Are you herring me? Restoring river herring through dam removal

1 year after a dam removal in CT

In 1965, commercial fishermen topped out at a catch of 65 million pounds of river herring in Maine. They were plentiful then and there was no worry they would ever be any less abundant. However as fishing techniques continued to advance, fishermen in Maine have only been able to catch just over 2 million pounds once since 1993. The population has dwindled down so much that a report on September 4, 2017, claims the federal government is reviewing the proposal for river herring to go under the Endangered Species Act (Whittle 2017). Once a bountiful fish, now on the brink of endangerment. Why? One of the causes is due to extreme damming, erupting 14,000 new dams in New England (Hall et al., 2012).

River herring are relatively small fish that rely on coastal rivers to spawn. They are anadromous fish, which means that they migrate between freshwater and saltwater during breeding portions of their life cycle. Once river herring swim up rivers, they spawn in streams and ponds in the spring. Their young will then return to the ocean in the fall. River herring need ponds, lakes, and slow moving small streams in order to spawn (Hall et al., 2012; Hall et al., 2010). The term river herring includes several species of fish such as alewives, blueback herring, and American shad. They are often collectively referred to as river herring because they share very similar biological characteristics. River herring are a key member of the food chain for many commercially and ecologically important species. They feed on lower, smaller organisms which allows them to potentially exist in large numbers (Hall et al., 2012). Without access to key coastal rivers, the adults have no place to spawn and entire watersheds lose these valuable fish. River herring are important members of many New England watersheds and coastal zones.

River herring numbers have shown a massive decline over the course of the colonization of New England (Hall et al., 2012). Since the 1600s, yearly available river herring biomass has decreased by 30 million kg, which is roughly 11.8 billion fish lost from potential yearly harvest (Hall et al., 2015). This means that river herring are not reproducing nearly as much as they used to. River herring were once vastly abundant fish that provided substantial amounts of nutrients to freshwater and marine ecosystems alike. New England has a history of fishing and Native Americans once harvested the seemingly unlimited bounty of fish. Even though New England river herring used to occur in the billions, their numbers quickly fell as their breeding grounds were cut off by dams.

River herring are a potential prey item for a variety of predatory fish, such as cod, striped bass, and many others (Hall et al., 2012; Willis et al., 2017). River herring are important prey items because they contain more nutrients than many other invertebrates. River herring have higher levels of proteins and lipids, making them a higher quality prey item for predatory fish (Willis et al., 2017). Due to restoration efforts striped bass numbers have risen, causing them to expend more pressure on other valuable species such as juvenile Atlantic salmon (Hall et al., 2012, Hall et al., 2010). This particular case is a result of a predator being restored without the presence of its typical prey item, causing striped bass to eat other unintended fish. Predator fish that eat river herring are major contributors to the local coastal economies of New England. In three major fishing communities in New England: New Bedford, MA, Gloucester, MA, and Portland, ME, caught ground fish that eat river herring were worth a total of  $48.7 million and employed 347 boats from large to small in 2016. These numbers represent only a fraction of the overall fishing industry in New England that are affected by river herring and show that there is a large economy that could benefit from their restoration. There is also a mussel, known as the alewife mussel, that depends on alewives to complete its life cycle. Following a trend in river herring restoration in 1985, alewife mussels experienced improved abundance and range expansion (Hall et al., 2012). This data clearly displays the importance of river herring in freshwater and marine ecosystems. By protecting river herring, we are indirectly helping numerous other organisms that are important to the New England economy.

With the importance of river herring in mind, the issue of dams arise. Dams have been constructed in waterways in the northeastern U.S. since the arrival of European colonists in the seventeenth century. Records dating back to the 1600s have proven that dams have significant impacts on watershed ecosystems. The impacts of damming include, but are not limited to: loss of habitat, stream alterations, and changes in water flow and temperature. These impacts can have serious implications for anadromous fish that inhabit dammed coastal waterways in New England, such as river herring. Dams can often block access to key spawning grounds for river herring. These physical barriers, unless modified with a fish ladder or passage, are almost always impassible and prevent river herring from spawning upstream of these areas. There are over 14,000 dams in New England alone that have caused virtually every watershed in the region to be affected by dams (Hall et al., 2012, Hall et al., 2010). Dams disrupt the flow of water and sediment to downstream portions of rivers, creating a poor habitat for several fish species (Hogg et al., 2015). Dams can also cause water temperature to increase, making much of the watershed uninhabitable for some fish, as well as disrupting migration patterns of river herring (Kornis et al., 2015). River herring are important spring and fall prey for predator fish and when increasingly warmer rivers disrupt these seasonal migration patterns, predator fish are adversely affected. From these observations, it can be inferred that dams have considerable, negative impacts on river herring and New England watersheds as a whole.

For centuries, dams have impeded river herring from crossing the boundary between freshwater and ocean water. Since river herring are anadromous, it is imperative that they have access to both freshwater and saltwater to complete spawning. When passage from the waterway to the ocean is inhibited, river herring experience a great loss of accessible habitat, causing detrimental shifts in their ability to thrive. From 1634 to 1850, significant reductions in anadromous spawning habitat, due to dam construction on tributaries and small watersheds, reduced river herring lake habitat in Maine by 95% (Hall, Jordaan, Fox, et al., 2010). Construction of large dams on primary river heads resulted in a virtually complete loss of available habitat by the 1860s (Hall et al., 2010). Such extensive habitat loss led to the severe decline of river herring, putting them on the brink of endangerment and giving them their current classification as a species of concern.

It is understood that of the 14,000 dams in New England, the vast majority of them have historical and personal values associated with local residents. As a result, there has not been a single dam removal project in New England without some type of opposing group (Sneddon et al., 2017, Fox et al., 2016). Opposing groups include local historical societies, residents with connections to local dams, and residents with specific views on the natural state of their watersheds. Dam removal projects such as the Warren Dam, East Burke Dam, Mill Pond Dam, and the Swanton Dam have been halted after concerted efforts to keep them (Fox et al., 2016). Residents often develop a cultural bond with their dams and resist dam removals due to perceived loss in heritage site (Sneddon et al., 2017, Fox et al., 2016). Fox et al. (2016) quote an example of a grassroots organization member in opposition of the Swift River dam removal in central Massachusetts who said, “If you kill the dam, you kill a part of me.” There is also a disconnect between what scientists believe is the natural state of a stream and what residents believe is the natural state of their watershed (Sneddon et al., 2017, Fox et al., 2016). Instead of viewing dam removal as a method of river restoration, many residents of New England tend to see it as a historical and ecological disturbance.

Local residents living near a dam may feel that the dam contributes to their cultural and ecological systems. Differing ideas about what counts as natural is attributed to three factors: attachment, attractive nature, and rurality (Jørgensen 2017 p.841). An example of contradicting viewpoints takes place in Nanaimo, Canada. There was a proposal to remove the Colliery Dams and the Colliery Dam Preservation Society protested the removal, claiming they would lose “the lakes in this very special park” and it was supposed to be a “legacy for our children, their children and all future generations” and that their rebuttal slideshow only provides a “glimpse into the beauty and uniqueness of a very special place” (Jørgensen 2017 p.847). This further proves that the driving factors of the Colliery Dam Preservation Society is due to their attachment, the attractive nature of this park, and their perception of rurality. In a debate between for and against- removal parties, Charles Thirkill, a fisheries biologist, criticizes those who spoke fondly of the fish in the lakes because they were farm-raised sterile fry, almost as artificial as the Atlantic salmon that are raised in net pens (Jørgensen 2017 p.848). This sparks a realization for those against dam removal and the preservation of the “natural” state of the park because what they were so fond of is really all artificial or man-made.

It is important to understand that all stakeholders have different perceptions of what is natural. As previously mentioned, Jørgensen (2017) explains all the perceptions of what the word natural means, however a man-made physical barrier does not happen without the work of man. Since it is decreasing the abundance of anadromous fish, dams should be removed for the sake of fish populations as well as other ecological benefits. Keeping a park intact is important for the culture of local communities however there are other ways of conserving a park even with the removal of a dam. Parks can be shifted over, it can incorporate the new river, or if a reservoir is drained out, it can be made into walkways, gardens, fields, and so forth.

New England differs from other parts in the country in that it is controlled by mostly private lands, meaning that locals have a strong influence on the decisions made in their town (Sneddon et al., 2017; Fox et al., 2016). As a result dam removal processes begin with long town hall like debates, where all parties voice their particular positions (Sneddon et al., 2017; Fox et al., 2016). In Durham, Vermont, the mill dam is a key feature of the town, its industrial history, a major tourist spot, and even appearing on the town seal. Yet after receiving two letters of deficiency from the state, residents claimed it is “one of the most photographed sites in Vermont and, it could be argued, is an essential part of the single most important resource in the town – it’s beauty,” (Fox et al., 2016, p.98). Despite the state’s suggestion to remove the dam, it still remains standing.Dams can play an important role in the culture of local communities and removing them can be hard for many. Removing dams can create newly revived rivers in which communities can find their own sense of beauty and culture. By embracing the benefits of dam removal and in many cases in cheaper costs than repairing dams, local historians may be able to accept the loss of one resource for the benefit of another.

Dams are historical structures and so the request to remove them may be hard for those who feel a strong connection to the dam. With this, it is important to consider the dangers of keeping an old dam. A case where dams go horribly wrong would be in Johnstown. In the late 1800s, Johnstown was a thriving town located in western Pennsylvania. Just 14 miles away was the South Fork Hunting & Fishing Club. This club restored an abandoned earthen dam and created Lake Conemaugh which was used for sailing and ice boating and was stocked with expensive game fish (Hutcheson 1989). The new dam raised concerns for Daniel Morell, one of Johnstown’s best civic leaders, and so he inspected it to find that this dam was in need of dire attention. He sent numerous letters to the club and the town hall, however they were all dismissed. After several days of heavy rainfall, on May 31, 1889, the dam breached (Hutcheson 1989). 20 million tons of water crashed down onto the town of Johnstown taking trees, railcars, and entire houses in its path leaving 2,200 dead. Chicago Herald’s editorial afterwards was entitled “Manslaughter or Murder?” shining light on South Fork Club’s complete negligence for several warnings of the dam’s breach (Hutcheson 1989). 13% of dams in the US are considered highly hazardous and could cause damage such as in Johnstown (NDSP). This means there are 1,820 dams in New England that could pose significant damage to their communities and may serve as potential clients for removal to avoid these potential disasters.

There are many benefits to dam removal yet these are often not fully understood or superseded by locals desire to keep dams as part of their cultural history. A dam removal in Greenfield, Massachusetts was halted after multiple years of 17 organizations coordinating the project with already $500,000 spent on the removal. Yet there are ways that advocates for dam removal can effectively achieve their goals. In Maine conservation, under the Natural Resources Protection act, advocates can petition to the state to remove a permanent structure if it poses significant harm to a natural resource, especially wetlands and watersheds (MDEP, 2016). This could give states more power to remove dams in Maine that harm their natural resources. Across New England there are many federal and state grants available to remove dams (EOEEA, 2007). In Rhode Island the Pawtuxet Falls dam was removed with the help of the Pawtuxet River Authority and Narragansett Bay Estuary Program that sought funding from a dozen sources, including, R.I. Saltwater Anglers Association, the US Environmental Protection Agency, the National Oceanic and Atmospheric Administration, and the US Fish and Wildlife Service (NRCSRI, 2011). These can allow conservation commissioners independent funding that is not depend on local town support. In the cases where dams are need of repairs were the cost is too high for the town to pay then conservation commissioners can pay for their removal.  There are 50 dams in New England currently under review for removal and as dams age this number will slowly increase (Fox et al. 2016). To Truly restore river herring their spawning habitat needs to be restored and this can happen by removing dams. By targeting dams with no economic benefits that are in need of costly repairs, a precedent can be set for slowly removing the many dams of New England and restoring river herring habitat.

The removal of the Edwards dam on the Kennebec River in Maine highlight the importance of dam removal for river herring (Hall et al. 2012, Robbins and Lewis, 2008). The Kennebec River is one of Maine’s largest river system and covers a full 132 miles. It provided an ample supply of anadromous fish until the Edwards Dam was constructed. This resulted in an immediate loss of 17 miles of spawning habitat for river herring (Robbins and Lewis 2008). After the removal of Edward’s Dam, four Atlantic Salmon in the first time in 162 years have finally reached the upper Kennebec River. From there, the amount of anadromous fish re-entering the Kennebec have continued to increase (Robbins and Lewis 2008). An ex post survey on the economic effects, it was concluded that more anglers have come to fish at the restored fishery and are willing to pay more for better angling opportunities since the removal of the Edward’s Dam (Robbins and Lewis 2008).

Removing dams have economic benefits to the surrounding area. Many cases such as Edwards Dam in Maine and Whittenton Pond Dam in Massachusetts, prove that their repairing outlived dams costs more than removing them. Not only is removing a dam more cost efficient, it also brings more jobs and revenue from the improvement of recreational fishing and activities.

Edward’s Dam is a prime example of a successful removal with economic benefits. As mentioned before, many residents in the surrounding area had ties to this dam and the park it was associated with. Alternatives were considered to improve the life cycle of anadromous fish and so to install fish passages it would cost $14.9 million. The cost to just remove the dam would be four million less at $10.9 million (FERC 1997). Edward’s Dam was thus removed and by doing so, they generated $397,000 -$2.7 million in new income, amounting to benefits totaling $4.9 million to $61.2 million over 30 years (Industrial Economics 2012). As well as generating vast income, another dam removal case proved to prevent a major financial loss.

Whittenton Pond Dam in Mill River, Massachusetts was beyond repair and was at risk for a catastrophic breach. This was a 10-foot high and 120-foot wide wood and concrete structure built in 1832 to power a textile mill and when the mill was shut down, the dam was no longer maintained (Headwaters Economics 2016). Removing the dam would have four benefits: cost effectiveness, avoided emergency response cost, protection of vulnerable species, and increased property values. The cost of removing the dam was $447,000 whereas to rebuilding it estimated to be $1.9 million, and options to repair the dam with a fish ladder or bypass would cost even more than rebuilding it (MDFG 2015). The dam was later removed in 2013, preventing $1.5 million in emergency response expenses if the dam was left for a catastrophic breach to occur. With these figures in mind, it is apparent that removing the Whittenton Pond Dam is the most cost effective option. Thus the dam was removed. This opened up 30 miles of river habitat to vulnerable fish species so that they can spawn, and have nutrients and minerals evenly distributed to previously blocked off areas (MDFG 2015). The removal of the dam is expected to increase property values upstream and downstream of the dam site, lifting the economy of the town (Lewis, Bohlen, and Wilson 2008).

Dam removal is a successful method for restoring river herring because they can rapidly colonize new areas (Hogg et al., 2015, Hall et al., 2012). Hogg et al. (2015) showed in their study that alewives colonized the above dam portion of the studied river within two years. This river had been cut off to those river herring for over a century (Hogg et al., 2015). Hall et al. (2012) claims river herring are ideal for restoration because of their high reproduction rate, allowing them to proliferate rapidly. Hall et al. (2012) also claims that river herring have a rate of straying, meaning that they visit other streams to spawn. This means that a healthy population can rapidly spread to other areas and colonize them. If broad scale stream restoration was done, then existing populations such as the Damariscotta River population in central Maine, would be able to easily colonize newly formed habitat. This shows that dam removal is an effective way of restoring river herring populations.

New England was once a hub for factories and the production of machined goods. We once needed dammed rivers to more through the industrial revolution but it has been well over a century since New England relied on water power. Even though many residents have become accustom to the status of our watersheds it has had major effects on the quality of our ecosystems. We longer need mills but recreational and commercial fishing has existed in New England for over 400 years and will continue to do so. We once made drastic changes to our environment to suit our need and it is now time to make more drastic changes in order to restore the damages that we have caused. There are many dams in New England that are in hazardous conditions that would be far cheaper to remove. By targeting these degraded dams, trying to convince or suppress locals that are against dam removals, and effectively fund these projects, dam removal can greatly restore New England watersheds. The benefits of removing dams will have noticeable and long last economic and environmental benefits to New Englanders and therefore dam removal should be a real consideration for restoring streams in the Northeast.


Quentin Nichols – Natural Resources Conservation

Jessica Vilensky – Natural Resources Conservation

Suzanna Yeung – Building & Construction Technology



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