Recreational fisheries make up a substantial portion of catch for many West Coast stocks and are economically, socially, and culturally important. It is difficult to predict how changes in recreational fisheries regulations (e.g. bag limits, size limits, seasonal closures) will influence recreational angler effort and recreational fishing mortality for both targeted and bycatch stocks. To better understand this, we are building a bio-economic model of marine groundfish and salmon recreational fisheries off Washington and Oregon. The economic component of this model is based on a mixed logit random utility model built on discrete choice experiment survey data. The biological component is based on stock assessment models, and for this reason we focus on recreationally important stocks that have stock assessments (e.g. lingcod, black rockfish) and overfished stocks for which bycatch in the recreational fishery may be important (e.g. yelloweye rockfish). I will present an overview of the current model and future directions for this work.
Prioritizing Data Needs to Support Migratory Fish Management and Conservation...Mekong Fish Network
This presentation was given as part of the October 2018 workshop "Needs, Techniques, and Risk Assessment: Towards a Vision for Management and Conservation of Migratory Fish Species in Cambodia," held in Phnom Penh. It highlights areas of needed research to answer questions about migratory fishes in Cambodia, including migration routes, migration patterns, breeding sites, and habitat hotspots.
Ideally, the role of data collection is to support the monitoring of stated objectives and support for management processes. States should ensure that timely, complete, and reliable statistics on catch and fishing efforts are collected and maintained in accordance with applicable international standards and practices and in sufficient detail to allow sound statistical analysis. Such data should be updated regularly and verified through an appropriate system.
Assessing the Sardine Multispecies Fishery of the Gulf of CaliforniaAI Publications
In the fishery of small pelagics at the Gulf of California, the South American pilchard Sardinops sagax (Jenyns, 1842) is the main target. In the years when the abundance of this species is poor and its catches are low, the fishery is diverted into other species such as the Pacific thread herring (Opisthonema libertate (Günter)), and the Pacific anchoveta (Cetengraulis mysticetus (Günter)). Since the 90s, the anchoveta (Engraulis mordax) appeared in the catch records and later on, other species of lesser importance appeared such as the mackerel (Scomberomorus sierra (Jordan & Starks)), the red eye-round herring (Etrumeus teres (DeKay)) and the shortjaw leatherjacket (Oligoplites refulgens Gilbert & Starks). When this fishery was analyzed by species, it was found that, although it is a very profitable activity, there is not a management strategy, leading it to the risk of overexploitation, as the maximum yield level of the target species (the South American pilchard), corresponds to levels of fishing mortality in which the other species of the group are depleted. It was found that there is a substitution of the dominant species over time, because at the beginning of this century the South American pilchard was the target species whilst in 2014 it was the Pacific thread herring. Therefore, this work is focused to the analysis of each species of the fishery, intending to derive recommendations for its management within a sustainable framework.45
Prioritizing Data Needs to Support Migratory Fish Management and Conservation...Mekong Fish Network
This presentation was given as part of the October 2018 workshop "Needs, Techniques, and Risk Assessment: Towards a Vision for Management and Conservation of Migratory Fish Species in Cambodia," held in Phnom Penh. It highlights areas of needed research to answer questions about migratory fishes in Cambodia, including migration routes, migration patterns, breeding sites, and habitat hotspots.
Ideally, the role of data collection is to support the monitoring of stated objectives and support for management processes. States should ensure that timely, complete, and reliable statistics on catch and fishing efforts are collected and maintained in accordance with applicable international standards and practices and in sufficient detail to allow sound statistical analysis. Such data should be updated regularly and verified through an appropriate system.
Assessing the Sardine Multispecies Fishery of the Gulf of CaliforniaAI Publications
In the fishery of small pelagics at the Gulf of California, the South American pilchard Sardinops sagax (Jenyns, 1842) is the main target. In the years when the abundance of this species is poor and its catches are low, the fishery is diverted into other species such as the Pacific thread herring (Opisthonema libertate (Günter)), and the Pacific anchoveta (Cetengraulis mysticetus (Günter)). Since the 90s, the anchoveta (Engraulis mordax) appeared in the catch records and later on, other species of lesser importance appeared such as the mackerel (Scomberomorus sierra (Jordan & Starks)), the red eye-round herring (Etrumeus teres (DeKay)) and the shortjaw leatherjacket (Oligoplites refulgens Gilbert & Starks). When this fishery was analyzed by species, it was found that, although it is a very profitable activity, there is not a management strategy, leading it to the risk of overexploitation, as the maximum yield level of the target species (the South American pilchard), corresponds to levels of fishing mortality in which the other species of the group are depleted. It was found that there is a substitution of the dominant species over time, because at the beginning of this century the South American pilchard was the target species whilst in 2014 it was the Pacific thread herring. Therefore, this work is focused to the analysis of each species of the fishery, intending to derive recommendations for its management within a sustainable framework.45
2012 08 The Work of the Devon and Severn Inshore Fisheries and Conservation A...SevernEstuary
Tamsyn Noble - Devon & Severn IFCA
The Work of the Devon and Severn Inshore Fisheries and Conservation Authority in the Severn
Tamsyn Noble is the recently appointed Senior Environment Officer for Devon and Severn Inshore Fisheries Authority (IFCA). Based in Bristol, Tamsyn is primarily responsible for the delivery of IFCA research objectives within the Severn area, having established survey programmes to assess the availability and use of sea fisheries resources, and habitats of conservation significance. Tamsyn graduated with a BSc (Hons) in Marine Biology and Coastal Ecology in 2005, before undertaking voluntary work in a variety of marine ecosystems, both in the UK and abroad. Following graduation from MSc Applied Ecology and Conservation in 2009, Tamsyn was recruited to the role of Marine Environmental Scientist in the offshore energy sector. During this period she worked both onshore and offshore to deliver environmental baseline and monitoring projects, and specialised in the assessment of Annex I habitats.
Devon and Severn Inshore Fisheries and Conservation Authority (D&S IFCA) was fully vested in 2011 under the Marine and Coastal Access Act 2009, to provide inshore fisheries and conservation management, with an increased focus on habitats and ecosystems. The district boundary of the IFCA, which previously encompassed only the Devon coastline to six nautical miles, was substantially increased to include the Severn Estuary and Inner Bristol Channel. Following establishment of a presence in the Severn area of the district, a programme of research activities has commenced, aiming to determine the extent of commercial and recreational use of its marine resources and habitats. This presentation will focus on the role of the IFCA within the Severn area, introducing key current and future research areas, and presenting preliminary data on recreational activities.
SEAKFHP unveils draft strategic action plan at 2013 SE AK Watershed Symposiumseakfhp
The Southeast Alaska Fish Habitat Partnership (SEAKFHP), a candidate partnership under the National Fish Habitat Action Plan, works to foster cooperative fish habitat conservation in freshwater, estuarine and marine ecosystems across southeast Alaska. The partnership formed under the belief that many benefits result when multiple partners come together to share resources, align strategic actions, and speak with a united voice about the conservation and value of productive and intact fish habitats at both local and regional scales. Partner expertise and focus is currently on populations of resident species and anadromous salmonids in freshwater systems as well as anadromous and marine species in estuarine and nearshore habitats. Our mission is to foster and facilitate regionally relevant strategies that will conserve and sustain the region’s fish habitat, fisheries-based economy, and culture. To achieve this broad mission the partnership is working to develop a strategic action plan. In this presentation we share a general overview of the partnership and introduce our draft strategic action plan.
+The state of the ocean’s ecosystems
+The design space – Fishery? Sustainable?
+Fisheries and their stakeholders – and supply chains
+The battle over sustainability – strategy and tactics
+How to design sustainable fisheries
(E5) Exercise #5: Gone Fishing
Goals
analyze annual fish landing, mortality, and biomass data;
explain what caused the collapse of groundfish populations in New
England;
define the terms overfishing and overfished;
understand how MPAs can be effective management tools for
preventing and reviving overfished populations;
and examine your role as a consumer in aiding the sustainability of fish
in our oceans.
Background
For as long as people have lived near water, people have fished. Sadly,
in many instances, the history of fishing is paralleled by a history of
overfishing. According to the 2006 Report of Status of U.S. Fisheries,
20% of U.S. fish stocks with known overfishing status are subject to
overfishing and 25% of stocks with known overfished status are
considered to be overfished. An additional four stocks currently
classified as not overfished are approaching overfished status.
Contributing factors to the current level of overfishing include:
technological advances that have made large-scale fishing easier;
too many fishing boats on the water;
international partnerships that allow foreign fleets to overfish in the waters of developing countries;
illegal fishing that violates fishing laws or agreements;
large amounts of bycatch of juvenile fish and non-target species; and
the shortcomings of fisheries conservation and management efforts.
The impacts of declining fish catches are being painfully felt by many coastal fishing communities around the globe.
Jobs are lost and food is scarce. Impacts are also felt in the oceans as other marine species are left with fewer fish to
eat. Overfishing affects the entire marine food web. But how do know when overfishing is occurring or when a
stock is overfished? More importantly, can these conditions be reversed?
Part 1: Overfishing in Georges Bank
Georges Bank is an underwater bank situated along the eastern edge of the Gulf of Maine between Cape Cod and
Nova Scotia. This region is one of the most biologically productive marine areas on the eastern seaboard,
historically accounting for a large percentage of New England's commercial fish landings. The Georges Bank fishery
is particularly well-known for its groundfish—species such as cod, haddock, and flounder that feed near the
bottom of the ocean.
Look at the graph on the next page of trends in Georges Bank haddock catch and mortality from 1969 through
2004.
The histogram shows the annual haddock landing—the amount of fish that are caught and kept to sell.
The red line shows the fishing mortality rate, F—the rate at which fish are removed from a population due
to fishing (as opposed to removals due to natural causes such as disease or predation). F can also be
thought of as the percentage of a population that die in one year due to fishing.
Map of the Gulf of Maine; Georges Bank is the light blue
region in the bottom center of the image. Image courtesy
of NOAA ...
Case examples of IUU fishing in the Asian region – links to Port State MeasuresSimon Funge-Smith
A summary of a regional review of Illegal, Unregulated and Unreported fishing by foreign vessels (2015). The review covers some of the findings of the review in particular the locations of IUU activity in the Asian region and the drivers behind this. Some summary figures of the losses are presented.
New Jersey's voluntary collection program for bluefish (Pomatomus saltatrix)Steve Luell
Presented by Steven Luell at the 2011 Mid-Atlantic Chapter of the American Fisheries Society Annual Meeting held at the Lighthouse Center for Natural Resource Education in Waretown, NJ.
Abstract
The bluefish (Pomatomus saltatrix) is an important marine fish species on the East Coast of the United States. They are popular amongst fishers, and are targeted both recreationally and commercially. Since 2005, the assessment of bluefish has been conducted via age structured assessment methods (ASAP). Concerns have been expressed about the adequacy of age information to assess this species. In an effort to help resolve these problems, the New Jersey Division of Fish and Wildlife initiated a pilot voluntary biological collection program in 2010. A number of sampling strategies was used to sample the recreational fishery, including: collections from volunteer anglers, fishing tournaments, party boats, and opportunistic collections associated with fishery-independent sampling programs for non-bluefish species. In 2010, otoliths were extracted from 219 bluefish harvested from a variety of locations in NJ between April and November. Thus far in 2011, otoliths were extracted from 214 bluefish. Comparison of the 2010 size frequency of bluefish from New Jersey with the coastal 2010 ALK shows that while there was some overlap, samples were often complementary but ALK gaps remain even when all data are combined.
Economics of sustainable catch issues, various regulatory measures to enhance fishery productivity.
John A. Dixon
from materials prepared by
J. Vincent, T. Sterner, J.E. Padilla, and
Marian delos Angeles
johnkailua@aol.com
World Bank Institute
2012 08 The Work of the Devon and Severn Inshore Fisheries and Conservation A...SevernEstuary
Tamsyn Noble - Devon & Severn IFCA
The Work of the Devon and Severn Inshore Fisheries and Conservation Authority in the Severn
Tamsyn Noble is the recently appointed Senior Environment Officer for Devon and Severn Inshore Fisheries Authority (IFCA). Based in Bristol, Tamsyn is primarily responsible for the delivery of IFCA research objectives within the Severn area, having established survey programmes to assess the availability and use of sea fisheries resources, and habitats of conservation significance. Tamsyn graduated with a BSc (Hons) in Marine Biology and Coastal Ecology in 2005, before undertaking voluntary work in a variety of marine ecosystems, both in the UK and abroad. Following graduation from MSc Applied Ecology and Conservation in 2009, Tamsyn was recruited to the role of Marine Environmental Scientist in the offshore energy sector. During this period she worked both onshore and offshore to deliver environmental baseline and monitoring projects, and specialised in the assessment of Annex I habitats.
Devon and Severn Inshore Fisheries and Conservation Authority (D&S IFCA) was fully vested in 2011 under the Marine and Coastal Access Act 2009, to provide inshore fisheries and conservation management, with an increased focus on habitats and ecosystems. The district boundary of the IFCA, which previously encompassed only the Devon coastline to six nautical miles, was substantially increased to include the Severn Estuary and Inner Bristol Channel. Following establishment of a presence in the Severn area of the district, a programme of research activities has commenced, aiming to determine the extent of commercial and recreational use of its marine resources and habitats. This presentation will focus on the role of the IFCA within the Severn area, introducing key current and future research areas, and presenting preliminary data on recreational activities.
SEAKFHP unveils draft strategic action plan at 2013 SE AK Watershed Symposiumseakfhp
The Southeast Alaska Fish Habitat Partnership (SEAKFHP), a candidate partnership under the National Fish Habitat Action Plan, works to foster cooperative fish habitat conservation in freshwater, estuarine and marine ecosystems across southeast Alaska. The partnership formed under the belief that many benefits result when multiple partners come together to share resources, align strategic actions, and speak with a united voice about the conservation and value of productive and intact fish habitats at both local and regional scales. Partner expertise and focus is currently on populations of resident species and anadromous salmonids in freshwater systems as well as anadromous and marine species in estuarine and nearshore habitats. Our mission is to foster and facilitate regionally relevant strategies that will conserve and sustain the region’s fish habitat, fisheries-based economy, and culture. To achieve this broad mission the partnership is working to develop a strategic action plan. In this presentation we share a general overview of the partnership and introduce our draft strategic action plan.
+The state of the ocean’s ecosystems
+The design space – Fishery? Sustainable?
+Fisheries and their stakeholders – and supply chains
+The battle over sustainability – strategy and tactics
+How to design sustainable fisheries
(E5) Exercise #5: Gone Fishing
Goals
analyze annual fish landing, mortality, and biomass data;
explain what caused the collapse of groundfish populations in New
England;
define the terms overfishing and overfished;
understand how MPAs can be effective management tools for
preventing and reviving overfished populations;
and examine your role as a consumer in aiding the sustainability of fish
in our oceans.
Background
For as long as people have lived near water, people have fished. Sadly,
in many instances, the history of fishing is paralleled by a history of
overfishing. According to the 2006 Report of Status of U.S. Fisheries,
20% of U.S. fish stocks with known overfishing status are subject to
overfishing and 25% of stocks with known overfished status are
considered to be overfished. An additional four stocks currently
classified as not overfished are approaching overfished status.
Contributing factors to the current level of overfishing include:
technological advances that have made large-scale fishing easier;
too many fishing boats on the water;
international partnerships that allow foreign fleets to overfish in the waters of developing countries;
illegal fishing that violates fishing laws or agreements;
large amounts of bycatch of juvenile fish and non-target species; and
the shortcomings of fisheries conservation and management efforts.
The impacts of declining fish catches are being painfully felt by many coastal fishing communities around the globe.
Jobs are lost and food is scarce. Impacts are also felt in the oceans as other marine species are left with fewer fish to
eat. Overfishing affects the entire marine food web. But how do know when overfishing is occurring or when a
stock is overfished? More importantly, can these conditions be reversed?
Part 1: Overfishing in Georges Bank
Georges Bank is an underwater bank situated along the eastern edge of the Gulf of Maine between Cape Cod and
Nova Scotia. This region is one of the most biologically productive marine areas on the eastern seaboard,
historically accounting for a large percentage of New England's commercial fish landings. The Georges Bank fishery
is particularly well-known for its groundfish—species such as cod, haddock, and flounder that feed near the
bottom of the ocean.
Look at the graph on the next page of trends in Georges Bank haddock catch and mortality from 1969 through
2004.
The histogram shows the annual haddock landing—the amount of fish that are caught and kept to sell.
The red line shows the fishing mortality rate, F—the rate at which fish are removed from a population due
to fishing (as opposed to removals due to natural causes such as disease or predation). F can also be
thought of as the percentage of a population that die in one year due to fishing.
Map of the Gulf of Maine; Georges Bank is the light blue
region in the bottom center of the image. Image courtesy
of NOAA ...
Case examples of IUU fishing in the Asian region – links to Port State MeasuresSimon Funge-Smith
A summary of a regional review of Illegal, Unregulated and Unreported fishing by foreign vessels (2015). The review covers some of the findings of the review in particular the locations of IUU activity in the Asian region and the drivers behind this. Some summary figures of the losses are presented.
New Jersey's voluntary collection program for bluefish (Pomatomus saltatrix)Steve Luell
Presented by Steven Luell at the 2011 Mid-Atlantic Chapter of the American Fisheries Society Annual Meeting held at the Lighthouse Center for Natural Resource Education in Waretown, NJ.
Abstract
The bluefish (Pomatomus saltatrix) is an important marine fish species on the East Coast of the United States. They are popular amongst fishers, and are targeted both recreationally and commercially. Since 2005, the assessment of bluefish has been conducted via age structured assessment methods (ASAP). Concerns have been expressed about the adequacy of age information to assess this species. In an effort to help resolve these problems, the New Jersey Division of Fish and Wildlife initiated a pilot voluntary biological collection program in 2010. A number of sampling strategies was used to sample the recreational fishery, including: collections from volunteer anglers, fishing tournaments, party boats, and opportunistic collections associated with fishery-independent sampling programs for non-bluefish species. In 2010, otoliths were extracted from 219 bluefish harvested from a variety of locations in NJ between April and November. Thus far in 2011, otoliths were extracted from 214 bluefish. Comparison of the 2010 size frequency of bluefish from New Jersey with the coastal 2010 ALK shows that while there was some overlap, samples were often complementary but ALK gaps remain even when all data are combined.
Economics of sustainable catch issues, various regulatory measures to enhance fishery productivity.
John A. Dixon
from materials prepared by
J. Vincent, T. Sterner, J.E. Padilla, and
Marian delos Angeles
johnkailua@aol.com
World Bank Institute
Similar to A Bio-economic Model of Marine Recreational Fisheries off Washington and Oregon (20)
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
A Bio-economic Model of Marine Recreational Fisheries off Washington and Oregon
1. A Bio-economic Model
of Marine Recreational
Fisheries off
Washington and OregonNorthwest
Fisheries
Science Center
Megan Stachura, Leif Anderson, and Owen Hamel
December 11, 2015
2. Motivation
• Off the West Coast in 2013, more than 1.7 million recreational
anglers took part in an estimated 7.5 million fishing trips.
These anglers spent about $1.9 billion on fishing trips and
equipment, which supported over 21 thousand jobs
• Bring together biological and economic models to look at how
management affects recreational fishing behavior and
recreational fishing affects the stocks being fished
• Examine the effects of management on:
• Staying within target population ranges
• Economic value of the recreational fishery
• The recovery of depleted populations
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
3. Related Research
• Bio-economic model of recreational cod and haddock
fisheries in the Northeast U.S. (Steinback et al.)
• Bio-economic model looked at how changes in water
quality may affect the Atlantic Coast summer flounder
recreational fishery (Massey et al., 2006)
• Theoretical recreational bio-economic modeling work
on the influence of fish life history, angler behavior,
discard mortality, and non-compliance on optimal
recreational fishery management (Johnston et al.,
2010, 2013, and 2015)
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
4. Model Overview
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
Economic Sub-Model
Simulate Recreational
Fishing
Retained & Released
Recreational Catch
Biological Sub-Model
Angler Effort
Management
5. Model Focus
• Oregon and Washington, not including Puget Sound
• Marine groundfish and salmon recreational fisheries
• Boat (private and charter) recreational fishing, not
shore fishing
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
6. Economic sub-model
• Built on data from a discrete choice experiment survey
conducted in 2007 in Washington and Oregon
• Simplified discrete choice experiment question:
• Which trip do you prefer?
• Would you prefer to take a trip or do something
else?
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
Trip A Trip B Trip C
Catch 1 1 2
Size 2 lb. 4 lb. 4 lb.
Cost $15 $30 $30
7.
8. Economic sub-model
• Logit random utility model
• Anderson and Lee (2013)
• Anderson, Lee, and Levin (2013)
• Incorporates many of the trade-offs important to
anglers:
• Number of fish caught
• Size of fish caught
• Number of fish that can be kept
• Cost
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
10. Biological sub-model
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
Initial
population
Number of
fish at age
Recruitment
Recreational
removals
Commercial
removals
Natural
mortality
Annually
2 Month
Waves
11. Biological sub-model
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
Initial
population
Number of
fish at age
Number of
fish at length
Recruitment
Recreational
removals
Commercial
removals
Natural
mortality
Retained and
dead discarded
fish
Simulate
recreational
fishing
Annually
2 Month
Waves
12. Biological sub-model
• Age-structured population dynamics model
• Completed for lingcod
• Planning to include black rockfish, yelloweye
rockfish, and canary rockfish
• For additional species, only modeling the recreational
catch based on catch from recent years
• Wild and hatchery chinook and coho salmon
• Pacific halibut
• Other rockfish
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
13. Simulating “expected” catch for a trip
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
Draw
number
of fish
caught
Draw fish
length
Greater than legal
minimum size?
Retain
Yes
No
Release
Reached
possession
limit?
NoYes
End
Reached
number of
fish
caught?
No
Yes
14. How many fishing trips will occur?
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
Expected catch
of all species
Economic sub-model
Utility of the trip
Utility of other options (e.g.,
river fishing, not fishing)
Probability the
trip occurs
Divide log utility of trip
by sum of log utility for
all options
Other trip characteristics
Total number of
trips of this type
taken
15. Simulating “actual” catch for a trip
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
Draw
number
of fish
caught
Draw fish
length
Greater than legal
minimum size?
Retain
Yes
No
Release
Reached
possession
limit?
NoYes
End
Reached
number of
fish
caught?
No
Yes
16. How many fish are caught per trip?
• Modeled the catch-per-trip based on data from
observed recreational fishing trips
• Modeled each species, trip type, and area
separately
• Considered four possible models:
• Poisson
• Negative binomial
• Zero-inflated Poisson
• Zero-inflated negative binomial
• In most cases, the zero-inflated negative binomial was
chosen as the best model
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
17. Zero-inflated negative binomial model of catch-per-trip
• Probability of an inflated zero is modeled as a
binomial process with a logit link:
𝑝𝑝 =
𝑒𝑒(𝛼𝛼𝑧𝑧𝑧𝑧+𝜷𝜷𝑧𝑧𝑧𝑧 𝑿𝑿𝑧𝑧𝑧𝑧)
1 + 𝑒𝑒(𝛼𝛼𝑧𝑧𝑧𝑧+𝜷𝜷𝑧𝑧𝑧𝑧 𝑿𝑿𝑧𝑧𝑧𝑧)
• 𝛼𝛼𝑧𝑧𝑧𝑧 is the intercept
• 𝜷𝜷𝑧𝑧𝑧𝑧 is a vector of coefficients for the covariates
𝑿𝑿𝑧𝑧𝑧𝑧
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
18. Zero-inflated negative binomial model of catch-per-trip
• When there is not an inflated zero, catch is modeled
as a negative binomial process with a log link, where
the mean catch-per-trip is:
𝜇𝜇 = 𝑎𝑎 × 𝑒𝑒 𝛼𝛼𝑐𝑐+𝜷𝜷𝑐𝑐 𝑿𝑿𝑐𝑐
• 𝑎𝑎 is the number of anglers on the trip (constant
offset)
• 𝛼𝛼𝑐𝑐 is the intercept
• 𝜷𝜷𝑐𝑐 is a vector of coefficients for the matrix of
covariates 𝑿𝑿𝑐𝑐
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
19. Zero-inflated negative binomial model of catch-per-trip
• Same covariates considered for both the zero-inflated and
negative binomial portions of the model:
• Estimated number of fish available to the recreational
fishery
• Only for stocks for which the population dynamics are
modeled
• Calculated based on the number of fish in the population and
recreational selectivity by length
• Boat type: charter or private
• Two month “wave”
• Estuary or ocean trip (Oregon only)
• Two-way interactions of boat type, wave, and
estuary/ocean
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
20. Washington bottomfish trip lingcod catch-per-trip model
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
Variable Est. S.E.
(Intercept) 1.672 0.146***
log(LingcodAvailable) -0.502 0.021***
BoatTypePrivate 0.974 0.031***
(Intercept) -2.053 0.061***
log(LingcodAvailable) 0.312 0.008***
Wave3 -0.414 0.026***
Wave4 -0.712 0.028***
Wave5 -0.923 0.039***
BoatTypePrivate 0.179 0.030***
Wave3:BoatTypePrivate -0.185 0.032***
Wave4:BoatTypePrivate -0.187 0.035***
Wave5:BoatTypePrivate 0.073 0.050
Log(theta) -0.157 0.013***
Negative binomial model coefficients
Zero-inflation model coefficients
22. U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
Washington bottomfish trip lingcod catch-per-trip model
25. Next steps
• Finish incorporating the catch-per-trip modeling into
the bio-economic model
• Incorporate the full age-structured model for
additional stocks
• Calibrate the number of “potential” trips (angler
choice occasions) so the number of model
predicted trips taken is similar to what has been
observed under similar conditions
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
26. Next steps
• Examine what occurs under different management
measures
• Bag limits
• Size limits
• Open/closed seasons
• Simulate changes in catch rates for stocks we are
not modeling (e.g. poor salmon returns) and see
how that affects angler effort and other stocks
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Northwest Fisheries Science Center
27. Potential future improvements
• Include California stocks and fisheries in the model
once information is available from an updated
economic survey
• Incorporate information from fully observed fishing
trips (Oregon onboard charter survey)
• Account for changes in behavior with changes in
regulations in modeling catch-per-trip
U.S. Department of Commerce | National Oceanic and Atmospheric Administration | NOAA Fisheries | Page 27
