1. Mark Hudy Senior Science Advisor – Fisheries USGS
Comparing Apples, Oranges and Pineapples: Brook trout data; Lessons learned from the Eastern Brook Trout Joint Venture
Mark Hudy
Senior Science Advisor – Fisheries
USGS

2. Objectives

3. USDA Forest Service Fish and Aquatic Ecology Unit
Objectives
Brief History
Transition from subwatershed “currency”
Occupancy databases
GIS databases
Products
Scale paper
Climate resilience data
Climate web project
Genetic patch sampling
USDA Forest Service Fish and Aquatic Ecology Unit

4. History

5. Case History: Eastern Brook Trout Joint Venture
Evaluate the distribution of brook trout for the 2005 EBTJV assessment.
Context:
-lots of states
-inconsistent fine scale data
3. Hudy et al NAJFM 28:

6. Currency: Subwatersheds
A good start
Not fine enough for many questions?
Only short term option for some states
USDA Forest Service Fish and Aquatic Ecology Unit

7. Transition from Subwatershed Currency

8. Assessment Scales Sub-basins (4th HUC; 8 digit)
220 (avg size= 254,172 ha)
Watersheds (5th HUC;
10 digit)
1,472 (avg size = 41,201 ha)
Subwatersheds (6th HUC;
12 digit)
6,833 (avg size = 8,879 ha)
Catchments (14 digit ?)
243,874 (avg size = 237 ha)

9. Case Study:The scale at which results are reported can bias impressions of the true distribution.

10. Case Study: The scale at which results are reported can bias impressions of the true distribution.
Corollary lesson: “The same database will be used to support opposite opinions”!

12. Sub-basins (4th HUC) 100%

13. Watersheds (5th HUC) 76%

14. Subwatersheds (6th HUC) 33%

15. Catchments 11%

16. Patch Metrics

17. Identification of Brook Trout “Patches”
“Patch”= a group of contiguous catchments occupied by wild brook trout.
Patches not connected physically
Dams, warm water habitat, downstream invasive species
Assumed to be genetically isolated populations

18. USDA Forest Service Fish and Aquatic Ecology Unit
Patches
USDA Forest Service Fish and Aquatic Ecology Unit

19. USDA Forest Service Fish and Aquatic Ecology Unit

20. USDA Forest Service Fish and Aquatic Ecology Unit
Patch - “Populations”
Number of patches
2,698
Average size
1,541 ha
Median size
855 ha
USDA Forest Service Fish and Aquatic Ecology Unit

21. Patch Metrics (based on occupancy sampling of catchments)
Spatial Metrics
# of patches
# of patches with increasing size/connectivity(additional upstream and downstream catchments with brook trout)
# of patches decreasing in size/connectivity( loss of catchments)
Average patch size of the entire resource
# of patches with allopatric or sympatric(with brown or rainbow) populations

22. Why Patches ? Current Population Estimates
Mark-Recapture
Depletion Removal
Problems:
Not viable for large scale monitoring
Expense
Inability to detect trend (i.e. large coefficient of variation % 50 adults; % 121 YOY)
Expansion to entire stream

23. Occupancy Database

24. Occupancy: Brook, Brown and Rainbow
Sub-basins (4th HUC; 8 digit)
107 (avg size= 254,172 ha)
Watersheds (5th HUC;
10 digit)
808 (avg size = 41,201 ha)
Subwatersheds (6th HUC;
12 digit)
3,804 (avg size = 8,879 ha)
Catchments (14 digit ?)
132,321,688 (avg size = 237 ha)

25. Brook Trout Distribution: Sub-basin (4th HUC)
78% of 107 sub-basins
“Brook trout are well distributed throughout their native range”.

26. Brook Trout Distribution: Watershed (5th HUC)
52% of 808 watersheds
“There have been some losses of brook trout but they are still found in approximately half of their range”.

27. Brook Trout Distribution: Subwatershed (6th HUC)
32 % of 3,804 subwatersheds
“Brook trout have been extirpated from over 66% of their historic subwatersheds”.

28. Brook Trout Distribution: Catchments
14 % of 132,321
catchments
“Brook trout have been extirpated from 86% of their historic catchments”.

29. GIS Database

30. USDA Forest Service Fish and Aquatic Ecology Unit
Multiple Metrics (85)
Geology, soils
NLCD 2001
NLCD 2006
Dams, roads, road xing
Pollution
Elevation, air temp.
Occupancy
USDA Forest Service Fish and Aquatic Ecology Unit

31. USDA Forest Service Fish and Aquatic Ecology Unit
Multiple Scales
Sub-basin (HUC 8)
Watershed (HUC 10)
Sub-watershed(HUC 12)
Local Catchment
Local Catchment –Corridor
Network Catchment
Network Catchment -Corridor
USDA Forest Service Fish and Aquatic Ecology Unit

32. Products

33. Scale Paper

34. CART Model : Extirpated (76%); Reduced (64%); Intact (79%)
% Forest
Deposition kg/ha
% Agriculture
Road Density km/km2
% Forest Riparian

35. Core Metric: % Forest Subwatershed threshold 68% forested land
Only 6% of Intact subwatersheds have less than 68% Total Forest.
85% of Extirpated subwatersheds < 68% Total Forest
68%
I believe that land managers should be concerned when subwatersheds drop below 68% forested land
68%

36. Assessment Scales Sub-basins (4th HUC; 8 digit)
220 (avg size= 254,172 ha)
Watersheds (5th HUC;
10 digit)
1,472 (avg size = 41,201 ha)
Subwatersheds (6th HUC;
12 digit)
6,833 (avg size = 8,879 ha)
Catchments (14 digit ?)
243,874 (avg size = 237 ha)

37. Climate Resilience

38. Under various climate change scenarios, brook trout are predicted to be extirpated from parts of the historic range: Chesapeake Bay
Flebbe et al Spatial Modeling to Project Southern Appalachian Trout Distribution in a Warmer Climate. TAFS
Clark et al Predicting Climate Change Effects on Appalachian Trout: Combining GIS and Individual –Based Modeling. Ecological Applications.
Meisner Effect of Climatic Warming on the southern margins of the Native Brook Trout . CJAS

39. Secondary Data Used in Regional Models
Air Temperature:
Mean annual maximum air temperature (PRISM; 800 m grid)
Air Temperature from Elevation or Elevation/Latitude models
Models from local weather stations ( i.e. airports, NOAA)
Water Temperature:
Usually no direct measurements
Assume a steady relationship between air and water temperatures (i.e. 1°C air temp rise = 0.8°C water temp rise)

40. Sensitivity

41. LE/HS HE/HS LE/LS HE/LS Sensitivity Exposure
Figure 1. Conceptual vulnerability classification model for brook trout populations; brook trout populations are classified into one of four quadrants based on direct measurements or model predictions of sensitivity and exposure. Low exposure, low sensitivity populations are most likely to persist under various climate change scenarios.

42. Subsample 100 reproducing brook trout patches in WV,VA and MD
Cluster Metrics
Elevation
Max air
% ground water
% Forest
Solar gain

43. Onset HOBO Water Temp Pro v2
Directly Measure Exposure and Sensitivity with Paired Air and Water: Thermographs
30 minute intervals with focus on the critical summer periods (July-September 30)
Focus on daily maximum water (DMAXW) and daily maximum air (DMAXA)
Onset HOBO Water Temp Pro v2
Operation Range: -20 to 70°C
Accuracy: 0.2°C over 0° to 50°C
Resolution: 0.02°C at 25°C

44. Predictive Metrics
Exposure: 81.1 % concordance Elevation (m) % Forest Corridor Watershed Area (km2)
Sensitivity: 75.2% concordance Maximum Air (°C) Watershed Area (km2) Solar_mean_corridor

46. Climate Metrics

47. Predictive Metrics
Exposure: 81.1 % concordance Elevation (m) % Forest Corridor Watershed Area (km2)
Sensitivity: 75.2% concordance Maximum Air (°C) Watershed Area (km2) Solar_mean_corridor

48. Solar Gain – 30 meter pixel
Topography
Aspect
Elevation
Latitude
Longitude
Riparian cover

50. Solar radiation (upper quartile) Canopy cover (<70%)

53. Genetic Patch Metrics

54. USDA Forest Service Fish and Aquatic Ecology UnitNe Nb
diversity
USDA Forest Service Fish and Aquatic Ecology Unit

55. Genetic Monitoring Metrics
Nb = # of individual brook trout(regardless of age) contributing to year class; -Not the data requirements of Ne (Whiteley et al. 2012)
2. Amount of genetic diversity within a patch can evaluate changes in relative abundance

56. Virginia Pilot Study Stream Name 131 (95-192) 28 (14-93) 5 (3-9)
Patch Size (Ha)
Adult N (95% CL)
YOY N (95% CL)
Nb (95%CL)
Nb/N
Fridley's Gap* (above Karl's dam)
590
1,004(882-1,145)
459(188-1,789)
131 (95-192) 
 0.13
Skidmore Fork (above Todd Lake)
993
268( )
47(42-130)
28 (14-93) 
 0.10
Dry Run (above Dry Run Dam)
1217
83(78-156)
117(86-367)
5 (3-9) 
 0.06
Briery Branch (above Briery Branch Lake)
2438
366( )
236( )
26 (21-33) 
 0.07
Dry River (above Switzer lake)
3807
1,982(1,726-2,202)
1,285(843-2,077)
67 (58-77) 
 0.03
Little River (above Hearthstone Lake)
4121
728( )
463( )
46 (40-53) 

57. Virginia Pilot Study

58. Interpreting the Nb Metric
Increasing Nb trends: positive response from improved habitat or increasing population.
Decreasing Nb trends: suggest habitat loss and decreasing populations.

59. Number of Sample Starting Locations1

60. Number of Sample Starting Locations2

61. Number of Sample Starting Locations3

62. Number of Sample Starting Locations4

63. Conclusions Sample size of at least 75 3 starting locations
For genetic monitoring headwater brook trout populations, we recommend:
Sample size of at least 75
3 starting locations
Focus on Nb of age-0 cohort
Works across brook trout populations with varying family structure
Should be general outcome for monitoring Nb of headwater trout populations

64. Monitoring Design

65. Proposed Monitoring Design and Methods: VA example
Cluster analysis to subsample existing 331 patches:
Sentinel samples- (yearly trends)
Panel samples every 5 years (long-term trends)
Example:
125 sites from cluster analysis-
25 are designated “sentinel” to be sampled yearly.
Additional 20 sites sampled yearly on a rotating panel (each site visited every 5 years)
Equals 45 sites monitored statewide per year.

66. Lessons Learned

67. Lessons Learned Observed

68. Thanks to the Partners!

70. USDA Forest Service Fish and Aquatic Ecology Unit

71. Smith Creek: NFWF