scholarly journals A Decade in Review: Alaska’s Adaptive Management of an Invasive Apex Predator

Fishes ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 12
Author(s):  
Kristine Dunker ◽  
Robert Massengill ◽  
Parker Bradley ◽  
Cody Jacobson ◽  
Nicole Swenson ◽  
...  
Keyword(s):  
Adaptive Management ◽  
Northern Pike ◽  
Fish Populations ◽  
Native Fish ◽  
Apex Predator ◽  
Cook Inlet ◽  
Kenai Peninsula ◽  
Control Actions ◽  
Southcentral Alaska ◽  
Population Suppression

Northern pike are an invasive species in southcentral Alaska and have caused the decline and extirpation of salmonids and other native fish populations across the region. Over the last decade, adaptive management of invasive pike populations has included population suppression, eradication, outreach, angler engagement, and research to mitigate damages from pike where feasible. Pike suppression efforts have been focused in open drainages of the northern and western Cook Inlet areas, and eradication efforts have been primarily focused on the Kenai Peninsula and the municipality of Anchorage. Between 2010 and 2020, almost 40,000 pike were removed from southcentral Alaska waters as a result of suppression programs, and pike have been successfully eradicated from over 20 lakes and creeks from the Kenai Peninsula and Anchorage, nearly completing total eradication of pike from known distributions in those areas. Northern pike control actions are tailored to the unique conditions of waters prioritized for their management, and all efforts support the goal of preventing further spread of this invasive aquatic apex predator to vulnerable waters.

General Limnology of Lakes Near Cook Inlet, Southcentral Alaska

2003 ◽  
Vol 19 (2) ◽  
pp. 141-149 ◽  
Author(s):  
John R. Jones ◽  
Michael A. Bell ◽  
John A. Baker ◽  
Jeffrey P. Koenings
Keyword(s):  
Cook Inlet ◽  
Southcentral Alaska

Freshwater, Fish and the Future: Proceedings of the Global Cross-Sectoral Conference

2016 ◽  
Keyword(s):  
Fish Populations ◽  
Native Fish ◽  
Partnership Model ◽  
European Settlement ◽  
Southeastern Australia ◽  
Murray Darling Basin ◽  
Wide Range ◽  
Funding Opportunities ◽  
Funding Cuts

<em>Abstract</em> .—The Murray–Darling basin (MDB) in southeastern Australia, covers 1.1 million km<sup>2</sup>, involves six partner jurisdictions with a myriad of different government agencies, and, hence, provides an excellent example of the complexities of multijurisdictional management across a range of social and political tiers. In the MDB, fish and fisheries compete for water with agriculture, which is the traditional water user and is driven by national economics. Murray–Darling basin rivers are now highly regulated and generally in poor health, with native fish populations estimated to be at only about 10% of their pre-European settlement abundances. All native commercial fisheries are now closed, and the only harvest is by a recreational fishery. The six partner jurisdictions developed a Native Fish Strategy (NFS) to rehabilitate native fish populations to 60% of pre-European settlement levels after 50 years of implementation by addressing priority threats through a coordinated, long-term, whole-of-fish-community (all native fishes) approach. As there are a wide range of stakeholders, broad engagement was needed at a broad range of government and community levels. The NFS funding was discontinued after 10 years, not because of its lack of successes or project governance, but due to jurisdictional political changes and funding cuts that resulted in a failure of the collaborative funding structure. The withdrawal of considerable funding by one jurisdiction led to collective decline in monetary contributions and posed a threat to the multijurisdictional structures for both water and natural resource management (NRM) within the MDB. As a consequence, there was a review and reduction in NRM programs and a subsequent reduction in focus to the core business of water delivery. Reflection on the NFS, however, provides some useful insights as to the successes (many) and failures (funding) of this partnership model. Overall, the strategy and its structure was effective, as exhibited by an audit of outputs, outcomes, and networks; by the evident ongoing advocacy by NRM practitioners and the community; and by the continuation of ideas under other funding opportunities. This has provided a powerful legacy for future management of fishes in the MDB.

Comparison of Spawning Areas and Times for Two Runs of Chinook Salmon (Oncorhynchus tshawytscha) in the Kenai River, Alaska

1985 ◽  
Vol 42 (4) ◽  
pp. 693-700 ◽  
Author(s):  
Carl V. Burger ◽  
Richard L. Wilmot ◽  
David B. Wangaard
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Main Stem ◽  
Upstream Migration ◽  
Cook Inlet ◽  
Large Lakes ◽  
Spawning Areas ◽  
Winter Temperatures ◽  
Southcentral Alaska ◽  
Radio Transmitters

From 1979 to 1982,188 chinook salmon (Oncorhynchus tshawytscha) were tagged with radio transmitters to locate spawning areas in the glacial Kenai River, southcentral Alaska. Results confirmed that an early run entered the river in May and June and spawned in tributaries, and a late run entered the river from late June through August and spawned in the main stem. Spawning peaked during August in tributaries influenced by lakes, but during July in other tributaries. Lakes may have increased fall and winter temperatures of downstream waters, enabling successful reproduction for later spawning fish within these tributaries. This hypothesis assumes that hatching and emergence can be completed in a shorter time in lake-influenced waters. The time of upstream migration and spawning (mid- to late August) of the late run is unique among chinook stocks in Cook Inlet. This behavior may have developed only because two large lakes (Kenai and Skilak) directly influence the main-stem Kenai River. If run timing is genetically controlled, and if the various components of the two runs are isolated stocks that have adapted to predictable stream temperatures, there are implications for stock transplantation programs and for any activities of man that alter stream temperatures.

Rapid food web recovery in response to removal of an introduced apex predator

2006 ◽  
Vol 63 (3) ◽  
pp. 569-575 ◽  
Author(s):  
Jesse M Lepak ◽  
Clifford E Kraft ◽  
Brian C Weidel
Keyword(s):  
Food Web ◽  
Native Species ◽  
Fish Community ◽  
Lake Trout ◽  
Trophic Position ◽  
Fish Communities ◽  
Stomach Contents ◽  
Smallmouth Bass ◽  
Native Fish ◽  
Apex Predator

Non-native species have increased extinction rates, decreased diversity, altered organism distributions, and constrained ecosystem functioning in native aquatic and terrestrial communities. Although widespread fish introductions have dramatically altered fish communities in north temperate lakes, restoration of native fish communities has been rarely accomplished. This study evaluated a native fish community restoration using a stable isotope based metric. Stable isotopes from a native apex predator (lake trout (Salvelinus namaycush)) were used to measure food web changes following removal of a dominant non-native apex predator (smallmouth bass (Micropterus dolomieu)). Prior to bass removal, lake trout consumed primarily invertebrates. Within 2 years of the initiation of an experimental removal effort, lake trout δ13C values (–25.9‰ to –24.9‰) and trophic position (3.5–3.9) increased, reflecting a switch to prey fish consumption that was supported by stomach contents analyses. Here, we show the rapid reestablishment of food web linkages within a native fish community in response to changes in principal energy sources and trophic position of a native apex predator along with the ability to quantify the extent of these changes.

Seven considerations about dingoes as biodiversity engineers: the socioecological niches of dogs in Australia

2012 ◽  
Vol 34 (1) ◽  
pp. 119 ◽  
Author(s):  
Peter J. S. Fleming ◽  
Benjamin L. Allen ◽  
Guy-Anthony Ballard
Keyword(s):  
Biodiversity Conservation ◽  
Adaptive Management ◽  
Landscape Changes ◽  
Apex Predator ◽  
Mesopredator Release ◽  
Negative Effects ◽  
Top Down ◽  
Management Framework ◽  
Human Perceptions ◽  
Threatened Fauna

Australian dingoes have recently been suggested as a tool to aid biodiversity conservation through the reversal or prevention of trophic cascades and mesopredator release. However, at least seven ecological and sociological considerations must be addressed before dog populations are positively managed.Domestication and feralisation of dingoes have resulted in behavioural changes that continue to expose a broad range of native and introduced fauna to predation.Dingoes and other dogs are classic mesopredators, while humans are the apex predator and primary ecosystem engineers in Australia.Anthropogenic landscape changes could prevent modern dingoes from fulfilling their pre-European roles.Dingoes are known to exploit many of the same species they are often presumed to ‘protect’, predisposing them to present direct risks to many threatened species.The assertion that contemporary dog control facilitates the release of mesopredators disregards the realities of effective dog control, which simultaneously reduces fox and dog abundance and is unlikely to enable increases in fox abundance.The processes affecting threatened fauna are likely a combination of both top-down and bottom-up effects, which will not be solved or reversed by concentrating efforts on managing only predator effects.Most importantly, human social and economic niches are highly variable across the ecosystems where dingoes are present or proposed. Human perceptions will ultimately determine acceptance of positive dingo management.Outside of an adaptive management framework, positively managing dingoes while ignoring these seven considerations is unlikely to succeed in conserving native faunal biodiversity but is likely to have negative effects on ecological, social and economic values.

scholarly journals Vulnerability of Pacific salmon to invasion of northern pike (Esox lucius) in Southcentral Alaska

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254097
Author(s):  
Chase S. Jalbert ◽  
Jeffrey A. Falke ◽  
J. Andrés López ◽  
Kristine J. Dunker ◽  
Adam J. Sepulveda ◽  
...  
Keyword(s):  
Coho Salmon ◽  
Pacific Salmon ◽  
Management Strategies ◽  
Pink Salmon ◽  
Cost Effective ◽  
Northern Pike ◽  
Esox Lucius ◽  
Potential Habitat ◽  
Proactive Management ◽  
Southcentral Alaska

The relentless role of invasive species in the extinction of native biota requires predictions of ecosystem vulnerability to inform proactive management strategies. The worldwide invasion and range expansion of predatory northern pike (Esox lucius) has been linked to the decline of native fishes and tools are needed to predict the vulnerability of habitats to invasion over broad geographic scales. To address this need, we coupled an intrinsic potential habitat modelling approach with a Bayesian network to evaluate the vulnerability of five culturally and economically vital species of Pacific salmon (Oncorhynchus spp.) to invasion by northern pike. This study was conducted along 22,875 stream km in the Southcentral region of Alaska, USA. Pink salmon (O. gorbuscha) were the most vulnerable species, with 15.2% (2,458 km) of their calculated extent identified as “highly” vulnerable, followed closely by chum salmon (O. keta, 14.8%; 2,557 km) and coho salmon (O. kisutch, 14.7%; 2,536 km). Moreover, all five Pacific salmon species were highly vulnerable in 1,001 stream km of shared habitat. This simple to implement, adaptable, and cost-effective framework will allow prioritizing habitats for early detection and monitoring of invading northern pike.

Sign in / Sign up

Export Citation Format

Share Document