Importance of Baitworms and their Live Algal Packing Materials to the Mid-Atlantic Vector Characterization and Management

Principal Investigator:

A. Whitman Miller

Start/End Year:

2011 - 2013


Smithsonian Environmental Research Center

Strategic focus area:

Resilient ecosystem processes and responses


OBJECTIVES: Our project focuses on the Mid-Atlantic region as a model vector system for the transport and sale of marine baitworms and packing algae from Maine. We propose: 1) To describe the potential pool of species that may be transported with baitworms/algae to the Mid-Atlantic and the organisms sold in bait-boxes by determining species quantity and diversity from: (a) marine algae in the Maine source area; (b) bait-boxes sold by Maine distributors; and (c) bait-boxes sold in mid-Atlantic bait shops. 2) To identify management opportunities along the invasion pathway to limit or eliminate the movement of hitchhiking species with baitworms/algae, including: (a) prevention of initial entrainment (i.e., alternative packing materials); (b) removal/prevention from pathway (i.e., rinsing materials prior to use); and (c) inoculation prevention (i.e., proper disposal of materials). 3) To test the efficacy of advisory labels/informational materials on the behavior of fishermen buying baitworms in the Mid-Atlantic. This final component includes three major social science goals: 1) Identifying the socio-ecological system of marine bait worms as potential aquatic invasive species; and 2) Eliciting cultural and socio-economic information contextualizing bait worms as vectors for AIS; and 3) Intervention, analysis and dissemination of findings.

METHODOLOGY: Diversity of marine macro-organisms associated with baitworms/packing algae will be assessed in three ways: random quadrats in Maine source habitats, bait-boxes sold in Maine, and bait-boxes sold in Mid- Atlantic bait shops, which will be chosen based on advertised sale of live marine worms, proximity to major fishing spots, and geographic location. Organisms will be counted and identified to lowest taxonomic level at three successional stages (spring, summer, fall) and assigned to native, non-indigenous, and cryptogenic categories. For Mid-Atlantic bait-boxes, associated parasites and pathogens (Vibrio cholerae) will also be identified. To avoid underestimating local richness, we will perform rarefaction analyses. We will also experiment with alternative packing materials and will assess whether washing algae prior to shipment reduces abundance/diversity of associated organisms. For the social science component, we will document the marine bait worm socio-ecological system in the Maine to Mid-Atlantic region, then review this socio-ecological system to identify potential intervention points and then elicit and analyze what are the core cultural and socioeconomic factors that will affect implementation of up to three interventions. Finally, we will conduct several surveys of fishers to address: their awareness of introduced species; behavior regarding algal disposal; and whether behavior would change with signage, informational materials, or advisory labeling linked to our intervention strategies.

RATIONALE: Maine polychaetes are used extensively as bait in the Mid-Atlantic; however, no quantitative examination of the baitworm vector has been completed for the region. Dealers ship large quantities of live polychaetes, packed in live algae, to the Mid-Atlantic and globally via over-night services. We will quantify the live macrofauna (i.e., species and phylogenetic diversities) and screen for parasites and Vibrio cholerae in bait containers to understand the risk of species introductions. We will identify opportunities for management interventions of the vector. Given the nature of this vector, results from a Mid-Atlantic study should reflect the risk of introduction to other recipient regions, serving as a model system for understanding numerous similar pathways. Our research will test the viability of alternatives to algae for packaging and will seek to understand behavior of fishermen in disposing of baitworm/algae and whether such behaviors can be affected by clear advisory labels, signage, and informational materials.


This section describes how this project has advanced scientific knowledge and made a difference in the lives of coastal residents, communities, and environments. Maryland Sea Grant has reported these details to the National Oceanic and Atmospheric Administration (NOAA), one of our funding sponsors.

SUMMARY: Marine bloodworms are packed in algal material and widely shipped as live bait. These sales are a known pathway for introducing aquatic invasive species globally. Maryland Sea Grant supported research to understand and manage this vector. The project developed economical ways to rid the algae of potentially unwanted ‘hitchhiker species.’ The research indicated that baitworm distributors could effectively reduce invasive species introductions by changing how they pack these worms.

RELEVANCE: It is well documented that the introduction of non-native species in ecosystems can cause both economic and ecological harm. Prevention of introduction is best done through vector management. A vector is the system by which unwanted aquatic species are introduced into a new environment where they can become a nuisance.

RESPONSE: Scientists from multiple institutions in the Mid-Atlantic region teamed up in a highly collaborative project of research and outreach. Participants were the University of Maryland, College Park (UMCP), the Smithsonian Environmental Research Center (SERC), and the Mid-Atlantic Sea Grant (MASG) programs. Maryland Sea Grant’s director, Fredrika Moser, served as principal investigator, and Maryland Sea Grant managed the project. The participating scientists focused on the live bait trade, specifically, the brown algae wormweed, Ascophyllum nodosummarine, the packing material for the bloodworm, Glycera dibranchiate, which is popularly used as bait.

Researchers designed an experiment to compare treated packing material with non-treated packing material shipped from Harbor Bait, a bloodworm dealer in Wiscasset, Maine. Mid-Atlantic Sea Grant Extension teams and UMCP collected social science information about the use and disposal of marine worms in the Mid-Atlantic region by talking with fishers, dealers, and regulators about the bloodworm industry. MASG staff and Extension agents administered questionnaires throughout the Mid-Atlantic.

RESULTS: The findings include a cost-effective intervention that dealers of live bait could take to reduce transmission of invasive species: to wash the algae used as packing material before shipping the bait. In June 2013 project researchers held mini-workshops with a subset of the Maine bait dealers, in which the researchers presented the option of adopting this practice or several alternatives to the current packing method. Surveys of anglers indicated that most already discard packing material and leftover bait in the garbage and that anglers demonstrate a willingness to take precautionary steps to prevent invasions if provided with clearly presented prevention measures. In April 2013, several team members presented research findings at the International Conference on Aquatic Invasive Species during a special symposium chaired by Sea Grant researchers on the live bait trade.

Related Publications:

Blakeslee, A; Fowler, A; Couture, J; Grosholz, E; Ruiz, G; Miller, AW. 2016. Vector management reduces marine organisms transferred with live saltwater bait Management of Biological Invasions7(4):389 -398. doi:10.3391/mbi.2016.7.4.08. UM-SG-RS-2016-25.

Fowler, AE; Blakeslee, AMH; Canning-Clode, J; Repetto, MF, Phillip, AM; Carlton, JT; Moser, FC; Ruiz, GM; Miller, AW. 2016. Opening Pandora's bait box: a potent vector for biological invasions of live marine species. Diversity and Distributions22(1):30 -42. doi:10.1111/ddi.12376. UM-SG-RS-2016-02.

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