Shellfish Transplants
Purpose: The overarching goals of the quahog transplant program (i.e., controlled relay) are to move quahogs from high density areas classified as Restricted or Conditionally Restricted to shellfish harvest due to poor water quality, into areas classified as Approved or Conditionally Approved with cleaner water to allow the shellfish to purge contaminants by filtering clean water. The areas transplanted into are managed for shellfishing to restore and enhance stock abundance of quahogs (especially areas where adult broodstock may be reduced). Transplants allow for utilization of otherwise inaccessible resources to improve seasonal harvest opportunities and to increase the spawning stock (adult quahogs) near or within shellfish management areas. In turn, larvae/juvenile clams may settle and supply local recruitment in the hopes of helping sustain the fishery.
Upcoming Transplants
There are no planned transplants at this time. Transplants are contingent on funding, as described below. Information will be posted here regarding upcoming transplants whenever funding becomes available.
History: The practice of relocating – or transplanting – quahogs in Rhode Island (from polluted waters into cleaner harvestable areas) dates back to 1954. By the late 1970s the program had become a regular annual operation funded by the state of Rhode Island and staffed by volunteer harvesters and University of Rhode Island (URI) graduate students running the dredge vessel. As the program expanded over the years being facilitated by the following groups: Rhode Island Department of Environmental Management (RIDEM), the Rhode Island Department of Health (RIDOH), commercial quahoggers, URI, the Narragansett Bay Commission (NBC), and others. These groups have assisted with funding, administrative help and personnel support. In the early 2000’s quahog transplants occurred regularly into multiple management areas within the Narragansett Bay (Greenwich Bay Shellfish Management Area, High Banks, Greene’s River/Potowomut, and Bristol Harbor Shellfish Management Area). Transplants typically occur in the spring before the first spawning event and become accessible in the shellfish management areas in the fall/winter when the area opens to harvest. This allows for depuration (filtering) of the quahogs to occur before they are harvested for human consumption.
Requirements: Rhode Island only allows for shellfish controlled relays/ quahog transplants, which means that they occur under direct supervision of the State Authority 250-RICR-90-00-4 § 4.20 (RIDEM and RIDOH) as outlined in the RIDEM Office of Water Resources (OWR) Shellfish Program’s “Standard Operating Procedures” (SOP). Prior to a transplant, a representative subsample of shellstock must be collected to assess suitability for transplant from the area and the RIDOH does a baseline shellfish meat analysis. These testing results must meet the requirements of the National Shellfish Sanitation Program Model Ordinance (NSSP – MO), which sets the Federally approved minimum requirements for shellfish sanitation that all states must meet. The NSSP MO requires a minimum depuration period of sixty (60) days for transplanted shellstock to flush contaminants before harvest for human consumption. Additionally, Rhode Island’s biosecurity zones, established based on regions of Narragansett Bay, the Coastal Salt Ponds, and Block Island, restrict the movement of shellfish between regions without disease test result to confirm low risk. This aims to prevent inadvertent pathogen transfer to other regions to protect wild shellfish populations. Thus, disease testing is performed to assess for QPX (Mucochytrium quahogii), Dermo disease (Perkinsus spp.) and Hemocytic neoplasia prior to any transplant.
Common Contaminants Tested For Prior to Transplant:
Funding: During the earlier period of transplants (1950’s – 1980s) the program was state funded via legislative appropriations (anywhere from $75,000 - $250,000 per year), which allowed for millions of pounds of quahogs to be transplanted. Funding shifted to fines levied on municipal wastewater treatment facilities (WWTFs) whose permit violations lead to shellfish harvest closures.
Contact: Anna Gerber-Williams anna.gerberwilliams@dem.ri.gov