Collaborative research in southwest Alaska: Mussels, mollusks and more, part 3

Seattle Aquarium Animal Care Specialist Caroline Hempstead traveled to the coastline of Alaska’s Katmai National Park and Preserve from June 28 to July 10, 2019. Caroline assisted with a variety of research being conducted as part of a long-term monitoring program of the area. These efforts were part of the National Park Service’s Southwest Alaska Inventory and Monitoring Network as well as part of Gulf Watch Alaska, the long-term ecosystem monitoring program of the Exxon Valdez Oil Spill Trustee Council for the marine ecosystem affected by the 1989 oil spill. Check out Caroline’s account of her experiences in Alaska below!

 

PART 3: MUSSELS, OYSTERCATCHERS AND BROWN BEARS

DAYS 7 AND 8

 

Map of Katmai National Park
Map of Katmai National Park.

 

Day 7

This was the third day of intertidal sampling. I joined Jim and Brenda to assist them with the mussel site on Takli Island in Amalik Bay. Another incredibly beautiful site!

 

Jim and Brenda sampling a mussel bed at low tide on Takli Island.
Jim and Brenda sampling a mussel bed at low tide on Takli Island.

 

I recorded the sampling method at the mussel site using a GoPro camera set up on the beach and programmed it to take a photo every 15 seconds. Insert video of ‘Mussel sampling on Takli Island’ here. While sampling, we found a handful of California mussels (Mytilus californianus), which are not common around the area. Jim and Brenda also noticed an increase in the number of a snail species (Nucella spp.), so a random sample was taken for future comparisons. Insert video of ‘Nucella sampling on Takli Island’ here.

 

California mussel (foreground) found on Takli Island.
California mussel (foreground) found on Takli Island.

 

After the mussel site was sampled, we hiked to the other side of Takli Island to collect sea otter foraging data.

 

Wildflowers on Takli Island with Jim observing sea otters on top of the bluff.
Wildflowers on Takli Island with Jim observing sea otters on top of the bluff.

 

Once we reached the top of the bluff, we immediately saw sea otters feeding. Jim spotted a sea otter eating a giant Pacific octopus weighing an estimated 50 pounds! The weight was based on the size of the arms on the octopus and the area it covered on the otter’s belly. Another otter in the area was also feeding on the octopus. We were able to collect foraging data on several other sea otters that were munching on clams and mussels.

After lunch, Jim, Lena, Elsie and I went out on a skiff to survey for black oystercatchers (Haematopus bachmani) along the designated transects. I think these birds should have been named “black musselcatchers,” because they often feed on mussels, not oysters, at least around Katmai. The surveys of these birds were conducted to determine breeding density, and each nest was checked for the presence of chicks and/or eggs to determine productivity. Prey remains are collected and identified to species to determine what the parents have been feeding their chicks.

In addition to surveying the oystercatcher transects, Lena was working on a project through SFU in Vancouver, British Columbia. Although most black oystercatchers breeding in Alaska migrate south for the winter, some remain in Alaska year-round. This phenomenon, known as partial migration, has puzzled ornithologists for decades. Researchers at SFU are testing hypotheses for partial migration in black oystercatchers using a combination of light-sensitive and GPS tracking technology, morphological measurements and stable isotope analysis. This project is paired with a study asking how migratory Alaskan oystercatchers and sedentary British Columbia oystercatchers share their winter habitat along the British Columbia coast. The two projects will advance understanding of the drivers of movement and habitat use in black oystercatchers, an important indicator of rocky intertidal ecosystem health.

 

Black oystercatcher helping scientists answer some questions.
Black oystercatcher helping scientists answer some questions.

 

On our way to studying the black oystercatcher, we came across a brown bear feeding on a dead whale near one of the islands in Amalik Bay. Brown bears are omnivores and opportunistic eaters, with a diet consisting of berries, flowers, grasses, some marine invertebrates, small and large mammals, salmon, and marine mammal carcasses. They require a very high caloric intake of food and will eat 80 pounds of food per day in the summer and fall in order to have enough fat storage for the winter. It was quite a sight to witness this kind of foraging behavior!

 

 

Day 8

Before heading out to our intertidal sites in the morning, a few more black rockfish and kelp greenlings were added to our collection. I joined Jim and Brenda on another mussel site in Amalik Bay while the other teams went out to the soft sediment and rocky sites.

 

Scientists sampling at a rocky intertidal site in Amalik Bay.
Scientists sampling at a rocky intertidal site in Amalik Bay.

 

Scientists sampling at a soft sediment site in Amalik Bay.
Scientists sampling at a soft sediment site in Amalik Bay.

 

As Jim, Brenda and I were approaching the mussel site, we noticed a sea otter diving and eating just off the beach, so we quickly set up a tripod and scope on a rocky outcrop and collected more foraging data. This otter was eating mostly clams. After the mussel site was completed, we went back to the Miss Diane to process the black rockfish and kelp greenlings. I learned a new technique on how to skillfully remove the otoliths from the rockfish. A messy job, but the new method was spot-on every time.

In the afternoon and evening hours, the teams divided up again to collect sea otter foraging data, fish for black rockfish and kelp greenlings and survey the black oystercatcher transects. Once back on the Miss Diane, we measured more mussels and clams from the morning’s sampling of the intertidal transects. The Miss Diane then pulled up anchor and headed north to Kinak Bay.

 

Questar spotting scope used to collect sea otter foraging data at viewpoint looking at Amalik Bay.
Questar spotting scope used to collect sea otter foraging data at viewpoint looking at Amalik Bay.

 

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