Geoduck Clam Biotoxin Monitoring Plan
Alaska Marine Biotoxin Management for the Harvest of Commercial Geoduck Clams
Effective October 1, 2024 - September 30, 2025
Alaska’s plan to manage risks associated with biotoxins that may be present in Alaska’s waters at unacceptable levels
Purpose and Scope
This document outlines Alaska’s plan to mitigate the risks to public health that are present in geoduck clams as a result of marine biotoxins, particularly Paralytic Shellfish Toxin (PST). This document has been developed in accordance with the National Shellfish Sanitation Plan Model Ordinance (NSSP-MO) (adopted by reference at 18 AAC 34 under the authority of AS 17.20.005). Specifically, NSSP MO Sec II, Chapter IV @.04 requires Alaska define procedures and resources necessary to prevent harvest of shellfish affected by marine biotoxins.
This plan is adopted under the NSSP-MO1 to define the administrative procedures and resources, and actions necessary to:
- Initiate an emergency shellfish sampling and assay program;
- Close growing areas and embargo shellfish;
- Prevent harvesting of contaminated species;
- Provide for product recall;
- Disseminate information on occurrences of toxic algal blooms and/or toxicity in shellfish meats to the shellfish industry, and local health agencies or communities; and
- Coordinate control action taken by the department.
The department may deviate from this uniform shellfish geoduck sampling plan and require a different PSP sampling program for a classified area when a review of environmental factors, epidemiology and all PSP toxin data necessitates a change. If the department develops a different plan, it will notify affected growers, harvesters, and shellstock shippers. Nothing in this plan relieves a harvester, dealer, shucker-packer, or shipper from meeting requirements of the NSSP-MO.
1Section II, Chapter IV @.04(A)
Definitions
The definitions provided below are consistent in intent with the Alaska Marine Biotoxin Monitoring & Contingency Plan for Geoduck Clams
- Beds
- Known areas of wild geoduck clams.
- Commingle or Commingling
- The act of combining different lots of shellfish.
- Harvest Area
- An area that contains commercial quantities of shellstock and may include aquaculture sites and facilities.
- Lot
- A single type of bulk shellstock or containers of shellstock of no more than one day's harvest from a single, defined harvest area gathered by one or more harvesters.
- Rejected Lot
- When the pre-harvest sampled lot has a PST result above the regulatory limit at or above 80µg/100 g of tissue and no harvest may occur based on the sampling event.
- Subarea
- An ADF&G designated geoduck area within an ADEC classified shellfish growing area.
Overview
The State of Alaska does not maintain continuous phytoplankton monitoring stations due to the vast and expansive coastline and the remote nature of the majority of classified shellfish growing areas. Monitoring and control of PST is accomplished through pre-harvest lot testing of shellfish meat collected from the intended harvest area. This sampling strategy allows for a short period of time for harvesting following testing and pending acceptable PST levels.
All geoducks commercially harvested and intended for human consumption must come from a shellfish growing area that:
- The Alaska Department of Environmental Conservation (ADEC) has classified as Approved;
- ADEC has designated in the open status; and
- The Alaska Department of Fish and Game (ADF&G) or other appropriate resource manager2 has opened to harvest.
For biotoxin management purposes, growing areas that ADEC have classified as approved are subdivided by an ADF&G subarea designation or the Metlakatla Indian Community – Annette Islands Reserves Department of Fish and Wildlife (MIC – AIR DFW) designation. Each growing area may encompass several subareas designated by ADF&G for purposes of wild geoduck management as well as some geoduck aquaculture sites. Within each subarea are beds of wild geoduck, some of which are known and mapped.
An ADEC shellfish growing area may be classified as "Approved" while ADF&G or MIC-AIR DFW subareas within an Approved shellfish growing area have a closed status. This is due to the periodic presence of marine biotoxins in concentrations of public health concern, and because Alaska has no routine harmful algal bloom monitoring or monitoring of sentinel species. ADF&G or MIC-AIR DFW subareas within a classified shellfish growing area are open for harvesting only after the required pre-harvest sample collection is conducted in accordance with this plan and other applicable agreements, and analysis shows acceptable levels of biotoxins and ADEC changes the subarea status to open.
ADEC will designate an approved growing area in the open status and ADF&G or MIC-AIR DFW will open a subarea to harvest after receiving notification from ADEC that one acceptable sample from that subarea shows PST levels less than 80 µg/100 g of tissue.
Prior to the start of each harvest season (October 1 – September 30), ADF&G announces which subareas may be available to wild harvest based on population assessment surveys and establishes the guideline harvest levels for each subarea. For fishery management reasons, the subareas that may be available to wild harvest rotate with each harvest season.
A list of growing areas from which geoduck clams are harvested that ADEC has classified as approved as of the date of this plan and each area’s associated ADF&G-designated or MIC-AIR DFW subarea names or farm site location can be located in Tables 1-3.
- The ADF&G–managed subareas designated to be opened for the 2021-22 season are indicated Table 1.1.
- Annette Island has a separate and independent subarea identification system that is managed by the Metlakatla Indian Community |Annette Islands Reserves Department of Fish and Wildlife (MIC-AIR DFW) and the harvest areas for Annette Island area indicated in Table 2.
- Aquatic sites that farm geoducks can be located in Table 3.
2 ADF&G manages state resource of wild geoduck harvest areas and the Metlakatla Indian Community | Annette Islands Reserve (MIC – AIR) Department of Fish & Wildlife (DFW) manages the Annette Island Reserve’s wild geoduck resources.
Biotoxins of Concern
Historically, the only known biotoxin that is periodically present in Alaska waters and shellfish at levels of concern is the toxin that causes Paralytic Shellfish Poisoning (PSP). This plan describes Alaska’s management relative to this particular toxin, Paralytic Shellfish Toxin (PST). There are no approved growing areas where geoduck are harvested that are considered "biotoxin free" and this plan applies to all sub-tidal commercial harvest of wild and farmed geoduck clams in Alaska.
Paralytic Shellfish Toxin (PST) is a naturally occurring marine biotoxin that is produced by some species of microscopic algae. Shellfish are filter-feeders that eat these algae and can retain and accumulate the toxin in their tissue. Illness can occur when shellfish contaminated with PST are consumed. This biotoxin affects the nervous system and paralyzes muscles, thus the term paralytic shellfish poison (PSP). High levels of PST can cause severe illness and death. There have been no direct correlations found between active algal blooms and PST levels in geoduck clams in Alaska.
Amnesiac Shellfish Poisoning (ASP) is caused by the toxin Domoic Acid and was detected in Alaskan razor clams in the mid- 1990s at levels well below the regulatory limit of 2 mg domoic acid/100 g (20 ppm). The department conducts surveillance through opportunistic batch testing that is completed approximately every 12 months as time, staffing, and funding allows.
Diarrhetic Shellfish Poison (DSP) toxins and Neurotoxic Shellfish Poison (NSP) toxins are not known to be found in Alaska, and there is no required monitoring for these toxins at this time under the Alaska Marine Biotoxin Monitoring Plan for Geoduck Clams.
Plan Modifications
In determining whether to designate a subarea within an approved growing area in the open status and whether contingencies, deviations, or other modifications to this plan are necessary during a season, ADEC may consider requirements of the NSSP-MO and 18 AAC 34, historical data (e.g., PST levels, frequency, and other trends), reported illness, and other factors that ADEC determines are relevant to protect the public’s health.
Modifications to this plan may include:
- Increased number of samples from a subarea;
- Increased frequency of sampling;
- Mandatory labeling of geoduck products;
- Mandatory shucking of geoduck to remove the visceral ball; and/or,
- Other measures that ADEC determines allow the Department to reliably determine that changing a subarea’s status from closed to open is protective of the public’s health.
ADEC will not initiate a post-harvest lot sampling program if all the sampling requirements set out in this plan are adhered to.
Harvest Durations
Depending on the location of the fishery or anticipated harvest, samples are collected five to seven days prior to each anticipated harvest and is restricted by passing PST levels (below 80 µg/100 g of tissue). Subareas that are sampled are opened based on acceptable PST levels. The following provides details for the harvest durations of state-managed harvests areas in Ketchikan, state-managed harvest areas in Sitka, and aquaculture and the Annette Island geoduck fishery.
For state-managed harvest subareas in the Ketchikan area:
- Sampling occurs on Saturday, Sunday, or Monday3.
- Harvest duration is five (5) consecutive calendar days from the sample collection date.
For state-managed harvest subareas in the Sitka area:
- Sampling occurs on Saturday, Sunday or Monday4.
- Harvest duration is six (6) consecutive calendar days from the sample collection date.
For aquaculture and the Annette Island fishery:
- The sampler notifies ADEC (FSS and the Environmental Health Laboratory) at least two (2) business days before anticipated sampling.
- Harvest duration is five (5) consecutive calendar days from the sample collection date.
- 3Unless the sampler has obtained written authorization from ADEC to sample on another day of the week.
- 4Unless the sampler has obtained written authorization from ADEC to sample on another day of the week.
Sample Submission Harvest Durations
Geoduck submitted to the Environmental Health Laboratory (EHL) for analysis must be prepared, handled, and submitted in accordance with the EH Lab Sample Submission Manual.
The EHL provides assistance with timing of sample collections, completion of submission forms, packaging and temperature requirements, shipping, and sample tracking. Additionally, the EHL requires that, prior to sampling, individuals contact the EHL regarding sampling, planned sampling activities, and shipping notifications:
- Phone: 907-375-8231
- Email: EH-Lab-ShippingReceiving@alaska.gov
Sample Size
A sampling event will consist of one composite sample5 comprised of four (4) undamaged geoducks from each subarea that is representative of the population of geoducks in the bed(s) anticipated for harvest within that subarea, and they must submitted to certified laboratory for analysis.
5If the sampling event is occurring to reopen a closed area from a previously failed PST sample, the sampling event may consist of up to two composite samples of four (4) geoduck clams. See Reopening Criteria for more details.
Sample Collection
In accordance with this plan, applicable Letters of Understanding (LOU), 18 AAC 34, NSSP-MO, and the ADEC Environmental Health Laboratory (EHL) Laboratory Submission Manual, industry will collect and submit for analysis6 four (4), undamaged geoducks from each subarea that is representative of the population of geoducks in bed(s) anticipated for harvest within that subarea.
Collecting geoducks for samples involves using a vessel equipped with a GPS-tracking unit to remote areas where known geoduck beds are located. Sample collectors wear diving gear to dive into the subtidal range to attempt to find and collect geoducks using a water hose.
A vessel used by a sampler must meet the minimum safety requirements set forth by the US Coast Guard if an ADEC observer is on board. ADEC reserves the right to require a sampler submit to a vessel inspection allow an onboard observer during sampling. Should the minimum vessel safety requirements not be met upon inspection by ADEC or a sampler refuses to allow an onboard observer during sampling, any samples collected during that trip will not be analyzed, resulting in subarea(s) remaining in the closed status. If an ADEC observer is on board a sampling vessel, then the State is responsible for all appropriate insurance and providing all personnel safety equipment including a USCG approved personal floatation device and survival suit.
6All laboratory analysis must be performed by a laboratory found to conform or provisionally conform by the FDA in accordance with the requirements established under the NSSP MO in Chapter III. If a sampler submits samples for analysis to a lab other than the Alaska Environmental Health Laboratory, the servicing laboratory must submit the analysis results directly to the Alaska Shellfish Authority (ADEC) for review.
Representative Sample
Samplers must collect geoducks from bed(s) within a subarea that represent the population of geoduck in bed(s) within that subarea that will be harvested. Geoducks collected for a sample may be collected from a single dive from a single harvest area if the sample collector is randomly choosing geoducks up to the full span of the dive gear hose (600 feet). The submitted samples must include the latitude and longitude coordinates of the collection site on the sample submission form for the department to verify that the samples were collected from the intended harvest area.
Exceptions include the following situations:
- Inclement weather at the time of sample collection prevents the sampler’s access to geoduck beds within a subarea where harvest is planned;
- The size of a subarea and proximity of geoduck beds to one another within that subarea are limited; or,
- The planned harvest is limited to one geoduck bed within a subarea.
In one of the situations listed above where a sampler does not collect samples from geoduck bed(s) within a subarea that represents the harvested geoduck population, the sampler will document the reason for deviation from this plan on the laboratory submission form at the time of collection. ADEC may request additional information to support the documented reason, including weather reports and information detailing harvest locations.
Analysis
Live Geoducks
The procedures for allowing live whole geoducks to be sold into commerce requires a result from a certified laboratory showing PST levels less than 80 μg/100 g of tissue from one composite sample consisting of four (4) geoduck clams collected from one subarea. The EHL analyzes the visceral of four (4) composited geoduck clams utilizing approved laboratory analysis methods specified in the NSSP-MO.
Processed Geoducks
For geoduck clams intended to be processed after harvest before entering commerce, the EHL analyzes the mantle and siphon of four (4) geoduck clams (one composite sample), and excluding the visceral ball, utilizing approved laboratory analysis methods by AOAC as specified in the NSSP-MO.
All geoduck product harvested with the intention to be eviscerated and processed must be labeled with the following statement in bold, capital text: "Not for Live Market."
Toxin Action Level
The regulatory limit for PSP toxins in geoduck is 80μg per 100g of edible portion, meaning that PSP toxins must be <80 μg to allow for harvest. Preliminary results from the EHL may be provided to assist the department and the operators in determining whether action must be taken on the harvested lot of sampled shellfish and growing area.
Regulatory samples of PST in all commercial bivalve shellfish must be <80 μg to allow for harvest.
Rejected Lot Procedures
Samples that are not collected or submitted in accordance with this plan or applicable Letters of Understanding (LOU), 18 AAC 34, NSSP-MO, and the ADEC Environmental Health Laboratory (EHL) Laboratory Submission Manual may not be analyzed for regulatory purposes, and the area cannot be open for live sale harvest7.
If a pre-harvest lot sample analysis shows a concentration of PSP toxin that equals or exceeds the regulatory limit (≥80µg/100g) in a composite sample of four (4) geoducks collected for a sampling event, then no harvest may occur based on the pre-harvest sampling event and the reopening criteria must be met for an area may be reopened for harvest.
- For ADF&G-managed areas of wild geoducks, an advisory announcement is issued by ADF&G stating that there will be no geoduck fishery from the pre-harvest sampled subarea for the week of the sampling event.
- For MIC-AIR DFW-managed areas of wild geoducks, an advisory announcement is issued by MIC-AIR DFW stating that there will be no geoduck fishery from the pre-harvest sampled subarea for the week of the sampling event.
- For aquatic geoduck farm sites, the area status will be set to Closed by ADEC.
7Except if the sampler obtains written approval from the Alaska Shellfish Authority.
Reopening Criteria
If a subarea is closed to harvest due to PSP toxin levels at or above 80 μg/100 grams of tissue, the department will only reopen the area after one of the following reopening criteria is met:
- Two composite samples consisting of four (4) geoduck clams each collected from one subarea with PSP toxin levels less than 80 μg/100 g of tissue for each sample; OR,
- Area remains closed to harvest for at least 14 calendar days from the failed sampled date and may reopen with an acceptable PST sample result less than 80 μg/100 grams from one composite sample consisting of four (4) geoduck clams collected from the closed subarea following the 14 day closure.
Tables
Table 1. ADF&G Managed Wild Geoduck Harvest Areas
| ADEC Classified Shellfish Growing Area (SGA) | ADF&G Subareas of Classified SGA |
|---|---|
| Duke Island East and West | Kelp Island (101-21-001) |
| Duke Island East and West | Cat and Dog Island (101-23, 41-005) |
| Duke Island East and West | Percy Islands (101-25-002) |
| Duke Island East and West | Vegas/Hotspur Island (101-25-003) |
| Gravina Island West | Vallenar Bay (101-29-004) |
| Gravina Island West | South Vallenar Point (101-29-003) |
| Gravina Island West | Middle Gravina (101-29-002) |
| Gravina Island West | Nehenta Bay (101-29-001) |
| Gravina Island West | Southern Gravina (101-29-005) |
| Kah Shakes | North Kirk Point/Bullhead (101-23-003) |
| Kah Shakes | Foggy Bay (101-23-001) |
| Long Island (Kaigani Strait) | Kaigani Strait (103-30-001) |
| Lower Cordova Bay | Lower Cordova Bay (102-10, 103-11, 103-21) |
| Nakat Bay | Nakat Bay (101-11-001) |
| Prince of Wales Island West | Maurelle Islands (103-70, 80, 104-40, 50-009) |
| Prince of Wales Island West | Little Steamboat Bay (103-70-002) |
| Prince of Wales Island West | Ulitka Bay (103-70-001) |
| Prince of Wales Island West | Steamboat Bay (103-70-003) |
| Prince of Wales Island West | St. Nicholas Channel/North Lulu Island (103-70-007) |
| Prince of Wales Island West | Cone Island North (103-50-005, 104-40-005) |
| Prince of Wales Island West | Cone Island South/Paloma Pass (103-50-006, 104-35-006) |
| Prince of Wales Island West | Port Real Marina (103-50-007) |
| Prince of Wales Island West | Portillo Channel (103-50-008) |
| Prince of Wales Island West | East San Fernando Island (103-60-001) |
| Prince of Wales Island West | Palisade Island (103-70-003) |
| Prince of Wales Island West | Blanquizal Island (103-70-005) |
| Sea Otter Sound Davidson Inlet & Warren Kosciusko | Davidson Inlet (103-90-004) |
| Sea Otter Sound Davidson Inlet & Warren Kosciusko | Warren Island and Kosciusko Island (103-90-005, 105-41, 43, 50-005) |
| Sea Otter Sound Davidson Inlet & Warren Kosciusko | Port Alice/Cone Bay (103-90-002) |
| Sea Otter Sound Davidson Inlet & Warren Kosciusko | Turn Point (103-90-003) |
| Sitka Sound South | Symonds Bay (113-31-002) |
| Sitka Sound South | Taigud /Kolosh Islands (113-31-004, 113-41-004) |
| Sitka Sound South | Biorka/Legma Islands (113-31-003) |
| Sitka Sound South | Elevoi/Golf/Gornoi Islands (113-31-005) |
| Slate Island | Slate Island (101-23-004) |
| Tlevak Strait and SW POW | Port Santa Cruz (104-30-002) |
| Tlevak Strait and SW POW | Northwest Dall Island (104-20, 30-003) |
| Tlevak Strait and SW POW | Bucareli Bay (103-50-003) |
| Tlevak Strait and SW POW | Tlevak Strait (103-40, 50-009) |
Table 2. Metlakatla Indian Community DF&W Managed Wild Geoduck Harvest Areas
| ADEC Classified Shellfish Growing Area (SGA) | Metlakatla Indian Community | Annette Islands Reserves Department of Fish & Wildlife Area |
|---|---|
| Annette Island | Area 1 Walden Point to Cedar Point |
| Annette Island | Area 2 Cedar Point to Point Davison |
| Annette Island | Area 3 Walden Point to Kwain Hookoff |
| Annette Island | Area 4 Kwain Hookoff to Point Davison |
Table 3. Aquacultured Geoduck Harvest Sites
| ADEC Classified Shellfish Growing Area (SGA) | Business | ADF&G Site Name | ADF&G Permit # | ADNR Lease # |
|---|---|---|---|---|
| Gravina Island West | Pac Alaska LLC | West Gravina | 2002-03B-AF-SE | 106850 |
| Gravina Island West | Pac Alaska LLC | West Gravina | 2002-01B-AF-SE | 106848 |
| Slate Island | Alaska Longneck Farms LLC | Point Alava Extension | 2002-03D-AF-SE | 107075 |
| Slate Island | Alaska Shellfish | Coho Cove | 2000-18C-AF-SE | 107002 |
| Slate Island | Alaska Shellfish | Point Sykes | 2006-01-AF-SE | 107092 |
| Slate Island | Cornelis Bakker Inc. | Black Island | 2007-04-AF-SE | 107362 |
| Slate Island | Cornelis Bakker Inc. | Slate Island | 2002-02B-AF-SE | 106844 |
| Slate Island | Pac Alaska LLC | Black Island | 2002-03E-AF-SE | 107077 |
| Slate Island | Pac Alaska LLC | Point Alava | 2002-03C-AF-SE | 107001 |
| Slate Island | Pac Alaska LLC | South Sykes | 2002-01A-AF-SE | 106572 |
Table 4.1 Ketchikan Harvest Area Duration
ADF&G-Managed Harvest Subareas in the Ketchikan Area
| Sampling days | Saturday, Sunday, or Monday |
|---|---|
| Harvest Duration | Five (5) calendar days from the sample collection date |
| Acceptable PST Levels | Sample must be <80µg/100 for harvest |
Table 4.2. Sitka Harvest Area Duration
ADF&G-Managed Harvest Subareas in the Sitka Area
| Sampling days | Saturday, Sunday, or Monday |
|---|---|
| Harvest Duration | Six (6) calendar days from the sample collection date |
| Acceptable PST Levels | Sample must be <80 µg/100 for harvest |
Table 4.3 Annette Island Harvest Area Duration
Metlakatla Indian Community DFW-Managed Harvest Subareas in the Annette Island area
| Sampling days | ADEC FSS & EHL must be notified at least two (2) days before anticipated sampling event |
|---|---|
| Harvest Duration | Five (5) calendar days from the sample collection date |
| Acceptable PST Levels | Sample must be <80 µg/100 for harvest |
Table 4.4 Aquaculture Harvest Area Duration
ADEC-Managed Harvest of Aquacultured Geoduck Clams
| Sampling days | ADEC FSS & EHL must be notified at least two (2) days before anticipated sampling event |
|---|---|
| Harvest Duration | Five (5) calendar days sample collection date |
| Acceptable PST Levels | Sample must be <80 µg/100 for harvest |
Resources
ADF&G – Commercial Geoduck Dive Fisheries
Overview of ADF&G management of the wild geoduck fishery in Southeast Alaska.
ADEC – Environmental Health Lab (EHL)
The mission of the Environmental Health Laboratory (EHL) is to provide analytical and technical information in support of state and national environmental health programs. Such programs include but are not limited to those associated with the surveillance of: air, food, seafood, soil, water, and zoonotic diseases from domestic and wild animals.
SARDFA – Southeast Alaska Regional Dive Fisheries Association
SARDFA is a private non-profit, economic development organization representing the harvest divers, processors, and communities of Southeast Alaska.
Metlakatla Indian Community | Annette Islands Reserve Dept. of Fish & Wildlife
The mission of the AIR Department of Fish and Wildlife is to develop and manage the Reserve’s fish and wildlife resources to maximize economic benefit while ensuring the sustainability of such resources while minimizing adverse environmental consequences or adverse impacts to fish and wildlife.
Indicates an external site.