Hello everyone! There was a question on my last post about how habitat type is discerned and incorporated into our hook and line sampling design. Habitat type is discerned using various underwater camera systems such as sleds, ROVs, and landers. The data received from these deployments are then used to generate habitat type which can subsequently be incorporated into an ArcGIS program. There are also other methods of distinguishing habitat type such as SONAR, LIDAR, and satellite imagery, but I do not know the extent to which these are used for our habitat maps.

Anyway, this past week I again found myself out at sea helping with the hook and line fishing surveys in the Cascade Head Marine Reserve, which is about an hour trip by boat from Depoe Bay. We fished for two consecutive days and caught a wide variety of rock fish and round fish species including: kelp greenling, black rockfish, blue rockfish, lingcod, yellow eye, yellowtail, canary, china, and quillback. The black rockfish and kelp greenling are euthanized and kept for age dating purposes, while the others are quickly released after capture. Fish that suffer from barotrauma are hooked to a descender device and are released at the depth at which they were caught so that their swim bladder can recompress. Some rock fish species are more susceptible to barotrauma than others; blue rock fish are notoriously prone, while others such as kelp greenling and lingcod do not require any assistant at descending to depth.  Although assisting in these hook and line surveys take up the majority of the week, I did find time to assist in another project: benthic extraction.

Benthic extraction is a study of the benthic invertebrate community. It is one way in which marine biodiversity is assessed and quantified. It involves SCUBA divers scraping invertebrates off quarter meter square rock structure and bagging the samples into mesh bags. The samples are then brought to a lab where they are sorted according to phyla and put into sample jars. The samples are then preserved with formalin and sent to an eco-analyst where they are then sorted into lower taxonomical ranks. Species diversity, abundance, and biomass are quantified which will serve as indicators of biodiversity. The goal of benthic extraction is to compare biodiversity between marine reserves and their associated comparison areas to observe how biodiversity and benthic community structure may change over time. This, along with hook and line surveys, are a couple ways to evaluate the effectiveness of Oregon Marine Reserves as a management tool.