A5024614172- Fish Ecology and Management Studies
- Marine and fisheries research
- Marine animal studies overview
- Underwater Acoustics Research
- Aquatic Invertebrate Ecology and Behavior
- Fish Biology and Ecology Studies
- Avian ecology and behavior
- Animal Vocal Communication and Behavior
- Genetic diversity and population structure
- Marine Bivalve and Aquaculture Studies
- Environmental DNA in Biodiversity Studies
- Identification and Quantification in Food
- Underwater Vehicles and Communication Systems
- Wildlife Ecology and Conservation
- Ichthyology and Marine Biology
- Isotope Analysis in Ecology
- Fish biology, ecology, and behavior
- Ocean Acidification Effects and Responses
- Marine and coastal plant biology
- Arctic and Antarctic ice dynamics
- Reproductive biology and impacts on aquatic species
- Bat Biology and Ecology Studies
- Crustacean biology and ecology
- Genetic and phenotypic traits in livestock
- Hydrology and Sediment Transport Processes
NOAA National Marine Fisheries Service
2011-2023
National Oceanic and Atmospheric Administration
2008-2023
NOAA National Marine Fisheries Service Northeast Fisheries Science Center
2016-2023
NOAA National Marine Fisheries Service Southwest Fisheries Science Center
2007-2019
University of California, Santa Cruz
1997-2016
NOAA National Marine Fisheries Service Northwest Fisheries Science Center
2015
Simon Fraser University
2015
University of California, Berkeley
2015
To investigate the role that estuaries play in survival of steelhead, Oncorhynchus mykiss , we compared juvenile size at ocean entry with back-calculated measures for returning adults Scott Creek, a representative California coastal stream. During annual spring emigration, largest smolts (>150 mm fork length (FL)) move directly to sea, while some smaller remain estuary until sandbar formation creates closed freshwater lagoon. High growth rates throughout summer result near doubling from...
Adaptation to novel habitats and phenotypic plasticity can be counteracting forces in evolution, but both are key characteristics of the life history steelhead/rainbow trout (Oncorhynchus mykiss). Anadromous steelhead reproduce freshwater river systems small coastal streams grow mature ocean. Resident rainbow trout, either sympatric with or isolated above barrier dams waterfalls, represent an alternative life-history form that lives entirely freshwater. We analyzed population genetic data...
Abstract We monitored growth and life history pathways of juvenile steelhead Oncorhynchus mykiss compared rates between the upper watershed estuary in Scott Creek, a typical California coastal stream. Growth was approximately linear from May to December for age‐0 fish. For passive integrated transponder (PIT) tagged, age‐1+ fish, transitioned cyclic pattern, peaking at 0.2% per day during February‐April, when maximum flows temperatures 7‐12°C occurred. PIT‐tagged fish then slowed...
Expression of phenotypic plasticity depends on reaction norms adapted to historic selective regimes; anthropogenic changes in these selection regimes necessitate contemporary evolution or declines productivity and possibly extinction. Adaptation conditional strategies following a change the regime requires either environmentally influenced cue (e.g., size-at-age) state size threshold) at which an individual switches between alternative tactics. Using population steelhead (Oncorhynchus...
Abstract Anthropogenic stressors are the leading causes of species and biodiversity declines, driving wide‐scale ecosystem changes. Additionally, synergistic effects multiple anthropogenic modifications, including introductions habitat alterations, can have complex outcomes for native species. We assessed how a nonnative predator (the Striped Bass Morone saxatilis ) alterations (a small diversion dam other altered habitats) interacted to influence mortality juvenile Chinook Salmon...
Abstract We analyzed scales from returning Willamette River yearling Chinook salmon Oncorhynchus tshawytscha to explore the effects of size at release on subsequent adult returns. tested hypothesis that survival adulthood is independent ocean entry for salmon. Significant size‐selective mortality, indicated by a larger among surviving adults than all released juveniles, was observed in 2002–2004 but not those 2005. Juvenile entered less 150 mm fork length were underrepresented populations....
Generalist predators can contribute to extinction risk of imperiled prey populations even through incidental predation. Quantifying predation on small is important manage their recovery, however often challenging observe directly. Recovery tags at predator colonies indirectly provide minimum estimates predation, overall rates remain unquantifiable because an unknown proportion are deposited off‐colony. Here, we estimated threatened wild juvenile steelhead ( Oncorhynchus mykiss ) by...
We examined the role of individual size and origin (wild versus hatchery) to predation risk marine survival for threatened juvenile steelhead (Oncorhynchus mykiss) in a coastal California watershed. In this study, we found that were strongly associated with increased by generalist avian predator (western gull, Larus occidentalis) reproduction tracking fate tagged passive integrated transponder (PIT) tags. Across six cohorts (2005–2010), larger (>170 mm fork length (FL)) experienced rates...
Changes in the diving behavior of individual free-ranging juvenile northern elephant seals, Mirounga angustirostris, exposed to acoustic thermometry ocean climate (ATOC) sound source were examined using data loggers. Data loggers attached animals and measured swim speed, maximum depth dive, dive duration, surface interval, descent ascent rate, angle along with pressure level (SPL). The ATOC was at a 939 m transmitted 195 dB re: 1 μPa centered 75 Hz 37.5-Hz bandwidth. Sound levels (SPL) seal...
We investigated emigration behavior, habitat use, and Na + ,K -ATPase activity levels of juvenile steelhead trout (sea-run rainbow trout; Oncorhynchus mykiss ) in Scott Creek, a small coastal watershed with seasonally closed estuary central California, USA. Migratory fish moved downstream the spring elevated levels. Larger (>150 mm) during February March, leaving stream, whereas moving between April June were typically smaller tended to recruit estuary. The estuarine varied summer as...
Migratory salmon move nutrients both in and out of fresh waters during the different parts their life cycle. We used a mass-balance approach to quantify recent changes phosphorus (P) fluxes six coastal California, USA, watersheds that have recently experienced dramatic decreases populations. As adults, semelparous Chinook ( Oncorhynchus tshawytscha ) coho kisutch imported 8.3 10.4 times more P from ocean, respectively, than they exported as smolts, while iteroparous steelhead (i.e., sea-run...
Abstract We investigated the interaction among genetically identified origin, behavioral tendency to emigrate, and Na + , K ‐ATPase enzyme activity in recently diverged subpopulations of resident (above‐barrier) rainbow trout Oncorhynchus mykiss steelhead (anadromous trout) Scott Creek, California. Genetic assignment tests found that frequency anadromous origin fish varied by sampling location within watershed. Individuals immediately below barriers assigned both above‐barrier (37%) (63%)...
Abstract Anadromous salmonids vary considerably in their age at ocean entry, timing of entry within a year, and the extent to which they use multiple habitat types freshwater. To better understand movement timing, we developed broadly applicable model state‐dependent movements among habitats, was parameterized based on case study steelhead Oncorhynchus mykiss California coastal watershed with seasonally closed lagoonal estuary. The correctly predicted population‐level patterns, including...
The frequency and magnitude of wildfires in North America have increased by four‐fold over the last two decades. However, impacts on thermal environments freshwaters, potential effects coldwater fishes are incompletely understood. We examined short‐term a wildfire temperatures Steelhead/Rainbow Trout ( Oncorhynchus mykiss ) bioenergetics distribution California coastal stream. One year after wildfire, mean daily stream were elevated up to 0.6°C burned compared unburned pools. Among pools,...
Abstract The Patagonian Shelf Large Marine Ecosystem supports high levels of biodiversity and endemism is one the most productive marine ecosystems in world. Despite important role predators play structuring ecosystems, areas diversity where multiple congregate remains poorly known on Shelf. Here, we used biotelemetry biologging tags to track movements six seabird species three pinniped breeding at Falkland Islands. Using Generalized Additive Models, then modelled these animals’ use space as...
Abstract We present a new, low‐cost, low‐power, half/full‐duplex passive integrated transponder (PIT) tag interrogation antenna for use in detecting fish movements small streams. New technology by Allflex‐USA allowed us to develop reading system with an 279.4 cm wide × 60.9 high that reads both common types used fisheries today about US$1,000. An instream of this size and price makes high‐resolution tracking movement streams feasible where cost tag‐type restrictions were prohibitive. For...
Abstract There is currently only a limited understanding of the relationship between water quality and predation on Pacific salmon Oncorhynchus spp. smolts. We addressed hypothesis that poor will decrease smolt's swimming performance presumably its predator evasion capabilities. Predation major factor affecting smolt survival throughout San Joaquin River Sacramento–San Delta California. Prior studies have quantified rates, but effect capability has not previously been evaluated. juvenile...
The Sacramento-San Joaquin Delta is a major survival bottleneck for imperiled California salmonid populations, which partially due to multitude of non-native fish predators that have proliferated there throughout the 20th century. Understanding diets critical understanding their individual impacts, role in food web, and implications potential management actions. We collected stomach contents Striped Bass Morone saxatilis, Largemouth Micropterus salmoides, Channel Catfish Ictalurus punctatus...
Comparative analyses of the roar vocalization male harbor seals from ten sites throughout their distribution showed that vocal variation occurs at oceanic, regional, population, and subpopulation level. Genetic barriers based on physical distance between seal populations present a likely explanation for some observed variation. However, site-specific variations were genetically mixed subpopulations in California. A tree-based classification analysis grouped Scottish together with eastern...
A bstract Compared to the harem and resource defense systems of terrestrial mating pinnipeds, males aquatic species appear unable monopolize females or resources. We investigated movements, acoustics, territorial behavior male harbor seals, Phoca vitulina richardii , in Elkhorn Slough, California, using VHF telemetry, hydrophones, acoustic playback experiments. During season 22 increased time spent water away from haul‐out locations, exhibiting activity patterns similar Atlantic subspecies....
Abstract The population of anadromous steelhead Oncorhynchus mykiss in the Keogh River has been studied intensively, part because its pattern declining recruitment, which is largely attributed to poor marine survival. Climate variability changed productivity salmonid species all regions North Pacific, with areas alternately shifting between periods enhanced and depressed productivity. mechanisms governing survival adult recruitment are central contemporary resource management concerns but...
Abstract Estimating the escapement of small populations steelhead Oncorhynchus mykiss (ocean‐migrating rainbow trout) is challenging and requires innovative methods. Difficulties arise from rare episodic occurrence individuals, high turbidity levels during migration, need to minimize jeopardy fish, which have led a lack population estimates, especially in California. Here we show that dual‐frequency identification sonar (DIDSON) can be used produce estimates for Scott Creek, Santa Cruz...