Here's the update from ESPchris during this past week's effort to collect "ground truth" samples at the mooring site...

From water samples collected next to ESPchris, no Alexandrium catenella cells were microscopically observed at the mooring site on either Tuesday or Wednesday (May 14-15). Given the lack of cells at the moored instrument, we mounted a 7-station cross-shore transect on Thursday May 16 that extended from inshore of ESP-1 near Cape Neddick just to the east of Jeffries Ledge--about 30nm offshore. Samples for Alexandrium catenella, Pseudo-nitzschia sp. and nutrients were collected. Live counts were completed from surface samples collected at each station while underway. No Alexandrium catenella cells were observed from those samples either. A few colonies of large Pseudo-nitzschia sp. were present, but only in the sample from the mooring site.

ESPchris continues to sample each day and even sampled 2-3 times per day while we were on site collecting samples. The remote results sent from ESPchris this week generally agreed with the ground truth samples. While ESPchris did return weak positive Alexandrium catenella signals early in the week (50-100 cell/L range), those signals disappeared by late Tuesday through Friday, consistent with the lack of A. catenella cells in the area.

Since no significant population has been observed, we are considering slowing the ESP sampling down and conserving onboard resources towards the end of the mission, while prepping the next ESP for deployment later this month.

Bruce Keafer
Research Associate in the Anderson Lab
WHOI Laboratory for Ocean Sensors and Observing Systems (LOSOS)

On Sunday, May 12, 2013, ESPchris woke up and started sampling at noon. After processing the sample, at 4:00pm it reported its first positive signal of the 2013 bloom season for Alexandrium catenella. Based on lab calibrations from known concentrations using cultured cells, the field concentration was calculated to be in the 50-100 cells/Liter range, just above our detection limit. No other probes on the array showed a positive signal.

Just a brief time ago on its Monday noon sampling, ESPchris woke up again to do his job...and reported another positive signal in the same range as Sunday's sample...two days in a row with weak positive signals.

Note that the ESP sample intake is at about 1.5 meters, just below the surface buoy, so all reports are from that depth. The sample is delivered through the hollow stretch to the ESP at 20m for processing...that configuration insulates the sensitive ESP from heavy wave action. A Seabird CTD (with fluorescence sensor) and a SUNA nitrate analyzer are located near the intake. The CTD data is reported in near real time, while the SUNA data is recorded internally and will not be available until recovery of the mooring. Dr. Dave Townsend and Maura Thomas are an integral part of the ESP team. They have been calibrating the SUNA instrument at the bench and collecting nutrient samples right along with the Alexandrium and Pseudo-nitzschia samples. Next year, we expect to integrate the SUNA data stream into the near real time ESP data stream through the new electronics architecture...so that improvement is coming.

We are currently mobilizing to sample near the mooring. The R/V Tioga left the dock today and will be on site Tuesday morning through Thursday to collect samples alongside ESPchris, if the weather permits.

We're thrilled that ESPchris is doing its job as planned and will report back the ground truth findings at the end of the week.

Bruce Keafer
Research Associate in the Anderson Lab
WHOI Laboratory for Ocean Sensors and Observing Systems (LOSOS)

I am pleased to report that on Sunday April 28^th, 2013, we successfully deployed the ESP-1 mooring with ESPchris onboard. After delaying several days due to weather, the cruise to the site on the R/V Tioga and the actual deployment over the side was done with ease during a calm sea (see pics attached and video embedded press release below). The mission was started that day and since then, we have been monitoring all systems closely. ESP-1 mooring is anchored offshore of southern Maine.

New this year, we established an internet connection from the ESP to the surface buoy and from the buoy to shore.  A smart cell phone router with antennae located at the top of the buoy utilizes ATT services with a static IP address to securely link the ESP all the way to the WHOI network as if the instrument is sitting on the bench here in the lab…Very Nice! The link over the ATT network to WHOI network is solid to at least 15 nautical miles from shore. Thanks to WHOI electrical engineers, Keith von der Heydt and Neil McPhee with software support from Brent Roman (MBARI) for that huge effort!

This year we have two assays onboard. The standard harmful algal bloom (hab) assay and a new saxitoxin (stx) assay. The hab array is spotted with probes for Alexandrium catenella (NA-1) and several probes for Pseudo-nitzschia sp. that Dr. Kate Hubbard (former post-doc in the Anderson Lab now at FLA Fish & Wildlife Research Institute) is currently testing for cross reactivity in Gulf of Maine waters. “Bonus” probe spots for Heterosigma akashiwo were added in the final printing onto the filters. It’s no easy task to print these arrays, so thanks to Roman Marin (MBARI) for that tedious effort.

The saxitoxin assay (stx) was developed by Dr. Greg Doucette, Greg’s postdoc Jinking Asong and others at the NOAA Marine Biotoxin Lab in Charleston, SC in collaboration with Juliette Smith, a post-doc in the Anderson lab. That assay uses a different filter array and specifically targets the toxin molecules, not the nucleic acids as in the hab array. It is a competitive ELISA format modeled after successful deployments of a domoic acid assay onboard ESPs off the west coast targeting the toxins from Pseudo-nitzschia sp. by Greg, Chris Scholin (MBARI) and others.

Currently, the preliminary results from both the hab and stx assays are negative, which is consistent with the general lack of toxicity reported along the coast of Maine, NH, Massachusetts to date. We are mounting a ground truth survey next week to sample the waters at the ESP site while the instrument is sampling to confirm the ESP data. After ESPchris’ (named after Chris Scholin) mission ends in late May, we plan to follow this deployment with another ESP to sustain the measurements. That ESP is affectionately named ESPdon (after my supervisor and lead PI on this project, Dr. Don Anderson).

Finally,

In addition to those mentioned above, I’d like to express my sincere gratitude to all those that contributed the extra effort to overcome the challenges that made this two ESP deployment effort a potential reality…we are just starting, but to get to this point was a enormous challenge. Specifically, Roman Marin and Brent Roman and the Scholin team from MBARI were essential to the success of every phase this effort with Roman Marin coming here to WHOI for the final preparations. WHOI engineers, Keith, Neil along with Brent from MBARI, I cannot thank you enough for advancing the electronics architecture to allow data transmission via the ethernet connection from ESP to the WHOI network. Thanks also to the seasoned pros at EOMoffshore, Inc. and in the WHOI buoy group (Will Ostrom and Jeff Pietro) for their efforts readying the mooring and getting it over the side safely…and thanks to Captain Ken Houtler and Ian, the mate of Tioga…it’s a big package deployed from a small ship. Tom Fougere (McLane Research, Inc., manufacturer of ESP under license from Spyglass Biosecurity, now Spyglass Technologies, Inc.) was always available to help with the ESPs, when needed. Lastly, I want to especially thank my Northeastern University Co-op student, Isaac Rosenthal, for his tireless effort on nights and weekends. He was at my side every step of the way since he came here in January of this year. Isaac is now an ideal candidate to move forward with the next generation of ESPs.

Expect an update later next week or sooner if things change,

Bruce Keafer
Research Associate in the Anderson Lab
WHOI Laboratory for Ocean Sensors and Observing Systems (LOSOS)