Tag: Craig Young

Differences in the Morphology and Reproduction of Boltenia villosa Across a Latitudinal Gradient

Presenter: Carmen Sanchez-Reddick – Marine Biology

Faculty Mentor(s): Craig Young, Caitlin Plowman

Session: (Virtual) Poster Presentation

While the larval and early juvenile stages of Boltenia villosa are well documented in the literature, little is known about the adults. Early documentation of B. villosa describes a relationship between the body size and the stalk length as individuals with smaller bodies tend to have longer stalks and individuals with larger bodies tend to possess very short stalks. Anecdotal evidence suggests that larger individuals with short stalks make up the populations found in Washington, while Oregon populations consist of smaller individuals with longer stalks. The present study aimed to develop a qualitative understanding of the changes across the latitudinal gradient of Boltenia villosa. This was achieved by using a combination of morphometrics to determine any significant differences between different populations and histology to compare reproductive output. Preliminary results suggest a significant morphological difference between the two populations in body proportions and spine character despite their genetic similarities. Our understanding of the reproductive differences are continuing to be developed. These results indicate the possible existence of a subspecies of Boltenia villosa due to the distinct populations, but more research into each morphotype’s range is needed. This research also provides a broader understanding of how different marine environments can curate specific characteristics to appear in their inhabitants’ populations.

Invertebrate Species Richness on Deep Cobble and Gravel Bottoms off Cape Arago, Oregon

Presenter: Nick Hayman

Mentor: Craig Young

PM Poster Presentation

Poster 14

Although conservation of marine diversity is a major goal of an ongoing process to establish marine reserves in the Oregon Territorial Sea, virtually all subtidal studies off Oregon have considered only fishes and the largest invertebrates. Using dredge samples, we assembled comprehensive species lists of sessile and motile invertebrates on cobble and gravel substrata between 50 and 70m depths off Cape Arago, Oregon. The species richness on cobble substratum (112 species) was much higher than species richness on gravel sub- stratum (31 species). Species accumulation curves suggest that we found most of the species on the cobble substratum but that more samples would be required to fully assess the cobble community. Sessile invertebrates were more common than mobile invertebrates. The data also showed significant patchiness, as indicated by between-sample differences. This study shows that sea-floor mapping that does not resolve substratum particle size cannot be used to predict richness of the rocky-bottom community.

The Ecology and Distribution of the Invasive Violet Tunicate (Botrylloides violaceus) in the Coos Estuary (OR)

Presenter: Sandra Dorning

Faculty Mentor: Craig Young

Presentation Type: Poster 58

Primary Research Area: Science

Major: Marine Biology

Funding Source: Undergraduate Research Opportunity Program Mini-Grant, University of Oregon Undergraduate Research Opportunity Program, $1000

Marine fouling communities on docks and other manmade structures are frequently susceptible to invasions of non-native ascidians—sessile, sac-like marine invertebrates. Botrylloides violaceus, the violet tunicate, has invaded such communities in harbors around the world, including Oregon’s Coos Estuary. In this study, I aim to explain the mechanisms behind the invasion and establishment of B. violaceus in this bay. I propose three potential factors influencing the distribution of this species in the Coos Estuary: 1) abiotic conditions (water temperature, salinity, and water current speed), 2) biotic conditions (competitive relationships with other fouling organisms), and 3)
limited transportation between fouling sites. I conducted quarterly photo quadrat surveys to determine the seasonal distribution of B. violaceus, in addition to short-term permanent quadrat and settlement plate monitoring to document B. violaceus growth patterns and interactions with other fouling species. In addition, I conducted laboratory experiments to determine the temperature and salinity tolerance of B. violaceus. Future experiments in this study will include transplantation of B. violaceus colonies for evaluating survival at currently uninvaded sites. The results of this project will document the extent of and mechanisms behind the Coos Estuary B. violaceus invasion. Understanding the interactions between B. violaceus and native fouling organisms and the potential for this species to expand its distribution is important for conserving native biodiversity and improving invasive species management in the Coos Estuary.

Plastic debris in deep-sea canyon, estuarine, and shoreline sediments.

Presenter(s): Ellie Jones

Faculty Mentor(s): Craig Young & Alan Shanks

Poster 55

Session: Sciences

Recent calculations estimate there are currently 5.25 trillion plastic particles afloat in the world’s oceans. Many of these plastics are characterized as microplastics < 5 mm in diameter. Studies within the past few decades show that no ecosystem is exempt from plastic contamination. This study examined sediment samples from Norfolk Canyon off the coast of Virginia, the Coos Bay Estuary in Oregon, and headlands along the Oregon shoreline to characterize the abundance of microplastics within various marine sediments. Box core sediment samples were taken from within Norfolk Canyon and from the adjacent continental slope. Plastics were removed by density differentiation using a saturated salt solution. Nineteen pieces of plastic were found from the nine samples within the canyon, while only eight pieces were found from the seven samples on the continental slope. This suggests that canyons can be accumulation zones for microplastics due to strong down-canyon currents. Next, box core and Poner grab sediment samples were taken from within the Coos Bay Estuary and the adjacent continental shelf. Plastics were removed by density differentiation, and the majority of plastics were found within the mouth of the bay. This suggests that plastics can become concentrated in areas where fronts are created between two bodies of water (in this case, the ocean and the estuary.) To analyze shoreline sediment, belt transects were taken during January and February on the northern and southern sides of Yaquina Bay Head, Cape Perpetua, and Cape Blanco. The majority of plastics were found on the southern side of each headland. This suggests that microplastics are carried onshore by winds, which are blowing onto southern-facing beaches on Oregon’s coast during the winter. Knowing where plastics settle in the ocean can influence mitigation and management decisions. Therefore, it is important to determine possible places for microplastic accumulation to manage and conserve natural resources.