Geomorphology: Researchers are
photographing the river, conducting bathymetry and seismology studies,
and analyzing grain size data. Over the two-year
monitoring period, few changes were noted in river bathymetry or bank
characteristics. Channel sediment characterization revealed that, within the
study area, the Penobscot River channel in both flowing and impounded reaches
is dominated by coarse sediment with a predominately sand matrix. This is in
striking contrast to fine-grained sediment storage noted in many impoundments.
Geological Survey work underway on the Penobscot ... watch the VIDEO describing how this is done.
Water Quality/Insect Diversity: The Penobscot Indian Nation Water Resources Program monitored aquatic benthic
macroinvertebrates from seven locations associated within the
impoundment and tailwater areas of the Great Works and Veazie dams, as well as
the tailwater area of the Milford Dam. To characterize water quality conditions
prior to dam removal we collected water samples and measurements from 10 sites
within the Great Works and Veazie dams project areas. Water quality parameters collected included
dissolved oxygen, temperature, conductivity, BOD, bacteria, turbidity, secchi
transparency, total suspended solids, pH, chlorophyll, and total phosphorous.
Transfer: Researchers collect samples throughout the system that are
used for stable isotope studies. The studies can be compared to provide
information on nutrient cycling and feeding habits of the various
species at different places and times throughout the system. Stable isotope
studies are based on the idea that "you are what you eat" because isotope
signatures of consumers reflect the isotope values of their prey, which in turn
can be used to infer food chain level and habitat associations (in this case
marine vs. freshwater). Pre-dam removal data collected in 2009-2011 shows
strong isotopic distinctions between the freshwater and marine food webs.
PIT detection: Atlantic salmon adults
and other tagged fish are being tracked as they move past dams on their
upstream migration. Antennas (loops
of wire a tagged fish must swim through to be read) are located near the
entrances and exits of fishways ... to determine if a fish entered a fishway,
and, if so, was it successful in passing upstream ... the use of PIT tag
technology allowed large numbers of fish to be tracked. This research will continue throughout
the dam removal period.
Smolt telemetry: Atlantic salmon smolt, both hatchery and wild, are being tagged and tracked as they descend the river, passing over and through dams, to the Atlantic. Several years of
results indicate that in the Penobscot River, migrating salmon move more
quickly through areas without dams than those with dams. Survival is markedly
higher in river reaches without dams.
Shortnose Sturgeon: Researchers are catching sturgeon, tagging them and seeing if they spawn in the Penobscot River. The presence of
reproductive females and suitable spawning habitat in the upper river has been
documented. Reproductive females from the Penobscot River have been tracked moving
to the Kennebec River, potentially indicating a complex reproductive migration
Check out our spotlight on sturgeon page, which includes photos and video of ongoing sturgeon research in the Penobscot River.
Hydroacoustics: SONAR systems are used to monitor fish presence, abundance and movements
in rivers, estuaries, and oceans. Our goal is to measure and understand changes
in fish populations before and after the Penobscot River Restoration Project.
We have been developing a standardized approach for long-term SONAR monitoring,
and collecting pre-restoration data that will be the baseline for comparison in
subsequent years following restoration activities. When correlated with other data, it is hoped that
hydroacoustics will provide accurate estimates not only of biomass, but
also of fish species.
Fish Community: Researchers are electrofishing throughout the
Penobscot, providing detailed information on total fish biomass,
abundance, and species. Findings show
that many diadromous fishes were restricted to tidal waters below Veazie Dam,
although Atlantic salmon, sea lamprey, and American eel were captured or
observed upstream. Species richness was relatively high below Veazie Dam ... These data indicate that the restoration of
connectivity through dam removal will likely result in predictable shifts in
Meet the Scientist!: Steve Coghlan describes the impact of dam removal on sea-run fish and his work investigating fish communities pre-dam removal.
Wetlands: Researchers are collecting data on wetlands, rare plants, and invasive plants.
Restoration Research Network (DSRRN)
Maine Interagency Stream Connectivity Work Group 2009-2010
(Year One) Summary and Recommendations.
Penobscot River Science and Monitoring Archives