It was nerve-wracking not to have the permit.  Without permission, we could gather neither algae nor slugs, so experiments were at a standstill.  Fortunately, we could get started on a few things, like surveying different sites for slugs, and optimizing conditions for the DNA experiments.

Snorkeling in front of the station allowed us an extended period to observe the animals and their habitat.  It was also fun, and gave the students lots of practice at slug hunting.  It was a good year for Elysia at the station, and we saw plenty .  All the more frustrating that we could not collect them.

Elysia diomedea in front of field station. 6/26/18

Finding them is never trivial, however.  Below is a medium-small slug with a finger for scale.  It would be a lot easier if they got as big as E. clarki, but I have never seen them larger than 5 cm or so.

Elysia diomedea on human finger. BLA field station 6/23/18.

There was a lot of Codium, and multiple other species of green algae that could potentially interest the slugs.  I even found a small patch of Bryopsis, which is reputed to be a favorite of captive E. diomedea.

Bryopsis species, probably B. pennata. In front of BLA field station 6/26/18.

We also had the chance to play with the new PCR primers I designed for use in NextGen sequencing.  I had not had much of a chance to test them before I left Maryland, so we took some time in the morning to set up a reaction using DNA I had brought for use as a positive control.

Results of playing with parameters for PCR amplification, using DNA from the alga Avrainvillea nigricans extracted in Maryland. First lane is ladder, which failed for some reason. The rest of the lanes contain DNA amplified using varying amounts of algal DNA and primers. 6/29/18.

The results were encouraging, but imperfect.  The PCR products had two bands, instead of one, suggesting the conditions needed to be modified to amplify only the rbcL gene.

The following day, we set off for a slug survey at Playa La Gringa, a beach area near the north end of the bay.  It is a beautiful spot for a snorkel, and has a lot of potential for slug hunting.  Once there, we suited up and got ready.

The Photobiology Research Group at Playa la Gringa. From left: Maria, Bennie, Lily, DIana, Elizabeth, Zaira, Keyla, Melanie. 6/29/18

They were soon in the water, exploring and enjoying.  This part of the beach receives cold water directly from the Gulf, so the students were happy to have their wetsuits.

Students in the water at La Gringa. 6/29/18.

The rocky bottom looked promising, with a wide range of mixed algae species.

Many species of green, red, and brown algae on rocks at Playa La Gringa. 6/29/18.

Detail of rocky bottom, showing green, red, and brown algae, along with small gorgonian corals. 6/29/18

There were plenty of small treasures, such as urchins, sponges, and hydroids, along with a profusion of fishes.

Hydroids among the algae. Playa La Gringa. 6/29/18.

Codium was also plentiful, in at least two growth forms (or species, not sure), which might indicate the presence of Elysia.

Large growths of Codium at Playa La Gringa. 6/29/18.

Codium with sparser, longer branches. Playa La Gringa, 6/29/18.

Toward the south end of the beach, the rocks were relatively bare, with very little green algae visible.  The brown alga, Padina, was still abundant.

Area to the southeast with heavy growth of Padina, but no visible green algae. 6/29/18.

Despite intensive searching by many eyes, we did not find any Elysia anywhere along the beach.  This does not mean that the slugs are not there, but they certainly did not make their presence known.

At this point, Ric and I had been improvising, or exercising “adaptive management,” for many days, and were running out of tricks.  I had requested that the crew in Maryland send some more DNA samples, but they would not arrive until the following week.  Although despair is way too strong a word, there was a profound sense of “now what?”

It was at that point that the intensive lobbying by Ocean Discovery paid off, and the permit finally came through.  The group could collect slugs and algae, and start work on the planned experiments.