACE METER, 1354Z 16 DEC 1998 TO 1204Z 4 JAN 1999

Current meter deployments (results)

Current measurements in Bolinao

Current measurements in Lake Taal – at 10 meters

3/30/06 9:36 3/30/06 19:12 3/31/06 4:48 3/31/06 14:24 4/1/06 0:00 4/1/06 9:36D a te Tim e

0

2

4

6

8

10

12

14C

urr

ent

sp

eed

(cm

/s)

0

45

90

135

180

225

270

315

360

Dir

ecti

on

Oxygen and temperature in Lake Taal – at 10 meters

3/30/06 9:36 3/30/06 19:12 3/31/06 4:48 3/31/06 14:24 4/1/06 0:00 4/1/06 9:36D a te Tim e

23.2

23.6

24

24.4

24.8

25.2

Te

mp

era

ture

°C

120

160

200

240

280

320

Oxy

gen

Drifting buoy surveys (objectives)

The level of water dispersion near a fish farm is an important factor as it determines how well wastes are dispersed and water bodies are reoxygenated. The main factors of interest are:

• how quickly released drifters spread out relative to one another

• How far apart the drifters have spread out at the end of the release period

• the measurement of unusual hydrodynamic conditions in the surrounding area

Drifting buoy surveys (drogues)

The drifting buoys are buoys marked with flags that are pulled along by subsurface water currents by sails. They are released in a group and their movement monitored

Drifting buoy surveys (results)

An example of a release made from a cage group. The drifters show a clockwise circulation which would be difficult to measure with a single current meter mooring

1 2 3 4 5 6 Cage group

100 m

N

Release start: 11:56Release end: 15:13

Turbidity and measurements

Water depth is recorded when secci disc can no longer been seen

Conductivity, Temperature and Dissolved oxygen (CTDO)

The CTDO measures, calculates and records:

•Water salinity (conductivity) •Temperature•Oxygen level•Turbidity

•Possibilities to make isoplets and profiles for the different parameters

Also can add•Chlorophyll

Water column sampling by CTD

Water column measurements

CTD is dropped to the bottom (seabed) and retrieved slowly to the surface (records data every 5th second)

Water column sampling

Water column is sampled for dissolved oxygen, salinity and temperature

CTD transect

CTD transectCTD transect

Horizontal plot of oxygen in Lake Taal at 1 meter

CTD-profile in Lake Taal - April 2006

26 27 28 29 30

Tem perature °C

100

80

60

40

20

0

De

pth

0 40 80 120 160Oxygen %

0 2 4 6 8C hlorophyll (µg/l)

0 1 2 3 4 5Turbidity FTU

Transects – vertical profiles in Bolinao

1 61 41 21 0

86420

35.38

35.48

35.58

35.68

35.78

35.80

Salinity, transect 1

1 61 41 21 0

86420

30.0

30.2

30.4

30.6

30.8

31.0

31.1

Temperature, transect 1

Water quality

Water samples are taken and analyzed for parameters that relevant for measuring the environmental conditions

•chlorophyll-a

•ammonia

•nitrate

•nitrite

•phosphate

Chlorophyll

Sediment studies - sampling

Samples or taken by grab

Sediments

Larger particles are collected, preserved and stained

High organic content- close to a fish cage

Low organic content- far away from a fish cage

Bolinao – station with bad conditions

Bolinao – marine station with good conditions

Grab movie

Sediment sample analysis - taxonomy

Samples are analysed for benthic diversity Station 1:

Taxon Number

1. Cirratulus sp. (polychaeta) 338

2. Dorvillea sp. (polychaeta) 1763. Nereis sp. (polychaeta) 1234. Cirratulidae indet (polychaeta) 36

5. Loripes lucinalis (mollusca) 146. Paguridae indet (crustacea) 8

7. Lumbrineris sp. (polychaeta) 8

8. Paraonis sp. (polychaeta) 8

9. Typosyllis sp. (polychaeta) 8

10. Tellina donacina (mollusca) 7

Reference station:

Taxon Number

1. Tellina donacina (mollusca) 39

2. Lucinella divaricata (mollusca) 23

3. Gouldia minima (mollusca) 21

4. Owenia fusiformis (polychaeta) 20

5. Aspidosiphon mulleri (polychaeta) 196. Ascidiacea indet (tunicata) 17

7. Nuculana pella (mollusca) 15

8. Gonilia calliglypta (mollusca) 159. Tanaidacea indet (crustacea) 13

10. Lumbrineris sp. (polychaeta) 13

Sediments – chemical samples

Samples are taken of the surface layer for chemical analysis (TOC, grain size, ++)

Fish Farm registration

The coordinates of every fish farm are recorded and note taken if operational

Page 1 CONSULTANCY AND RESEARCH IN AQUACULTURE AND THE AQUATIC ENVIRONMENT A Company in the...

Documents

Transcript of Page 1 CONSULTANCY AND RESEARCH IN AQUACULTURE AND THE AQUATIC ENVIRONMENT A Company in the...