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Diadromous Fish


Extent Condition Protection/Restoration


Overview


Migratory fish populations, or "diadromous fish," are an important part of Massachusetts' near-shore fauna. Migratory fish includes both anadromous and catadromous fish species. Diadromous fish habitat includes areas that support nurseries, feeding, migration (fish runs), and spawning. Intact waterways (as opposed to waterways fragmented by dams) with sinuous channels and diverse structure are most likely to support fish runs, feeding, and spawning areas. Such waterways might include areas with sandy or gravelly substrate, riffle and pool sequences, slightly undercut banks, fallen logs or boulders, flowing water, wetlands, riparian habitats, vegetative buffers, a diverse benthic community, as well as clean and adequate water flow. These conditions provide food for the aquatic invertebrates preyed upon by migratory fish. These conditions also cool the water and stabilize the riverbanks, preventing soil erosion, high water turbidity and siltation of fish eggs. Note that fish runs occur in waterways and adjacent areas that meet certain water quality standards and drain into coastal ponds and Boston Harbor.



Blueback Herring
Figure 1a: Blueback herring (Cornell University)
Alewife
Figure 1b: Alewife (Cornell University)
Rainbow Smelt
Figure 1c: Rainbow smelt (Cornell University)

Anadromous fish begin life in freshwater, then migrate to the ocean to spend the majority of their life. Eventually, they return to freshwater rivers or to the brackish upper reaches of estuaries to spawn and lay eggs. Then, in the autumn, most of the juveniles head back downstream to more brackish water. Over 15 species of anadromous fish occur in inland and marine waters along the Commonwealth's coast, including within the Mystic, Back, Charles and Neponset Rivers, for example, and historically within the Weir River. Anadromous fish that currently use the Boston Harbor Watershed include American shad (Charles River contains a principal fish run), blueback herring (Back River) alewives (Charles River), Atlantic salmon, striped bass (Parker River, although no spawning), rainbow smelt (Neponset River estuary), sea-run brook trout (Salvelinus fontinalis), and sea lamprey (Petromyzon marinus). Also present in Massachusetts waters are sea-run brown trout (Salmo trutta) and Pacific salmon species (Oncoryhnchus spp.), both introduced species. Anadromous shortnose sturgeon (Acipenser brevirostrum) and Atlantic sturgeon historically were present in the Charles River, but have been extirpated.


Catadromous fish species begin life at sea and then migrate to freshwater, where they live for most of their adult lives. Eventually, they return to the ocean to spawn and die. The catadromous American eel (Anguilla rostrata) is born at sea, then migrates to freshwater lakes and ponds, eventually returning to the Sargasso Sea to spawn and die.

American Shad
Figure 2: American shad (B. Byrnes)

Unfortunately, these fish and their habitat have diminished over the last several hundred years throughout Boston Harbor Watershed and beyond. Because diadromous fish migrate between fresh- and saltwater, they are affected by conditions in both. Dams, habitat alterations, pollution, and overfishing have led to declines in migratory fish numbers. In the Boston Harbor Watershed, dams have negatively affected migratory fish species since the mid-1600s, when water-powered mills hummed with activity on Massachusetts rivers. Species such as American shad (Alosa sapidissima), Atlantic salmon (Salmo salar), alewife (Alosa pseudoharengus), blueback herring (Alosa aestivalis), striped bass (Morone saxatilis), and rainbow smelt (Osmerus mordax) were all declining in southern New England by 1870, at least in part because of dams that blocked migrations and because of significant water pollution near towns and mills. These species' numbers remain below historic levels. Overexploitation, primarily by commercial fishers, also has reduced populations of migratory fish such as striped bass, Atlantic salmon and Atlantic sturgeon (Acipenser oxyrinchus).


Extent


Migratory fish species seek out different habitat characteristics.

With its many waterways, the Boston Harbor region provides a diversity of habitats resulting in a range of migratory fish species.

Fish eggs
Figure 4: Smelt eggs at Lower Mills (T. Palmer)

Unfortunately, the distribution of migratory fish populations and their habitat has waned over the years, due especially to degradation and reduction of habitat. Consider the historic of just a few of the anadromous fish species that occur in the Boston Harbor Watershed:

Condition


The condition of anadromous fish habitat has declined significantly, due in part to water pollution, blocked fish passage along waterways key to spawning migrations, alteration of riparian habitat, and low stream flow, among other factors. Because migratory fish use both fresh and salt water over their lifetimes, they are vulnerable to changes in both areas. In the words of John Moring in the "Recent Trends in Anadromous Fishes" chapter of The Decline of Fisheries Resources in New England: Evaluating the Impact of Overfishing, Contamination, and Habitat Degradation, edited by Robert Buchsbaum, Judith Pederson and William E. Robinson, 2005:

    "Because these fishes are dependent on diverse environments during different portions of their life cycle, they can be especially vulnerable to a variety of environmental changes. During their early life stages, these fishes are sensitive to deleterious alterations in freshwater. Later, when they pass through estuaries and into the marine environment, coastal pollution can affect survival. At maturity, habitat alterations, pollution, and commercial harvest can have profound impacts on spawning grounds. Therefore, not only are anadromous fishes subject to environmental and harvest pressures at sea, they encounter dams, pollution, urbanization impacts, and habitat changes in freshwater."

The reduction and degradation of migratory fish habitat can be described within four main categories. Each of these stressors are prevalent in the Boston Harbor region.

Protection and Restoration Potential


To restore and rehabilitate anadromous fish populations, we must protect and improve the condition of the freshwater and estuarine resources on which they rely, by implementing projects to reduce aquatic pollution, restore fish passage, reduce water withdrawals, and rehabilitate or protect nursery and spawning habitats. When planning such conservation efforts, it is beneficial to consider the interplay of directly affected and other species. In the words of John Moring in the "Recent Trends in Anadromous Fishes" chapter of The Decline of Fisheries Resources in New England: Evaluating the Impact of Overfishing, Contamination, and Habitat Degradation, edited by Robert Buchsbaum, Judith Pederson and William E. Robinson, 2005:

    "[A]s striped bass numbers increase, more of these predators will be entering the lower portions of New England rivers. The success of their feeding in these habitats will depend, among other things, on the success of programs to increase runs of Atlantic salmon and American shad. Survival of Atlantic salmon smolts, rainbow smelt, and alewives, in turn will be influenced by the breeding success of federally-protected aquatic birds, such as double-crested cormorants (Phalacrocorax auritius), the popularity of new sea-run brown trout sportfisheries (potential predators of smolts and prey for striped bass), and the success of striped bass restoration programs, as well as fishing and nonfishing human activities. Thus, rehabilitation programs must be managed from a broader perspective."

A range of agencies has worked to maintain, restore and boost diadromous fish populations and habitat in the Boston Harbor Watershed, and their efforts occur within a network of national, regional and state-level guidelines concerning species management. Such efforts to restore diadromous fish populations and habitat in the Boston Harbor Watershed targeted species key to recreational fisheries, like rainbow smelt, American shad and river herring that also are important members of the food web, feeding predators like striped bass and bluefish. These efforts have experienced some success fish populations have been established in areas where they previously had disappeared due to human activities, fish passage for some species has been restored along some waterways, and populations of migratory fish have increased in some areas. However, it should be noted that although a migratory fish species may be observed to increase in number here in Massachusetts that increase may be due to restoration efforts elsewhere in their migratory path (e.g., striped bass, which no longer spawn in Massachusetts).

A sampling of agencies involved in migratory fish and/or aquatic resources conservation in Massachusetts include:

Neponset River
Figure 5: Neponset River, Quincy (T. Palmer)
the Massachusetts Division of Marine Fisheries (DMF, MarineFisheries), U.S. Fish and Wildlife Service (USFWS), Massachusetts Office of Coastal Zone Management, Massachusetts Bays Program, Massachusetts Division of Ecological Restoration (Riverways Program), river watershed associations, conservation organizations, National Oceanic and Atmospheric Administration (NOAA), U.S. Army Corps of Engineers (ACOE), National Marine Fisheries Service, National Park Service, Natural Resources Conservation Service, U.S. Environmental Protection Agency, U.S. Fish & Wildlife Service, U.S. Geologic Survey, American Rivers, Coastal America Foundation, Conservation Law Foundation, Corporate Wetlands Restoration Partnership, Ducks Unlimited, Fish American Foundation, MassAudubon, Massachusetts Association of Conservation Commission, The Nature Conservancy, Trout Unlimited, The Trustees of Reservations, etc.

Anadromous fish habitat restoration efforts may be divided into these categories:

Walter Baker Dam
Figure 7: Walter Baker Dam, Neponset River (T. Palmer)

A migratory fish restoration technique that is less directly tied to habitat is to propagate fish to re-stock depleted waterways. Fish, their larvae or eggs can be harvested from one river and moved to another. The juvenile fish imprint on the new site and eventually return there to spawn, thereby boosting local fish populations. River herring and American shad have benefited from propagation.

Protection and restoration opportunities for diadromous fish habitat in the Boston Harbor region include the following:


Literature Cited

Aquatic Habitat Restoration Task Force, Charting the Course: A Blueprint for the Future of Aquatic Habitat Restoration in Massachusetts, A Report of the Aquatic Habitat Restoration Task Force, January 2008.

Brady, Phillips D., Reback, Kenneth E., McLaughlin, Katherine D., and Milliken, Cheryl G., "A Survey of Anadromous Fish Passage in Coastal Massachusetts. Part 4. Boston Harbor, North Shore and Merrimack River," Technical Report TR-18, of Michael P. Armstrong, ed., Massachusetts Division of Marine Fisheries Technical Report Series, Massachusetts Division of Marine Fisheries, MA DMF Southshore Field Station, Pocasset, MA, Department of Fisheries and Game, Wildlife and Environmental Law Enforcement., Executive Office of Environmental Affairs. Commonwealth of Massachusetts, January 2005.

Environmental Data Center, Rhode Island's Coastal Habitats: Anadromous Fish Habitats. Restoring Coastal Habitats for Rhode Island's Future, University of Rhode Island, Website created through a partnership of the Coastal Resources Management Council, Narragansett Bay Estuary Program, and Save The Bay. http://www.edc.uri.edu/restoration/html/intro/fish.htm, June 2011.

Gulf of Maine Council on the Marine Environment. Anadromous Fish Habitat: Priority Habitats and Threats. http://restoration.gulfofmaine.org/habitatsandthreats/anadromousfishhabitat.php, June 17, 2011.

Kocik, J. "River Herring," in Stephen H. Clark, ed., Status of the Fishery Resources off the Northeastern United States, (Resource Evaluation and Assessment Division, Northeast Fisheries Science Center, Massachusetts Division of Fisheries & Wildlife, Massachusetts Department of Fish and Game, 1998), http://www.mass.gov/dfwele/dfw/fisheries/anadromous/river_herring.htm, June 22, 2011.

Kocik, J. "American Shad," in Stephen H. Clark, ed., Status of the Fishery Resources off the Northeastern United States, (Resource Evaluation and Assessment Division, Northeast Fisheries Science Center, Division of Fisheries & Wildlife, Massachusetts Department of Fish and Game, 1998), Massachusetts, http://www.mass.gov/dfwele/dfw/fisheries/anadromous/american_shad.htm, June 22, 2011.

Kraft, C.E., D.M. Carlson, and M. Carlson. 2006. Inland Fisheries of New York Online, Version 4.0. Department of Natural Resources, Cornell University, and the New York State Department of Environmental Conservation.

Moring, John, "Recent Trends in Anadromous Fishes," in Robert Buchsbaum, Judith Pederson, William E. Robinson, ed., The Decline of Fisheries Resources in New England: Evaluating the Impact of Overfishing, Contamination, and Habitat Degradation (Cambridge: MIT Sea Grant College Program, MIT, 2005). http://massbay.mit.edu/publications/NEFishResources/index.html. Pp.25-42.

Massachusetts Bays Program. About the Massachusetts Bays Program, http://www.mass.gov/envir/massbays/aboutus.htm, June 22, 2011.

Massachusetts Division of Ecological Restoration Active Habitat Restoration Priority Projects, Massachusetts Division of Ecological Restoration, Department of Fish and Game, Mass.gov: http://www.mass.gov/dfwele/der/der_maps/pp_map.htm.

Massachusetts Division of Marine Fisheries. Anadromous Fish Restoration: Enhancing finfish resources in Massachusetts. Massachusetts Department of Fish and Game, 2005 or prior, http://www.mass.gov/dfwele/dmf/publications/hubline_anadromous_restoration_leaflet.pdf.

Massachusetts Division of Marine Fisheries, Programs and Projects. Anadromous Fisheries, Massachusetts Department of Fish and Game, http://www.mass.gov/dfwele/dmf/programsandprojects/anadrom.htm, June 17, 2011.

Massachusetts Division of Marine Fisheries. "Anadromous Fish Restoration in Massachusetts Bay" of Hubline Anadromous Fish 5-Year Completion Report. Massachusetts Department of Fish and Game, 2009, http://www.mass.gov/dfwele/dmf/programsandprojects/hubline/hubline_5yr_anadromous_fish_
restoration.pdf, http://www.mass.gov/dfwele/dmf/programsandprojects/hubline/admin.htm.

Marine Fisheries Advisory Board, Massachusetts Division of Marine Fisheries Strategic Plan 20102014, Commonwealth of Massachusetts, Executive Office of Energy and Environmental Affairs, Department of Fish and Game, Division of Marine Fisheries. http://www.mass.gov/dfwele/dmf/publications/dmf_strategic_plan.pdf

Massachusetts Ocean Coalition, The Commonwealth Releases First-In-The-Nation Final Ocean Management Plan, July 20, 2010, http://www.massoceanaction.org/, June 23, 2011.

Mills, Kathy, Enterline, Claire, and Chase, Brad, "Protecting a Threatened Coastal Fish Species Through Regional Collaboration." Great Bay National Estuarine Research Reserve, Maine Department of Marine Resources, and Massachusetts Division of Marine Fisheries. Shifting Shorelines: Adapting to the Future, The 22nd International Conference of The Coastal Society, June 13-16, 2010, Wilmington, North Carolina., Dec. 14, 2010.

Nelson, Gary.A., Brady, Phillips D., Sheppard, John J., and Armstrong, Michael P. "An Assessment of River Herring Stocks in Massachusetts," Technical Report TR-46, of Michael P. Armstrong, ed., Massachusetts Division of Marine Fisheries Technical Report Series, Massachusetts Division of Marine Fisheries, January 2011.

Reback, Kenneth E., Brady, Phillips D., McLaughlin, Katherine D., and Milliken, Cheryl G. "A Survey of Anadromous Fish Passage in Coastal Massachusetts, Part 1. Southeastern Massachusetts," Technical Report TR-15, of Michael P. Armstrong, ed., Massachusetts Division of Marine Fisheries Technical Report Series, Massachusetts Division of Marine Fisheries, Department of Fisheries and Game, Executive Office of Environmental Affairs, Commonwealth of Massachusetts, May 2004, http://www.mass.gov/dfwele/dmf/publications/tr15_anad_p1_intro.pdf.

Dowhan, Joseph, Significant Habitats and Habitat Complexes of the New York Bight Watershed. (Charlestown, Rhode Island: U.S. Fish and Wildlife Service, Southern New England New York Bight Coastal Ecosystems Program, November 1997), http://library.fws.gov/pubs5/web_link/text/int_fish.htm#Diadromous%20Fishes, June 23, 2011.

Chase, Bradford C., Plouff, Jeffrey H., Gabriel, Marea, "An Evaluation of the Use of Egg Transfers and Habitat Restoration to Establish an Anadromous Rainbow Smelt Spawning Population," Technical Report TR-33, of Michael P. Armstrong, ed., Massachusetts Division of Marine Fisheries Technical Report Series, Massachusetts Division of Marine Fisheries, Massachusetts Department of Fisheries and Game, Executive Office of Energy and Environmental Affairs, Commonwealth of Massachusetts, July 2008. http://www.docstoc.com/docs/45358689/Technical-TR-33.

Deegan, Linda, and Buchsbaum, Robert, "The Effect of Habitat Loss and Degradation on Fisheries," in Robert Buchsbaum, Judith Pederson, William E. Robinson, ed., The Decline of Fisheries Resources in New England: Evaluating the Impact of Overfishing, Contamination, and Habitat Degradation (Cambridge: MIT, 2005).

NOAA Fisheries Office of Protected Resources, Proactive Conservation Program: Species of Concern, Updated November 4, 2011, http://www.nmfs.noaa.gov/pr/species/concern/, National Oceanic and Atmospheric Administration Fisheries Service, November 11, 2011.

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Boston Harbor Habitat Atlas
Updated 12/31/2011