1. Thom Teears Department of Biology James Madison University
The Effects of pH, Alkalinity, and Water Hardness on the Development of Brook Trout (Salvelinus fontinalis) Eggs and Fry in an Aquaculture Setting
Thom Teears
Department of Biology
James Madison University

2. Anthropogenic impacts on Streams
Urbanization
Sedimentation from
agricultural land use
Industrialization

3. Aquaculture
History (Wedemeyer, 2001)
China 500 B.C.
Egypt 4,000 B.C.

4. Aquaculture today Demands Focus: Water Quality
Recreational and natural fisheries
Commercial and Retail
Global significance
Focus: Water Quality

5. Water Quality Temperature Dissolve Oxygen pH Alkalinity
Water Hardness (Calcium, Magnesium)

6. Relationships pH, alkalinity, hardness (Wurts and Durborow, 1992)
pH (H+)
Alkalinity (units: mg/l of CaCO3)
CO2 +H2 O=H2 CO3 HCO3- CO32-
Hardness (units: mg/l of CaCO3)
Ca2+,Mg2+

7. Acidification of natural streams
Fisheries decline (Mason, 1990; Sayer et. al., 1993)
Deposition of acidic compounds (Drever, 1997)
Combustion
Smelting
Mining (Sulfides)

8. Stream resistance to acidification
Alkalinity=ANC: Acid Neutralizing Capacity (Drever, 1997)
Geology governs water quality
Limestone, calcite (CaCO3), and alkalinity
High ANC in Limestone streams, resistant to acidification

9. Shenandoah National Park
Bioassays (MacAvoy and Bulger, 1995)
Higher ANC= increased survival

10. Recruitment failure Brook trout can reproduce effectively
Recruitment failure caused by acidification (Brown et. al., 1988)
Many studies focus on early life stage development

11. Water hardness
Ca2+,Mg2+ (Silva et. al. 2003, Wurts and Durborow, 1992)
Osmotic regulation
Loss of blood salts
Affects heart, muscle, nerves, bone, scales, metabolic functions etc..
Ca2+ from gills (primary) and diet (secondary)
(Hwang et. al., 1996; Hwang and Hirano, 1985)
Mg2+ from diet (primary) and gills (secondary)
(Bijvelds et. al., 1996)

12. Metal toxicity Sources: industrial and urban waste runoff
Higher Ca2+ reduce toxicity to:
Aluminum in brook trout (Ingersoll et. al., 1990)
Manganese in brown trout eggs (Stubblefield et. al., 1997)
Mercury in rainbow trout (Terzi and Verep, 2011)
Cadmium in Teleosts, Ca2+ major contributor, not Mg2+ (Michibata et. al., 1986)

13. (Ingersoll et. al., 1990)

14. Alkalinity vs. Water Hardness
Difficult to isolate variables
Calcium hardness protects rainbow trout against copper toxicity (Miller and Mackay, 1980)
Alkalinity protects against
copper toxicity in catfish
(Wurts and Perschbacher,
1994)

15. Methods Brook trout eggs: Marion Fish Hatchery
“Trout in the Classroom” protocols

16. Treatments: endpoints
Montebello Fish Cultural Station Spring Water: Low hardness and alkalinity
Marion Fish Hatchery Source Water: Moderate Ca2+, High Mg2+
High Ca2+ hardness, high alkalinity: 50 ppm CaCO3
High Mg2+ hardness, high alkalinity: 12 ppm MgCO3
High Ca2+ hardness, low alkalinity: 50 ppm CaSO4
High Mg2+ hardness, low alkalinity: 12 ppm MgSO4
Limit feed rates

17. Parameters Survival % Growth rate Feed conversion Hatch time
Yolk-sac absorption
Body condition
Length/ weight
Caloric content
Mineral content?

18. Engaging the community: “Trout in the Classroom” participation
Identify potential instructors in community
Students researchers
Perform directed
treatment
Gather data
Survival
Growth
Feed conversion
Body size
Monitor chemistry

19. South River deep springs:
Evaluate water quality for use in hatching and rearing of brook trout for VA Living Museum.
Gas concentration- CO2, N2, or O2
Temperature
Hardness , Alkalinity and pH
Experiment hatching BKT in spring?

23. Questions?