New bay tour offers science, sightseeing

  • Becca Matthias, a naturalist for the Center for Alaskan Coastal Studies, looks through a refractometer to measure salinity in an ocean water sample taken during a recent tour. The CACS tours, offered on Thursdays, are an opportunity to combine science and sightseeing.-Photo by Michael Armstrong, Homer News
  • Part of the Center for Alaskan Coastal Studies tour, Ocean Connection, includes a visit to the seabird rookery at Gull Island. It also includes a visit to an oyster farm, but otherwise is open ended.-Photo by Michael Armstrong, Homer News

All we needed were red knit caps.

On a recent weekday tour of Kachemak Bay, I felt like one of the crew of Jacques Cousteau’s famous ocean exploring boat, the Calypso. 

OK, at 28-feet long, Capt. Karl Stoltzfus’s Torega isn’t as big as the 139-foot Calypso. Center for Alaskan Coastal Studies naturalist Becca Matthias doesn’t speak with a French accent. But once she and naturalist Leah Thon got me and several other passengers involved in scientific observations, I felt like I had embarked on a great oceanographic expedition — even if it was to Peterson Bay and not the Antarctic Ocean.

We didn’t make any major discoveries, but we did learn about an issue of concern that scientists with the Kachemak Bay Research Reserve and NOAA’s Kasitsna Bay Laboratory have been studying, the possibility of a harmful algal bloom (see story, page 3)

Billed as a “fam” tour — tourist industry slang for “familiarization” tour — CACS invited me and other people connected to the visitor industry on its latest tour, Ocean Connection. 

Every Thursday through the summer, Ocean Connection takes up to 10 people on a flexible tour of Kachemak Bay highlights that day. The tour includes a visit to the seabird rookery at Gull Island and to an oyster farm, but otherwise is open ended.

“You can see things you won’t otherwise. It’s a really cool way to spend time on the bay,” said Melanie Dufour, CACS outreach and marketing director, who came along on the trip.

While Gull Island and Peterson Bay can be stops on other Kachemak Bay tours, Ocean Connection adds a twist: you get to do science. On June 26, we operated a remotely operated vehicle, or ROV, with a waterproof camera that dove like a minisubmarine into kelp beds. We did plankton tows and — even cooler — looked at plankton in a microscope. A video camera projected the image onto a monitor as we puzzled out identifying phytoplankton and zooplankton — plant and animal plankton. We also sampled ocean water at various depths and took salinity readings.

The trip began with one of the staples of any bay tour, a visit to the Gull Island bird rookery. Aptly named, Gull Island attracts several species of birds that nest in its crags, including black-legged kittiwakes, glaucous gulls, cormorants and horned puffins. The puffins nest in burrows in a grassy mound at the top of the island. Huge rafts of hundreds of common murres drift off Gull Island, but probably because of predation by eagles, haven’t made nests this year. A lone immature bald eagle sat on top of the island, and when it flew up, spooked the gulls, causing them to whirl around in a screeching whirlwind of white wings.

Off Gull Island, Thon brought out the ROV, a contraption of wires, electronics and propellers wrapped in a cage of white plastic tubing. It looked like something cobbled together at a maker lab. A long tether provided power to the ROV and kept it from drifting away.

Thon said that on CACS school trips, young scientists make their own ROVs and try them out in the harbor. Currents whipped up sediment, so when I ran the ROV, I had a hard time seeing anything other than a ribbon of bull kelp. When I hauled the ROV back onboard, I saw why: the ROV had captured some kelp.

“You can see so much more in the harbor,” Thon said.

The plankton tow captured everyone’s attention. In a cone-shaped net with a jar at the bottom, the plankton get caught in the net and are washed down with seawater into the jar. When Matthias held up the jar, it looked like goopy brown soup.

Taking a tear dropper full of plankton soup, Matthias showed us how to make slides that then go under the microscope. A thin glass plate squishes the sample to keep critters from moving around. Matthias also made a slide without a plate. At the micro scale we saw what we had been looking for in the ROV: an ocean teeming with life. A little video camera on the microscope projected images onto a monitor.

One zooplankton looked like an alien bug eyed monster. Using a handy guide provided, Matthias pointed out the critter was a zoea, a very young crab moving into the next stage of its life, a megalops. 

Another slide showed dozens of long, thin strands of phytoplankton. That got Matthias’ attention. Could those be pseudo-nitzschia? Blooms of pseudo-nitzschia have raised concerns in the Pacific Northwest, because the little plankton can produce domoic acid, a chemical harmful to fish and shellfish like razor clams and oysters and the people who eat them. 

Using a handout, we citizen scientists puzzled over if the plankton could be pseudo-nitzschia or rhizosolenia. Looking at photos emailed to him, Kasitsna Bay Laboratory biologist Dominic Hondolero said most of the plankton we saw were rhizosolenia. Rhizosolenia have chloroplasts — block-like rectangles — throughout the cell while pseudo-nitzschia has just two chloroplast and is smaller.

Cruising off Peterson Bay, we did some more science, taking water samples. Using a device called a Niskin bottle, a tube with two stoppers held open by springs is lowered down into the waters. Tick marks every foot on the rope show how deep the Niskin bottle goes. When it’s at the desired depth, a donut-shaped brass weight called a messenger is dropped. When it slides down the rope and hits the Niskin bottle, it trips the springs, closing the watertight stoppers. The bottle is then raised up and the water sample emptied into a bucket.

Using a device called a refractometer, we then measured the salinity of our sample. A drop of water is placed in the refractometer, and looking through it I saw a scale of numbers. Matthias has us all look through the refractometer and take a measurement, but not say anything. When we were done, we all agreed on numbers between 25 and 27 parts per 1,000. With fresh water coming from glaciers and streams, that’s about right for Kachemak Bay compared to salinity in the open ocean of about 35 parts per 1,000.

As a treat at the end of the day, we all sampled oysters, a way to understand a practical application of all this science. Oyster farmers need to measure things like water temperature and keep an eye on algal blooms. We didn’t visit an oyster farm, but we did try our hand at shucking oysters. Once shucked, of course, the oysters had to be eaten.

Learning about real-world science, exploring the bay and seeing it from islands to the nearly invisible is the whole idea of Ocean Connection — without getting wet, CACS says in its flier describing the tour.

“We want to do a top-down, bottom-up connection,” Dufour said.

Michael Armstrong can be reached at michael.armstrong@homernews.com.

 

Ocean Connection

Center for Alaskan Coastal Studies

When: 1-5 p.m. Thursdays 

What: 4-hour tour with CACS naturalists and Capt. Karl Stoltzfus on the Torega. Not bound by a specific route, you’ll see the highlights of Kachemak Bay that day. Visit Gull Island and look for birds and wildlife. Learn about ocean ecology by running a remotely operated vehicle with a camera, doing plankton tows, looking at plankton with an onboard microscope and taking scientific measurements. 

The tour includes a stop at an oyster farm to taste and purchase fresh oysters. Learn about oyster farming and try your hand at shucking oysters.

Cost: $99 adults, $80 children; includes snack. 

For reservations: Call 235-6667 or visit akcoastalstudies.rezdy.com/20713/make-an-ocean-connection-reach-beneath-the-bay-and-you-don-t-even-have-to-get-wet

 

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