Domoic Acid Testing in Lobster: current status and future challenges

It is not surprising that many lobster fishermen are scratching their heads about the new domoic acid testing strategy and response that California agencies are pursuing (the Agencies involved are: CA Departments of Fish and Wildlife, Public Health and The Office of Environmental Health Hazard Assessment). Some fishermen have guessed that maybe the Agencies have decided to alternate rock crab and lobster testing each year, and this is a ‘lobster year’. It might seem that way, but no.  Because the Agencies have very abruptly changed their testing rational, and possible responses, over the past year without much clear communication about it, we can only guess at the logic and rules guiding their actions. Here’s what we know so far.

Because rock crab is open year round, testing for DA in rock crab in a region or county normally occurs only when bivalves from CDPH’s shellfish sampling program in the region reports levels of DA above 10 ppm. (Note there can be other prompts to test DA in rock crab, such as during pre-season testing for Dungeness crab[i], marine mammal strandings, bird die-offs, and academic field monitoring results[ii].) Because no shellfish samples in the Santa Barbara Channel have exceed 10 ppm this fall, rock crab samples here have not been tested. (Note that rock crab samples from Morro Bay and farther north were tested for DA in August and September, and levels were moderate).

It would seem logical that lobster would be tested under the same circumstances as rock crab, and the agencies have indicated that indeed, any time rock crab are being tested for DA, lobster samples will also be tested from now on. However, we haven’t yet seen this situation come to pass yet, thanks to the low levels of DA in the seawater and shellfish samples taken over the past few months.

Rock crab fisheries are open year round, whereas lobster season is only open from early October to March.  Now that lobster will be routinely included in the Agencies’ DA monitoring, pre-season testing in lobster was initiated for the first time, akin to pre-season testing in Dungeness. The likely thinking was that it would be ‘cleaner’ for DFW to delay the season opener than shut it down within days or weeks of the opener if DA is found to be a problem in lobster this Fall.

DFW collected lobster before the season opening from Catalina Island, Long Beach Breakwall, Santa Barbara Coast, San Diego and Santa Cruz Island for DA testing (however, not all these results were posted before the opener).  They continued collecting and testing samples after the opener too - as of October 14, the most recently posted test results[iii], samples were collected post-opener from Santa Cruz Island and two blocks from the Port Hueneme area. It is unclear presently whether the (delayed) ‘pre-season’ testing of DA in lobster is finished for the time being, or if more sample results will be released.

In total, DA test results of 8 samples have been released by CDPH to date (a sample typically consists of a set of 6 animals, but have ranged 3-7 animals). Three of the 8 samples showed all animals had non-detectable levels of DA, and one sample had very low levels. We were told in September by the Agencies that areas that test clean will not be retested until and unless there is some reason to do so.  However, 4 samples were not 100% ‘clean’ – each showed a single animal which exceeded the 20 ppm action level (these ranged between 27-45 ppm DA in the viscera).  

The agencies have not released any statement about what levels and how many animals it takes to trigger a regulatory response. We heard from the Agencies in September that when a sample doesn’t test 100% clean, they plan to take a second sample from the same fishing block. If that second sample comes back 100% clean, no action will be taken and the area will not continue to be re-tested.  To date, only one of the four ‘dirty’ areas has been retested – Block 708 at Santa Cruz Island – and that second test was clean.

Agency reps have indicated that if one of these areas did not test 100% clean in the follow-up testing an appropriate management response would be then determined, with an aim to keep the area under advisory or closure small in geographic scope.  Note that advisories may come with evisceration order[iv], but a fishery closure isn’t expected unless and until the level of DA in the meat of the lobster exceeds 20 ppm.  Anecdotal information suggests DA levels in the viscera would have to be near 200 ppm to result in levels near 20 ppm in the meat. So far, only lobster viscera has been tested this season.

Moving Forward

We can be grateful that this inaugural year of monitoring DA in lobster has been free of any fishery disruptions so far, thanks to the favorable ocean conditions. However, moving forward there are several grey areas to be problem-solved, preferably sooner rather than later – and certainly before we get hit with the first DA advisory and go into crisis mode.

As stated above, high levels of DA in bivalves triggers testing of DA in rock crab (as do a number of other factors). Currently, there are no bivalve testing sites in much of the So Cal Bight (e.g., Los Angeles and all of the Islands); therefore, unless the Agencies start to collect bivalves from these locations, high levels of DA in bivalves cannot be used as a prompt to initiate routine testing in lobster from many fishing grounds. Note also that in past years, CDPH felt that testing of rock crab south of the Ventura county line was unwarranted because ‘DA doesn’t occur that far south.’ However, in the case of lobster this year, they have chosen to test throughout Southern California. This choice was probably based on a number of reasons including fairness to the fleet, and building a dataset for future comparisons if harmful algal blooms intensify in future years as some are predicting[v]. Consequently, we don’t yet know if in future years lobster will continue to be tested throughout Southern California while rock crab is tested only North of Ventura, or the two sampling programs will be made consistent.

We are unsure whether pre-season testing of lobster is the new normal, or if in future years, pre-season testing will only occur if other indicators suggest DA levels could be elevated. DFW has been planning to collect lobster samples for DA testing this fall for nearly a year now, but currently there are no formal policies, procedures and/or protocols in place for monitoring DA in lobster. The Agencies do acknowledge that industry is under no legal obligation to provide samples and to do so would have created an undue financial burden to participating harvesters as there is no mechanism currently in place to reimburse fishermen for their time and/or expenses. This will be a key action item for us as we look toward future seasons. In particular, fishermen have expressed concern that they be shown a pre-season sampling plan in advance that demonstrates fairness and parity to the fleet and fishing grounds, and outlines sound regulatory responses.  DFW could work through designated leaders approved by the fleet to source samples from the fleet, instead of hand-picking individual fishermen directly to represent the entire fleet without clear rationale.  Agency support for the verification of sample methods and results by an independent testing laboratory would also put many fishermen at ease that sample results from the Agencies are robust and reliable.

In the meantime, CFSB is working with Carrie Culver of Sea Grant to encourage and facilitate new academic research on two urgent topics: 1. Developing accurate field testing kits for DA in crab and lobster that fishermen could use in making decisions out on the water about where to harvest their catch and 2. Doing controlled lab experiments on the how quickly DA purges or ‘depurates’ from lobster meat and viscera. If lobster were to show high levels of DA, it is possible that holding them for several days may be all that is necessary for the levels to fall below the action level of 20 ppm and continue on to market. Dr. Culver has set up an analytical lab at UCSB for in-house HPLC testing of DA (i.e., the same procedure used by the State labs) to enable this research, and we will partner with her to find adequate research funds to initiate the work and engage fishermen in providing her animals for study.

Copyright 2016 Kim Selkoe

Relevant resources available online:

·      CDPH’s Marine Biotoxin Monitoring Program’s monthly reports on DA testing of water samples, bivalves and crustaceans can be found here.

·      There is a delay to posting of reports, but you can sign up to receive the monthly report as it is generated by submitting a request to

·      Weekly updates are viewable with a mapping tool here. Levels of Pseudo-nitzschia ('Pn' in the legend), the diatom that produces domoic acid, are shown in green. Note Pn can be high without producing high levels of Domoic Acid.

·      A recorded message updated with each lobster DA test result was set up by Mike Conroy of West Coast Fisheries Consultants and APEX Wild Seafoods. Dial (614) 636-6642.  The message reports advisories, closures and/or test results as they occur, so that a fisherman can make informed decisions about moving gear if an area goes under advisory or closure.



[i] For example – on October 13, 2016 the DPH tested 6 rock crab samples in Monterey, all of which had non-detectable levels of DA.  See CDPH's report

[ii] See page 15:  FAQ – Harmful Algal Blooms and California’s Fisheries produced by California Ocean Science Trust.

[iii] See CDPH's lobster report

[iv] See CFSB’s Summary of Recent Events (September 10, 2016)

[v] See Ocean Science Trust’s just released report: Framing the Scientific Opportunities on Harmful Algal Blooms and California Fisheries: Scientific Insights, Recommendations and Guidance for California.