Kobuk Selawik Estuarine System Environmental Sciences Essay

A Management Plan for Sheefish in the Kobuk-Selawik Estuarine System. Sheefish, a big grey fish from the whitefish household, are important to the lives of Alaskan Native peoples. These fish are common in northwest Last frontier in the Kobuk-Selawik Estuary ( KSE ) and spend the bulk of their lives within this estuary. With approaching development and clime alteration, the demand for a direction program is indispensable to keep current or increased crop degrees. The direction program will depict the actions required and costs involved. This will be achieved through a series of baseline surveies, followed by supervising plans that track the wellness of the estuary and its resident sheefish.

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Introduction 1

Background 1

Location 1

Harvest 2

Life History 3

Feeding 3

Migration 3

Engendering 3

Known V. Unknown 4

Estuary Comparison 5

Management Plan 5

Introduction 5

Baseline 6

Monitoring 7

Final Phase 7

Budget 8

Narrative-Baseline Surveies 8

Narrative-Monitoring Surveies 9

Decision 10

Tables and Figures 11

Literature Cited 17


The end of our research squad is to develop a direction program that maintains the Kobuk-Selawik estuary ( KSE ) ecosystem at a degree that ensures sustainable subsistence crops of sheefish ( Stenodus leucichthys ) . Sheefish, ( or inconnu which means ‘unknown ‘ in Old French ) , have been a important portion of the subsistence life style for Native people in Northwest Alaska for over 10,000 old ages and are a basis of their diet and traditions. Presently, the KSE is healthy and productive, making the ideal environment for the Kobuk-Selawik sheefish which spend the huge bulk of their lifetime in the KSE part. Baseline cognition of this untasted ecosystem, before the coming of any development and farther clime alteration, is needed for the saving of the KSE. The cardinal piece to the proposed program is the acknowledgment that the KSE is a pristine ecosystem and sheefish within the system are an index species of the ecosystem ‘s wellness.



The KSE system is located merely inside the coastal Waterss of Northwest Alaska [ Figure 1 ] . The KSE part includes Hotham Inlet, Selawik Lake, and the lower ranges of the feeders run outing into them. The Kobuk and Selawik feeders drain 32,000 and 11,700 km2, severally. The lake and inlet screen 1,046 and 2,560 km2, severally. The estuarine home ground

consists of comparatively shallow brackish Waterss with a combination of sandy, silty, and bouldery undersides. A assortment of little bushs and trees coupled with grasses and tundra surround the bulk of the recess and lake. Aquatic flora is reasonably consistent throughout the country and includes grass wrack, lichens, pondlilly, pondweeds, and peat moss mosses. The KSE is place to

sheefish, Arctic char and Arctic grayling, eelpout, buddy, lake trout, northern expressway, and whitefish. The estuary and environing tundra besides back up the Western Arctic Caribou Herd.


In the northwest part, Native Alaskans rely to a great extent on the subsistence crop of sheefish for cultural and economic grounds. For illustration, every twelvemonth the mean one-year subsistence crop in six communities is over 25,000 fish ( J. Savereide, personal communicating, November 12, 2012 ) . The subsistence crop has immense economic importance as a addendum to their diet. In add-on, angling traditions and cognition are passed down to guarantee future coevalss will be able to use this resource. Sheefish are harvested in winter and summer subsistence and athletics piscaries. Subsistence fishermen use gill cyberspaces, beach Seines, and hook and line to capture sheefish during their one-year migrations in and out of the KSE. Sport fishermen use hook and line in the summer and winter. The bulk of the sheefish crop occurs in the Kotzebue District, which includes the KSE and the Kobuk and Selawik rivers [ Figure 1 ] .

Life History

The life history of sheefish is complex and varies throughout Alaska. The sheefish is a big Ag colored fish that belongs to the whitefish subfamily Coregoninae. Mature females are typically larger than male sheefish [ Figure 2 ] . Sheefish in the KSE are considered estuarial anadromous or amphidromous, intending they spawn in fresh water and overwinter in brackish H2O ( Alt 1987 ) . Unlike salmon, which are semelparous, sheefish are iteroparous, which means they can engender multiple times. Sheefish throughout Alaska and Russia mature around age seven

and typically spawn in non-consecutive old ages ; nevertheless, back-to-back twelvemonth spawning has been documented on several rivers in Alaska including the Kobuk River ( Berg 1948, Brown 2000, Taube and Wuttig 1998, Stuby In imperativeness, Savereide In homework ) .


Sheefish spend their winters and the bulk of their summers in the KSE eating on juvenile salmon and sheefish, herring, runt, and smelt ( Alt 1965 ) . Juvenile sheefish provender chiefly on insects or plankton, but sheefish in their first twelvemonth have been observed feeding on other immature fish ( Alt 1967 ) . Sheefish throughout Alaska typically utilize the same countries every twelvemonth to feed, which is known as site fidelity ( Brown 2000, Stuby In imperativeness ) . Kirilov ( 1962 ) noted that some sheefish continue to feed during their upriver spawning land migration, but Nikolski ( 1954 ) and Vork ( 1948 ) reported a feeding surcease until after engendering. During recent surveies on the Kobuk River, tummy of engendering sheefish were sampled and juvenile lamper eel, expressway, and grayling were found ( Savereide personal communicating ) .


Surveies have shown that upriver migrations to their spawning evidences are protracted and span from early June until late August or early September, whereas their downstream migration is rapid and merely spans a few hebdomads [ Figure 3, Stuby In imperativeness, Brown 2000, Savereide In homework ] . The Kobuk River engendering country spans about 96 kilometer from an country called Kalla upstream to the Reed River. The Selawik River engendering evidences are smaller and found in two countries within the drainage: a little subdivision on the Tagagawik River and a 10 kilometre subdivision between Ekiek and Ingruksukruk Creeks [ Figure 4 ] . Recent engendering copiousness estimations range from

25,000 to 40,000 on the Kobuk River and 23,000 to 46,000 on the Selawik River ( Taube and Wuttig 1998, Hander et Al. 2008 ) .

The Kobuk-Selawik sheefish engendering countries portion similar home ground features. Both countries have reasonably fleet currents that keep the bottom silt-free, which is of import because the eggs need interstitial infinite under the crushed rock to last ( Alt 1987 ) . Sheefish are broadcast spawners, intending their eggs are dispersed by females straight into the H2O column while the tracking males disperse the soft roe ( Alt 1987 ) . Peak engendering occurs at temperatures between 2.6 and 3.2 grades Celsius in H2O deepnesss between 1.5 and 1.8 m. Spawning occurs along the cut bank and in the centre of the channel, but ne’er over gravel bars or on the inside curve of the river ( Alt 1987 ) . Optimum engendering substrate is composed of otherwise sized coarse crushed rock ( 25 to 100 millimeters ) with some sand but no silt nowadays ( Alt 1967 ) . This assortment of gravel size ensures the fertilized eggs will lodge into the interstitial infinites where they will develop throughout the winter ( Alt 1987, Hander et Al. 2008 ) . There is no information available on juvenile outgrowth in Alaska, but Russian surveies have documented a 182-day incubation period, which puts outgrowth around mid-April ( Vork 1948 ) .

Known V. Unknown

There is ample information about grownup sheefish in the KSE but there is really small known about juvenile fish. The KSE is a big country that encompasses a assortment of habitat types, but summer and winter migration surveies have shown the bulk of grownup sheefish overwinter and provender in the northern part of Hotham Inlet and Selawik Lake [ Figure 5, Smith In prep ] . In add-on, Alt ( 1987 ) has demonstrated that grownup sheefish typically enter the lower subdivision of the

feeders to feed during early summer, but merely migrate further upstream if they are traveling to engender. Even though these countries are known at that place have been no home ground surveies to find why they spend the bulk of their clip in these countries. Like grownups, juvenile sheefish spend most of their lives in the KSE ( Alt 1987 ) , but in contrast, the home grounds utilized while rise uping and the seasonal migrations within the KSE are non known. In fact, other than a small information about their diet, the lone information we have about juveniles is their entryway timing into the KSE after outgrowth, which is dictated by high spring flows due to dissolving ice and snow.

Estuary Comparison

Southwest England is home to the Tamar composite of estuaries. The Tamar complex contains many species of national importance, similar to the cultural importance of inconnu in the KSE. This part, historically, has been adversely affected by human development, including industrial and sewage discharge, overfishing of shellfish, and edifice development. Much of this occurred long earlier important research and monitoring of this estuarine system was in topographic point and as such, there is no baseline that shows how this system behaves when it is absolutely healthy. This has led to complicated and expensive programs affecting home ground sweetening, which even so is merely possible on the little graduated table ( Our South West 1999 ) .

Management Plan


Based on the old grounds, a direction program that ensures sustainable subsistence crop of sheefish by protecting the KSE is needed before effects of development and clime alteration threaten the subsistence life style that has thrived for 1000s of old ages. There are a

figure of ways to develop and keep a direction program, but in this state of affairs the most appropriate first measure is to place any informations spreads or information that are needed to pull off the country. Our research squad has identified the undermentioned spreads: background surveies on juvenile sheefish and home ground surveies based on grownup and juvenile migrations. The methods, logistics, and monies needed to transport out an grownup sheefish monitoring plan are already known. The combination of the current and new cognition will be used to establish a monitoring plan that will let our squad to do direction determinations.


The baseline surveies will be broken down into two classs: juvenile sheefish appraisals and habitat appraisals [ Table 1 ] . The juvenile sheefish surveies will include: mark- recapture ( M-R ) experiments to gauge the copiousness of juvenile sheefish, and a coincident familial survey that will let us to find copiousness estimations by stock ( Kobuk and Selawik ) . Another facet of juvenile sheefish life history is the migrations they undergo while rise uping in the estuary. To find these forms, an intensive acoustic tagging plan, similar to Smith et Al. ( In homework ) , will be conducted, with an array of echo sounder buoys placed throughout the KSE.

The home ground appraisals will concentrate on the countries where juvenile and grownup sheefish have been observed during raising, eating, and engendering. These surveies will analyze the physicochemical belongingss of the H2O ( pH, turbidness, hardness, and flow ) every bit good as the physical features of the country ( substrate, flora, and presence of species ) .


Upon completion of the baseline surveies, supervising surveies will be conducted at regular intervals to track the ecosystem wellness of the KSE and subsistence crop of sheefish [ Table 1 ] . These surveies are of import as they are the lone manner to estimate the effects of any development and/or clime alteration. Monitoring the subsistence crop is besides of import to guarantee sustainable crops and ecosystem wellness. Unmet crop degrees will act upon our direction squad determinations. For this ground, one-year subsistence harvest studies for sheefish will be required for all subsistence fishermen in the country. Adult copiousness surveies will be conducted every three old ages with echo sounder engineering, which is less invasive and less expensive than an M-R experiment. M-R experiments will be used for juvenile copiousness surveies every three old ages, because echo sounder techniques are uneffective. Adult and juvenile migration surveies are the most intensive and expensive undertakings to carry on, so they will be performed every five old ages. It is of import to go on the migration surveies because their home ground usage forms may alter over clip. These differences will probably be due to a alteration in the ecosystem, which may be connected to development or clime alteration. Finally, habitat appraisals of the engendering evidences and estuary, which are comparatively cheap, will be conducted every three old ages to supervise the wellness of the ecosystem.

Concluding Phase

The concluding stage of our direction program inside informations the actions the squad would take to guarantee our end of sustainable sheefish subsistence crops. Basically, if the subsistence crops remain stable or better, there will be no extra action beyond supervising the system. If the subsistence crops are worsening and/or fishermen have to use more attempt to reap, the

analysis of the monitoring plan can place possible grounds for the diminution. If the diminution is purely sheefish-related, so targeted fishing limitations will be used to restrict the crop to guarantee a sustainable spawning copiousness. If the diminution is an result of a mensurable home ground status, such as heavy metal discharge or loss of rise uping countries, so a combination of actions will be introduced. These could include fishing limitations, habitat sweetening, and development ordinances used to restrict crop, better the quality of home ground, and guarantee sustainable engendering copiousness.


All costs for each peculiar undertaking are detailed by class over a 15 twelvemonth timeline [ Table 1 ] . These costs will be borne by legion stakeholders, including Federal, State, and Non-Governmental bureaus such as Fish and Wildlife, Fish and Game, NANA Incorporated.

Narrative – Baseline Surveies

Habitat surveies for juveniles and grownups will be completed with one crew of three people, utilizing a combination of big and little skiffs equipped with pertinent trying equipment. These surveies can be conducted at the same time over a one- to biennial period.

The initial stage of juvenile copiousness surveies will measure a assortment of gaining control techniques. Then the M-R experiments, utilizing the most appropriate cogwheel, will be carried out on the lower Selawik and Kobuk rivers. From experience, these surveies are much more intensive and will affect two crews of three people per river. Crew members will utilize big and little

skiffs to capture and label juvenile sheefish during early June. Attempts to recapture these tagged fish will take topographic point in early August.

Juvenile migration surveies will retroflex Smith et Al. ( In homework ) and effort to label juveniles with acoustic tickets to track their motions throughout the KSE. The gaining control and labeling part of the survey can agree with the juvenile copiousness undertaking ( the same is true for the grownup migration surveies ) . In add-on, an array of acoustic buoys will be anchored in the H2O throughout the estuary. These buoys will enter the day of the month, clip, and deepness of labeled fish as they migrate through the ensonified country. These type of surveies are less intensive but rather dearly-won because of the acoustic tickets and array of echo sounder buoys.

Narrative – Monitoring Surveies

Monitoring surveies are broken down into five classs: harvest studies, engendering copiousness, juvenile copiousness, migration, and habitat appraisals. Once all baseline surveies are finished, harvest studies will be conducted yearly to guarantee that all subsistence demands are being met. These surveies will be completed on different timelines depending on demand, cost, and degree of trouble. Abundance surveies will be conducted every three old ages because of their cost and the fact that any dismaying lessening in stock size can be easy detected during this timeframe. Migration surveies are expensive and the information provided by these does non necessitate to be updated rather so frequently. Alternatively, these undertakings will be conducted every five old ages unless subsistence demands are non being met. Habitat surveies are comparatively cheap and will be conducted every three old ages unless a significant lessening in sheefish crop is observed.


The sheefish of the KSE part are of monumental cultural and economic importance to the Native Alaskans of the part, asking the creative activity and execution of a direction program to guarantee that, irrespective of human development and environmental alteration, sheefish are at that place to remain. The direction program begins by turn toing the fact that many belongingss of the KSE and the wonts of the sheefish within are, as of yet, unknown. Once these information spreads have been filled the KSE will be better understood under pristine conditions. This will supply a baseline from which to compare the consequences of subsequent migration, stock, and home ground surveies, procuring our ability to keep sustainable subsistence crop of sheefish


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