Getting out Ahead of Invasive Species

This summer, Save The Bay has been working with local residents in Rehoboth, Massachusetts to remove invasive water chestnut from Shad Factory Pond. Water Chestnut is an annual plant that is rooted in the pond bottom and has floating leaves and small white flowers. Large black nuts form under the surface and have very sharp barbs that can stick to animals and can float downstream. The nuts stay viable in the sediment for up to 12 years, and each nut can produce 10-15 plants, so you can see how hard it is to eliminate this plant once it gets established in a waterbody.

Thick mats of floating water chestnut leaves can take over in ponds and slow moving rivers by shading out other plants and reducing oxygen in the water. It spreads rapidly and displaces native species. The most common method for removal is to hand-pull the plants in mid-summer before the nuts fall. This hand-pulling is hard work, but over several years can effectively limit the spread of the plant. When the problem gets too big for volunteers, mechanical harvesters are often used to pull plants on a large scale.

Water Chestnut is of particular concern on Shad Factory Pond because the Palmer River is an important fish run for herring and shad. Save The Bay is beginning a study this summer in partnership with the Massachusetts Division of Marine Fisheries to study spawning habitat in the pond. We are looking at dissolved oxygen, water clarity, pH, nutrients and spawning substrate to see if there is enough suitable habitat for fish. In addition to the water chestnut, other invasive plants including milfoil and fanwort along with native pond lilies and other submerged plants are limiting the available oxygen and harming spawning substrate.

Central Pond in East Providence, part of the Ten Mile River, also has a large infestation of water chestnut. This is of concern because fish passage was recently restored to this system as well. Harmful algae blooms have also been an issue on this pond, and invasive species can make the problem worse. As we try to re-introduce fish to river systems around the Bay, we also need to be concerned with what they will find when they arrive.

Omega Pond Fish Ladder opens up the Ten Mile River

After several delays and technical challenges, the Omega Pond fish ladder at the mouth of the Ten Mile River was finally opened just in time for this year's spring fish run. Herring were waiting at the dam when the ladder was opened, and fish were seen making their way to Hunt's Mill where an annual fish count is done by volunteers.

Save The Bay's connection to this project began in 1996, when  Paul Bettencourt took Wenley Ferguson on a tour of the ponds where he once fished for herring, now long since filled in. They stopped at the Omega Pond dam, where Paul shared his vision of restoring the fish run. Dick Quinn, an engineer with the US Fish and Wildlife Service, completed a conceptual design for three fish ladders, and the project began in 2001 with an Army Corps of Engineers feasibility study. The project was a collaboration between many state, federal and local partners including Save The Bay, the CRMC, DEM, the City of East Providence and the Ten Mile River Watershed Council.

About 65% percent of the funding for the project was provided by federal agencies including the U.S. Environmental Protection Agency (EPA), the National Oceanic and Atmospheric Administration (NOAA), and the U.S. Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS). This funding includes about $5 million from the Army Corps of Engineers. 

Now that three fish ladders are in place, herring have three river miles and about 340 acres of habitat in which to spawn. They can now make their way to the Massachusetts state line, where they find the next dam at the Pawtucket Country Club. This dam is part of the Ten Mile River Reservation and is owned by RI DEM. The Massachusetts Division of Marine Fisheries has been supporting this project and provided fish from the Nemasket River herring run in Middleboro. These fish were stocked into the upper Ten Mile River to help maintain the run. The run was also maintained by a group of fishermen who for over ten years scooped returning herring and stocked them into the river under cover of darkness. These scooping events became celebrations as more and more fish returned and several thousand fish were helped over Omega Pond dam. 

Save The Bay will continue to work on this project and will advocate for continued river restoration. Water quality improvements are still desperately needed and the upper Turner Reservoir and Central Ponds often experience blooms of toxic blue-green algae. The flow in the Ten Mile River, like many of the Bay's small tributaries, is dominated by wastewater effluent. The Attleboro treatment plant is under strict new permit limits, but nutrient pollution in stormwater and from birds and wildlife is still contaminating the river. Opening up the fish passage is only part of the story. True habitat restoration will take work on many fronts including water quality and in stream habitat. We can now begin a dialogue with Massachusetts about additional restoration opportunities over the border, and the work is just beginning!

One Fish, Two Fish...

Spring has arrived, even if it doesn't feel like it. Increased stream flow and warmer water are triggers for migrating fish that it is time to mate. When they feel the urge, they come back to their home rivers to lay and fertilize their eggs. Right on cue, a river herring was seen on Buckeye Brook in Warwick near the first day of spring. The numbers of river herring returning to Narragansett Bay are extremely low when compared with recent history, as I discussed in my last blog post. While we try to reverse the trend, volunteer fish counts are an important way to keep an accurate estimate of the population size of local fish runs.

Groups of volunteers will be out again this spring to count herring at several locations around Rhode Island. Volunteers spend 10 minutes at a site counting the number of fish that pass upstream. The three largest runs that are monitored by RI DEM are Gilbert Stuart Mill in North Kingstown, Nonquit Pond in Tiverton, and Buckeye Brook in Warwick. At Gilbert Stuart and Nonquit, electronic counters at fish ladders assist DEM in addition to visual counts. Buckeye Brook is one of the few places in the Narragansett Bay watershed where migrating fish are unimpeded by a dam and can swim freely to their spawning area in Warwick Pond. At Buckeye Brook, fish are counted by volunteers at a culvert utilizing a white board that is placed on the stream bed to help see the swimming fish. Last year's count revealed that an estimated 45,244 fish returned to the river, while in 2012, the count was closer to 90,000.

The last several years have brought newly opened fish runs in to focus as well. New fish ladders and a dam removal on the Woonasquatucket River have opened up an historic fish run that will hopefully grow through the years. Counts will begin April 1st at both Rising Sun Mill and Riverside Park in Providence. The Ten Mile River Watershed Alliance will be conducting fish counts at Hunts Mill on the Ten Mile River.

A newly completed fishway project at Kenyon Mill will allow fish access to the entire reach of the Pawcatuck River up to Worden's Pond, and the removal of the Pawtuxet Falls Dam in 2010 has opened up the first seven miles of the Pawcatuck River in Warwick and Cranston. While the volunteers are out mostly counting river herring, several other species migrate to our rivers in the spring including American shad, sea lamprey, white perch, and American eel, which arrive in their juvenile stage to live their adult lives in fresh water.

A video monitoring system will be in use again this year on the Mill River in Taunton to help the Massachusetts Division of Marine Fisheries study recovery of that system. Many species of fish were seen last year including those that migrate within the river, like yellow perch and brook trout. With so many restoration success stories, this is a perfect time to learn more about the sometimes mysterious life cycles of these important fish species.

Spring fish runs are off to a great start

The annual fish run is off to a great start this spring, and fish are being monitored by volunteers throughout the watershed. On the Ten Mile River, over two thousand fish had been netted by this week and lifted over the dam at Omega Pond. A fish count is being conducted this year at Hunts Mill where the fish ladder is now complete.

Fish are also being lifted over the Saugatucket River dam on Main Street in Wakefield. This site has a poorly designed fish ladder, and fish often get caught below the dam. DEM uses this spot to fill their truck and bring fish to both Indian Lake, which is the headwaters of the Saugatucket River, and to Worden's Pond, the headwaters of the Pawcatuck River. Fish will be able to use a new ladder at Horseshoe Falls on the Pawcatuck this year, and with the addition of a fishway at Kenyon Mill, by next year they will be able to reach Worden's Pond.

On the Mill River in Taunton, fish have been spotted above the Hopewell Mills dam for the first time in over 200 years. This dam was removed last fall and is the first in a series of three dam removals on the Mill River. Because this is a large restoration project, the Massachusetts Division of Marine Fisheries has installed a video monitoring station on the river to better understand the population of this run and what fish are using the river. This bar rack directs the fish past the video monitor. It is apparent now that there has been a small surviving run of fish, because several hundred herring have been counted, as have many yellow perch and white suckers which also migrate upstream to spawn. We are very excited to see the fish return to the Bay, and love to get reports from dedicated volunteers and partners who work hard on river restoration projects.

Ten Mile River fish ladder project is starting construction

The Ten Mile River will be getting three new fish ladders, starting with Turner Reservoir. The water levels in the reservoir are currently being drawn down in preparation for installation of the fish ladder later this month.

Water levels will be lowered 30-42 inches and it is expected that about 15 feet of shoreline will be exposed during this time. Sampling of Turner Reservoir conducted by the MA Department of Public Health on September 1st confirmed high concentrations of the blue-green algae, Microcystis. DEM will notify the public when it is safe to resume recreational activities, but boating and other recreation on the river is currently not advised. You should also not allow your pets to drink the water due to toxins in this algae.

The project will continue into next year with the completion of fish ladders at Hunts Mill and Omega Pond. This will allow anadromous fish to gain access to the river up to the dam just above Slater Park in Pawtucket. There is a combination of 340 acres of spawning habitat in the three ponds for alewife and about three miles of river spawning area for blueback herring and American shad.

Ten Mile River Herring Scoop

The Ten Mile River Watershed Council conducted its annual herring scoop and cleanup at Omega Pond Dam in East Providence on Saturday. Last year over 200 herring were netted and transferred during the scoop. For many years the scoop was done by an informal group of fishermen as they collected fish for bait. Now the taking of fish is prohibited and all the scooped fish go into the pond.

Soon the scoop won't be necessary. Three fish ladders will be going up on the Ten Mile River, starting this summer with the Hunts Mills and Turner Reservoir. This could eventually result in a run of over 200,000 herring. The river is also an historic shad run with a potential for 25,000 fish. An eelway will also be installed for American eel which migrate upstream as juveniles after spawning in the Sargasso Sea.

The project is a partnership of the Army Corps of Engineers, the DEM Division of Fish and Wildlife, the City of East Providence, the Narragansett Bay Estuary Program and Save The Bay. You can read more about the project on our Ten Mile River web page.