New Jersey Field Office
Northeast Region

Seabeach Amaranth (Amaranthus pumilus) [threatened]

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Additional Information

Seabeach amaranth


Sandy beaches

Main Threats:
Habitat stabilization
Vehicle use/mechanical beach raking Herbivory

Fun Fact:
Other members of the Amaranthus genus are cultivated around the world as important grain and vegetable crops.


Seabeach amaranth was federally listed as a threatened species in 1993.

An annual member of the amaranth family, seabeach amaranth has reddish stems and small, rounded, notched, spinach-green leaves. In New Jersey, these low-growing plants are typically about 4 inches across by late summer, but can occasionally reach 2 or 3 feet in diameter. The small white flowers and dark seeds are located in inconspicuous clusters along the stems. Germination begins in May and continues through the summer. Flowering begins as soon as plants reach sufficient size (June or July) and continues until the plants die between September and December.

Seabeach amaranth is native (endemic) to Atlantic Coast beaches and barrier islands. The primary habitat of seabeach amaranth consists of overwash flats at accreting ends of islands, lower foredunes, and upper strands of non-eroding beaches (landward of the wrackline), although the species occasionally establishes small temporary populations in other habitats, including sound-side beaches, blowouts in foredunes, inter-dunal areas, and on sand and shell material deposited for beach replenishment or as dredge spoil. Seabeach amaranth usually grows on a nearly pure sand substrate, occasionally with shell fragments mixed in.

Seabeach amaranth occupies elevations from 8 inches to 5 feet above mean high tide. The plant grows in the upper beach zone above the high tide line, and is intolerant of even occasional flooding during its growing season. The habitat of seabeach amaranth is sparsely vegetated with annual herbs and, less commonly, perennial herbs (mostly grasses) and scattered shrubs. Vegetative associates of seabeach amaranth include sea rocket (Cakile edentula), seabeach spurge (Chamaesyce polygonifolia), and other species that require open, sandy beach habitats. However, this species is intolerant of competition and does not occur on well-vegetated sites. Seabeach amaranth is often associated with beaches managed for the protection of beach nesting birds such as the piping plover (Charadrius melodus) and least tern (Sterna antillarum).

Threats to seabeach amaranth include beach stabilization (particularly the use of beach armoring, such as sea walls and riprap), intensive recreational use, mechanical beach raking, and herbivory by insects.

Map of seabeach amaranth distribution in the U.S.
Seabeach amaranth distribution in the U.S.

Map of seabeach amaranth distribution in New Jersey by municipality
Seabeach amaranth distribution in New Jersey by municipality


Species Range: Seabeach amaranth occurs on coastal beaches from New York to South Carolina. The species historically occurred in Rhode Island and Massachusetts.

Distribution in New Jersey: Seabeach amaranth occurs in Monmouth, Ocean, Atlantic, and Cape May Counties.

Examples of actions that may affect this species

The following is provided as technical assistance only and is not intended as a comprehensive list of all activities that may affect this species.

Within a beach, dune, or inter-tidal area:

  • construction of any new permanent or temporary structure
  • new or modified beach or dune management practices including but not limited to beach nourishment, permanent or temporary placement of dredged or fill material, sand transfers, grading, sand (snow) fence installation/modification/removal, vegetation planting or removal, mechanical beach raking, and equipment storage
  • new or increased discharges of herbicides, pesticides, or environmental contaminants
  • any new or expanded human activity during the nesting season of May 15 to November 30, especially but not limited to activities involving motorized vehicles

Within 1.0 mile of a beach, dune, or inter-tidal area:

  • new or expanded facilities to provide public access to the beach

Best Management Practices

The following Best Management Practices are examples of typical Conservation Measures frequently recommended by the New Jersey Field Office in the course of consultation or technical assistance.

  • Avoid permanent or temporary modification of seabeach amaranth habitat including but not limited to creation or expansion of new stabilizing structures (e.g., jetties, groins, sea walls, sand fencing, stabilized dunes) and adverse changes in elevation such as through sand removal, deposition, or transfers.

  • Avoid the introduction or spread of dense or invasive vegetation. Thoroughly clean construction equipment before use on a beach to avoid unintended spread of invasive plants. Contact the Service prior to any beach plantings (except routine maintenance plantings undertaken in accordance with an approved Beach Management Plan).

  • Seasonally restrict work that might damage seabeach amaranth plants during the growing season of May 15 to November 30, particularly work involving use of motorized vehicles. Alternatively, in consultation with the Service, fence and avoid any plants in the work area as follows.

    • Conduct a thorough survey of the area of disturbance no more than 1 week prior to the start of work.
    • Survey by walking slowly and carefully in a zig-zag fashion from the high-water line (seaward limit of vegetation) to the dune, seawall, boardwalk, or other landward limit of the beach, ensuring complete survey coverage of the area of disturbance. See the NJFO's collection of amaranth photos, and note that seedlings may be small and inconspicuous.
    • Use symbolic string-and-post fencing to encircle each plant or group of plants, allowing a 10-foot buffer on all sides. Do NOT use snow fence. Mark the fencing with flagging and signs.
    • Instruct all work crews to avoid fenced areas (e.g., do not enter on foot or via motor vehicle, do not stage or store materials or equipment in or near fencing, locate access routes away from fenced areas, do not grade sand in or near fencing).
    • Notify the Service of the survey results.
    • Remove symbolic fencing upon completion of work.
  • Avoid mechanical beach raking during the growing season of May 15 to November 30 to protect plants and habitat characteristics such as wrack materials.

  • Plan and carry out fireworks displays in accordance with the Service's Guidelines for Managing Fireworks in the Vicinity of Piping Plovers and Seabeach Amaranth on the U.S. Atlantic Coast .

  • Work with the Service and the New Jersey Endangered and Nongame Species Program to prepare a Beach Management Plan. Plan and carry out projects, events, and habitat management in accordance with the provisions of approved plans.

What to do if this species occurs on your property or project site

  • Contact the Service early in planning for any project or activity that may affect seabeach amaranth or its habitat; see New Jersey Field Office Procedures for Consultation and Technical Assistance for instructions. Through the technical assistance or consultation processes of the Endangered Species Act, the Service will provide project-specific recommendations to avoid or minimize adverse effects to listed species.

  • Individual beach-front property owners can also contact the Service for proactive conservation recommendations. Most land in New Jersey is privately owned. Voluntary conservation efforts by New Jersey's residents are critical in the conservation and recovery of threatened and endangered species.

  • Municipalities and other beach managers are encouraged to contact the Service for conservation recommendations to benefit listed species. See Beach Management Planning in New Jersey [PDF].

  • Also see "Endangered Species and You" Frequently Asked Questions.


Click the image for full-size version.

Seabeach amaranth seedlings Seabeach amaranth Seabeach amaranth
Seabeach amaranth Seabeach amaranth Seabeach amaranth

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Last updated: May 16, 2018
New Jersey Field Office
Northeast Region Ecological Services
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