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The management of razor clams and the setting of recreational seasons has become quite complicated in recent years. Historically, the Washington Department of Fish & Wildlife - (WDFW), formally the Department of Fisheries, conducted mark/recapture population estimates and then set the same season for all the major management beaches on the coast. Usually these were fairly liberal seasons that depended on limits and other restrictions to balance the resource with the number of users. Dramatic increases in the number of clam diggers, a devastating clam disease, the addition of tribal harvesting and increases in marine toxins have lead to the need for a more conservative and scientific approach to management.
Historical clam seasons of nine months of every day digging have now been reduced to as few as 15 to 35 days of harvest for the entire year given recent declines in the razor clam populations. Each beach is now managed as a separate entity with individual seasons. We find that the digging public is very flexible and with the ease of transportation, diggers who have traditionally only dug at one particular beach are going to which ever beach is open. Driving distance is not usually an issue.
The season setting process starts with a very detailed population analysis of each beach. After population sampling is completed, the total number of clams is estimated along with an estimate of the number of clams under 3 inches (pre-recruits) and clams over 3 inches (recruits). Pre-recruits sized clams are not considered part of the population available for harvest. Such small clams do not tend to "show" and are not usually part of the catch.
The population is calculated by multiplying the number of clams per square meter and the estimated number of square meters considered viable clam habitat on each beach. Again, this is further separated into the recruit and pre-recruit categories. For each beach, a Total Allowable Catch (TAC) is then calculated providing for a 25.4% harvest of all clams over 3 inches. This is further modified on all beaches north of the mouth of Grays Harbor that have tribal co-management. Tribal co- management refers to the policy of sharing not only the harvest, but also the management of the razor clam resource with coastal tribes that have fishing rights in their usual and accustomed area (U&A). There are currently two tribes that we co-manage the razor clam resource with; the Quinault Tribe which has fishing rights from the north jetty at the mouth of Grays Harbor to the Moclips River and the beach at Kalaloch and the Hoh Tribe which also has shellfish rights at Kalaloch. After the population is determined, the TAC is calculated and the formula is divided by 50% to determine the non-tribal share. Where more than one tribe is involved, their 50% share is further divided by the number of tribes involved.
A simplified example of how a TAC is calculated is shown below. (Note) The actual calculations done by computer are more involved then this. Areas are also further separated by tidal height and beach location.
Let's say the average population based on sampling is calculated to be 0.42 clams per square meter. The beach has a total of 3,520,000 square meters of viable clam habitat on the 12 miles of beach.
1. 3,520,000 X 0.42 = 1,478,400 total clams
If the population sampling found that 60% of the clams were 3 inches and over in length then;
2. 1,478,400 X 0.60 = 887,040 clams over 3 inches
If it is a beach with no tribal harvest then the TAC is:
3. 887,040 X .254 (preferred harvest rate) = 225,308 clams allowed to be harvested
If it is a beach with tribal harvest than the TAC for non-tribal digging is:
4. 225,308/2 or (50%) = 112,654 clams can be harvested
Now the difficult part of the equation begins, actually determining the number of days that it would take to harvest the calculated TAC. In the past, we have used 5 year averages of daily harvest, but we are finding that because of shorter seasons, sometimes we have effort levels that far exceed any historical averages. It that case, we have to look at comparable months and week days and/or weekends and take the highest counts of digger trips and harvest. So if last year we had unusually high effort and harvest and the daily average harvest was 9,000 clams per day, then for step #3 we have a season of twenty five (25) days (rounding down). On co-managed beaches the season would be half as long.
225,308/9,000 = 25.03 = 25 daysCo-managed Beach: 25 days / 2 = 12 days
Other factors we have to consider are based on input we receive during public meetings held before we set the seasons each year. Some folks like digging in the fall and winter (usually night tides), others like spring tides during warmer weather. Some folks want digging days in a row, while other like the every- other day season structure. There are also social-economic concerns like businesses that depend on clam seasons for income and then we have outside factors like marine toxins that may prevent having seasons during certain times of the year. All of this information is compiled and then a recommendation is formulated. We meet with the coastal tribes to get agreement and then present the recommendation to the Director for final approval. Only after the Director has approved the season and adequate Health Department sampling for marine toxins has taken place are we able to announce the season. Unfortunately, all this takes a great deal of time and more often then not, we are announcing the seasons with very little lead time.
Our hope is that through conservative
management, clam populations will again come back to historical levels, allowing
us more flexibility to provide greater harvest opportunities and more lead time
for clam diggers to plan their clam digging vacations.
