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

Source – Sub-stressor Linkage Matrix Agriculture Urban WTP Roads Dams Fisheries Marinas Forested Area Industrial Parks External Aquatic Barriers Terrestrial barriers Physical environmental changes

Source – Sub-stressor Significance Matrix Agriculture Urban WTP Roads Dams Fisheries Marinas Forested Area Industrial Parks External Aquatic Barriers Terrestrial barriers Physical environmental changes Weighted Total

Sub-stressor – Habitat Linkage Matrix LC <6LC >6 Lakes/ ponds Rivers/ Streams Developed Forest Herbaceous Agriculture Wetlands Aquatic Barriers Terrestrial barriers Physical environmental changes

Sub-stressor – Habitat Significance Matrix LC <6LC >6 Lakes/ ponds Rivers/ Streams Developed Forest Herbaceous Agriculture Wetlands Aquatic Barriers Terrestrial Barriers Physical environmental changes Weighted Total

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 pre- linkage 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?