Archive for the ‘Monitoring Methods’ Category

Yellowstone River Oil Spill- Redeux

Tuesday, August 23rd, 2011

Well, you may have noticed that I have not said anything about the Yellowstone River Oil Spill since our original entry. Yet, in truth, we have been busily working on the project in-house.  The experience has not been all-together positive; quite the contrary. This entry deals with how the public loses because of bureaucracy; bureaucracy of the corporate breed, not the  governmental red tape I’d expected.

After the oil spill, we contacted Montana Department of Environmental Quality (MT DEQ) for information, they put us in contact with Montana Fish Wildlife and Parks, who deferred us to ExxonMoble’s contact, who put us in touch with a consultant. We discussed my qualifications and my previous work and he reckoned they could use me and my team for the aquatic insect assessments to describe the impact and the recovery of the Yellowstone ecosystem. He sent me an email about once a week to say, they were still trying to bring us on board. After several weeks, he said I better get an OSHA hazardous materials certification and that there was no way around the requirement if I want to work on the Yellowstone River. Several hundred dollars and 3 working-days later (per trainee), we completed the certification.  I informed the contact that we had completed OSHA training as required and didn’t hear back from him for over a week. He said, sorry, “Sorry don’t think its going to work out.” I wrote him a scathing letter; which he apparently passes along to ARCADIS (Exxon’s Primary firm for everything), the next thing I know, I received an 158-page listing of ExxonMoble’s contracting requirements and several 6-9 page contract specifics and insurance requirements.   Again, these were corporate regulations, not governmental regulations.  I had my insurance agent looking into the extra coverages required and it was apparent that it was going to be very costly to bring our $2-million insurance coverage up to the “required” $9-million; just to collect insects by the riverside.

We were working on finalizing their insurance needs when I recieved the following note (today).

“Brett,
It looks like the clock has run out. We have had to mobilize a small field effort to obtain representative macroinvertebrate samples from the spill area. We needed to get out there before fall influenced the life stages we are sampling. Apologies to you if I was in any way misleading regarding your potential role, but we simply did not comprehend the bureaucratic log jams we ran into. Best of luck in the future.”

Ok. So, I am a little embarrassed by my trusting nature and the way I let the corporate dudes string me along.  And, I have always been critical of critics, even when I am the critic.  It is easy to criticize a process or organization, but unless you offer a viable alternative, it amounts to nothing but whining.  My way of dealing with this is to turn it in to something positive.

I reckon that, in preparation for this project it has cost me time, materials, and training fees, totaling nearly $7,300. Interesting that for just another 3o hours of my staff’s time, vehicle costs, and motel lodging, we can collect the samples in a scientifically relevant way.  Therefore, I am proud to announce that we are initiating the Yellowstone Biological Assessment Project, independently, as a community service. There will be laboratory time as well, but hey, that’s what winter nights are for, right…. (?)

If we do not ante up, and get this done right, there will be lots of paper pushed, but the world will be no closer to understanding the impacts of Exxon’s Oil spill on the Yellowstone River ecosystem. Our survey will not be able to cover everything, but it will provide more information than either the state, or Exxon will gather.

We will be sampling this week.   I’ll keep you posted. Full-speed ahead!

I have to screen comments to keep the spam out, but please, I do appreciate them. Click the link below to comment :)

Tags: , , , , , , , , , , , , ,
Posted in Ecology, Education, Monitoring Methods, Projects, Yellowstone River | No Comments »

Biological Monitoring Covariates

Thursday, August 5th, 2010

When monitoring environmental impacts of anthropogenic activities, it is useful to collect ancillary data to use as covariates. These variables can help account for natural variation in the communities studies, which helps prevent their confounding of observations. In our work with benthic macroinvertebrate assemblages, we always collect flow measures for this purpose (near-substrate flow measures can account for much of the variation in simple benthic communities (e.g., Hart & Finelli 1999). With a sufficiently rigorous sampling design, the effects of flow on the community can be “teased” out of the analysis, so that the effects of anthropogenic stressors on benthic communities changes can be more accurately assessed–assuming, of course, that flow is not part of the anthropogenic impact in the study area.

Moss, macrophytes, and filamentous algae can also alter the abundance of certain types of macroinvertebrates. Moss, is not palatable to most macroinvertebrates because of the presence of protective chemicals. However, it does offer refuge from the sheer-forces of fast water. It also traps detritus (food), and can increase the amount of surface area available for colonization. Thus the presence of moss can have a strong influence on the structure of macroinvertebrate assembleges sampled in an assessment. When we want to account for this variation, we have found that the simplest (and effective) way, is to take a known amount of alcohol from the preserved samples and rank their Greenness. The Rank can be a very useful covariate when the data are analyzed. Other important covariates usually include a particle index, velocity, and depth.

The assumption is that the “Greenness” of the sample’s preservative is proportional to the amount of material soaking in alcohol for a given amount of time.  Thus, more greenness indicates there is more living plant material collected in the sample. Samples of similar greenness were probably influenced by living plants similarly, whereas the community composition of a very pale sample was probably influenced less by plant material than a sample with deep green preservative.

There are other nuances as well. For example, periphyton may cause a different kind of green tint to preservative than moss does–and it is likely to have a different influence on the benthic assemblage. Fortunately, for our purposes, moss seems to have much stronger effect on the sample’s color than periphyton. Also, you need to ensure that all samples are preserved with the same type and strength of preservative (95% ethanol, or 90% Isopropanol, or 90% denatured ethanol, not some of all three). Samples preserved in formalin would need to be transferred to alcohol before analysis–and even then should not be compared with samples preserved only with ethanol because of formalin’s ability to “fix” pigments.

Tags: , , , , , , , , , ,
Posted in Ecology, Monitoring Methods, Projects | No Comments »

Aquatic Insect Identifications

Monday, June 28th, 2010

Identification of macroinvertebrate samples from Sublette County, WY is progressing at faster pace with the addition of Esmeralda to our team.  She is a meticulous sorter and has a sorting efficiency of 97-100%!  This is impressive to me because, some of the other companies I have worked for have the sorters strive for 90%.  The idea is that if sorters remove 90% or more on the first sort, that the sample passes the Quality Assurance Standards of most bioassessment programs BUT that if they exceed it “too much” they are spending too much time on a sample.  Since laboratory work is usually conducted at a fixed price (per sample, regardless of how long it takes), one way to increase the profit margin is to ensure that employees spend as little time on each sample as possible. I wonder, if it is truely more cost effective to have the sorters aim a little lower.

For Example, if a sorting technician speeds through a sample, knowingly missing a few specimens, aiming for 90% efficiency, actually only sorts 70% of the insects. The sample would fail the QA/QC check and need to be re-sorted.  If the rechecked sample is sorted t0 88%, the entire processed portion needs to be sorted… again… Personally, I don’t think this would work well in my lab.  I think that it is more cost effective to take 20% longer to aim 10% higher (aim for 100%), than it is to retrieve the sample from storage, resort it, amending the data later–even if you only have to do that to a small portion of the samples.  But then we are a small capacity laboratory and it feels like our infrastructure is better suited for minimizing re-sorts.  I think it is a fairly valid assumption that the sample that has been re-sorted to 98% efficiency is just as good as the sample that was sorted to 98% efficiency the first time, so it is really about how the labs handle logistics–not so much about data quality. So, Esmeralda, keep up the highly efficient sorting–it is a good fit here!

I did just realized that some readers may not know about the two standard types of Quality Assurance measures applied to benthic macroinvertebrate sample processing: Sorting efficiency, and subsampling consistency.  We just discussed sorting efficiency (above). It is the portion of the total number of specimens found relative to the actual number in the sample. To calculate this number, one person sorts the sample and removes all the specimens from the sample. Later, another investigator examines the sample and removes all the specimens they find.  If the first person found 90 critters, and the second found 10, the first sorter’s efficiency would be 90%.

Sorting efficiency is a measure of the completeness of the sorting effort in the laboratory’s staff and may indicate the need for corrective action, whereas “subsampling consistency” describes some inherent characteristic of the of the samples composition–the clumpiness. Most bioassessment samples are not completely sorted–they are usually subsampled. So, if 25% of a sample was sorted to reach the SOP’s target number of organisms, (100, 200, 300, 500, or 1,000) then another equal portion of the sample (25%) would be analyzed in the laboratory. Both the taxonomic composition and total number of organisms are issues for comparison. Ideally the composition of the two portions taken from the same sample would be very very similar. However, in some instances specimens remain clumped together and one subsample is quite different from another portion of the sample. There is really nothing that can be done about this within the confines of study design.  If you add the two samples together, the new sample represents twice as much effort as the other samples in the study and would violate several assumptions in the analysis. If you keep them separate they violate other assumptions. Thus the number serves as a warning sign about the amount of variation with in a sample… Subsampling consistency involves as much work as a new sample, so it costs the same as an additional sample. Thus, most clients do not elect to perform this analysis on their benthic samples.  If a state agency routinely sends out 300 samples in a year, they would need to pay for 30 additional (~$9,000) samples to have subsampling consistency checks on 10% of their samples.  I think I can understand their desire to spend those funds sampling additional samples rather than describing an uncontrollable aspect of  sample composition. The flip side is if they assume the samples are 100% uniform and representative, some poor decisions can be made.

More on the effect of subsampling efficiency latter. Meanwhile, here is a thought question: Why do you think sorting efficiency matters?

Tags: , , , , , ,
Posted in Monitoring Methods, Projects | No Comments »