Workshop 2021-Topic Sessions

Topic Sessions

Topic 1. Salmon production in changing environments

Moderators: Ed Farley* (SC & TCG-1), Jim Irvine* (SC), Ju Kyoung Kim (SC & TCG-1), Svetlana Naydenko (SC), and Hiromichi Ueno (TCG-1) *session co-leader

The response of Pacific salmon to climate-driven environmental changes is variable and differs by species, populations, life stages, geographical locations, and/or seasonal timing. Variation in the early marine survival of salmon has been hypothesized to have a major role in determining brood year strength. However, there has been limited evidence to support this hypothesis. We need to understand the causes and mechanisms of mortalities at each stage of the salmon life cycle. This is necessary to understand and predict the responses of salmon to climate change and other factors, and to prepare for future scenarios. In the ocean, for example, climate change may result in significant variability and overall declines in the carrying capacity and usable habitat of Pacific salmon in the North Pacific Ocean, potentially leading to expanded use of the Arctic Ocean. An improved understanding of linkages between environmental changes and salmon production will help to enhance our predictions of changes to the distribution, abundance, and vulnerability of salmon populations to climate change for sustainable resource management.

1-1. Status and trends of key salmon populations and their environments

Time series of regional salmon production and biological and physical characteristics of key salmon populations and their ocean habitat provide broad scale perspectives necessary to examine the underpinnings of ocean salmon production and marine ecosystem conditions. The purpose of this sub-session is to understand the current status and trends of Pacific salmon production and their habitat.

(Keywords: key salmon populations, trend, spawning escapement, catch, survival rate, body size, fecundity, smolt production, distribution, abundance, habitat conditions, and others)

1-2. EFFECTS of freshwater habitat changes on salmon production

Physical changes to freshwater ecosystems resulting from human impacts and climate change will degrade and diminish available habitat, reduce reproductive success, and impact migration of salmon. Increasing water temperatures may cause direct and indirect impacts on salmon including physiological stress, increased depletion of energy reserves, increased susceptibility and exposure to diseases, and disruptions to breeding efforts. The sub-session will: (1) review the impact of freshwater habitat changes on salmon production; and (2) evaluate effectiveness of habitat restoration programs to enhance resilience of salmon.

(Keywords: freshwater salmon habitat, human impact, climate change, reproductive success, growth, migration, physiological stress, diseases, mortality, restoration, resilience, and others)

1-3. SURVIVAL mechanism of juvenile salmon in changing ocean environments

There is growing recognition that size-dependent mortality of juveniles within the first ocean year regulates Pacific salmon production, which also suggests that environmental influences are greater in the first ocean year than later. The sub-session aims to increase our understanding of survival mechanisms of juvenile salmon and their responses to changing environments including SST, salinity, currents, prey abundance, inter- and intra-specific competition, and predators.

(Keywords: juvenile salmon, marine survival mechanism, ocean entry, feeding, growth, migration, SST, salinity, currents, prey, competition, predators, and others)

1-4. Winter ocean ecology and survival of pacific salmon

One hypothesis is that winter is a critical period for Pacific salmon in the ocean, but winter surveys have been limited, and have yet to fully test this hypothesis. Key gaps in our understanding of winter ocean ecology and survival of salmon include: (1) winter ocean distribution and abundance by species and population, (2) ocean habitat environments including prey abundance, (3) key factors influencing winter distribution and abundance, (4) effects of changing winter environments on feeding, growth and metabolism, and (5) mechanisms determining winter survival. The international Gulf of Alaska expedition conducted in 2019 was the first comprehensive survey of Pacific salmon in winter/spring in the North Pacific Ocean in several decades. Results from this expedition will be presented to fill gaps in our knowledge of winter salmon in the ocean. Other presentations on winter salmon ecology and survival are welcome.

(Keywords: winter salmon, spatial and temporal dynamics of habitat conditions, stock-specific distribution and abundance, preys, food web, feeding, metabolism, growth, trophic and health conditions, survival mechanisms, and others)

1-5. LINKAGES between salmon production and climate/ocean changes

The future of salmon is uncertain. Climate change may increase variability in the carrying capacity and usable habitat (distribution) of salmon in the ocean. Improved understanding of linkages between environmental changes and salmon production will help anticipate the economic consequences of these changes. The objectives of the sub-session are to: (1) understand and quantify the effects of environmental variability and anthropogenic factors affecting salmon distribution and abundance; (2) develop methods to predict future changes in salmon distribution and abundance with climate change, and (3) predict implications of climate/ocean environmental changes on salmon management.

(Keywords: climate impact, distribution, abundance, carrying capacity, linkage between salmon, climate and ocean changes, forecast models, energy budget models, biophysical models, and others)

1-6. Summary and discussion


Topic 2. New technologies/integrated information systems for salmon research and management

Moderators: Kazushi Miyashita (TCG-3), Dion Oxman (TCG-3), Shunpei Sato (TCG-3), and Mark Saunders* (SC) *session leader

With recent advancements in technology, data processing, and analytical methods, new tools are available to better study and manage salmon. The IYS aims to further advance the development of new and emerging technologies and analytical methods that are immediately available for salmon research and management. In addition, the IYS seeks to create open-access information systems for salmon research and management, and to develop management systems to aid the sustainable conservation of salmon in a changing climate.

2-1. new technologies

Novel stock and fish identification methods including molecular analyses, genomics, environmental DNA (eDNA), hatchery mass marking, intelligent tags, and remote sensing, continue to be developed, and these tools are integral to the formulation of effective models predicting the distribution and abundance of salmon populations. This sub-session will emphasize: (1) eDNA as an indicator of salmon distribution and abundance in aquatic ecosystems; (2) use of existing scale and otolith collections to determine ocean distribution of salmon (otolith microchemistry) and analyses of growth patterns to examine size-dependent mortality hypotheses; (3) potential for the application of real-time GSI and detection of pathogens at sea; and (4) intelligent data logger and tacking methods to determine migration behavior and survival.

(Keywords: genomics, environmental DNA, molecular identification, mass marking, intelligent tags, salmon observation systems, remote sensing, microchemistry, and others)

2-2. integrated information and management systems

The IYS seeks to develop integrated information/data management systems using new and existing data sets to increase the resiliency of salmon and people in a changing world, to support research and management, and to increase public understanding of the role salmon have in ocean ecosystems. For the sustainable conservation of uncertain salmon populations, we need to develop integrated management systems including ecosystem-based management, improved management strategies for harvest and escapements, long-term sustainable conservation of genetic units and diversity, restoration and protection of marine and freshwater habitat, control of diseases and pollution, resilient salmon enhancement/hatchery technologies, and application of indigenous and local/traditional knowledge.

(Keywords: integrated information system, management strategy of harvest and escapements, genetic conservation, habitat restoration and protection, control of diseases and pollution, renovation of enhancement/hatchery technologies, indigenous and local/traditional knowledges and others)

2-3. Summary and discussion


Topic 3 (Special Session). Resilience for salmon and people: lessons from the Great East Japan Earthquake in 2011

Moderators: Jun Aoyama* (SC & TCG-2), Masahide Kaeriyama (TCG-1), and Shigehiko Urawa (SC & TCG-4) *session leader

The IYS is seeking to ensure that salmon and people are resilient to changing environments. The Great East Japan Earthquake (GEJE) on March 11, 2011 was devastating for salmon and people. It created a massive tsunami that killed more than 18,000 people and gravely damaged the coastal zone systems, including salmon habitats, hatcheries and fishery facilities along the Pacific coast of northern Honshu. Tohoku Ecosystem-Associated Marine Sciences (TEAMS) was launched in January 2012 as a decade-long project to clarify the impacts of the GEJE and the restoration process of marine ecosystems for the reconstruction of local subsistence and fishery industries. In conjunction with TEAMS, this special session is planned to review the impact of the GEJE on salmon, people and coastal ecosystems, and the recovery processes for human security and risk management. Lessons learned from this project should contribute to enhancing the resilience of salmon and people in the face of future challenges elsewhere.

3-1. Restoration of ecosystems and human society in the coastal zone systems

Salmon have a long historical association with local people in northern Honshu, being a vital resource for various aspects such as food, economy, recreation, culture and education. The GEJE damaged coastal ecosystems as well as human society connecting with salmon and other marine resources. Long-term monitoring surveys have been initiated by TEAMS to assess changes in the marine ecosystems and human society affected by the GEJE. This sub-session introduces the outcomes of TEAMS to understand the process and mechanism of restoration in coastal ecosystems and the recovery of human society.

(Keywords: coastal ecosystem, human society, impact of earthquake/tsunami, restoration, and others)

3-2. Research for retrieval and sustainable management of salmon populations

Chum salmon are an important fish resource in northern Japan, and most populations have been maintained by hatchery releases. This sub-session introduces research results of TEAMS in order to: (1) assess the impact of the GEJE and other factors on the behavior, survival and returns of chum salmon; and (2) review the procedure of recovery and sustainable management for chum salmon populations.

(Keywords: chum salmon, survival, impact of earthquake/tsunami, recovery procedure, sustainable management, and others)

3-3. Risk Management and sustainability for the coastal zone systems and salmon production

As a result of the huge tsunami, millions of tonnes of marine debris including live organisms were widely dispersed into the Pacific Ocean. Radioactive materials were also released into freshwater and marine environments from the damaged Fukushima Daiichi nuclear power plant. In addition, non-native coho salmon escaped from broken net-pens in coastal waters. The sub-session intends to recommend: (1) risk management approaches including the adaptive management, precautionary principle and feedback control between monitoring and modeling; and (2) sustainable processes for the coastal zone systems and salmon production from catastrophic disaster, such as the GEJE and global warming effects.

(Keywords: risk management, adaptive management, monitoring, modeling, sustainable process, coastal zone system, salmon production, and others)

3-4. Summary and discussion: Overview of lessons learned for future challenges