SAFS hosts weekly lunch-time seminars where students and faculty share findings from their current research. Read through our past seminars to get an idea of topics covered and be sure to check out our events calendar to download upcoming seminars on your calendar.
Title: Modelling the trade-off between biodiversity and harvest.
Much of the debate in marine conservation centers around the trade-off between long term benefits from the fishery (food, jobs, profit) and the impact on biodiversity. I explore this trade-off using a set of models of different marine ecosystems. Two surprising results have commonly emerged. First there are often solutions where you can have almost maximum catch with little loss in biodiversity. Second; the optimal solutions often do not include any no-take marine protected areas.
Dr. Dan Ovando(Post Doc, UW SAFS)
Title: Of Fish and Fishermen: Using Human Behavior to Improve Marine Resource Management
People around the world depend on the ocean for their livelihoods and cultural identity. Properly done, marine resource management can help communities balance their extractive needs with the importance of maintaining healthy ecosystems. But, limited data and understanding often inhibits our ability to effectively manage our interactions with the sea, threatening both food security and ecological integrity. My research uses simulation modeling and quantitative methods to demonstrate how integrating data and theories of human behavior with ecological information can improve our understanding and management of marine ecosystems. For this talk, I will be giving a brief tour of some of my current research interests. First, I ask whether we can use satellite data on the behavior of fishermen, provided by Global Fishing Watch, to predict the abundance of fish. We show that while a reasonably strong predictive model can be made from the effort data, environmental data is a better predictor, and neither is reliable in new times or locations. My next line of research shows that the region-wide conservation and fishery effects of Marine Protected Areas may be smaller, more variable, and harder to detect than we thought, and demonstrate an empirical approach for estimating these regional MPA effects in the Channel Islands National Marine Sanctuary. Lastly, I present a novel approach for using local historic economic information, together with biological data, to improve the ability of communities to estimate the health of their fishery. We show that integration of bio-economic theory, along with data on costs, prices, and profitability, can in many cases improve the ability of our model to provide accurate estimates of fishing mortality rates.
Dr. Noble Hendrix (Biometrician, QEDA consulting)
Title:Evaluating management effectiveness to reduce ship strikes of whales
Lethal collisions between large ships and whales (ship strikes) can have significant population, management, and public-relation consequences for agencies, shipping companies and species under conservation status. Ship strikes are a type of extreme event (low frequency, high consequence), statistically mirroring other disciplines such as financial systems (e.g., market collapses), hydrology (e.g., floods), and meteorology (e.g., hurricanes) in which rare events are important. While ship strike events themselves are rare, they are known to depend on quantities such as the distance between a whale and ship, which can be measured much more readily. We developed a novel application of extreme event modeling to estimate ship strikes by fitting the generalized Pareto distribution (GPD) to distances of ship-whale encounters in a Bayesian framework. We also quantified strike probabilities per vessel by combining the per-encounter distances with a model for number of encounters per transit. To illustrate the approach and estimate model parameters, we used sighting data from a 2006 – 2012 study that included distance measurements and encounters inside Glacier Bay National Park (GLBA), Alaska, USA and outside GLBA. We then developed a simulation model to evaluate inference on the effectiveness of actions in two management areas. Current methods use carcass detection, therefore we calculated the expected value of collecting and analyzing distance data. We compared inference under combinations of the following dimensions: 1) low strike rates vs high strike rates, 2) whale distribution shifting between management areas versus remaining static and 3) effectiveness of management actions (high, low, none). We found that when strike rates are high, whale distributions are static, and actions are highly effective, carcass collection can provide useful inference; however, under other conditions there is value, in some cases substantial, to collecting the distance data and performing the GPD analysis.
Jane Rogosch (Graduate Student, UW SAFS)
Title: Hydrologic drought favors non-native fishes in a changing climate: a multispecies demographic model approach
Modelling the structure of novel biological assemblages in response to non-stationary environments remains a central challenge in ecology. Demographic approaches to modeling species assemblages show promise because they capture fundamental relationships between population dynamics and environmental conditions. In dryland rivers of the Southwest, expectations of a rapidly changing climate represents a significant threat to fish communities. In this talk, I will present work colleagues and I are doing to develop a coupled multispecies demographic model to project changes for a community of native and invasive fishes in the Verde River, Arizona. By linking populations of commonly occurring fish species together through a community-wide carrying capacity and using recorded flow data from the Verde River, we are simulating community dynamics over the past half century. Model validation against a long-term fish monitoring dataset revealed analogous trends between model projections and observed data. Model projections beyond the observed data predicted a shift from a native dominant to a nonnative dominant assemblage. The trade-off between native and nonnative species dominance emerged from differences in mortality in response to the changing sequence of major flow events, with increased drought frequency and the absence of major flood events. If droughts continue to be as severe and frequent as the past decade, nonnative fishes are likely to continue becoming the most dominant community members in dryland rivers.
Dr. Kate Richerson (Research Fish Biologist, NOAA Fisheries, Northwest Fisheries Science Center)
Title: A half century of high but sustainable exploitation in the Dungeness crab (Cancer magister) fishery
Kate Richerson, André E. Punt, Daniel Holland, Kelly Corbett
The fishery for Dungeness crab (Cancer magister) is one of the largest and most valuable on the US West Coast. Though conventional wisdom holds that the fishery takes the vast majority of legal-sized crab coast-wide each year, this has not been demonstrated empirically. We use catch and effort data and a hierarchical Bayesian depletion estimator to estimate pre-season abundance of the coastal population of Dungeness crab from 1969-2016 (California) or 1982-2016 (Oregon and Washington) and find that the fishery takes ~27%-100% of the available population each year, averaging ~79%. In spite of the high rate of exploitation and large year-to-year fluctuations, the pre-season abundance appears to be stable or increasing in all areas over the period considered. In Central/Southern California, pre-season abundance has shown a particularly rapid increase during the past decade after a long period of low abundance, likely due to changing oceanographic conditions.
Dr. Melissa Haltuch (Research Fish Biologist, NOAA Fisheries, Northwest Fisheries Science Center)
Title: Assessing the effects of climate change on U.S. West Coast sablefish productivity and on the performance of alternative management strategies
Melissa A. Haltuch1*, Teresa A’mar2, Nicholas Bond3, Juan L. Valero4
1 Fisheries Research Analysis and Monitoring, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, USA. *Corresponding Author: Email: Melissa.firstname.lastname@example.org, Phone: 1-206-860-3480, Fax: 1-206-860-6792
2 Fred Hutchinson Cancer Research Center, Seattle, WA, USA
3 University of Washington, JISAO, Seattle, WA, USA
4 CAPAM, La Jolla, CA, USA
US West Coast sablefish are economically valuable, making assessing and understanding the impact of climate change on the California Current (CC) stock a priority for (1) forecasting future stock productivity, and (2) testing the robustness of management strategies to climate impacts. Sablefish recruitment is related to large-scale climate forcing that drives regional alongshore and cross-shelf ocean transport that affects regionally correlated sea level (SL), zooplankton communities that pelagic young-of-the-year sablefish feed upon. This study forecasts trends in future sablefish productivity using SL from Global Climate Models (GCMs) and explores the robustness of harvest control rules (HCRs) to climate driven changes in recruitment using management strategy evaluation (MSE).
LaTreese Denson (Graduate Student, University of Miami RSMAS)
Spatiotemporal variation in indices of abundance used for King Mackerel in the Gulf of Mexico
LaTreese S. Denson*, Elizabeth A. Babcock
Recreationally, in the United States, King mackerel (Somberomorus cavalla) represent the second most commonly landed species in the Scombridae family, by weight. The current assessment of King mackerel in the Gulf of Mexico uses larval data from the Southeast Area Monitoring and Assessment Program (SEAMAP) Fall Plankton Survey. The data is used to derive an index of abundance for spawning stock biomass, however the index currently does not explicitly consider the effect of fine scale spatiotemporal variation on abundance trends and changes in catchability, which are inherent to the data. This can be an issue as King mackerel migrate seasonally and change their distribution based on the quality of their environment causing shifts in their spawning locations from year to year. Shifts of the adult distribution also impact the larval stage as their distribution is dependent on the location of spawning, and the local oceanography. These changes in distribution affect King Mackerel larvae catchability and therefore affect indices of abundance derived from survey data. For this study we quantify spatiotemporal variability using a geostatistical model and compare performance of the estimated index of abundance over time, to the current modeling method.
*Contact author: LaTreese S. Denson, University of Miami Rosenstiel School of Marine, and Atmospheric Sciences, email@example.com
Dr. Andrew Berdahl (Assistant Professor, UW SAFS, UW QERM)
Title: Fishery-induced evolution of schooling behaviour
Schooling is a ubiquitous behaviour in fishes and is thought to have evolved largely as a mechanism to reduce predation risk. In perhaps the simplest example, the probability that an individual in a group is consumed by a predator may be diluted in a large group. In contrast, humans, using modern fishing tactics, can capture an entire school of fish, thus removing this safety-in-numbers. Moreover, in this scenario, larger groups may be more attractive and conspicuous (using radar and aerial spotting). We hypothesize that such modern fishing tactics could alter the selection landscape for social behaviour, specifically selecting against social behaviour that lead to aggregation. Here I will present a model we are developing to make testable predictions about the evolution of social behaviour in the marine Anthropocene. What makes this non-trivial is that we are evolving individual-level traits but selection is operating on group-level traits (in this case group size).
Dr. Trevor Branch (Associate Professor, UW SAFS, UW QERM)
Title: What models can tell us about blue whales
As the largest animals ever to have lived on the earth, blue whales have been both an object of fascination and a primary target of whaling. Many populations were whaled to extremely low levels (notably the Antarctic, down to <0.2% of pre-whaling levels), while others have since nearly fully recovered. In recent years, advances in modeling have allowed the re-examination of old whaling data, some from illegal Soviet voyages, to estimate population trends, subdivide blue whales into subspecies and populations, and estimate survival, birth intervals, and other basic life history parameters with greater accuracy. In this talk I will outline the latest research on blue whales, present models that account for whale stretching and rounding, and highlight the massive impact that humans have had on blue whale populations.
Olivia Sanderfoot* (Graduate Student, UW SEFS)
Title: Canary in the coal mine: Quantifying the impact of exposure to health-damaging air pollutants on avian communities
Abstract: Despite the well-established links between air pollution and human health, less attention has been paid to the potential impact of exposure to reactive gases and aerosols on wildlife, including birds. Birds are more sensitive to inhalation exposure to air pollutants than other animals due to the unique structure of the avian respiratory system. Air pollution has been linked to numerous negative health effects in birds that impair individual fitness, including respiratory distress and illness, increased detoxification effort, elevated stress levels, immunosuppression, and behavioral changes. Exposure to air pollution may also contribute to declines in the reproductive success of birds. These effects may have demographic consequences, including declines in population density or shifts in community composition, though this knowledge gap is vastly underexplored. I will present what we believe is the first-ever model linking air quality measurements and bird observations made by citizen scientists. This work constitutes a key step in determining if detection and/or abundance of wild birds may be impacted by exposure to air pollution. As climate change may increase exposure to air pollution in regions around the world, we believe it is critical that ecologists identify avian responses to air pollution both to inform wildlife management and conservation planning and improve air quality policy.