Sunday, April 17, 2011

Week Three: Fish Week

Steven and Wendel ready to dissect a rockfish

Monday April 11th: Today started our 2nd course of the term: fish. We met our teacher Wade Smith and his TA Margot Hessing-Lewis. The highlight of the day was going to the lab to partner up and dissect different species of thawed-out fish. Each team was responsible for identifying their fish using a dichotomous key, describing distinct external characteristics, and some major internal organs. Some of the more exciting species dissected were the ocean sunfish, Mola mola and the horn shark, Heterodontus francisci. The second part of the lab exercise consisted of breaking into groups and each creating a unique dichotomous key for a set of preserved species that were all fairly similar. Each group was responsible for thoroughly examining each specimen in their set, and being able to distinguish why one was a separate species than the next.

Tuesday April 12th: We went out to two locations today to start collecting fish! Our first location was the by the pumphouse in Yaquina Bay, and the second was the estuary flats of Yaquina Bay. Two large seine nets (a long and shorter trawling net with wooden poles attached on either end) were used to trawl small portions of the Bay in order to collect fish. A total of 10 trawls were completed between the two sites, with the students wading chest deep in the water and dragging the net landward once both sides were parallel to shore. All of the fish caught were counted in the field, and while most were released back to the bay, a few representatives were taken back to the lab for further identification.
Paul and Wade pulling the seine net to shore

Wednesday April 13th: The morning portion of the day consisted of going to the lab to each individually dissect a preserved fish to locate and extract a pair of otoliths. These are tiny, calcareous plates located near the brain that are used by scientists to estimate the fish's daily and annual age and growth patterns. We also were given microscope slides containing sample otoliths that we examined to practice counting the band patterns and estimate age. In the afternoon, the group headed back to Boiler Bay, this time to collect fish from the tide pools and channels. Low tide occured around 3:00 pm with sunny skies. 25 fish were collected, most of which were various sculpin species. Some of the other fish collected were Apodichthys flavidus (the penpoint gunnel), Gobiesox maeandricus (the northern clingfish), and Hexagrammos lagocephalus (the rock greenling).

Thursday April 14th: Earlier in the week, students were assigned some scientific research papers to read that covered an array of topics, such as adaptations to living in an estuary and some personal adaptations of Porichthys notatus (plainfin midshipman). Today, the students were divided into two discussion groups, where we critiqued and reflected on these papers.
Although the weather was unfavorable, a trip to Strawberry Hill took place in the afternoon with strong winds and heavy rainfall. We were collecting fish using a variety of sizes of nets in the tide pools. 34 sculpins were captured, as well as 2 more penpoint gunnels.

Friday April 15th: Jose R. Marin Jarrin came to class to give a guest presentation about salmon on the Pacific Coast, and his research related to them. He has been monitoring salmon abundance in the surf zones along the Oregon coast to see if these habitats play a significant role in their life history. Salmon are born in freshwater streams and rivers, and will migrate to estuaries in their juvenile stage, which is a mixture of fresh and salt water. This classifies them as anadromous, which refers to fish that are born in fresh water, migrate to the ocean, and then return to freshwater to spawn, die, and pass on ocean-derived nutrients for their offspring. After, we had our final fish lectures for the course, and had the afternoon off to catch up on lab work and various assignments.

Saturday April 16th: Yes, Saturday class! This was the only day available to use the Elakha aluminum research boat for some fish trawling within Yaquina Bay. The boat's name Elakha is the Native American word for "sea otter", and has been in Newport since August 2000. The students were divided into two groups, half of which went on the boat in the morning, while the other half went to the Oregon Coast Aquarium to complete a lab exercise. Students on the boat assisted in deploying the fishing net and also pulling it back on board to examine the catch. The boat had a large metal A-frame powered by hydraulics that was lowered in order for the trawl net to deploy completely. Three trawls were completed by each of the groups, catching a large assortment of fish as well as some invertebrates. Some interesting species caught were Platichthys stellatus (the starry flounder), Ophiodon elongatus (juvenile lingcod), Liparis cyclopus (ribbon snailfish), and Pholis ornata (saddleback gunnel).
Allan, Wade and Jessie lowering the net

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