http://hdl.handle.net/1957/1315 Search the Channel search http://ir.library.oregonstate.edu/jspui/simple-search http://hdl.handle.net/1957/12050 Title: Are there two subgroups of albacore, Thunnus alalunga, in the North Pacific? Evidence from variability in catch, seasonal migrations, and length composition for two subgroups in the coastal fishery of North America<br/><br/>Authors: Barr, Charles M.<br/><br/>Abstract: North Pacific albacore (Thunnus alalunga) is a highly migratory andcommercially valuable species of tuna. All stock assessments and managementdecisions for North Pacific albacore are presently based on the assumption of a single,uniform stock. However, a growing body of evidence from diverse sources suggeststhat there are two subgroups of albacore in the coastal fishery of North America.These subgroups are believed to occur north and south of 400 North latitude. Thisstudy investigated the existence of the proposed subgroups using more than 40 yearsof albacore logbook and port sampler data provided by the Southwest FisheriesScience Center. I examined regional differences in the coastal albacore fishery usingthree metrics: 1) catch per unit effort (CPUE), 2) entry and exit date, and 3) sizecomposition. Distinct regional differences were observed for each metric. Spatialmapping of average CPUE by month suggested that migration into the coastal fisheryoccurs at two distinct locations: approximately 450 North latitude and 300 Northlatitude. Availability within seasons, expressed as average CPUE by month, differedbetween the two regions. Average entry and exit dates were also different between thetwo regions, with the northern region starting on average one month later (July) andending one month earlier (October) than the southern region. Moreover, albacorefrom the southern region averaged 2.5 cm longer than those caught in the northernregion. These results support previous findings and suggest that the coastal albacorefishery is comprised of two subgroups with distinct migration routes and sizecharacteristics. The results may have implications for the management of this fishery,particularly if these subgroups represent separate and distinct stocks. Because thisstudy did not examine spawning distribution, further research (possibly using genetics)is needed to determine if the subgroups spawn independently in space and time.<br/><br/>Description: Graduation date: 2010 http://hdl.handle.net/1957/12002 Title: The development and evaluation of an interactive exhibit to support real-time water quality data interpretation by the public at an informal education setting<br/><br/>Authors: Mikulak, Sarah E.<br/><br/>Abstract: Ocean observing groups are currently making efforts to work with well-defined end-user groups, like boaters and fishermen, to provide meaningful and effective real-time data (RTD) products and visualizations. However, providing meaningful data products for undefined groups such as the general public is not straightforward. In Oregon, several industry, science, and education organizations have formed a unique collaborative partnership to understand how to present and interpret water quality RTD to accomplish this goal. The project outlined here is the development of an interactive, computer-based exhibit, which interprets near-real time (NRT) data from Yaquina Bay as collected by a Land/Ocean Biogeochemical Observatory (LOBO), to facilitate the general public's understanding and analytical thinking about natural variability within an estuary and provide them with information that allows them to make more informed decisions about their environment. Housed as a permanent exhibit at the Hatfield Marine Science Center Visitors Center, a free-choice learning facility, a prototype exhibit module composed of several levels of increasing complexity was developed to interpret salinity patterns using an iterative, formative evaluation process of unobtrusive observations and interviews to guide exhibit modifications and to increase engagement by the audience. Two versions of the exhibit were evaluated and visitor use was measured in three ways: 1) where they visited within the exhibit; 2) how much time they spent at the exhibit; and 3) types of talking that occurred during the use of the exhibit. Findings reveal that visitors of all ages enjoy and understand the information presented in the exhibit, and that use of the exhibit and engagement in learning-indicative behaviors differs between social group types. Visitor use also changed in the direction that we were hoping from the first version to the second version; however, visitors did not engage with the NRT dataset online, which was one of the main goals of the exhibit. Because of this, we conclude that, whereas the easier levels of the exhibit are appropriate as an interactive educational tool to support visitor understanding of NRT data, the expectation that visitors at a free-choice learning facility will interact with the actual dataset, which is central in the harder levels of the exhibit, may be unrealistic. Recommendations for ocean observing entities interested in developing educational products for an informal, general public audience are outlined.<br/><br/>Description: Graduation date: 2010 http://hdl.handle.net/1957/12486 Title: Investigation of polycyclic aromatic hydrocarbons (PAHs) transport by suspendedparticulate matter (SPM) in the lower Columbia River and its estuary<br/><br/>Authors: Gregg, Tiffany<br/><br/>Abstract: This study aims to improve knowledge of how suspended particulate matter(SPM) affects hydrophobic contaminant transport in the lower Columbia River and itsestuary, using polycyclic aromatic hydrocarbons (PAHs) as model compounds. It ishypothesized that PAHs are transported to the estuarine turbidity maximum (ETM), aprime feeding zone in the Columbia estuary, where organisms encounter and consumecontaminants adhered to particles as part of their diet. During a CMOP (Center forCoastal Margin Observation and Protection) cruise aboard the RV Barnes in August2007, water samples were collected from sites throughout this study region. In addition,bi-monthly water samples were collected over a one-year period in coordination with theUSGS NASQAN program. The PAH content and composition was analyzed in allsamples and interpreted in perspective with the SPM concentration and particulateorganic carbon content of the SPM.Results show that the dominant source of PAH to the study region is acharacteristic suite of compounds derived from high temperature combustion. Perylene,a compound of yet to be determined natural origin, represents a PAH of comparablequantitative significance. These compounds are transported via riverborne SPM to theestuary and hydrodynamically trapped in the ETM with the trapping process operatingsomewhat differently between the two sources. The concentration of individualcombustion PAHs measured in SPM from the Columbia River and its estuary exceed thethresholds of concern stipulated by environmental protection policies. Surprisingly,measured PAH levels are similar to those measured in other, far more industrialized riverand estuarine systems around the world.<br/><br/>Description: Graduation date: 2010 http://hdl.handle.net/1957/12047 Title: Identifying habitat factors for canary rockfish (Sebastes pinniger) off Washington and Oregon using environmental data and trawl logbooks<br/><br/>Authors: Vestfals, Cathleen D.<br/><br/>Abstract: If fisheries managers are to effectively manage commercially exploited fishpopulations, a basic understanding of the factors that influence fish distribution andabundance is required. In 2005, efforts to identify Essential Fish Habitat (EFH) for the82 groundfish species managed by the Pacific Fishery Management Council along theWest Coast resulted in the entire continental margin being designated as EFH. Clearly,our knowledge of EFH needs to be refined, which can be accomplished by gaininginsight into how environmental variables shape the distribution of managed species.Habitat is commonly used to describe a set of environmental variables that arethought to influence occupancy. The aim of this thesis research is to detect andanalyze the quantitative relationships between canary rockfish (Sebastes pinniger)presence/absence data, their spatial distribution, and various biotic and abiotic factors.The presence of canary rockfish at various locations was correlated against co-locatedenvironmental variables including bottom depths, temperatures, locations (latitude andlongitude), seafloor substrate types, canary rockfish hotspots, and thepresence/absence of other groundfish and invertebrate species. The statistical analysiswas conducted using the generalized additive model (GAM), which is a nonparametricregression technique very well suited to model nonlinear speciesenvironmentinteractions. The GAM analysis was conducted using informationcollected from four different data sources. Data collected by the Alaska FisheriesScience Center (AFSC) from 1986 to 2001 provided information at distinct locationsand times on the presence/absence of canary rockfish and other groundfish andinvertebrate species, and associated depths and temperatures. Seafloor lithology mapsfor Oregon and Washington and 100-meter gridded bathymetric data, obtained fromthe Active Tectonics and Seafloor Mapping Lab at Oregon State University, providedinformation on the physical characteristics of the seafloor. These data were used inconjunction with the AFSC bottom trawl survey data to investigate the relationshipsbetween substrate type, slope and rugosity, and the presence of canary rockfish.Finally, locations of canary rockfish hotspots, or areas with high canary rockfish catch,were identified from Oregon commercial trawl logbook data (1995-2001) andprovided information on distinct areas where the trawl fishing fleet had successfullycaught canary rockfish in the past.Canary rockfish presence in trawl survey tows was associated with specificlocations and ranges of bathymetry, temperatures, and substrate types, as well asproximity to canary rockfish hotspots, and particular fish and invertebratecommunities. Survey year had a strong effect on the presence of canary rockfish, asdid location (latitude and longitude) and depth. The geographic location of a surveytow had a negative effect on the presence of canary rockfish in the nearshore region,and a positive effect the further the location was from the coastline, with canaryrockfish presence being highest off the Washington coast between 47.5°N and 48.5°N.While canary rockfish were found at depths between 57 m and 307 m in the survey,the majority of the tows with canary rockfish catch, over 90%, occurred between thedepths of 57 m and 199 m. Though temperature did not have a significant effect oncanary rockfish presence in the GAM, canary rockfish were associated with specifictemperature ranges, only being caught at temperatures between 6.2°C and 9.0°C in thesurvey. Over 89% of the tows with canary rockfish catch occurred between 6.2°C and7.9°C. Since temperature and bottom depth of the trawl survey tows were highlycorrelated, it was difficult to determine which variable was the causative factor indetermining the probability of a canary rockfish being present. Canary rockfishpresence was higher in survey tows made closer to canary rockfish hotspots, as well ashard bottom types. Finally, the presence of lingcod, yellowtail, silvergray, or redstriperockfish in a survey tow increased the likelihood of canary rockfish being present, asdid the presence of basketstars and corals.By studying the relationships between species and their environment, we canbegin to understand the relative importance of how environmental variables shape thedistribution of managed species. For ecosystem-based management strategies to besuccessful, the functional relationships between organisms and their habitat must beunderstood. The predictive model developed in this study can be used to identify areasoff Oregon and Washington where canary rockfish are likely to be found in relation tovarious habitat factors, and can potentially be used to delineate areas that should besampled in future surveys of canary rockfish. Additionally, this research will help toimprove our understanding of the factors that influence canary rockfish distribution,which may produce a more realistic definition of canary rockfish habitat, and improveassessment. This study specifically focuses on canary rockfish, because this speciescurrently constrains many West Coast fisheries for groundfish, however, the methodsoutlined here could be applied more generally to other species of interest.<br/><br/>Description: Graduation date: 2010