Transcript Barriers to Aquatic Organisms By: Aaron Rice, Michael Tchen, and Leo Bertolino.

Barriers to Aquatic Organisms
By: Aaron Rice, Michael Tchen, and Leo Bertolino
Problem Statement
Barriers to aquatic
organisms have a
detrimental effect
on organism’s
natural habitat
range and fitness.
Goal/Purpose
To establish a relative risk model for
barriers to aquatic organisms including
associated sources and habitats
Objectives
1. Establish connections rankings between
sources and sub-stressors.
2. Establish significance rankings between sources
and sub-stressors.
3. Establish connections rankings between sub-
stressors and habitats.
4. Establish significance rankings between sub-
stressors and habitats.
Sub-stressors
Terrestrial barriers
ex. roads
Aquatic barriers
ex. dams
Physical environmental changes as a barrier
ex. sedimentation
Aquatic Barriers
A barrier to movements of aquatic organisms
that is found in the water.
Sources of Aquatic Barriers
Dams (2)
Migratory fish
Roads – Culverts (2)
Upstream travel
Marinas? (0)
Possible link - unsure
Effects of Aquatic Barriers on
Habitats
Lake Champlain <6ft (1)
Fish specie loss
Lakes/Ponds (1)
Connected to rivers
Wetlands (1)
Connected to bodies of water
Forests (indirect?) (.5)
Bottom up effect?
Streams/Rivers (2)
Dams and culverts
Terrestrial Barriers
Land based barriers to aquatic organisms.
Sources of Terrestrial Barriers
Agriculture (.5)
Fragmentation of landscape
Urban (2)
Inhospitable passage
Roads (2)
Car traffic
Industrial (1)
Impassible
Effects of Terrestrial Barriers
on Habitats
Lakes/Ponds (2)
Streams/Rivers (2)
Forests (1)
Herps add less to total biodiversity
Wetlands (2)

Effect due to loss of herpetofauna
•
Frogs, turtles, salamanders, etc.
Physical Environmental
Changes as a Barrier
Changes to the hydrology and
physical characteristics of
water bodies causing a barrier
to aquatic organism
movement.
Sources of Physical
Environmental Changes as a
Barrier
Agriculture (1)
Urban (2)
Roads – culverts (1)
Increase stream flow
Waste water treatment plants (1)
Dams (2)
Industrial (1)
Increased water temperature
External (1)
Climate change ?
o Increased
runoff
causing sedimentation
and increase stream flow
Effects of Physical
Environmental Changes as a
Barrier on Habitats
Lake Champlain <6ft (1)
Decreased stream accessibility
Lake Champlain >6ft (.5)
Loss of fish
Lakes/ponds (1)
Loss of habitat and in turn species
Rivers/streams (2)
Loss of spawning habitat
Less upstream colonization
Wetlands (1)
sedimentation
Agriculture
Urban
WTP
Roads
Dams
Fisheries
Marinas
Forested
Area
Industrial
Parks
External
Source – Sub-stressor Linkage
Matrix
Aquatic
Barriers
0
0
0
1
1
0
.5
0
0
0
0
Terrestrial
barriers
1
1
0
1
0
0
0
0
1
0
0
Physical
environmental
changes
1
1
1
1
1
0
.5
0
1
0
1
Agriculture
Urban
WTP
Roads
Dams
Fisheries
Marinas
Forested
Area
Industrial
Parks
External
Source – Sub-stressor
Significance Matrix
Aquatic
Barriers
0
0
0
2
2
0
0
0
0
0
0
Terrestrial
barriers
.5
1
0
2
0
0
0
0
1
0
0
Physical
environmental
changes
1
2
1
1
2
0
0
0
1
0
1
Weighted Total .4
.8
.2
1.8
1.2
0
0
0
.6
0
.2
LC <6
LC >6
Lakes/ ponds
Rivers/
Streams
Developed
Forest
Herbaceous
Agriculture
Wetlands
Sub-stressor – Habitat Linkage
Matrix
Aquatic
Barriers
.5
0
1
1
0
.5
0
0
1
Terrestrial
barriers
0
0
1
1
0
1
0
0
1
Physical
environmental
changes
1
1
1
1
0
0
0
0
1
LC <6
LC >6
Lakes/
ponds
Rivers/
Streams
Developed
Forest
Herbaceous
Agriculture
Wetlands
Sub-stressor – Habitat
Significance Matrix
Aquatic
Barriers
1
0
1
2
0
.5
0
0
1
Terrestrial
Barriers
0
0
2
2
0
1
0
0
2
Physical
environmental
changes
1
.5
1
2
0
0
0
0
1
Weighted
Total
.6
.1
1.4
2
0
.6
0
0
1.4
Total Ranking System
Weighted average
Multiply the linkage matrix by the significance matrix.
Terrestrial and Aquatic Barriers weight 2x physical
environmental barriers.
The weighted totals on the significance matrices are prelinkage adjustment.
Recommendations for Dams
Provide large economic
benefits
Fish ladders around
larger dams
(questionable
effectiveness)
Careful removal of old
dams
One large dam will
prevent all upstream
travel
Recommendations for
Culverts
Identify Causeways using GIS
Modify road culverts- sediment substrate, allow light
Add temporary drift fence to culvert
Establish 289m core habitat and 50m buffer zone
(Semlitsch and Bodie 2003)
Recommendations for
Culverts cont.
Culverts- site by site
No long culverts-more chance to not passs through and
cuts off bends
Undersized culverts-hourglass syndrome
Take into consideration Vertical adjustment range
(VAR)
Physical Environmental Changes
Plant buffer crops along rivers and
streams
Increase culvert sizes to reduce flow speed
Better management of waste water
Reduce impassible dams which impede
water flow
Decrease urban impervious surface
Permeable pavement
Natural sinks for storm water drainage
Questions?