The ongoing climate crisis is enabling an invasive predator, the northern pike, to wreak havoc on Alaska's iconic fish populations. This issue is particularly concerning in the Matanuska-Susitna region of Southcentral Alaska, where the pike's voracious appetite and expanding range are devastating native fish species and local sportfishing businesses. The situation is a stark reminder of the interconnectedness of ecosystems and the far-reaching consequences of climate change.
The Alaska Department of Fish and Game is actively trying to control the pike population, but the challenge is significant. The pike, an invasive species in this region, were likely introduced illegally in the 1950s and have since spread rapidly. They have already invaded over 150 waterways around Anchorage and the Matanuska-Susitna region, decimating native fish species and causing economic harm to local sportfishing lodges and air charter businesses.
A recent study published in the journal Biological Invasions highlights the alarming impact of climate change on pike behavior. As water temperatures rise, the pike's metabolism accelerates, leading to increased hunger and aggression. The study found that young pike have eaten 63% more compared to those from a decade earlier, and this trend is expected to worsen by 2100, with a projected 6-12% increase in their appetites. This is particularly concerning for the Deshka River, a once-premier sportfishing destination for chinook or king salmon, which is now closed to sport fishing due to low productivity.
Adding to the complexity, another study revealed that pike can navigate through saltwater, opening up new colonization opportunities. This discovery is significant because it means that the pike can potentially move through estuaries like Cook Inlet, which connects the Gulf of Alaska with major river systems. The implications for salmon, trout, and other species are profound, as adult pike are known to prey on a variety of animals, including ducklings, eagle chicks, and even juvenile pike.
The economic impact of the pike invasion is substantial. Economic studies show that as native fish populations decline, direct spending on sportfishing in the Mat-Su region has plummeted by 47% between 2007 and 2017, from $141 million to $57 million. This has had a devastating effect on local businesses, including fishing lodges and air charter companies, with many having to close down.
One such business owner, Mike Williams, a retired Army veteran, lost his salmon runs due to the pike invasion, leading to the closure of his sport fishing lodge. The decline in salmon populations has also affected bears, wolves, and the duck population in the area. Andy Couch, a longtime guide and fishing columnist, has seen his business dwindle due to the pike's impact on salmon populations.
Despite the dire situation, there is some hope. The Alaska Department of Fish and Game is implementing suppression efforts, prioritizing key waterways with gillnetting and the use of a plant-based pesticide called rotenone. These measures aim to contain the pike in areas crucial for sportfishing and related businesses. Parker Bradley, the regional invasive species coordinator, describes the Mat-Su region as a 'growing dumpster fire' for pike predation, but he remains optimistic about the efforts to control the pike population.
However, there are concerns about public perception and support for pike suppression. Some fishers might not understand the devastating impact of the pike on native fish and could potentially embrace pike fishing. Dave Atcheson, a fly-fishing instructor, worries that newcomers might not appreciate the harm caused by the pike and might not support suppression efforts. Nevertheless, he takes a long-term view, suggesting that pike and salmon might eventually coexist in certain areas, much like they do in western and northern Alaska.
In conclusion, the climate crisis is exacerbating the challenges posed by the northern pike invasion in Alaska. The interconnectedness of ecosystems and the potential for further ecological disruption highlight the urgency of addressing this issue. While suppression efforts are ongoing, public awareness and support are crucial to ensuring the long-term survival of Alaska's iconic fish populations and the preservation of its natural heritage.
