Authors: Shanks, Alan; Bingham, Julia; Thomas, Michael

Year: 2017

View PDF

In Spain, gooseneck barnacles, “percebes,” are an overfished delicacy fetching a high market price ($50/lb.). Oregon fishing communities show interest in developing a percebes market utilizing Pollicipes polymerus. The incormation compiled in this report aims to inform resource managers to avoid over harvesting Oregon goosenecks.

In summer 2016, researchers investigated the current status of P. polymerus populations with three primary objectives:

A. Describe Oregon gooseneck populations on coastal jetties to inform harvest management.

B. Explore possible mariculture development for onshore gooseneck production.

C. Establish a collaborative multistakeholder framework for sustainable fishery development.

Researchers surveyed eight southern Oregon jetties using transect sampling and photographic documentation of gooseneck populations, which were then characterized by size-frequency distribution and density. Researchers observed spatially explicit trends according to tidal height and large variability in populations between jetties. Only 2% of these are of harvest-size, providing an Oregon percebes stock of up to 235,000 kg. Surveys suggest that wild populations of P. polymerus are unlikely to sustain long-term commercial harvest should the market significantly expand beyond its current size without implementing adaptive management practices. Affordable mariculture should be established to avoid overharvest in a growing market. Researchers designed a promising prototype for a relatively simple, affordable and effective onshore mariculture design to supplement commercial gooseneck production, with the ability to enhance barnacle growth rates using food supplementation.

Throughout the project, researchers maintained frequent communication with multiple stakeholders to focus the objectives and used public seminars to communicate findings and their implications to interested harvesters, managers, and the public. This research expands the knowledge base informing a viable, sustainable fishery. It uniquely joins science, management and fishery expansion in a preemptive approach to combat overfishing and a later need for restorative management while pursuing collaborative and sustainable small-scale fishery development.

Authors: De Wit, P.; Durland, E.; Ventura, A.; Langdon, C.J

Year: 2018

View PDF

Despite recent work to characterize gene expression changes associated with larval development in oysters, the mechanism by which the larval shell is first formed is still largely unknown. In Crassostrea gigas, this shell forms within the first 24 h post fertilization, and it has been demonstrated that changes in water chemistry can cause delays in shell formation, shell deformations and higher mortality rates. In this study, researchers use the delay in shell formation associated with exposure to CO2-acidified seawater to identify genes correlated with initial shell deposition.

By fitting linear models to gene expression data in ambient and low aragonite saturation treatments, we are able to isolate 37 annotated genes correlated with initial larval shell formation, which can be categorized into 1) ion transporters, 2) shell matrix proteins and 3) protease inhibitors. Clustering of the gene expression data into co-expression networks further supports the result of the linear models, and also implies an important role of dynein motor proteins as transporters of cellular components during the initial shell formation process.

Using an RNA-Seq approach with high temporal resolution allows us to identify a conceptual model for how oyster larval calcification is initiated. This work provides a foundation for further studies on how genetic variation in these identified genes could affect fitness of oyster populations subjected to future environmental changes, such as ocean acidification.

Lead PI: Matt Hawkyard (Chris Langdon Co-PI)

College/Dept:  OSU College of Agriculture, Fisheries and Wildlife

Funded by: USDA Western Regional Aquaculture Center (WRAC)

Authors: Dane H. Klinger, Simon A. Levin and James R. Watson

Year: 2017

PDF icon klinger_global.pdf (917.34 KB)

Aquaculture production is projected to expand from land-based operations to the open ocean as demand for seafood grows and competition increases for inputs to land-based aquaculture, such as freshwater and suitable land. In contrast to land-based production, open-ocean aquaculture is constrained by oceanographic factors, such as current speeds and seawater temperature, which are dynamic in time and space, and cannot easily be controlled. As such, the potential for offshore aquaculture to increase seafood production is tied to the physical state of the oceans. We employ a novel spatial model to estimate the potential of open-ocean finfish aquaculture globally, given physical, biological and technological constraints. Finfish growth potential for three common aquaculture species representing different ther- mal guilds—Atlantic salmon (Salmo salar), gilthead seabream (Sparus aurata) and cobia (Rachycentron canadum)—is compared across species and regions and with climate change, based on outputs of a high-resolution global cli- mate model. Globally, there are ample areas that are physically suitable for fish growth and potential expansion of the nascent aquaculture industry. The effects of climate change are heterogeneous across species and regions, but areas with existing aquaculture industries are likely to see increases in growth rates. In areas where climate change results in reduced growth rates, adaptation measures, such as selective breeding, can probably offset potential production losses.

Authors: James R. Watson, Fredrik Armerin, Dane H. Klinger, Ben Belton

Year: 2018

PDF icon watson_risk.pdf (1.58 MB)

Aquaculture is a booming industry. It currently supplies almost half of all fish and shellfish eaten today, and it continues to grow faster than any other food production sector. But it is immature relative to terrestrial crop and livestock sectors, and as a consequence it lags behind in terms of the use of aquaculture specific financial risk management tools. In particular, the use of insurance instruments to manage weather related losses is little used. In the aquaculture industry there is a need for new insurance products that achieve both financial gains, in terms of reduced production and revenue risk, and environmental wins, in terms of incentivizing improved management practices. Here, we have developed a cooperative form of indemnity insurance for application to small-holder aquaculture communities in developing nations. We use and advance the theory of risk pools, applying it to an aquaculture community in Myanmar, using empirical data recently collected from a comprehensive farm survey. These data were used to parameterize numerical simulations of this aquaculture system with and without a risk pool. Results highlight the benefits and costs of a risk pool, for various combinations of key parameters. This information reveals a path forward for creating new risk management products for aquaculturalists around the world.

Authors: Ramanan, Sundar; Rorrer, Gregory L.

Year: 2020


Abstract: This study compared the growth of Laminaria saccharina female gametophyte filamentous cell suspension cultures in a stirred-tank photobioreactor under batch and fed-batch nutrient addition modes over a 48-day cultivation period. Cultures were grown on GP2 artificial seawater medium (0.75 mM nitrate, N:P = 16:1) at pH 8.3 without iron or copper. Total equivalent nutrient loadings ranged from 0.5X to 9.1X GP2 for batch cultivation and 1.3X to 10.4X GP2 for fed-batch cultivation at delivery rates of 0.0067–0.16 mmol N L−1 day−1 based on nitrate. The multicellular, L. saccharina filamentous clumps were dispersed to nominal size of 100 μm by mechanical blending (~ 16,000 rpm, 5 s) prior to inoculation. Fed-batch addition of all nutrients enhanced biomass productivity by a factor of two over a batch cultivation process at equivalent total nutrient loadings in a stirred-tank photobioreactor. Peak productivity through fed-batch cultivation was 57 mg DCW L−1 day−1, and average final biomass densities exceeded 1800 mg DCW L−1, vs. 30 mg DCW L−1 day−1 and 800–900 mg DCW L−1 for batch cultivation. However, there was a limit to biomass productivity enhancement at cumulative nutrient loadings greater than 3X GP2 that was not the result of insufficient CO2 or light delivery. It is suggested that the formation of large, multicellular clumps approaching 1-mm diameter during stirred-tank cultivation may have ultimately reduced biomass productivity during fed-batch cultivation under nutrient-replete conditions. Therefore, future bioreactor processing strategies might consider mechanical blending to disperse the filament clumps during the cultivation process.

Authors: Durland, Evan; Waldbusser, George; Langdon, Chris

Year: 2019

Email Interlibrary Loan Request

Abstract: Ocean acidification (OA) has had significant negative effects on oyster populations on the west coast of North America over the past decade. Many studies have focused on the physiological challenges experienced by young oyster larvae in high pCO2/low pH seawater with reduced aragonite saturation state (Ωarag), which is characteristic of OA. Relatively few, by contrast, have evaluated these impacts upon fitness traits across multiple larval stages and between discrete oyster populations.

In this study, researchers conducted two replicated experiments, in 2015 and 2016, using larvae from naturalized ‘wild’ and selectively bred stocks of the Pacific oyster Crasso - strea gigas from the U.S. Pacific Northwest and reared them in ambient (~400 μatm) or high (~1600 μatm) pCO2 seawater from fertilization through final metamorphosis to juvenile ‘spat.’ In each year, high pCO2 seawater inhibited early larval development and affected the timing, but not the magnitude, of mortality during this stage. The effects of acidified seawater on metamorphosis of pediveligers to spat were variable between years, with no effect of seawater pCO2 in the first experiment but a ~42% reduction in spat in the second. Despite this variability, larvae from selectively bred oysters produced, on average, more (+ 55 and 37%) and larger (+ 5 and 23%) spat in ambient and high pCO2 seawater, respectively. These findings highlight the variable and stage-specific sensitivity of larval oysters to acidified seawater and the influence that genetic factors have in determining the larval performance of C. gigas exposed to high pCO2 seawater.