NOTE: From the biological report on the status of Atlantic Salmon - see Table of Contents and News Release for additional information.
SECTION 7: ANALYSIS OF LISTING FACTORS
The ESA defines an endangered species as any species in danger of extinction throughout all or a significant portion of its range; and a threatened species as any species likely to become endangered within the foreseeable future. Section 4(b)(1)(a) of the ESA requires that determinations of whether a species is threatened or endangered be based solely on the best scientific and commercial data available and after taking into account those efforts, if any, being made to protect the species.A species may be determined to be endangered or threatened due to any one or more of the following five factors described in section 4(a)(1) of the ESA:
- The present or threatened destruction, modification, or curtailment of habitat or range;
- Overutilization for commercial, recreational, scientific, or educational purposes;
- Disease or predation;
- The inadequacy of existing regulatory mechanisms;
- Other natural or manmade factors affecting its continued existence.
7.1 PRESENT OR THREATENED DESTRUCTION, MODIFICATION, OR CURTAILMENT OF HABITAT OR RANGE
7.1.1 Water Quality
The Maine Department of Environmental Protection (DEP) operates the program that designates water classifications within Maine. The rivers within the DPS are either class "AA" or "A", although the classification is not always consistent throughout the entire watershed. In some cases, streams are classified lower than the waterbody into which they flow. The water quality standards for class AA waters state that habitat must be free flowing and natural and class A standards state that habitat should be natural. Permits can be issued for activities affecting the water quality of rivers and streams but the existing uses of the habitat must be maintained. The DEP and EPA issue permits for point source discharges of water pollutants into waters of Maine. Licenses issued specify effluent limitations and conditions with the goal of ensuring that water quality classification standards are attained. The fact that the rivers within the DPS are in the highest categories within the water quality classification system in the State should afford them additional protection. As described below, there are some examples of water quality problems on the rivers that warrant further investigation and action.The Conservation Plan included a task to set up an ongoing water quality monitoring program on each river within the DPS as appropriate. DEP has conferred with the ASA, Land Use Regulatory Commission (LURC), Project SHARE (Salmon Habitat and River Enhancement), FWS, U.S. Geological Survey (USGS), and University of Maine at Orono and proposed a four part monitoring plan that began in 1998. The four parts of that plan are as follows: (1) initiate a regional low flow study; (2) provide ASA with multi-parameter data monitoring systems so that they can measure temperature, dissolved oxygen, conductivity, pH and depth while conducting population estimates at over 100 sites within the DPS; (3) collect and analyze nutrient data; and (4) analyze the impact of land use on macroinvertebrates and habitat characteristics such as sediments, temperature and other water quality parameters. Funding has not yet been secured for all portions of this monitoring plan. DEP has identified the need for a regional low flow study which would provide data to determine appropriate aquatic base flows for a number of Maine rivers. DEP also identified the lack of adequate flow information as the biggest gap in knowledge of baseline data for the salmon rivers (LWRC 1999). DEP noted that the Instream Flow Incremental Methodology (IFIM) studies ongoing would provide important information in that they will determine how much water is needed for salmon, but cautioned that they would not determine the ability of the watershed to support that flow. Secondly, the IFIM studies are specific only to the particular rivers and therefore cannot substitute for a regional low flow study.
As reported in the state's 1998 Annual Progress Report on Conservation Plan Implementation, DEP has identified sediment pollution as one of the more serious threats to stream health and developed a methodology "Assessment of In-Stream Sedimentation for Atlantic Salmon Conservation Plan" as a tool to help assess sediment pollution (LWRC 1999). DEP intends to work with the watershed councils to test the utility of this methodology (LWRC 1999). During the past year, DEP also reviewed the classification of State surface waters. The annual progress report states that several segments of water bodies within the salmon rivers will be recommended to be upgraded in assigned classification although the specific segments are not named and the process for finalizing this is not detailed (LWRC 1999). The Maine Department of Transportation (MDOT) also considers Atlantic salmon waters as extremely sensitive to impacts from erosion and sedimentation and proposes and implements controls accordingly. MDOT created an Atlantic Salmon Conservation Plan Committee to identify activities within their Department that could potentially impact Atlantic salmon and to develop strategies to avoid and minimize those impacts (LWRC 1999). The Maine Department of Agriculture, Food and Rural Resources has identified a need for an environmental toxicologist to be able to assess the potential impacts of any pesticide residues detected in the state water sampling program (LWRC 1999). Project SHARE worked with the Watershed Council Coordinator to secure a grant from DEP to correct water quality problems resulting from nonpoint source pollution. In addition, Project SHARE and the State worked together to contract with the River Watch Network for assistance in establishing a program of training volunteers in water quality monitoring and also to evaluate the organizational structure of the Watershed Councils, Project SHARE, the Downeast Salmon Federation and others involved in salmon management and habitat protection in Maine (LWRC 1999).
The EPA is currently completing an evaluation and will begin cleanup of a superfund site on the Dennys River. Site evaluation and remedial clean up is also scheduled for the Smith Junk Yard site also on the Dennys River. Both of these actions were given high priority within the Conservation Plan and are underway. Taylor (1973) measured nutrients and other water quality characteristics at two sites in the Machias River and at sites in nine other rivers, streams, and hatchery water sources. At the head of tide, the Machias River was found to have the highest concentrations of aluminum ions of all salmon rivers in the state of Maine. Waters of the Machias River were found to be acidic, with a pH in the range of 5.5-7.0 units. Similar to the East Machias River, the Machias River has a distinct water color that may be attributed to peat bogs as well as bark wastes and detritus from logging operations.
Hexazinone (velpar), a herbicide used during blueberry farming, has been detected at sites in the Narraguagus River. The herbicide was initially detected during routine sampling for an array of pesticides conducted in the spring and fall of 1991. Although the concentrations detected are low, its presence throughout the summer and fall at low flow periods suggests that it is entering the river through groundwater flow rather than storm runoff (Beland et al. 1993). Recent studies to determine the long-term changes in macroinvertebrate abundance, diversity, and taxa richness at sites in the river suggest that a deterioration in water quality has not occurred at these sites (Siebenmann and Gibbs 1994). These studies demonstrated that the river was capable of producing Atlantic salmon and the production was at a level considered normal given the adult abundance at that time. In the time since these early studies, fry abundance has increased dramatically without a commensurate increase in parr and smolt. This indicates that there may be a factor limiting production and affecting survival. Sedimentation, as identified by DEP, may be a potential cause and warrants further investigation to determine if and how it is affecting overwinter survival.
Water quality is acceptable for supporting Atlantic salmon in the Ducktrap and Sheepscot Rivers, but low flows in summer may result in high water temperatures increasing the potential for problems associated with low dissolved oxygen. Seasonal low flows limit access to spawning habitat and reduce rearing habitat which likely results in annual fluctuations in salmon production.
7.1.2 Dams and Obstructions to Migration
The construction of hydroelectric dams with either inefficient or non-existent fishways was a major cause for the decline of U.S. Atlantic salmon. In the late 1800's Atkins stated: "The disappearance of salmon from so many rivers appears to have been entirely the result of artificial causes, chief among which is the obstruction of the way to the breeding grounds by impassable dams" (1874). Ruggles (1980) identified the following unnatural conditions created by dams that can threaten anadromous salmonid populations: passage over spillways; passage through turbines; passage through impoundments; exposure to atmospheric gas saturation; exposure to pollutants, predators and disease organisms; and vulnerability to angling. Smolts are vulnerable to the impacts of dams and may become impinged or entrained on their migration downstream. Dams can alter the flow pattern of rivers, create ponds and reservoirs, increase water temperature and concentrate pollutants, all of which are factors that can adversely affect resident parr and migrating smolts (Foerster 1937; Saunders 1960).Historical records link the decline of Atlantic salmon with the construction of dams. Kendall (1935) reported that Atlantic salmon were plentiful in the Connecticut River until 1797, when a dam was built just below the mouth of Miller's River. Kendall (1935) also reported that the Merrimack River was one of the best Atlantic salmon rivers in the United States prior to the construction of dams at Lowell and Lawrence, MA and Manchester, NH. Rounsefell and Bond (1949) state that the Atlantic salmon run in the Dennys River was almost always in peril because of dams. The presence of dams on the Narraguagus, Machias, East Machias, and Pleasant Rivers was identified in the late 1940's as a threat to the continued existence of Atlantic salmon in those rivers (Rounsefell and Bond 1949). However, historic records suggest that many of the old, low-head timber crib dams had significant leakage and were not complete barriers to fish passage. Currently, there are no hydroelectric dams on rivers that support Atlantic salmon populations in the DPS. The Machias and Dennys Rivers have natural falls that have the potential to hinder the migration of Atlantic salmon at certain flows. The Prelisting Recovery Plan included a condition for a detailed engineering study of the Machias River gorge to determine if modifications would improve fish passage. All other obstructions on these rivers have been equipped with fishways, but to date the efficiency of these fishways has not been well documented (Baum et al. 1992).
Many of these rivers have numerous beaver dams and debris dams. These dams are typically partial obstructions and are ephemeral in nature (Havey and Fletcher 1956). However, these dams have the potential to temporarily alter habitat and reduce the production of salmonids. The ASA, USFWS, and Project SHARE (Salmon Habitat and River Enhancement) document obstructions on the seven rivers and their tributaries. Selected obstructions and dams within the DPS are displayed in Figure 7.1.2. Obstructions located on rivers that provide spawning habitat are breached to facilitate access to upstream habitat. In 1995, a total of 155 beaver dams and 19 debris dams were identified and of those 138 were breached. In 1996, a total of 85 obstructions were recorded, 71 of which were beaver dams. All that were located downstream of useable spawning habitat, 74, were breached or removed at least once in October. In 1997 and 1998, there were 114 (102 beaver and 12 debris) and 137 (103 beaver and 34 debris) obstructions identified, respectively. This resulted in the alteration of 96 obstructions in 1997 and 82 in 1998 (USFWS 1999 unpublished data). In the fall of 1998, Champion International Inc., ASA and Project SHARE removed a debris blockage on the Narraguagus River that was blocking adult migration. Generally, the ASA has determined that beaver dams are not limiting to upstream migration for adult Atlantic salmon in the mainstem of the Dennys, East Machias, Machias and Narraguagus Rivers. Tributaries to the East Machias, Machias and Narraguagus Rivers contain additional spawning habitat that may be blocked by beaver dams. The combination of low water levels and beaver dams in the mainstem in 1997 could have prevented access to some spawning areas in the Pleasant and Sheepscot Rivers. Dams in tributaries of all rivers may alter habitat by blocking sediment transport and degrade water quality by raising water temperatures (ASA 1998).
Figure 7.1.2: Selected Lowermost Dams or Restrictions
In 1815, a dam was constructed at Millseat near the mouth of the Dennys River that partially obstructed the passage of Atlantic salmon (Kendall 1894). The dam was destroyed by fire in 1858, and a fishway was built when a new dam was constructed in 1860. The fishway was modified periodically and in 1898 it was rebuilt (Goodwin 1942). By 1930, obstructions to fish passage on the main stem had been removed, and by 1962, either fishways had been constructed at barriers, or barriers had been removed on all tributaries in the drainage (Beland et al. 1982). Existing habitat for salmon exceeds that which was available historically. Construction of a fishway at the falls on Cathance Stream provides fish access to upstream reaches. A water control structure installed in 1974 at Meddybemps Lake provides storage and control of releases of water during summer low flow periods. Dam repair for flow augmentation and fishway restoration or replacement is currently planned at Marion Falls, Great Works Flowage and Cathance Lake. Funding for these projects is being provided by NRCS, Project SHARE, ASF and the NFWF (LWRC 1999).
Records suggest three dams built in East Machias and Jacksonville in the 1800's resulted in a decrease in the number of salmon that returned to the river. In early years, existing fishways were inefficient, but once repaired, salmon runs were reported to increase (Atkins 1874). Dams were also constructed in the upper reaches of the river for the storage and transport of logs and these may have impeded the migration of salmon. In 1935, Kendall noted that salmon persisted in the river and that spawning occurred in Chase's Mill Stream at the outlet of Gardner Lake. Rounsefell and Bond (1949) reported that salmon were taken below the dam in East Machias each spring. They cited easy poaching, an inadequate fishway, and a large unscreened power diversion as reasons for a depressed run. Numerous beaver dams were located on Northern Stream, but juvenile salmon were found upstream from the dams indicating that fish passage was not completely obstructed (ASRSC unpublished data). Plans are currently underway to remove the East Machias dam and power station in the town of East Machias. Funding for this removal will likely come from the U.S. Department of Agriculture Natural Resource Conservation Service (USDA NRCS) through its Wildlife Habitat Incentive Program (WHIP), U.S. Army Corps of Engineers, and the National Fish and Wildlife Foundation (LWRC 1999).
Salmon populations were greatly reduced following the construction of dams in the late 18th century (Atkins 1874). Kendall (1935) reported that the number of salmon returning to the Machias River had dropped dramatically, and that dams had significantly decreased their abundance. However, salmon persisted in the river, and it was anticipated that the Machias River offered a promising chance for the development of a large run of salmon (Rounsefell and Bond 1949). Two dams in the system, Harwood and Whitneyville Dams, were breached in 1963. A third dam at Machias gorge was breached by ice and spring freshets in 1970, and since that time the river has remained free flowing, affected by no man-made obstructions (Fletcher et al. 1982). Seventy-three obstructions to fish passage have been documented; the obstructions, primarily beaver dams and log jams, have been breached or removed where possible. Beaver dams and log jams are often temporary, but if they persist, they may pose problems for salmon and adversely affect habitat by inundating riffle-pool complexes and runs. Champion also installed six arch pipes on the Machias River in 1998 at stream crossings of existing roads to improve fish passage and protect water quality (LWRC 1999).
The construction of a dam on the Pleasant River at Columbia Falls impeded the upstream migration of Atlantic salmon. Rounsefell and Bond (1949) reported that salmon production in the Pleasant River was in jeopardy because of a three meter-high dam with no fishway located at the mouth of the river in Columbia Falls. The dam was not a barrier when opened at the discretion of the owner, an action that usually occurred in late fall. North Branch Stream is the only tributary that has a major natural obstruction to upstream fish migration, a 3.7 meter high vertical ledge falls. The falls are located a short distance from the stream confluence with the Pleasant River at Columbia Falls. A bypass channel and Denil fishway were constructed at Saco Falls on the mainstem in 1955 and provided access for the salmon to additional habitat. Pleasant River Lake Dam had also been equipped with a Denil fishway to provide fish access to the lake, but by 1982 the fishway was no longer functional for sea-run salmon. A new dam was constructed in 1982 at the Old Hathaway site in Columbia Falls. The dam was 3.7 m high and was equipped with a vertical slot fishway. The dam was subsequently breached in 1989 to enhance upstream fish passage. Remnants of the Pleasant River Dam in Columbia Falls were removed in 1998 by the Downeast Salmon Federation supported financially by the USDA NRCS WHIP . The primary benefit of this removal was for sea run smelt, however it does enhance the Pleasant River ecosystem (LWRC 1999).
As early as 1874, there were five wooden dams in Cherryfield located within 1.6 km of tidewater in the Narraguagus River. The dams were used to control river flow for the operation of mills and for the storage and transport of logs. It was not until the early 1900's that the river was reopened to anadromous fish as a result of the construction of fish passage facilities at the dams in Cherryfield. In the spring of 1942, ice and high flows destroyed the dams in Cherryfield and the number of salmon returning to the river increased considerably (Rounsefell and Bond 1949). Beddington Lake Dam, located in the headwaters was the last obstruction for Atlantic salmon, and was breached in 1951. The only artificial impoundment on the system is an ice control dam located in Cherryfield. A Denil fishway was installed at the dam, but during periods of high flow salmon have been observed to swim over the spillway (Baum and Jordan 1982). Recent modifications to the dam reduced fish passage over the spillway and directed them to the ladder and trap facilities. The ASA, Army Corps of Engineers (ACOE), and Town of Cherryfield are developing plans to modify the dam to facilitate salmon management (LWRC 1999). Champion also installed three arch pipes on the Narraguagus River in 1998 at stream crossings of existing roads to improve fish passage and protect water quality (LWRC 1999).
Historical information about riverine obstructions in the Ducktrap River is limited. Wells (1869) reported that a wooden dam approximately 4 m high and located 201m from tidewater was constructed in 1852. There is no mention of the date when the dam was removed. Bryant (1956) documented 12 natural and man-made obstructions in the drainage, which included weirs, ledges, debris jams and low-head stone dams. Many obstructions were partial barriers to anadromous fish, whereas others were intermittent barriers and impassable during low flows. Rounsefell and Bond (1949) reported that in 1880 some of the most successful salmon weirs in Penobscot Bay were close to the mouth of the river in Lincolnville. They suggested that if water could be impounded during the spring, then flows could be augmented in summer, and the quantity and quality of salmon habitat improved with the expectation of increasing adult runs.
Typical of other rivers in the region, salmon populations in the Sheepscot River were adversely impacted by the construction of dams. Dams were located at Sheepscot Falls and Head Tide by the late 1800's, and they obstructed the passage of anadromous fish. Remnant runs of anadromous fish may have relied on limited spawning and nursery areas downstream from the Head Tide Dam in Alna. Bryant (1956) identified 24 obstructions in the drainage. The Head Tide Dam was opened to fish passage in 1952 and subsequently breached in 1968. A fishway was provided at Coopers Mill Dam in 1960, eliminating a significant barrier to salmon migration on the main stem (Meister 1982). All historic Atlantic salmon habitat is currently accessible. The dam at Coopers Mills is currently leaking which causes the fishway to be inoperable. The NRCS, ACOE, ASA, DMR and Town of Coopers' Mills are working together to design a plan and secure funding for removal of this dam or rehabilitation of the fishway and restoration of upstream habitat (LWRC 1999). Investigations are also ongoing into the potential removal or breaching of a dam at the head of tide on the Sheepscot River (LWRC 1999).
7.1.3 Agricultural practices
Agricultural products grown in the Gulf of Maine DPS include the following: hay, silage corn, livestock (horses, dairy cows, beef cattle, sheep), Christmas trees, market vegetables, blueberries, cranberries, landscape and horticultural plants (Conservation Plan 1997). The primary form of agriculture in the Dennys, East Machias, Machias, Pleasant and Narraguagus Rivers is blueberry culture. Livestock production is the dominant form of agriculture in the Sheepscot River watershed.Agricultural practices have the potential to destroy, modify or alter habitat of importance to the Gulf of Maine DPS of Atlantic salmon. Normal farming practices are exempt from Wetland Alterations permit requirements under the Maine Natural Resources Protection Act (NRPA). Exemptions such as these for agricultural practices may not adequately protect the riparian zone and could lead to negative impacts on Atlantic salmon and their habitat. Pumping sites and water withdrawals are regulated by two agencies within the State of Maine. The Land Use Regulatory Commission (LURC) regulates these activities in unorganized towns and the Department of Environmental Protection (DEP) regulates them in organized towns. In order to obtain a permit to withdraw water from a waterway, an applicant must demonstrate that the withdrawal (volume, timing and rate of withdrawal) will not adversely affect existing uses and natural resources. Water quality and quantity can be affected by the withdrawal of water for irrigation, the discharge of process water, the input of pesticides, and the input of nutrients and sediment. Adequate water flow is critical to all life stages of Atlantic salmon, spawning, egg survival, fry emergence, juvenile survival, and smolt emigration. Currently, water withdrawals pose a threat to Atlantic salmon and their habitat in the Machias, Pleasant and Narraguagus Rivers. This threat, if unregulated, is likely to grow in the future based on industry projections of expansion of berry production and processing. As reported in the Conservation Plan, approximately 6,000 acres of blueberries are irrigated annually. The blueberry industry plans to double production by the year 2005. Current cranberry production is limited to less than 100 acres; however, there are plans to significantly increase production over the next five years.
Farming practices can also result in the discharge of nutrients, sediments and/or pesticides which could lead to habitat degradation and ultimately affect survival and recovery of Atlantic salmon. One of the most obvious and immediate impacts of sediment discharge in rivers is the filling of spaces between gravel and cobble, greatly reducing the value of the habitat for spawning and decreasing survival of early life stages.
The Conservation Plan identifies the following pesticides used on blueberries in Maine: herbicides include fluazifo-P, glyphosate, Hexazinone, Sethoxidm, Terbacil, 2,4-D Ester; insecticides include Azinophos-Methyls Sniper 2E, Javeline, Carbaryl, Diazinon, Malathion, Methoxychlor, and Phosmet; and fungicides include Benomyl, Captan, Captec and Triflorine. The Board of Pesticides Control (BPC) regulates the disposal, storage and application of pesticides in Maine. The BPC has the authority to designate areas where pesticide use is restricted to protect the health, welfare and the environment. The only areas currently designated are the Deblois Fish Hatchery and one section of the Dennys River. In setting levels of application, the LC50 is used which is the level that would be lethal to 50% of a sample population over a given period of time. Exposure at critical life stages such as fry emergence and smoltification has not been fully investigated. Further, the effects of chronic exposure to one or a number of these pesticides are largely unknown and need further study.
Lowbush blueberry agriculture is an important land use in eastern Maine watersheds. Water extraction and diversion associated with the production of blueberries and other agricultural products can make habitat unsuitable for Atlantic salmon. The herbicide hexazinone (velpar) is typically applied to blueberry fields prior to budding to eliminate competing vegetation. Fungicides are applied to prevent disease and a variety of insecticides are applied to kill pests. Extensive chemical spraying can cause immediate mortalities to juvenile Atlantic salmon or can have indirect effects when chemicals enter waterways. The chemicals also may cause mortalities of aquatic insects that contribute to the food base of salmon. Habitat studies conducted by the ASRSC have documented the repeated presence of hexazinone in the Narraguagus and Pleasant Rivers (ASRSC unpublished data). The impacts of hexazinone on Atlantic salmon in these rivers are uncertain at this time. Numerous measures are implemented to reduce the potential for contamination of waterways from blueberry agriculture. Measures include the maintenance of vegetation throughout the year to reduce erosion and sedimentation and the maintenance of riparian buffers to protect streams.
Best management practices (BMPs) have been developed, and farmers are encouraged to voluntarily adopt these to minimize nonpoint source pollution. The State has also worked with farmers to encourage the adoption of Integrated Crop Management that includes Integrated Pest Management. Maine has developed a Generic State Management Plan for Pesticides and Ground Water, a Strategy for Managing Nonpoint Source Pollution from Agricultural Sources and Best Management System Guidelines, and a Coast Nonpoint Source Control Program. These programs address sediments, nutrients, pesticides, manure, grazing management, and wastewater from confined animal facilities as potential pollutants. There is a mandatory compliance provision of the nonpoint source pollution program. Complaints can be submitted to the Maine Department of Agriculture, Food and Rural Resources (DAFRR). In response, the DAFRR investigates complaints and recommends site-specific BMPs. Failure by a farmer to adopt the BMPs can result in the case being referred to DEP for enforcement under the Water Discharge Law.
The DEP permits discharges into Maine waterways. In order to obtain a permit, an applicant must demonstrate that the discharge will not lower the water quality classification of the receiving waterbody. As reported in the Conservation Plan, there are two berry processing plants on the Narraguagus and one on the Machias all of which discharge directly into the river. The volume of agricultural process water discharged to the Narraguagus River is allowed to reach 627,000 gallons per day, up to 100,000 gallons per day is allowed to attain a discharge temperature of 26o C. Water temperatures in the vicinity of the discharge have not been monitored. Up to 70,000 gallons per day of agricultural process water is allowed to be discharged into the Machias River with a maximum temperature of 32o C. Although this temperature is, as reported in the Conservation Plan, lethal to both juveniles and adults, no monitoring of the effect on the river temperature and on Atlantic salmon has been conducted. Reports from ASA staff indicate that elevated water temperatures could affect habitat in some rivers within the DPS (Beland et al. 1995; Horton et al. 1995). Specifically, available data indicates that high water temperature may be a problem in some years in Cathance Stream in the Dennys River, and certain sections of the mainstem East Machias (ASA 1997).
The Conservation Plan identified the following actions addressing threats to salmon: (1) integrated crop management and best management practices for blueberry and cranberry production; (2) non-point source pollution program and Coastal Zone Management program; (3) the Generic State Management Plan for Pesticides and Ground Water and the Hexazinone State Management Plan for Protection of Ground Water; (4) Soil and Water Conservation Districts? technical assistance to farmers; and the (5) cooperative relationship between Department of Environmental Protection, Land Use Regulation Commission and Worcester Peat Company, the owner of the Denbo Heath Peat Mine. Actions proposed for enhanced protection from agriculture include the following: (1) develop and implement Total Water Use Management Plans for each watershed; (2) develop a watershed specific non-point source program for the Sheepscot River; (3) target integrated crop management (ICM) education programs and promote use of BMPs; (4) identify for protection wetlands with functions that are important for maintaining the integrity of Atlantic salmon habitat; (5) enhance Board of Pesticide Control programs that evaluate and mitigate the threats to Atlantic salmon associated with pesticide use; (6) improve the permit review process and standards for erosion control for Peat Mines; and (7) evaluate the threat to Atlantic salmon from water quality changes associated with peat mining.
The Conservation Plan recommended increased attention to best management and integrated crop management programs in the salmon watersheds. Further, it was stated that a watershed-specific nonpoint source pollution plan was being drafted by the State for the Sheepscot River watershed. It was suggested that a survey should be conducted on embeddedness and that a sedimentation monitoring program should be established to determine the effectiveness of BMPs in restoring or maintaining productive Atlantic salmon habitat. A need for an additional $30,000 a year was identified in order to develop a targeted non-point source pollution program for the Sheepscot. The Conservation Plan suggested that the BPC consult with other state agencies in order to identify resources for an environmental toxicologist. Further, it was suggested that a systematic review be conducted of all pesticides used in the salmon watersheds (aquatic risk assessment) and that a monitoring program be established. It was also suggested that BMPs be developed for all the pesticides used in the watersheds and that these be updated annually.
The Conservation Plan concluded that there is sufficient annual flow in the rivers to support the needs of Atlantic salmon and the agricultural industry and therefore characterizes the problem not as a water shortage problem but rather a water management challenge. That challenge emerged as a major issue to be dealt with during the first year of Conservation Plan implementation. In 1998, the LWRC established a workgroup to review a request to withdraw water from the Pleasant River and recommend a limit on that withdrawal. The workgroup, composed of representatives from state and federal agencies, recommended that permit conditions be based on individual monthly median flows. The LURC subsequently issued a permit for direct water withdrawal from the Pleasant River by Cherryfield Foods with a condition that withdrawal would cease if water levels reached 23 cfs. This level was reached in 1998 and pumping ceased. The permit that was issued was for only one year as it was hoped that a water use management plan for the Pleasant River would be completed in time for the 1999 summer/fall season. The State contracted with a consulting firm to gather and analyze the technical data necessary to set minimum flow requirements for Atlantic salmon at all life stages and seasons in the Machias, Pleasant and Narraguagus Rivers. A steering committee has been formed to review that material and design a water use management strategy. The work of that steering committee will not be completed prior to the 1999 summer/fall season so it is not clear at this time how permit conditions will be drafted. Rules to address water withdrawals on a statewide basis are currently being developed by the DEP.
The annual report on Conservation Plan implementation reported the following actions related to agricultural practices: (1) establishment of an enforceable limit on water withdrawals from the Pleasant River in the summer/fall 1998; (2) acquiring data and creating steering committees to draft water management plans for the Machias, Pleasant and Narraguagus Rivers; (3) drafting of rules to address water withdrawals on a statewide basis by the DEP; (4) Maine Cranberry Growers Association providing low cost consultation to growers interested in expanding cranberry beds and including design considerations to protect Atlantic salmon habitat; and (5) the preparation of a sediment methodology by DEP for watershed councils to measure sedimentation in their river. The USDA-NRCS provided funding in 1998 through its Environmental Quality Incentive Program (EQIP) to encourage integrated crop management for blueberries, forest erosion control and animal waste management. In FY98, the Sheepscot River Watershed was designated as a priority area for EQIP, and as a result, over $100,000 was allocated to 19 projects in the watershed focusing on nonpoint source pollution reduction from animal wastes and erosion reduction on agricultural lands and streambanks (LWRC 1999).
Lands in the Dennys, East Machias, Machias, Pleasant and Narraguagus River watersheds are managed for the production of lowbush blueberries that may result in point and non-point source pollution. Insecticides, herbicides, and preservative chemicals used in agricultural activities, water withdrawals and discharges have the potential to adversely impact salmon. Habitat studies conducted by the ASRSC have documented the repeated presence of hexazinone in the Narraguagus and Pleasant Rivers (ASRSC unpublished data). It is unknown whether chronic exposure to these background levels would adversely affect Atlantic salmon. A permit was issued in 1997 to Cherryfield Foods for development of a cranberry bog project in the Pleasant River watershed. In 1998, violations under the Natural Resources Protection Act occurred and following site reviews and assessments, the DEP and Cherryfield Foods ultimately entered into a Consent Agreement, which specified action to correct the violation.
Agriculture is most prevalent in the Sheepscot River watershed. The Sheepscot Valley Conservation Association (SVCA) has detected bacterial contamination in the river, the ASA has noted elevated water temperatures in some years, and the Sheepscot River Watershed Council, DEP and the Soil and Water Conservation District have worked with farmers to keep livestock out of the river. During 1998, the DEP provided technical assistance to the SVCA to conduct volunteer watershed surveys to identify significant sources of nonpoint source pollution in a portion of the West Branch of the Sheepscot River. DEP also provided technical and financial support to Knox-Lincoln County Soil and Water Conservation District for a project demonstrating four different livestock exclusion / alternative watering facility types and methods of revegetating riparian areas where livestock previously had free access to the Sheepscot River. Funds were also provided by DEP to the SVCA to establish conservation easements to protect riparian areas and to facilitate implementation of BMPs at sites previously prioritized during watershed surveys in 1996 and 1997. The DEP sends all applications for sludge spreading in the Sheepscot River watershed to the ASA for review and comment. The Conservation Plan stated that a land-use oriented watershed specific non-point source management program would be developed for the Sheepscot River. The program was to include the following components: (1) refinement and publication of BMPs specifically developed for Atlantic salmon; (2) monitoring of ground water and rivers for nutrients, pesticides and bacteria; (3) an on-site survey of farmers to determine the percentage adopting BMPs; and (4) an educational and technical assistance program to assist farmers in adopting BMPs. In the annual progress report, the Maine Department of Agriculture, Food, and Rural Resources, reported that funding was not available for many of these activities and that the Department needed a position dedicated to this effort with additional funding for monitoring and surveys (LWRC 1999).
7.1.4 Forestry
One of the predominant land uses of central and northern coastal Maine watersheds is the growth and harvest of forest products. These practices have short and long term impacts that may adversely affect Atlantic salmon. The Report of the Commission to Study Atlantic Salmon (Harrington 1946) stated that deforestation had destroyed the water retention of watersheds resulting in inadequate river flows. Other potential impacts from forestry may include an increase in water temperature due to the removal of vegetation along streambanks and the introduction of large amounts of woody debris and silt into waterways. Poor logging practices and road construction can cause erosion resulting in the deposition of silt and sediment in habitat occupied by juvenile Atlantic salmon. Poorly placed or ill-designed culverts placed as part of road construction can negatively impact access to habitat. Clear cutting of large areas can alter the hydrologic characteristics of watersheds and result in greater seasonal and daily variation in stream discharge. In addition, herbicides that are used to suppress vegetative competitors can negatively impact aquatic and riparian vegetation.Forestry is the dominant land use in the watersheds of the Dennys, East Machias, Machias, Pleasant and Narraguagus Rivers. The Conservation Plan reports that Champion International Corporation owns approximately 433,000 acres within the five eastern river watersheds. Georgia Pacific Corporation owns a large amount of land in the Dennys and East Machias watersheds. Timber harvest in the Ducktrap and Sheepscot Rivers is conducted primarily by smaller wood lot owners. Champion International Corporation developed and has implemented a riparian zone management program that exceeds state and federal regulations as part of its Stewardship and Sustainability Initiative in the Northeast. The Champion policy recognizes the wildlife diversity of riparian zones and strives to protect water quality and accommodate the needs of wildlife. A 100-foot-wide protection zone is established for both sides of first and second order streams. A 330-foot-wide protection zone is established for both sides of third-order streams and a 660-foot wide protection zone is established for both sides of fourth- and fifth-order streams.
The Conservation Plan noted that forest practices have the potential to affect Atlantic salmon habitat by producing non-point source pollution, altering stream temperatures and hydrology, directly disturbing habitat, blocking fish passage with poorly designed road crossings, or depositing woody debris in streams. The Conservation Plan identifies the following initiatives addressing threats from forestry practices: Project SHARE, Sustainable Forestry Initiative, Riparian Management Zones imposed by Champion, Maine Non-point Source Management Program, Code Enforcement Training and local shoreland zoning technical assistance, Sheepscot Valley Conservation Association, and Ducktrap River Coalition. Additional actions proposed in the Conservation Plan for enhanced protection include the following: implement best management practices to control non-point source pollution, protect important habitat through landowner agreements, maintain shade, and monitor pesticide use.
The Conservation Plan contained a goal of assuring that 80% of harvesters would use forestry BMPs by 1999. The exact number and percentage of foresters using BMPs is not available at this time, but an effort was made in 1998 to assign field foresters to train and assist watershed councils on BMPs, work with code enforcement officers, and consider the Plan in harvest site reviews. The Maine Department of Conservation initiated monitoring of forestry BMPs in the Dennys, East Machias, Machias, Pleasant and Narraguagus River watersheds (LWRC 1999). The Conservation Plan also included a goal of correcting 80% of the shore land zone harvesting violations by December 1999. The Maine DEP has recommended that benchmark be changed to a commitment to increase oversight of compliance of shoreland harvesting restrictions by providing additional training and increasing the number of code enforcement officers (LWRC 1999). During the first year of Conservation Plan implementation, numerous training workshops on proper forestry BMPs were conducted for foresters working in the DPS watersheds. In addition, DEP has established a new requirement, beginning in January 1999, that town enforcement officers of each town within the seven watersheds report annually to the DEP on shoreland zoning activity.
A recent study conducted by the Canadian Department of Fisheries and Oceans and Environment Canada identified a relationship between chemical use and salmon survival. The insecticide Metacil(1.8D was applied to forests in Atlantic Canada between 1975 and 1985 to control the spruce budworm (Choristoneura fumiferana). One of the insecticides sprayed during that time, Matacil(1.8D, is known to contain a high concentration of 4-nonylphenol (4-NP) which is an endocrine disrupting chemical. Estimated concentrations of 4-NP in water fell within a range where effects on fish might be anticipated. Spraying was timed to coincide with the development of the spruce budworm larvae which is also the time of the critical parr-smolt transformation for Atlantic salmon. The Canadian study confirmed that nonylphenol concentrations can interfere with the smoltification process, preventing some fish from successfully making the transition from fresh to salt water. These studies have direct application to the United States as similar insecticides were used in Maine to combat spruce budworm. Also, if it is the estrogen potential of 4-NP that is causing disruption of smoltification, then other endocrine disrupting chemicals in the environment must be examined for their effect. The researchers speculated that the effects of Matacil(1.8D could range from an altered chemical perception of home stream odor to direct or indirect effects on smolt growth or hypo-osmoregulatory ability. Although Metacil(1.8D is no longer used, current potential sources of 4-NP include pulp and paper mills, textile manufacturing plants, petroleum production and leather manufacturing. The USGS-BRD is conducting studies on Maine Atlantic salmon for detection of endocrine disrupters (Fairchild et al. 1998).
Lands in the Dennys, East Machias, Machias, Pleasant and Narraguagus River watersheds are managed for the production of forest products. Large scale land alteration has occurred from logging operations and there is use of pesticides and herbicides by forest products industries. Deforestation, road construction, water withdrawals, and chemical applications have the potential to adversely affect salmon in the watershed. A four hectare bark dump in Whitneyville, the product of pulp debarking during the period 1949-1969, may continue to alter the chemistry of waters in the lower Machias River by leaching tannin and lignin products (Fletcher et al. 1982). Further investigation is warranted to determine the effect on salmon.
Timber harvesting in the Sheepscot and Ducktrap River watersheds is conducted by smaller woodlot owners. There is some evidence in the Sheepscot River watersheds of woody debris from logging and the forest products industry. Aerial spraying to control insect infestations has occurred periodically throughout the years in these watersheds, and pesticides could enter the aquatic environment if not properly applied.
7.1.5 Peat mining
Many eastern Maine river watersheds hold deposits of peat. There is one peat mine in the Narraguagus River watershed in Deblois at Denbo Heath. There has been interest expressed in opening a new mine on Brandy Heath in the Machias River watershed. The LURC regulates peat mines in unorganized towns and the DEP regulates peat mines in organized towns. The Denbo Heath is located between the West Branch and the mainstem Narraguagus and can therefore affect habitat in both reaches. Atlantic salmon and their habitat in the Narraguagus River could be negatively impacted by peat mining in that watershed through the discharge of low pH water containing suspended peat silt and dissolved metals and pesticides. Farm Pond and McCoy Brook trap sediment before it reaches the mainstem Narraguagus River; however, sedimentation has been found in both the West Branch and the mainstem Narraguagus River. From 1990 to 1993, the ASA conducted an extensive pH monitoring program in the Narraguagus River drainage and the Pleasant River, which has peat bogs that are not mined (Beland et al. 1993; Beland et al. 1994). The ASA found that both the mined Denbo Heath on the Narraguagus and the unmined Great Heath on the Pleasant River have locally depressed pH. While conducting habitat studies on the Narraguagus River, the ASRSC discovered the repeated occurrence of pH below 5.0 on the West Branch, a factor that suggests the potential for negative effects upon juvenile salmon abundance. Fluctuations in the pH level of freshwater environments have been identified as a limiting factor for Atlantic salmon (Peterson et al. 1980). As part of the studies, juvenile abundance was found to be lower in the West Branch than elsewhere in the Narraguagus River.Six sedimentation basins were built during the winter of 1995 in an attempt to curb peat laden discharges from disturbed areas of Denbo Heath. A water quality monitoring program at Denbo Heath indicates that runoff from this area is 1-2 pH units lower than the Narraguagus River into which it flows. Partial failures of the new sedimentation basins were reported in the spring of 1996 and 1997 after which further corrections were made to the sedimentation ponds and collection systems. No berm failures, water quality or other problems were observed in 1998 (LWRC 1999).
Action items identified in the Conservation Plan included the development of guidelines for peat mining permit application reviews by LURC and DEP staff. Secondly, it was suggested that a team of qualified engineers and/or erosion control specialists review the literature, evaluate erosion control methods used at peat mines, and develop and/or revise standards to be included as permit conditions. The annual progress report on Conservation Plan implementation in 1998 states that staff from the Department of Inland Fisheries and Wildlife will be convening a group of state agencies to consider the issues surrounding sediment control from commercial peat mining operations. The last permit issued by the State for peat operations was issued in 1977. The Maine DEP recommended that the goal contained in the Conservation Plan of improving permit review and required standards be modified to maintain compliance with existing mining permits which would be implemented by conducting annual inspections of each facility and including the results in the annual progress report on Conservation Plan implementation (LWRC 1999).
7.1.6 Habitat Protection within the DPS
Watershed Councils: The Conservation Plan creates a very important role for watershed councils in protecting, enhancing and rehabilitating habitat within the DPS for Atlantic salmon. With financial assistance from the State and support from Project SHARE and ASF, Watershed Councils have formed on rivers within the DPS and are emerging as powerful local stewards of the resource. Much of the first year was spent organizing the Councils and establishing a purpose and plan of action for those Councils. State funding was provided for a Watershed Council coordinator who is working cooperatively with Project SHARE to assist in the formation and operation of the Watershed Councils in Washington County. A Downeast Rivers Coalition was formed to serve as a steering committee among the Dennys, East Machias, Machias, Narraguagus, and Pleasant Rivers. The purpose of the Coalition is to provide opportunities for communication and coordination among the watershed councils and assist with many of the administrative tasks that tend to stall progress of small groups such as grant writing and computer support.Watershed Councils have been formed on the Dennys, East Machias, Machias, Pleasant, and Narraguagus Rivers. All five councils have adopted bylaws and Boards have been established for Dennys and Pleasant River Watershed Councils and are in the process of being developed for the East Machias, Machias and Narraguagus River watersheds. Actions being undertaken by all five of these watersheds include the following: participating in water use planning committees; impact assessment of forestry and other land uses on salmon habitat; and removal of beaver dams to facilitate salmon access to habitat (LWRC 1999). Watershed Councils on the Sheepscot and Ducktrap Rivers grew out of existing coalitions and therefore avoided many of the initial stumbling blocks the other five Councils faced.
The Pleasant River Watershed Council has formed, elected officers, passed bylaws, completed administrative organizational tasks, and expanded its Board of Directors during 1998. Actions of the Pleasant River Watershed Council during 1998 included the following: collection of water quality baseline data; requested pesticide water analysis by the Board of Pesticide Control; supported the construction of a fish weir on the Pleasant River; easement and buffer protection for a canoe landing on the Pleasant River; and cooperated with other Watershed Councils and organizations to build and place educational kiosks on the rivers.
The Ducktrap Coalition serves as the watershed council for the Ducktrap River watershed. The Ducktrap Coalition is responsible for administration of the watershed council activities and one of its member organizations, Coastal Mountains Land Trust, coordinates administrative tasks for the Coalition. During 1998, the Ducktrap Coalition conducted the following activities: assessed riparian buffer areas and water quality conditions; began plans for an assessment of the status of vegetative cover of the riparian zone of the Ducktrap River using aerial photography and site surveys; identified a source of silt, sand and gravel discharge to the Ducktrap River (this property was purchased by the Trust and a corrective action plan for that site has been designed and is being implemented); and development and implementation of a plan for permanent conservation protection of the riparian area of the Ducktrap River, working cooperatively with landowners and using both conservation easements and fee simple acquisitions (LWRC 1999).
The Sheepscot River Watershed Council was able to build on the history of the Sheepscot Valley Conservation Association and get an early start by forming during the development of the Maine Conservation Plan. It identified the following critical information needs within the watershed: a survey of agricultural land use; a survey of nonpoint source pollution in the watershed; a survey of riparian buffers along the river and stream corridors in the watershed; and a survey of stream segments in the watershed which lack adequate canopy cover. The Council has secured funding for a watershed coordinator, installation of BMPs for nonpoint source pollution (primarily agricultural sources), salmon habitat protection activities, and the purchase of property adjacent to critical spawning, rearing and adult holding habitat on the West Branch and mainstem Sheepscot River. The Council has initiated a nonpoint source program by conducting a survey of the watershed to identify problem areas. The Sheepscot River Watershed Council has facilitated remediation on a few sites but identified the following limitations on remediation and installation of BMPs: willingness of landowners to adopt BMPs, availability of funding to pay for BMPs, and availability of staff and volunteer time to identify, design and implement appropriate action strategies. The Watershed Council has identified expanded participation by state agencies in the activities of the Council as a priority task.
Watershed Councils on the Narraguagus, Machias, East Machias and Dennys Rivers have also been formed and adopted bylaws and are at various stages of development.
In 1994, Project SHARE (Salmon Habitat and River Enhancement) was created by landowners, businesses, government officials, researchers, educators and conservation organizations to conserve and enhance Atlantic salmon habitat and populations in Downeast Maine. Over the past five years, Project SHARE has led, funded and participated in a number of projects to increase understanding of Atlantic salmon habitat and to improve access to and the quality of habitat. Meetings of Project SHARE are held every other month to provide presentations of current information on Atlantic salmon and their habitat and also to provide opportunities for open discussions of ways to protect and enhance salmon habitat for the Dennys, East Machias, Machias, Pleasant and Narraguagus River watersheds. A key objective in the Conservation Plan is the identification of critical habitat for Atlantic salmon and the protection of that habitat. Conservation easements and land acquisitions have been secured for some of this habitat although the priority and strategy varies among watersheds. Progress in protecting habitat within the DPS is displayed in the table below (Table 7.1.6). Habitat is considered "protected" if a management agreement or conservation easement is in place, or if it is directly owned by an organization that has secured it for the purpose of habitat protection.
Table 7.1.6: Riparian Habitat Protection
RIVER |
Riparian Habitat Adjacent to Spawning Habitat (linear meters) |
Riparian Habitat Adjacent to Rearing Habitat (linear meters) |
|||||
Total Amount |
Amount Protected |
% Protected |
Total Amount |
Amount Protected |
% Protected |
||
Dennys |
12,756 |
306 |
2.4% |
31,572 |
1,705 |
5.4% |
|
East Machias |
13,156 |
0 |
0% |
39,892 |
3,231 |
8.1% |
|
Machias |
25,044 |
1,653 |
6.6% |
71,798 |
2,298 |
3.2% |
|
Pleasant |
6,688 |
0 |
0% |
21,508 |
215 |
1.0% |
|
Narraguagus |
24,754 |
248 |
1.0% |
95,644 |
574 |
0.6% |
|
Ducktrap |
7,424 |
4,484 |
60.4% |
14,798 |
6,644 |
44.9% |
|
Sheepscot |
16,212 |
276 |
1.7% |
36,096 |
1,263 |
3.5% |
Although the amount of habitat currently being protected appears low, there has been considerable progress made in the last year through a variety of sources, such as the watershed councils and grants, and the mechanisms are in place to protect more habitat.
The State Planning Office (SPO) contracted with a private consultant during 1998 to prepare a scientific riparian buffer methodology that could be used to determine the appropriate size of a buffer to protect salmon habitat. The methodology incorporates information about local conditions such as soil type, slope, and vegetation to tailor the size of the buffer to the habitat conditions. The goal is to be able to use the methodology when working with landowners to secure long term protection agreements. The SPO has also prepared a database of riparian landowners (LWRC 1999).
7.1.7 Other Habitat Issues
The January 1, 1947, Report of the Commission to Study Atlantic Salmon documented that the resource had been depleted by dams, deforestation, pollution, overfishing, water diversions, and drought. In the Strategic Plan for Management of Atlantic Salmon in the State of Maine (1984), Beland reported that: "As colonization and development accelerated during the 17th and 18th centuries, the salmon habitat was degraded, destroyed, and/or made inaccessible. By 1947, less than 10% of the original habitat remained accessible to Atlantic salmon." The substrate and water quality of a river or stream must meet certain criteria in order for it to be suitable as Atlantic salmon spawning and nursery habitat. Specific conditions are discussed in detail in Section 3.0. The egg, alevin, fry, and parr stages of Atlantic salmon are especially sensitive to impacts associated with watershed development. During smoltification, salmon are particularly vulnerable. Potential impacts to habitat quality include alterations in water temperature, reductions in dissolved oxygen, the introduction of pollutants and sediment, and other factors that may alter substrate or river discharge. Water temperature can be impacted by introductions of heated effluent, reductions in riparian vegetation, or by impounding water. Water quality can also be affected by the introduction of chemicals such as chlorine added during sewage treatment, metals discharged with industrial effluent and herbicides and pesticides used in agriculture. The level of dissolved oxygen in water is reduced when biological activity increases to digest organic matter. Sources of organic matter could be domestic sewage, industrial waste, or livestock waste. Elson (1975) reported that growth and development of Atlantic salmon require dissolved oxygen concentrations of at least 6 mg/l. Respiration of adult Atlantic salmon is depressed at dissolved oxygen levels less than 5 mg/l (Kazokou and Khalyapina 1981).Habitat may also be made unsuitable for Atlantic salmon by acid precipitation. Salmon streams in New England typically lack sufficient buffering capacity and therefore are sensitive to acid rain (USFWS 1989). Acid precipitation, either in the form of rain or melting snow, can decrease the pH of a river or stream below the 4.7 level that could affect successful reproduction (USFWS 1989). Low pH (<5.0) has been demonstrated to cause pathological changes in Atlantic salmon eggs (Peterson et al. 1982; Haines 1981). Depressed pH levels (<4.7) have prevented salmon reproduction in several streams in Nova Scotia (Watt et al. 1983). Low pH has also been demonstrated to hinder the salmon's ability to transition from fresh to saltwater (McGee in press).
Erosion and watershed development can contribute sediment to the riverbed thus embedding particulate in gravel and making it unsuitable as spawning habitat. The overall productivity of the stream can be impacted by increased turbidity in the water column. Fry and parr find shelter in the interstitial spaces provided by gravel and cobble; sediments can clog spaces and, consequently, decrease survival and limit production at these critical life stages (McCrimmon 1954).
7.1.8 Summary of Habitat Issues
Demonstrated and potential impacts to Atlantic salmon habitat within the DPS watersheds result from the following causes: (1) water extraction; (2) sedimentation; (3) obstructions to passage caused by beaver and debris dams, poorly designed road crossings, and dams; (4) input of nutrients; (5) chronic exposure to insecticides, herbicides, fungicides, and pesticides (in particular, those used to control spruce budworm); (6) elevated water temperatures from processing water discharges; and (7) removal of vegetation along streambanks. The most obvious and immediate threat is posed by water extraction. Work is underway to address that threat through the creation of water use management plans and the promulgation of regulations by DEP to control extractions. Until those processes are completed, however, the threat of excessive or unregulated withdrawal remains.The threat of blocked passage due to debris or beaver dams is an annual one and the ASA, Project SHARE, and the Watershed Councils have demonstrated an ability to annually remove or reduce that threat. Impacts from chronic exposure to chemical residues in the water are a potential threat and one that warrants further investigation. In particular, potential impacts during the process of smoltification should be examined. Sedimentation from a variety of sources also warrants closer review as it may be altering habitat and rendering it incapable of supporting Atlantic salmon. Water temperatures in the vicinity of processing water discharges should be monitored to determine if they make habitat unsuitable for Atlantic salmon. Permitting exemptions for agriculture should evaluated to determine if they are or could result in inadequate protection of riparian habitat.
All of these potential impacts to Atlantic salmon habitat need to be examined in more detail for their individual and cumulative impacts. Study results on the Narraguagus River demonstrate that full freshwater production is not being achieved despite fry stocking efforts. These results could mean that one or a combination of factors within the rivers is negatively impacting freshwater habitat for Atlantic salmon. The relationship between these factors and freshwater production and survival of salmon needs to be studied in detail so that cause and effect connections can be determined or ruled out. Corrective actions can then be implemented as appropriate to enhance recovery.
Although there does not appear to be one particular habitat issue which poses a significant threat by itself, the cumulative impacts from habitat degradation discussed above may reduce habitat quality and limit habitat quantity available to salmon within the DPS at various stages in their life history within freshwater. Given current low levels of abundance, it is critical that efforts be undertaken to better understand, avoid, minimize and mitigate these factors.