Carrying capacity assessment and impact Carrying capacity assessment - - PowerPoint PPT Presentation

Carrying capacity assessment and impact Carrying capacity assessment and impact

• f aquaculture in Chinese bays
• f aquaculture in Chinese bays

http://www.ecowin.org/china/

*1,*2 *1,*2

J.G. Ferreira

Universidade Nova de Lisboa Faculdade de Ciências e Tecnologia

IMAR - Institute of MArine Research http://www.imar.pt

*1 – European Union INCO-DC contract Nº ERBIC4CT 98-0291

*2 - J.P. Nunes, J.G. Ferreira, F. Gazeau, J. Lencart-Silva, Zhang, X.L, Zhu M.Y., & Fang J.G., 2003. A model

for sustainable management of shellfish polyculture in coastal bays. Aquaculture, 219/1-4, 257-277

• Objectives

Objectives

• Locations

Locations

• Methodologies

Methodologies

• Modelling approaches and results

Modelling approaches and results

• Final comments

Final comments

Topics Topics

Slides

1 3 12 31+2 13 2

Carrying capacity assessment and impact of aquaculture on Chinese bays

Objectives Partners

• Europe

Europe IFREMER IFREMER PML PML IMAR IMAR

• China

China FIO FIO YSFRI YSFRI SMCI SMCI SIO SIO

• Study interactions between

Study interactions between aquaculture and environment in aquaculture and environment in coastal areas, including those coastal areas, including those between different types of aquaculture between different types of aquaculture

• r exploitation of natural resources,
• r exploitation of natural resources,

with an emphasis on with an emphasis on polyculture polyculture

• E

Establish stablish models that predict the models that predict the carrying capacity for aquaculture and carrying capacity for aquaculture and its resulting impacts according to its resulting impacts according to different types of aquaculture in different types of aquaculture in different environments different environments

• P

Provide rovide scientific information and scientific information and recommendations that facilitate recommendations that facilitate sustainable aquaculture management sustainable aquaculture management

Project funded by EU INCO-DC contract Nº ERBIC4CT 98-0291

Aquaculture in China

1096 1159 698 2431 2268 730 4450 2166 28117 526 657 698 707 994 1044 1292 2095 32444

Tonnage (103 metric tons) Value (106 USD) China India Japan Phillipines Indonesia Thailand

• Rep. Korea

Bangladesh Vietnam 10000 20000 30000 40000

Notes: (a) Only countries with production greater than 500,000 ton y-1 are shown (b) Over half the production is from marine and brackish waters

Two bays in Shandong Province

Jiaozhou Wan Sanggou Wan

Key features of the two bays

System Area Volume Cultivated Other Pressures (km2) (106 m3) species uses and issues Sanggou 140 100 Chinese scallop

• ~150,000 people

Bay Pacific oyster Heavy bivalve Kelp mortality Jiaozhou 400 2800 Bay scallop Sewage 6 million people Bay Chinese scallop Industrial waste Redfield ratio (N/P) Pacific oyster Shipping/port has changed from Manila clam Recreation 10 to 24 in 40 years

Methodologies

Fieldwork

• Key species,

Key species, cultivation and cultivation and system description system description

• Databases, GIS,

Databases, GIS, conversion of data conversion of data into information into information

Data processing

12 km 12 km 10 km 10 km

Modelling

• Models with different

Models with different

• bjectives, at different
• bjectives, at different

scales scales

Methodologies

Fieldwork

• Define culture practice (methods, timing and quantities)

Define culture practice (methods, timing and quantities)

• Experimentally determine growth parameters

Experimentally determine growth parameters for key species for key species

• Carry out growth trials for target species

Carry out growth trials for target species

• Measure water quality data in field campaigns for the two bays

Measure water quality data in field campaigns for the two bays

Once upon a time Once upon a time… … The (his)story of the The (his)story of the Mu Mu

Unit name Area Equivalent area ha area (m2) (m2) Mu 666.66 1/15 ha 10000 Sanggou Bay Culture Mu 1600-1800 1/15 Sanggou culture ha 25500 Jiaozhou Bay Culture Mu 3000-5000 1/15 Jiaozhou culture ha 45000-75000 Laizhou Bay Culture Mu 5000-8000 1/15 Laizhou culture ha 75000-120000

Note: The Culture Mu (like the medieval bushel) is also used in agriculture, and has a similar variability, being indexed to yield – The area of the Culture Mu is therefore linked to the exploitation carrying capacity.

Sanggou Bay monoculture – Pacific oyster

4.5m Oyster rope 1m 60-70m Longline

• 30 Scallop shells as base, about 10cm apart, with 6-10 oysters each.

400 ropes/Culture Mu, i.e. 400 culture ropes/1600-1800 m2, 250 oysters/ rope:40-75 oysters/m2.

• Ropes are 2-3m long.
• 6 longlines per culture Mu, 30 longlines per block, then 8m channel

for navigation.

Sanggou Bay polyculture - Kelp and scallop

4.5m Nets: 3m kelp 3m Kelp yield - 5kg dw per “double” rope inside the bay, 10kg outside the bay. 333-375 g dw/ m2. All harvested. Data calculated for inside the bay.

• Longline. In some

cases the ratio of kelp ropes:scallops is 1:1, others 1:2, others 2:1 Kelp rope- 2.5m, 30-35 plants X 2 for “double” rope

• 8-10 layers per Chinese lantern, 30 scallops per layer, 120 nets per

culture Mu, i.e. 120 culture nets/1600-1800 m2, 240-300/ net:16-22.5 scallops/ m2.

• Scallop nets are 2-3m long. 6 longlines per culture Mu, 30 longlines per

block, then 8m channel for navigation.

EcoWin EcoWin 2000 2000 – – Sanggou Sanggou Bay model Bay model

Culture practice Culture practice – – first approach (May 2001) first approach (May 2001)

Scallop seeding Day 180-211 Scallop harvest Day 181-211

Source: Culture practice data from FIO, YSFRI and SMCI (pers. com., May 2000)

Oyster harvest Day 304-365 Oyster seeding Day 303-365

Seed weight: 0.05 DW (1.7g TFW, Gazeau, 2000) Harvestable weight: > 65 g TFW (Tentative value)

Kelp harvest Kelp harvest in Sanggou in Sanggou Bay, China Bay, China

Growth of kelp (Laminaria japonica)

50 100 150 200 250 300 350 400 01-oct 20-nov 1 2 3 4

length (cm) Increase (cm day-1) Increase (cm day-1)

50 100 150 200 250 300 350 400 01-oct 20-nov 09-jan 28-feb 19-apr 08-june Time Length (cm) 1 2 3 4

Growth of Chinese Scallop (Chlamys farreri)

Methodologies

Information management

• Development of relational databases

Development of relational databases

• Geographical Information Systems

Geographical Information Systems

BarcaWin BarcaWin 2000 2000 Data assimilation Data assimilation

20 40 60 80

Historical data Full dataset

20000 40000 60000

JB JB SB SB JB JB SB SB 10 22 66 77 80 2728 20536 23621 Stations Samples 18 48 31 51 Results 677 23327 38717 51793 Parameters

Sanggou Bay cultivation areas 1993/94 Sanggou Bay cultivation areas 1993/94 GIS determination GIS determination

Scallop Kelp Scallop & Kelp

Aquaculture areas: Aquaculture areas: 4400 ha 4400 ha Kelp Kelp 3400 ha 3400 ha Scallop Scallop 391 ha 391 ha Oysters Oysters

Modelling approaches and results

• Individual based

Individual based modelling modelling

• Effects of culture structures on flow

Effects of culture structures on flow

• Farm

Farm-

• scale depletion modelling

scale depletion modelling

• Ecosystem

Ecosystem-

• scale (carrying capacity)

scale (carrying capacity) modelling modelling

Modelling

Individual growth modelling

Visual modelling platform, simulation of individual processes for the Chinese scallop. Hawkins et al, 2002. A functional model of responsive suspension-feeding and growth in bivalve shellfish, configured and validated for the scallop Chlamys farreri during culture in China. J.Exp.Mar.Biol.Ecol., 281: 13-40.

Modelling effects of culture structures

Finite element hydrodynamic model implemented in AquadynTM Default: No aquaculture Culture configuration 1 Culture configuration 2 Grant & Bacher, 2001. A numerical model

• f flow modification induced by

suspended aquaculture in a Chinese Bay. Can.J.Fish.Aquat.Sci., 58: 1003-1011.

Modelling farm-scale food depletion

Farm Inflow Outflow

Modelling farm-scale food depletion

Approach

• 1. A length scale of 1000m

was used (local depletion)

• 2. The depletion model

couples food transport, food consumption and scallop growth at scale of a cultivated area

• 3. Food transport is

determined from local current fields using a 1D model

• 4. Food supply is based
• n spatially discrete field

measurements

• 5. Food consumption (and

scallop growth) is based

• n individual growth

models

Density (nº m-3) of cultivated scallops predicted by the depletion model when only local density effects are considered Bacher et al, 2003. Modelling the effect of food depletion on scallop growth in Sungo Bay (China). Aquat. Living Resources, 16, 1, 10-240

Modelling ecosystem carrying capacity

EcoWin2000 model specifications

10 objects, including kelp, oysters and scallops and man Individual growth and demographic distribution for

• ysters and scallops, using multiple inheritance

About 40 state variables, not including derived variables Mass fluxes only are considered at ocean interface 6 year runtime (2190 days), with one hour timestep (takes about 2

minutes to run on a Pentium IV)

Deposition

Phytoplankton Shellfish Detritus

Uptake Mortality Filtration Egestion Filtration Temperature Turbidity Light Kelp Uptake Tidal exchange Mass Flux Influence

Phytoplankton Shellfish

Uptake Mineralization Egestion Temperature Turbidity Kelp Seeding Harvest Mass Flux Influence Mass Flux Influence Man Light

Nutrients

Mortality Tidal exchange Tidal exchange

10000 20000 30000 40000 50000 60000 70000 80000 90000 365 730 1095 1460 1825 2190 Julian Day ton TFW Oyster Biomass Scallop Biomass

EcoWin2000 modelling platform, full coupled model. Nunes et al, 2003. A model for sustainable management of shellfish polyculture in coastal bays. Aquaculture, 219/1-4, 257-277

Tuning the model

Dissolved Inorganic Nitrogen 5 10 15 20 25 30 35 40 45 100 200 300 Julian Day umol(N) L-1 simulated Sanggou Data (93/94) Dissolved Inorganic Nitrogen 5 10 15 20 25 30 35 40 45 100 200 300 Julian Day umol(N) L-1 simulated Sanggou Data (93/94)

Phytoplankton Biomass 2 4 6 8 10 12 14 16 18 20 100 200 300 Julian Day ug(Chl a) L-1 simulated Sanggou Data (93/94) Phytoplankton Biomass 2 4 6 8 10 12 14 16 18 20 100 200 300 Julian Day ug(Chl a) L-1 simulated Sanggou Data (93/94) Suspended Particulate Matter 50 100 150 200 250 100 200 300 Julian Day mg L-1 simulated Sanggou Data (93/94) Suspended Particulate Matter 50 100 150 200 250 100 200 300 Julian Day mg L-1 simulated Sanggou Data (93/94)

r = 0.91 r = 0.80 r = 0.96

EcoWin EcoWin 2000 2000 – – Sanggou Sanggou Bay model Bay model

Chinese scallop individual growth under different conditions Chinese scallop individual growth under different conditions

Single individual, all alone in the bay... Single individual, standard model 93-94 Single individual, 10X seeding rate, Model 93-94

Application of the EcoWin2000 model Application of the EcoWin2000 model to to Sanggou Sanggou Bay Bay

Annual scallop and oyster harvest Annual scallop and oyster harvest

10000 20000 30000 40000 50000 60000 70000 Simulated harvest 56500 18400 Scallops Oysters 60000 t y-1 Fisheries estimate Official data 24000 t y-1 42800 t y-1 13000 t y-1

Ton TFW y-1

Run conditions: 6 year run with 1h timestep, values for year 6, ten objects active

EcoWin EcoWin 2000 2000 – – Sanggou Sanggou Bay model Bay model Mass balance for phytoplankton Mass balance for phytoplankton (internal processes : standard model) (internal processes : standard model)

Sources ( Sources (gC gC m m-

• 2

2 y

y-

• 1

1)

) Net primary production Net primary production 63.97 63.97 Sub Sub-

• total

total 63.97 63.97 Sinks ( Sinks (gC gC m m-

• 2

2 y

y-

• 1

1)

) Natural mortality Natural mortality

• 18.9

18.9 Oyster phytoplankton uptake Oyster phytoplankton uptake

• 1.89

1.89 Scallop phytoplankton uptake Scallop phytoplankton uptake

• 3.48

3.48 Sub Sub-

• total

total

• 24.27

24.27 Total sources and sinks ( Total sources and sinks (gC gC m m-

• 2

2 y

y-

• 1

1)

) 39.70 39.70

Results for year 6 of the standard model

EcoWin EcoWin 2000 2000 – – Sanggou Sanggou Bay model Bay model Scallop Scallop overseeding

• verseeding

10000 20000 30000 40000 50000 60000 70000 80000 90000 5 10 15 20 25 30 Increase in seeding Harvest yield (ton TFW)

Maximum harvest: 81000 ton TFW

10000 20000 30000 40000 50000 60000 70000 80000 90000 5 10 15 20 25 30 Increase in seeding Harvest yield (ton TFW) Scallop Excess

Run conditions: 6 year run with 1h timestep, values for year 6, ten objects active

EcoWin EcoWin 2000 2000 – – Sanggou Sanggou Bay model Bay model

500 1000 1500 2000 2500 3000 10 20 30 40 50 60 Increase in seeding Harvest / seeding ratio 5 10 15 20 25 30 35 40 45 5 10 15 20 25 30 Increase in seeding Harvest / seeding ratio

Chinese scallop Pacific oyster

Harvesting and Harvesting and seeding: seeding: Scallop and oysters Scallop and oysters

Run conditions: 6 year run with 1h timestep, values for year 6, ten objects active

0.5 1 1.5 2 2.5 10 20 30 seeding pressure (X standard seeding) ug Chl(a) L-1

Comparison between Comparison between standard model standard model and scenario and scenario Phytoplankton Phytoplankton

• 60000
• 40000
• 20000

20000 40000 60000 NPP Mortality Shellfish uptake Boundary exchanges mgC m-2 y-1 x0.5 x1 x2 x5 x10 x15 x20 x25 x30 Phytoplankton concentration in the bay Phytoplankton mass balance

Movie credits Movie credits

Cedric Bacher, Mingyuan Zhu Cedric Bacher, Mingyuan Zhu Tony (3 pack) Hawkins Tony (3 pack) Hawkins Jean Jean-

• Marc Deslous

Marc Deslous-

• Paoli

Paoli Ganbei Ganbei

Thank Thank-

• you for

you for your attention your attention

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