PowerPoint Presentation - Shallow Estuarine Habitats Important by cometjunkie44

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									Temperature and Salinity Effects on the Growth and Survival of Juvenile Penaeid Shrimps: Implications for the Influence of River Diversions on Production

Lawrence P. Rozas1, Thomas J. Minello1, and Doran M. Mason2

Fisheries Service 2 NOAA Great Lakes Environmental Laboratory and Atlantic Oceanographic and Meteorological Laboratory

1NOAA

Caernarvon Freshwater Diver sion River Diversion into Breton Sound Estuary at Caernarvon, Louisiana Project
Big Mar

Diversion Structure

Coastal Habitats
• Estuarine-Dependent Species Account for >95% of Fishery Landings in the Gulf of Mexico and South Atlantic • Early Life Stages of Many Fishery Species (e.g., penaeid shrimps, blue crab) are Tightly Linked to Shallow Estuarine Habitats • Major Function of Estuarine Habitats = Support of Fishery Populations

OBJECTIVES
1. Establish the relationships between the distribution, growth, and survival of juvenile white shrimp and brown shrimp and two key environmental variables (water temperature and salinity) affected by freshwater inflows using a series of controlled lab experiments. 2. Test validity of these relationships using field experiments. 3. Examine relationship between shrimp growth rates in the field and availability of potential prey. 4. Incorporate experimental results into simulation models to predict effects of temperature and salinity on shrimp growth and survival.

Sectors

9 10 11

8

7

Gradient Drain

6 5 4

Each raceway Width 15 cm Length 636 cm Water depth 10 cm

12 13

Control Drain

3 2 1

14
Freshwater Inflow

Control Inflow

Control Inflow

Saltwater Inflow

15 16 17
Airstones Control Drain

28

27 26 25 19 20 21
Gradient Drain

18 24 22 23

Inflow Rate 2.0 L/min (x2) Current is 6.6 cm/min 4% exchange per min 24 min turnover

Whie shrimp (7 experiments) White Shrimp (7 experiments)
12

10

Experimental Control

Relative Frequency

8

6

4

2

0
2 2 2 3 4 4 6 6 7 9 10 13 13 17 17 21 21 25 25 29 29 31 31 33 33 34 34 34
Mean Salinity (ppt) in Sector

Experimental Design Experimental Design
• 4 Locations (Intermediate-Saline Zones) • 3 Treatments (Shallow Food, Shallow No Food, Deep) • 5 Shrimp per Enclosure • Duration: 7 days • Variables Measured: Salinity, Water Temperature, D.O., Water Depth, Prey Abundance, Shrimp Growth Rate

Marsh

F

F

F

F

Brackish Marsh, Barataria Basin - May 2007 Growth Experiments using Brown Shrimp

Modeling Component
Bioenergetics Growth, Survival, and Spatial Models
• Initial development from existing literature • Modified from results of laboratory experiments • Growth and survival models to be tested against field results

Future Research
1. Field growth experiments and additional laboratory gradient experiments using white shrimp. 2. Further develop bioenergetics models as results of lab and field experiments become available. 3. Continue to seek funding for Dr. Mark Peterson to conduct complementary laboratory growth experiments.


								
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