Discover the latest in ARF Pacific Albacore Tuna research.
These studies are peer-reviewed and conducted by scientists at independently funded organizations.
Migration and Behavior of Juvenile North Pacific Albacore (Thunnus alalunga)
This research provides a summary of the seasonal movements, migration patterns and vertical (diving) behavior of juvenile North Pacific albacore that are taken by the US and Canada troll and pole and line fisheries of the west coast. The albacore exhibited five distinct, seasonal migratory patterns. Diving behavior revealed that juvenile albacore spend more time at depth than previously thought which explains lower catchability during some years or seasons.
This information was made possible by position and depth data from archival (data storing) tags funded by ARF and analyzed by the NOAA Fisheries, Southwest Fisheries Science Center.
*Juvenile North Pacific Albacore refer to fish of 1 to 5 years of age that have entered the surface fishery but have not yet returned to the western Pacific to spawn. These are the fish that are sustainably harvested by ARF member vessels using troll gear.
Juvenile Albacore Tuna (Thunnus alalunga) Foraging Ecology Varies With Environmental Conditions in the California Current Large Marine Ecosystem.
Characterizing changes in albacore diet with changing environmental conditions is key to understanding variability in albacore abundance, distribution and availability to recreational and commercial fisheries. ARF has been keenly interested in changes in albacore foraging characteristics and has actively supported diet studies through the collection of stomach contents and associated data necessary to carry out these studies.
*Juvenile North Pacific Albacore refer to fish of 1 to 5 years of age that have entered the surface fishery but have not yet returned to the western Pacific to spawn. These are the fish that are sustainably harvested by ARF member vessels using troll gear.
Risk and Reward in Foraging Migrations of North Pacific Albacore Determined From Estimates of Energy Intake and Movement Costs
Archival tags are implanted in the body cavity of fish and record the internal body temperature at frequent intervals. This study used these temperature recordings to identify times and areas of feeding to examine the benefits vs costs of moving to seasonal feeding or wintering grounds that had been previously identified (Childers et al. 2011). The migratory paths and increased feeding were found in areas of estimated high plankton concentrations in the California Current and the North Pacific Transition Zone.
Dynamic Habitat Use of Albacore and Their Primary Prey Species in the California Current System
Juvenile north Pacific albacore (Thunnus alalunga) forage in the California Current System (CCS), supporting fisheries between Baja California and British Columbia. Within the CCS, their distribution, abundance, and foraging behaviors are strongly variable interannually. Here, we use catch logbook data and trawl survey records to investigate how juvenile albacore in the CCS use their oceanographic environment, and how their distributions overlap with the habitats of four key forage species.
Impact of the 2014–2016 marine heatwave on US and Canada West Coast fisheries: Surprises and lessons from key case studies
Marine heatwaves are increasingly affecting marine ecosystems, with cascading impacts on coastal economies, communities, and food systems. Studies of heatwaves provide crucial insights into potential ecosystem shifts under future climate change and put fisheries social-ecological systems through “stress tests” that expose both vulnerabilities and resilience. The 2014–16 Northeast Pacific heatwave was the strongest and longest marine heatwave on record and resulted in profound ecological changes that impacted fisheries, fisheries management, and human livelihoods. Here, we synthesize the impacts of the 2014–2016 marine heatwave on US and Canada West Coast fisheries and extract key lessons for preparing global fisheries science, management, and industries for the future.
Dynamic human, oceanographic, and ecological factors mediate transboundary fishery overlap across the Pacific high seas
The management and conservation of tuna and other transboundary marine species have to date been limited by an incomplete understanding of the oceanographic, ecological and socioeconomic factors mediating fishery overlap and interactions, and how these factors vary across expansive, open ocean habitats. Despite advances in fisheries monitoring and biologging technology, few attempts have been made to conduct integrated ecological analyses at basin scales relevant to pelagic fisheries and the highly migratory species they target. Here, we use vessel tracking data, archival tags, observer records, and machine learning to examine inter- and intra-annual variability in fisheries overlap (2013–2020) of five pelagic longline fishing fleets with North Pacific albacore tuna (Thunnus alalunga, Scombridae).
Changes to the structure and function of an albacore fishery reveal shifting social-ecological realities for Pacific Northwest fishermen
Marine fisheries around the globe are increasingly exposed to external drivers of social and ecological change. Though diversification and flexibility have historically helped marine resource users negotiate risk and adversity, much of modern fisheries management treats fishermen as specialists using specific gear types to target specific species. Here, we describe the evolution of harvest portfolios amongst Pacific Northwest fishermen over 35+ years with explicit attention to changes in the structure and function of the albacore (Thunnus alalunga, Scombridae) troll and pole-and-line fishery.
Clustering of disaggregated fisheries data reveals functional longline fleets across the Pacific
Ensuring the long-term sustainability of tuna, billfish, and other transboundary fisheries resources begins with data on the status of stocks, as well as information concerning who catches what fish, when, where, and how. Despite recent improvements in fisheries monitoring and surveillance, such dynamics remain poorly understood across the high seas. Here we delineate and describe pelagic longline activity in the Pacific Ocean using a framework that integrates descriptive vessel information and tracking data with species- specific catch reports. When parsed by distinct vessel behaviors and attributes, disaggregated fisheries data highlight the existence of multi-national, multi-specific (i.e., targeting multiple species) fishing fleets, many of which target waters that span more than one management area. Our findings emphasize the need for increased coordination across regional and sub-regional governance bodies and suggest that effective and equitable management of the sector may require efforts to move beyond single-species, single-area controls and operational distinctions based primarily on vessel flag and/or gear type alone.
Recommendations for quantifying and reducing uncertainty in climate projections of species distributions
Projecting the future distributions of commercially and ecologically important species has become a critical approach for ecosystem managers to strategically anticipate change, but large uncertainties in projections limit climate adaptation planning. Although distribution projections are primarily used to understand the scope of potential change—rather than accurately predict specific outcomes—it is nonetheless essential to understand where and why projections can give implausible results and to identify which processes contribute to uncertainty. Here, we use a series of simulated species distributions, an ensemble of 252 species distribution models, and an ensemble of three regional ocean climate projections, to isolate the influences of uncertainty from earth system model spread and from ecological modeling.
A shallow scattering layer structures the energy seascape of an open ocean predator
Large predators frequent the open ocean where subsurface light drives visually based trophic interactions. However, we lack knowledge on how predators achieve energy balance in the unproductive open ocean where prey biomass is minimal in well-lit surface waters but high in dim midwaters in the form of scattering layers. We use an interdisciplinary approach to assess how the bioenergetics of scattering layer forays by a model predator vary across biomes. We show that the mean metabolic cost rate of daytime deep foraging dives to scattering layers decreases as much as 26% from coastal to pelagic biomes. The more favorable energetics offshore are enabled by the addition of a shallow scattering layer that, if not present, would otherwise necessitate costlier dives to deeper layers. The unprecedented importance of this shallow scattering layer challenges assumptions that the globally ubiquitous primary deep scattering layer constitutes the only mesopelagic resource regularly targeted by apex predators.
Improving Stock Definitions and Understanding of Stock Boundaries for North Pacific Albacore
The overall goal of our research was to generate genomic data to help resolve some of these uncertainties and provide more definitive results regarding stock boundaries of albacore tuna in the North Pacific. This collaborative effort involved researchers from Oregon State University, NOAA’s Southwest Fisheries Science Center, the Pacific Community (SPC) Pacific Marine Specimen Tissue Bank and partners from the American Fishermen’s Research Foundation (now ARF) and the Western Fishboat Owner’s Association.