Franz J. Mueter results 27
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Phytoplankton communities change in response to environmental conditions, potentially impacting zooplankton through altered trophic interactions. In the Bering Sea, warm and cold stanzas in recent decades correlated with changes in community structure of zooplankton and fish. Attempts to link these trends to primary producers based on patterns in total chlorophyll a (Chl a ) concentration have been unsuccessful. Using Chl a as...
Atmospheric Pressure Rivalry Between the Arctic and Northern Pacific: Implications for Alaskan Climate VariabilityNARA Subscribed
Located at the confluence of the Arctic and North Pacific and with Alaska at its heart, the Pacific Arctic Region (PAR) is a unique and interconnected regional climate system. Significant climatic changes in the PAR are described by a novel, mobile monthly Alaska Arctic Front (AAF) index, which is defined by sea level pressure differences between the migratory cores of the Beaufort High and Aleutian Low. Regional climate varia...
Male sperm whales ( Physeter macrocephalus ) are known to interact with and depredate from commercial longline fishing vessels targeting sablefish ( Anoplopoma fimbria ) in the Gulf of Alaska (GOA). This study aims to better understand their movement patterns and diving behavior in this region, and in relation to depredation behavior. Between 2007 and 2016 a total of 33 satellite tags were deployed on sperm whales interacting...
Environmental Drivers of Nearshore Fish Community Composition and Size Structure in Glacially Influenced Gulf of Alaska EstuariesNARA Subscribed
Coastal ecosystems in Alaska are undergoing rapid change due to warming and glacier recession. We used a natural gradient of glacierized to non-glacierized watersheds (0–60% glacier coverage) in two regions along the Gulf of Alaska—Kachemak Bay and Lynn Canal—to evaluate relationships between local environmental conditions and estuarine fish communities. Multivariate analyses of fish community data collected from five sites pe...
Community assembly theory states that species assemble non-randomly as a result of dispersal limitation, biotic interactions, and environmental filtering. Strong environmental filtering likely leads to local assemblages that are similar in their functional trait composition (high trait convergence) while functional trait composition will be less similar (high trait divergence) under weaker environmental filters. We used two Ar...
The subarctic shelf of the Eastern Bering Sea (EBS) is one of the world's most productive marine environments, exposed to drastic climate changes characterized by extreme fluctuations in temperature, sea ice concentration, timing, and duration. These climatic changes elicit profound responses in species distribution, abundance, and community composition. Here, we examined the patterns of alpha and temporal beta diversity of 15...
Successful management and mitigation of marine challenges depends on cooperation and knowledge sharing which often occurs across culturally diverse geographic regions. Global ocean science collaboration is therefore essential for developing global solutions. Building effective global research networks that can enable collaboration also need to ensure inter- and transdisciplinary research approaches to tackle complex marine soc...
Social behavior increases in multipod aggregations of southern Alaska resident killer whales ( Orcinus orca )NARA Subscribed
Killer whales ( Orcinus orca ) are highly social and occasionally gather in large aggregations that reach 150 individuals. During 338 encounters with Southern Alaska resident killer whales, we collected 1,352 hr of behavioral data to assess the probability of various behaviors based on season, number of pods present, presence of rarely sighted pods, and number of mitochondrial DNA haplotypes present. A binomial generalized lin...
Multispecies biomass dynamics models reveal effects of ocean temperature on predation of juvenile pollock in the eastern Bering SeaNARA Subscribed
Walleye pollock ( Gadus chalcogrammus ) supports one of the largest commercial fisheries in the world. Juvenile pollock are important forage fish in the eastern Bering Sea (EBS) ecosystem, often representing the largest fraction in the diets of major Bering Sea piscivores. Large variability in the EBS pollock stock biomass in recent years has been attributed primarily to fluctuations in recruitment. It has been hypothesized th...
Effects of the North Pacific Current on the productivity of 163 Pacific salmon stocksNARA Subscribed
Horizontal ocean transport can influence the dynamics of higher‐trophic‐level species in coastal ecosystems by altering either physical oceanographic conditions or the advection of food resources into coastal areas. In this study, we investigated whether variability in two North Pacific Current (NPC) indices was associated with changes in productivity of North American Pacific salmon stocks. Specifically, we used Bayesian hier...
Ecosystem‐based fisheries management requires the development of physical and biological time series that index ocean productivity for stock assessment and recruitment forecasts for commercially important species. As recruitment in marine fish is related to ocean condition, we developed proxies for ocean conditions based on sea surface temperature ( SST ) and biometric measurements of chum salmon ( Oncorhynchus keta ) captured...
In areas of the North Pacific that are largely free of overfishing, climate regime shifts – abrupt changes in modes of low‐frequency climate variability – are seen as the dominant drivers of decadal‐scale ecological variability. We assessed the ability of leading modes of climate variability [Pacific Decadal Oscillation ( PDO ), North Pacific Gyre Oscillation ( NPGO ), Arctic Oscillation ( AO ), Pacific‐North American Pattern...