- Most of what we know about the ecology of Chinook in the Yukon comes from a very small part of the life history (during the upriver migration)
- First summer at sea in the nearshore, and in winter migrate south to the shelf break of the Bering Sea…a very productive region. Remember where Jim Ianelli said most pollock fishing occurs???
- Critical size/critical period hypothesis- states that in the early marine rearing period the smallest sized fish do not survive due to size dependent selection and lack of critical reserves
- Timing matters! Moving between ecosystems and the potential for hitting the conditions just right (or not), formally articulated as match/mismatch hypothesis
- Data on timing of juvenile migration available from 1986, 2014, 2015
- Sampling the delta of the Yukon River is a far from trivial task.
- Sampling in the Bering Sea August/September from Bering Sea 2002-2015 provides a longer record of ecology
- Differences in diets between relatively ‘warm’ or ‘cold’ water conditions. In cold years, larval capelin really important in ‘cold’ years and half as important in warm years. As larval fish key prey items, there is lots of potential for match vs. mismatch
- Chinook grow about ca. 230% over two months. Coho salmon triple in size, pink salmon quadruple in size.
- Outmigration timing not strongly associated with timing of ice break up in the lower river, but some association with water temperatures
- Approximately half of the young Chinook salmon caught in Bering Sea of Canadian origin
- 2013 onward showing some leading indication of increasing productivity. A glimmer of hope
- Tells us that marine survival pretty stable after first summer at sea
- Relationship between numbers of Chinook captured in August and September has strong predictive power to forecast adult returns in subsequent year
- There are MULTIPLE salmon fisheries on the US side of the Yukon River alone
- Caroline’s focus is on the people who rely on the salmon, not the salmon or the subsistence resources themselves
- A reminder that ca. 50% of Chinook salmon used by fishers is produced in Canada
- One way to think about communities is lower, middle, and upper along the river. They are grouped by history, availability of resources, and type of fishing gear
- “Lower river” communities exemplify ‘mixed-cash economies’; economies that are dynamic and interrelated; largely Yupik
- “Middle river” primarily Athabaskans, “Moose and Salmon” people, but highly diverse resource use
- “Upper river” Gwich’in and Han Athabaskans, similar resource base (riverine and boreal), but very different landscape to fish AND last resource users to encounter the fish. Largely fish wheel or set net
- Family-based economies at Fish Camps; but Fish Camps have decline precipitously associated with decline in Chinook abundance; hugely important for building family ties and are/were family markers and key to cultural transmission. Important site of cultural, economic, nutritional sharing
- Wage labor, changes in transportation, missionization, and host of factors changed the c
- Cultural dynamics in the Yukon
- Subsistence priority- State law that in times of conservation that priority goes to subsistence of fish and game over other user/cultural groups
- Subsistence uses means taking noncommercial customary and traditional uses for direct personal or family consumption for: food, shelter, fuel, clothing, tools, transportation, making or selling of handicrafts
- Transportation uses of salmon??? Duh, the dog teams need to eat!
- Customary trade selling subsistence caught fish (resources) for ‘small’ amounts of cash
- Reasonable amount of time for traditional use? How about a generation?
- Eight criteria to determine traditional and customary use
- Board of Fish uses eight criteria to determine whether a resource fits the definition of a ‘subsistence’ resource
- Distribution and sharing of products and reliance on a wide diversity of resources are HALLMARKS
- 30/70 rule. 70% of resources harvested by 30% of households
- Mixed cash economies do not focus on only one resource…they harvest a lot of all resources
- ANS…Amounts Reasonably Necessary for Subsistence. What is that? A numerical range of how much of a resource is necessary for subsistence. Clear right?
- While chum subsistence harvests have increased while Chinook salmon harvests have declined, chum do not replace or substitute for Chinook
- Salmon and Chinook salmon in particular in the center of exchange networks in Yukon communities
- An important (vital) step in stock assessment science is exploring how bad your assumptions are
- Necessarily understanding the consequences of decisions are assessed through simulation modeling given the difficulty and complexity of natural systems
- North Pacific Fishery Management Council (NPFMC, national body) manages fisheries 3-200 miles offshore
- Overarching principle of NPFMC comes from Magnuson-Stevens Act, including minimizing bycatch and bycatch mortality
- Most of the pollock fishery occurs along Eastern Bering Sea Shelf
- The pollock fishery accounts for 40% of all US landings and is the world’s largest whitefish fishery
- Pollock fishery recently re-certified by Marine Stewardship Council (MSC)
- Chinook Savings Area- Once a limit of bycatch reached, areas closed
- Lots of variability in where and when salmon are encountered…making set area closures difficult
- Rolling voluntary hotspot closures a tool being used; additional incentive options also in effect
- Salmon excluding nets that exploit different behavior between salmon and pollock currently being used
- Trying to avoid areas where Chinook/chum concentrated a tool; can use relationships between sea surface temperature
- 2011 hard caps on bycatch- if fishery catches 60,000 salmon it is CLOSED
- Current levels of bycatch (11,000-25,000)
- Incentive programs remain critical for further bycatch reduction
- 100% observer coverage; complete census of all salmon species by observers; key is having good observer program! Evidence suggests that the data collected from observers are very high quality
- Major task is to calculate how many fish would have survived in the absent of a fishery; called an Adult Equivalent.
- Approximately 10,000 Chinook are estimated to have returned to Western AK rivers in absence of Pollock fishery
- In the Yukon, pollock likely reduce the total return by 1-3% in a given (recent) year
- This effect is likely imperceptible given the difficulty of accurately counting fish and the error associated with those estimates (See summary from talk from Stephanie Schmidt)
- Despite the numbers and evidence that marine bycatch is not a prime suspect behind the decline of AYK Chinook salmon there is a challenge to communicate the issue among user cultures. The perceived issue of inequity seems to remain: one group catches and discards the fish overboard or gives away to food banks, while other cultures that have subsisted on Chinook salmon for centuries sits idle. There is no way to avoid the contentiousness of this issue.
Download readings and associated reading guides provided by guest speaker Gale Vick of Tanana Chiefs Conference HERE
Key challenges and Highlights
- Size of the river
- Cultures that depend
- Mixed stock
- Management structure
- Data uncertainty
- 43 villages with approximately 13,600 people
- Chinook in the Yukon…the King of kings due to oil content and nutritional value.
- Chinook linked to cultural sense of being and place
- Commercial fisheries did fuel a really important economy. Commercial fishery inextricably linked to the subsistence fishery…money made used to purchase fuel,ammo, boat, etc… that allows access to other subsistence resources
- No summer chum above the Tanana
- How you manage depends on where you are in the river and what stocks are swimming by…among other complications
- Top priority is meeting escapement needs then subsistence has priority
- Co-managed fishery with Federal government
- Federal government defers to ADF&G on management decisions. Close working relationship between ADF&G and USFWS (US Fish & Wildlife Service)
- Canadian’s get 23% of TAC (Total Allowable Catch)
- 150,000 Chinook needed to meet all escapement goals and provide for all subsistence fishing needs
- CPUE from test net fishery at the mouth explains only about 23% of the variability in final Chinook escapement numbers
- Key challenge, how do you provide opportunities to harvest abundant summer chum and not detrimentally impact depressed stocks of Chinook salmon
- Communication not enough…compassion is necessary
A GREAT WAY TO SPEND 10 MINUTES! Thanks to Mike Bradford for sharing this link.
This semester we’ll be using a product hosted at slack.com to interact relating to lab projects which involve modeling actual fisheries management and use scenarios.
First, though, you need to get the App.
As part of your pre-lab activity you’ll be required to stage the Slack app on the device you use the most. It’s suggested you install the app on a few devices (if you have more than one) so you can see how it works on multiple platforms. The messages synch between devices, so you can start a conversation on your desktop, use a browser on a school computer, and even finish up a communication thread using your phone. It’s up to you.
These are some of the things we’ll be doing with Slack:
- Make official public requests and posts based on your user role in the scenario
- Communicate with other users privately
- Share pictures and other files with your lab team
- Ask questions of your Instructor
You may want to view this quick Introduction to Slack. We’ll go over more specifics in lab and make sure everyone can use the tool.
More curious? You can check out some of the Slack product videos.
Some key insights from Mike Bradford
- Contemporary patterns of salmon production and ecology is shaped by deep time following the end of the last ice age
- Although the ‘Canadian’ Yukon comprises only 1/3 of the watershed, these streams produce approximately 1/2 of the fish
- Juvenile downstream movements (which Dr. Bradford termed ‘dispersal’) differ among watersheds with relatively large vs. small amounts of habitat
- Approximately 40% of Canadian produced salmon move downstream to non-natal streams
- Groundwater and ice dynamics are key in understanding the potential for a stream to be conducive to rearing juvenile Chinook Salmon
- Big changes in stock productivity (the numbers of recruits per spawner) has varied through time and most recent years the Canadian stock is more or less just barely replacing itself. Thus, little or no ‘surplus’ for harvest
- Although the Yukon River watershed relatively pristine compared to watersheds in the lower 48, substantial habitat modification in the form of placer mining. However, habitat disruption unlikely to sufficiently explain patterns of production
- Land in Canada belongs more to Provinces than Federal government compared to the US
- First nations and distributions of salmon spawning stocks are entwined
- Due to reduced harvest downstream in 2015, over 80,000 Chinook Salmon survived to make it back to the Canadian side of the border
- Alternative management strategies differ in complexity (single vs. multiple stocks), risk to small unproductive populations, and recognition to lack of recognition of diversity
These are a few of the things that emerged from today’s conversation with Erin Harrington
- Alaskan connections to salmon are virtually universal in the state and transcend simple political and religious lines
- Knowledge is place based, which is simultaneously empowering (individuals protect those things they love, and typically love the things they know locally) and inhibiting (creates a myopic bias that can keep individuals from seeing the bigger picture)
- Maintaining the connection and relationship to salmon by Alaskans is a tangible goal for increasing likelihood of sustainability
- Sustainability is, at least in large part, an emergent property of locally adapted salmon populations and habitat diversity
- A single assessment of ‘the state of Alaska salmon’ would be misleading as the issues are local (place-based) and differ among regions
- Salmon issues are often (usually?) depicted in the context of conflict among user groups
- Measuring success of social campaigns is difficult at best