In 2022 the presence of the Japanese sardine, Sardinops melanosticta (Temminck and Schlegel), was detected in the eastern Pacific Ocean, far outside its known western North Pacific range. The species was collected along with the Pacific sardine, Sardinops sagax (Jenyns), which is native to the eastern Pacific Ocean. Here, we report the first direct evidence for spawning by S. melanosticta in the eastern Pacific Ocean.

Effects of climate change on ocean ecosystem dynamics are widespread. Oceanographic conditions vital to biological communities have already shown changes, resulting in negative impacts on several of the world’s largest fisheries. The Northern California Current (NCC) is a highly productive system that supports many important fisheries. In addition to large-scale oceanographic forcing and seasonal up- and downwelling cycles, in...

Changing ocean conditions are leading to spatial redistribution of many marine species, including those that support fisheries. A combination of gradual climate trends and shorter‐lived extreme events, such as marine heatwaves, can change the availability of species or stocks to fishing ports, impacting fishing communities and challenging fisheries management frameworks. Pacific sardine ( Sardinops sagax ) in the California Cu...

Changing environmental conditions are leading to shifts in the timing of seasonal events globally. In the ocean, environmental cues affecting larval fish (ichthyoplankton) abundance may not be synchronized with factors optimizing larval and juvenile survival, making the study of ichthyoplankton phenology in the context of a changing environment critical. In the southern California Current Ecosystem (CCE), a major eastern bound...

2022 marked the third consecutive La Niña and extended the longest consecutive stretch of negative Oceanic Niño Index since 1998-2001. While physical and biological conditions in winter and spring largely adhered to prior La Niña conditions, summer and fall were very different. Similar to past La Niña events, in winter and spring coastal upwelling was either average or above average, temperature average or below average, salin...

In late 2020, models predicted that a strong La Niña would take place for the first time since 2013, and we assessed whether physical and biological indicators in 2021 were similar to past La Niñas in the California Current Ecosystem (CCE). The Pacific Decadal Oscillation and Oceanic Niño Index indeed remained negative throughout 2021; the North Pacific Gyre Oscillation Index, however, remained strongly negative. The seventh l...

The California Current System (CCS) has experienced large fluctuations in environmental conditions in recent years that have dramatically affected the biological community. Here we synthesize remotely sensed, hydrographic, and biological survey data from throughout the CCS in 2019–2020 to evaluate how recent changes in environmental conditions have affected community dynamics at multiple trophic levels. A marine heatwave forme...

The effects of climate warming on ecosystem dynamics are widespread throughout the world's oceans. In the Northeast Pacific, large‐scale climate patterns such as the El Niño/Southern Oscillation and Pacific Decadal Oscillation, and recently unprecedented warm ocean conditions from 2014 to 2016, referred to as a marine heatwave (MHW), resulted in large‐scale ecosystem changes. Larval fishes quickly respond to environmental vari...

Understanding changes in the migratory and reproductive phenology of fish stocks in relation to climate change is critical for accurate ecosystem‐based fisheries management. Relocation and changes in timing of reproduction can have dramatic effects upon the success of fish populations and throughout the food web. During anomalously warm conditions (1–4°C above normal) in the northeast Pacific Ocean during 2015–2016, we documen...

The distributions, concentrations, and community structure of pelagic larval fishes collected from the central and northern California Current in the northeast Pacific Ocean during May 2004, 2005, and 2006 were analyzed to investigate inter‐annual, latitudinal, cross‐shelf, and depth‐stratified variability. The inter‐annual climate‐induced variability during the sampling period provided a unique opportunity to observe how larv...