Eastern Oyster Population in the Lower Choptank River

1. Eastern Oyster Population in the Lower Choptank River By Matthew Cuber, Rodney Hosler, Angela Kuzma 7/1/10

2. Research Question • To what extent does turbidity caused by storm surge affect the Eastern Oyster populations, in the Lower Choptank River?

3. The Choptank River • A major tributary of the Chesapeake Bay • Watershed is 1,004 sq mi • 68 mi long • Longest river on Eastern shore

4. The Choptank River Species • The river is home to an estimated: • 3.9 million fish • Including 30 different species • 11 species of reptiles/amphibians • 3 freshwater mussel species • AND THE EASTERN OYSTER

5. The Eastern Oyster • Crassostreavirginica or American oyster • Bivalve (2 shells) • Lives on bottom • Appearance is due to its habitat • 4-5” typical growth in Choptank and Bay • Native to bay • Found in: • Eastern coast of the USA to St. Lawrence in Canada to Key Biscayne, FA • Mexico, Caribbean and Venezuela

6. The Eastern oyster diet/reproduction • Eat algae and filter water • Spawn in the water column • Oyster is fertilized and attaches to bottom • Like hard substrate like other oyster shells • Prefer salty water (10-28 ppt) • Once oyster attaches to bottom it is called a SPAT

7. Video of Oyster Reproductive Process • http://hpl.umces.edu/hatchery/home.html

9. Oyster harvests over the years • 125 yrs - Lt. Francis Winslow - Tangier Sound (1878-1879) • Spurred into action by the Oyster Wars (Oyster Navy-1868) • 1880 - MD oyster industry valued at $4 million; 24,000 watermen • Principal protein source of the East coast (no railroad) • 1882 - first MD wide oyster survey (Oyster Commission) • 1884 - estimated 15 million oysters harvested • 1889 - estimated 9.5 million oysters harvested • 12 watermen killed on Hog Island over oyster dispute

10. The Oyster Wars

11. Oyster harvests contd. • Oyster harvested declined for 40 yrs from the high point in 1884 • 1916 - Maryland Conservation Commission formed • Transplant “stunted” seed oysters • Planting shells for clean substrate attachment (records from 1939) • Oysters populations stabilized 1920-1980s, never reached 1800s level again • 1980s – today - diseases (MSX Dermo) begin to lower harvests

13. Class Survey • Do you eat oysters? • 46.2 % Yes • 53.8 % No Don’t Eat My Oysters!

14. Turbidity and the Oyster Turbidity Sucks • Turbidity is the cloudiness or haziness of a fluid caused by individual suspended particles • Suspended soils interfere with the filter feeding and breathing of the oyster • Silt and other materials can prevent oyster larvae from “setting” • Turbidity reduces the oyster food supply by blocking light (preventing underwater photosynthesis in algae) • Email interview with Victor Kennedy - University of MD Center for Environmental and Estuarine Studies Horn Point Environmental Laboratory

15. DNR Data

16. Storm Surge • A storm surge is an offshore rise in water do to a low pressure weather system • Storm surges stir up sediment and silt which cause a rise in turbidity in waterways Say no to storm surge

17. Issue Web

18. Players Chart

19. Our Data

20. Conclusions/Inferences • The background research shows there is a correlation between turbidity and the health of the eastern oyster • Our data shows a lower turbidity than the most recent data (as of June) found in the Choptank (via DNR’s monitoring site at Ganey’s Warf Station)

21. Error/Problems/Issues • Lack of sampling time • Lack of time • Lack of locations • Lack of data • Sampling of convenience • Boat stirring up water/sediment? • Etc…

22. Recommendations • More (A LOT) background research/data is needed for comparison (getting data after storms to see storm surge effects) • More sampling is needed for reproducibility (over time, location, etc.)

23. Action Plan • Educate our students about the problems with the eastern oyster • Do not buy/eat oysters from the Chesapeake Bay till populations have increased (severely) • Resurvey the area from time to time to see any future trends

24. I Pity the Fool Who Eats Choptank Oysters!