After a restful weekend we started the community ecology section. We met our new professor Laura Petes and teaching assistant Dafne Eerkes-Medrano. Bruce Menge and some of his lab techs came by for a visit too. The next two weeks look really exciting! We are going to spend a lot of time in the field collecting data. We are going to have to put what we learned in the invertebrate, fish and algae sections to the test so that we can collect accurate data. The class has been divided into two person field teams that will collect specific data during our upcoming field trips. We will then analyze the data, and next week, present our findings.
Today we had two lectures. The first was a general overview of marine ecology with a review of data that we may encounter over the next two weeks. Second, Dafne gave a lecture on her PhD thesis work. She has been studying the effects hypoxia on the larval stage of many invertebrates. Tomorrow we head out to Boiler Bay at 6am for our first day of data collection!
|Steven sleepily counts snails|
Today began with an early trip to Boiler Bay. With coffee and tea in hand, students set out at 6am in groups of two to three to either measure species abundance using Transect-Quadrats, or measure feeding and predation by two common Rocky Intertidal whelk species, Nucella ostrina and Nucella canaliculata. After four hours of thorough surveying, measurements, and observations students headed back to Hatfield to clean up and have lunch before the first lecture of the day. This lecture covered the spatial, species, size, and trophic structure and biodiversity of marine life communities in different parts of the world. After the lecture, field groups met in the library for raw data entry and analysis into excel spread sheets. The day finished off with a very interesting lecture by Sarah Close about her graduate work studying nutrient uptake, availability, and limitation in marine environments.
|Lisa and Vathani discuss their data while Jesse looks on|
We had another early start today. Instead of Boiler Bay we headed south to Strawberry Hill. We continued to collect transect-quadrat, belt transect, tidepool diversity data and feeding surveys of whelks and Pisaster ochraceaus. The weather cooperated which made the data collection much more enjoyable. When we returned to HMSC we had a lecture on how the environment effects species interactions. The lectures and field trips of this section have gotten a lot of students thinking about their research projects for later in the term. Some students began collecting species such as Cryptochiton stelleri, Pisaster ochraceaus, and others to use in their research. The rest of the afternoon was spent doing data entry, but some of us found time for volleyball.
Happy cinco de mayo! We got to sleep in a little later today but we headed back out to the field to collect biodiversity and mobile predator data at Boiler Bay. The field teams broke into two groups. One went to Boiler Bay proper (where we have been going all term) and the other went to different part of Boiler Bay called Manipulation Bay. Manipulation Bay got its name from being a research site for many OSU students over the years. Some students even witnessed seagulls feeding on the arms of a giant Pacific octopus (Enteroctopus dolfeni) on the rocks! The weather turned a little nasty but it was not nearly as bad as earlier in the term.
Our afternoon lecture was on complex community interactions and community structure. One of the major topics was trophic cascades. Trophic cascades are a central part of ecology. First, a trophic level is defined as the place in the food chain that an organism occupies. A trophic cascade is the phenomenon by which top predators control the abundance of their prey and therefore indirectly affect the population sizes of lower trophic levels. Picture this example food chain. Killer whales eat sea otters which eat sea urchins which eat kelp. When killer whale populations are high they directly control the population of sea otters. The low population size of otters trickles down the food chain allowing for high urchin populations and low kelp abundance.
|A group of students surveying biodiversity at Strawberry Hill|
Last early morning! We set out to Strawberry Hill again but this time to collect biodiversity and mobile predator data. While it has been a very long week it was sad that it would be our last class field trip to the rocky intertidal. The biodiversity surveys were completed in 10 minute increments for a total of 120 minutes of surveying. We did surveys at low, mid, and high tidal zones in both wave exposed and wave protected areas of the site.
Our afternoon lecture was short, which allowed for students to catch up on sleep, readings and data entry. Next week we will be analyzing the data we collected this week. We will present our findings to our classmates on Wednesday night.
|It has been a long week for Reed|