A5078982255- Marine and fisheries research
- Fish Ecology and Management Studies
- Marine Bivalve and Aquaculture Studies
- Marine animal studies overview
- Arctic and Antarctic ice dynamics
- Coral and Marine Ecosystems Studies
- Isotope Analysis in Ecology
- Bayesian Modeling and Causal Inference
- Marine and coastal plant biology
- Fish Biology and Ecology Studies
- Maritime Navigation and Safety
- Statistical Methods and Bayesian Inference
- Environmental Impact and Sustainability
- Bayesian Methods and Mixture Models
- Species Distribution and Climate Change
- Markov Chains and Monte Carlo Methods
- Scientific Research and Discoveries
- Recycling and Waste Management Techniques
- Ichthyology and Marine Biology
- 3D Modeling in Geospatial Applications
- Avian ecology and behavior
- Underwater Acoustics Research
- Insurance, Mortality, Demography, Risk Management
- Microplastics and Plastic Pollution
- Underwater Vehicles and Communication Systems
National Oceanic and Atmospheric Administration
2020-2025
NOAA National Marine Fisheries Service Alaska Fisheries Science Center
2020-2025
NOAA National Marine Fisheries Service
2021-2024
University of Washington
2014-2021
University of Concepción
2018-2019
A mess of plastic It is not clear what strategies will be most effective in mitigating harm from the global problem pollution. Borrelle et al. and Lau discuss possible solutions their impacts. Both groups found that substantial reductions plastic-waste generation can made coming decades with immediate, concerted, vigorous action, but even best case scenario, huge quantities still accumulate environment. Science , this issue p. 1515 1455
Summary Bayesian inference is a powerful tool to better understand ecological processes across varied subfields in ecology, and often implemented generic flexible software packages such as the widely used BUGS family (BUGS, WinBUGS, OpenBUGS JAGS). However, some models have prohibitively long run times when BUGS. A relatively new platform called Stan uses Hamiltonian Monte Carlo (HMC), of Markov chain (MCMC) algorithms which promise improved efficiency faster relative those by gaining...
Abstract Retrospective patterns are systematic changes in estimates of population size, or other assessment model-derived quantities, that occur as additional years data added to, removed from, a stock assessment. These an insidious problem, and can lead to severe errors when providing management advice. Here, we use simulation framework show temporal selectivity, natural mortality, growth induce retrospective integrated, age-structured models. We explore the potential effects on catch...
Abstract A typical assumption used in most fishery stock assessments is that natural mortality (M) constant across time and age. However, M rarely reality as a result of the combined impacts exploitation history, predation, environmental factors, physiological trade-offs. Misspecification or poor estimation can lead to bias quantities estimated using assessment methods, potentially resulting biased estimates reference points catch limits, with magnitude being influenced by life history...
Abstract Blue whales were targeted in the North Pacific from 1905–1971 and are listed as endangered by IUCN . Despite decades without whaling, abundance estimates for eastern ( ENP ) blue Balaenoptera musculus suggest little evidence a recent increase. One possible reason is fatal strikes large ships, which have affected populations of other cetaceans resulted mitigation. We used population dynamics model to assess trends status whales, effects ship strikes. estimate likely never dropped...
Statistical inference is a widely-used, powerful tool for learning about natural processes in diverse fields. The statistical software platforms AD Model Builder (ADMB) and Template (TMB) are particularly popular the ecological literature, where they typically used to perform frequentist of complex models. However, both lack capabilities flexible efficient Markov chain Monte Carlo (MCMC) integration. Recently, no-U-turn sampler (NUTS) MCMC algorithm has gained popularity Bayesian through...
Abstract Management of marine resources depends on the assessment stock status in relation to established reference points. However, many factors contribute uncertainty outcomes, including data type and availability, life history, exploitation history. A simulation–estimation framework was used examine level bias accuracy model estimates related quality quantity length age composition across three life-history types (cod-, flatfish-, sardine-like species) fishing scenarios. All models were...
Abstract Implementation of the United Nations Sustainable Development Goals requires assessments global state fish populations. While we have reliable estimates stock status for populations accounting approximately half recent catch, our knowledge majority world's “unassessed” stocks remains highly uncertain. Numerous publications produced these unassessed fisheries, but limited quantity and quality data along with methodological differences counterintuitive conflicting results. Here, show...
Abstract Climate-driven changes in the timing of spawning or migration can affect availability fish to surveys designed monitor their abundance, complicating efforts assess stock status and sustainably manage fisheries. From 2017 2019, trends biomass estimates from four used Gulf Alaska pollock diverged. These conflicting increased uncertainty assessment occurred during a time rapid environmental change. We hypothesized that spawn affected winter survey targets pre-spawning aggregations. To...
Ecologists often use time-series models to approximate dynamics arising from density dependence, species interactions, community synchrony, and other processes. Dynamic structural equation can represent simultaneous lagged interactions among variables with missing data, therefore encompasses a wide family of analyses (linear regression, vector autoregressive models, dynamic factor analysis). However, their interpretation as causal (i.e., counterfactual analysis) requires validating that the...
ABSTRACT In the Southern Hemisphere and northern Indian Ocean, there are at least five populations of pygmy blue whales, Balaenoptera musculus brevicauda , residing in Northwest Ocean (NWIO, Oman), central (CIO, Sri Lanka), Southwest (SWIO, Madagascar to Subantarctic), Southeast (SEIO, Australia Indonesia), Pacific (SWPO, New Zealand). Each population produces a distinctive repeated song, but none have assessments or reliable measures historical whaling pressure. Here we created whale catch...
Simulation testing is an important approach to evaluating fishery stock assessment methods. In the last decade, fisheries modeling framework Stock Synthesis (SS3) has become widely used around world. However, there lacks a generalized and scriptable for SS3 simulation testing. Here, we introduce ss3sim, R package that facilitates reproducible, flexible, rapid end-to-end with SS3. ss3sim requires existing model configuration along plain-text control files describing alternative population...
Abstract In 2020, the developing COVID-19 pandemic disrupted fisheries surveys to an unprecedented extent. Many were cancelled, including those for walleye pollock (Gadus chalcogrammus) in eastern Bering Sea (EBS), largest fishery United States. To partially mitigate loss of survey information, we deployed three uncrewed surface vehicles (USVs) equipped with echosounders extend ship-based acoustic-trawl time series abundance. Trawling was not possible from USVs, so empirical relationship...
Blue whales (Balaenoptera musculus) were exploited extensively around the world and remain endangered. In North Pacific their population structure is unclear current status unknown, with exception of a well-studied eastern (ENP) population. Despite existing abundance estimates for ENP population, it difficult to estimate pre-exploitation levels gauge recovery because historical catches are separate from other populations in Pacific. We collated previously unreported Soviet combined these...
Abstract Abundance indices from scientific surveys are key stock assessment inputs, but when the availability of fish varies in space and time, estimated associated uncertainties do not accurately reflect changes population abundance. For example, for many semi-pelagic species rely on acoustic bottom trawl gear that differ water column coverage, so spatiotemporal trends vertical distribution affect to each type. The gears together cover whole column, principle allow estimation more accurate,...
Abstract Bayesian inference is an appealing alternative to maximum likelihood estimation, but estimation can be prohibitively long for integrated fisheries stock assessments. Here, we investigated potential causes of run times including high dimensionality, complex model structure, and inefficient algorithms four US assessments written in AD Model Builder (ADMB), both custom built Stock Synthesis models. The biggest culprit was overparameterization they were reduced from months days by...
Catch per unit effort (CPUE) is a widely used index of population abundance for informing stock assessments the purpose estimating status and setting fishing policies. However, CPUE to be an unbiased index, influences that are not related (e.g., spatial variation in temporal changes gear efficiency) must accounted analyses known as standardization. In longline fisheries, one important factor can affect spacing between hooks ('spacing effect'), which effective has largely been ignored...
Abstract In 2003 a feeding aggregation of southeastern Pacific humpback whales ( Megaptera novaeangliae ) was reported in the Magellan Strait. While Chile established its first marine national park Strait to protect whale habitat, fatal ship strikes remain concern because overlap with busy shipping lane. To better understand population risk, we estimated abundance and survival for this using Bayesian robust‐design mark‐recapture models fit photographic data from 2004 2016. Overall, model...