The Week the Rains and Salmon Came to Hoonah

When something you expect and love (although sometimes you may not know you love it) is absent for a long time you experience great joy in its return. When the rains returned to Hoonah after the second  driest July in 20 years I rejoiced in how quickly it rejuvenated the ecosystem and in the resilience and patience of salmon.

A July Without Rain

In July 2018, there was something very obviously missing from Hoonah, Alaska : rain.  Even though this was only my third summer in Hoonah, it was not difficult for me to think back to previous summers and acknowledge how the lack of rain was impacting our local berry patches,  rivers, salmon, and forests. The conditions reduced the wet muskegs to patches of brittle sphagnum moss and sedges. There was a noticeable impact on our salmon berries and blueberries. Very few salmon berries ripened, and blueberry barrens normally laden with ripening berries had nearly blank bushes. Our local temperature rainforest ecosystem was struggling without rain.

Bear, Coastal Brown Bear, Hoonah, Alaska, Game Creek
Coastal Brown Bears feed on Chum Salmon that made it into the river despite the low flows. The salmon were easily captured because they lacked the ability to escape.

The lack of rain resulted in a lack of spawning salmon. It is expected in July that Pink and Chum Salmon would fill the holes throughout the rivers. However, the drought-like conditions reduced rivers to minimum baseflows and kept Chum and Pink Salmon from easily returning to rivers.  Especially Pink Salmon were almost absent from all of Hoonah’s major rivers because they were trapped in the mouths. Without a large rain event they would remain at the mouths until desperation and time forced them upstream.

Bear, Coastal Brown Bear, Hoonah, Alaska, Game Creek
A Coastal Brown Bear snatches a Chum Salmon from Game Creek outside of Hoonah Alaska. Only half of the river had active flow in it and the breeding Chum Salmon were subject to high predation from waiting Bears.
Chum Salmon, Dog Salmon, Hoonah, Alaska, Spasski River, Underwater
During July Chum Salmon were able to get into the rivers because they are larger than Pink Salmon and can skirt up the riffles more easily.

Climate Norms

It is easy for time to erase the memory, and for past perceptions about the weather to vary widely. However, I talked  to many in Hoonah who could never remember the rivers so low. I was curious to know if that was true or if time had changed the memory.  Although Hoonah does not have a river baseflow station I used precipitation data and assumed that low monthly precipitation results in low rivers.  The summarized data showed that we received 1.11 inches in July 2018 and that only 2009 was lower with 0.9 inches. 1999 was noteably low with 1.51. inches. As Hoonah is centered in a temperature rainforest each of those years was far different than the average of 3.95 inches of rain that Hoonah would expect in July. These results made July 2018 the 2nd driest in 20 years!

Rain, Analysis, Hoonah, Climate, Weather, Precipitation
Total rainfall accumlation at the Hoonah airport from 1998 to 2018. In the last 20 years there have been two instances where July has been very dry – 1999 and 2009. I would infer in those years that rivers were similarly low as our 2018 July. Data are summarized from the NCDC NOAA Daily Summaries dataset (https://www.ncdc.noaa.gov/cdo-web/datasets#GHCND)

I was struck when summarizing the data in the amount of variation of precipitation over the last 20 years in Hoonah. Even 2018 was an example of that.  It was in stark contrast to July 2017 which was noted as the “10th wettest” by Juneau weatherman Rick Fritsch.  I needed to keep this summer in perspective : although it was obvious that our rivers, berries, and salmon were stressing from the heat and lack of precipitation, each had been through this before.

The Relief of Rain

In early August the drought came to an end. It rained and poured for nearly a week as an “atmospheric river” brought in moist air from the Gulf of Alaska. I can say with confidence I have never been so relieved to get rain. Overnight the muskeg ponds were filled and returned to the wetlands they were meant to be. The rivers were choked with water and soon after brimming with salmon. Despite the drought and the longer wait at sea they had returned anyway. I could only smile as I watched them in the rivers circling in the holes and splashing up the riffles.

Salmon, Alaska, Hoonah, Pink Salmon, Split Level, Underwater, Go Pro
Pink salmon followed the rain in and filled the upper holes of local rivers.

With global climate change already heavily impacting Alaska the drought felt like a warning knell for times to come.  Scientific modeling for the region suggests we will continue to warm drastically but that precipitation amounts will remain about the same.  The outlook for salmon in a warming climate has different endings depending on who you will talk to. Certainly there is a lot of variability between glacial systems, snow systems, mountains, rain regimes, and so much else which makes a certain future hard to predict. Global warming will impact each salmon species differently (some potentially positively and some negatively) and there is no scientific concurrence how exactly what the impact of a warming world will be for salmon. My views are generally pessimistic for our salmon in the next 50 years, but their patience and resilience this year give me hope they will find a way to survive in the future, too.

Cascade, Hoonah, Alaska, River, Long Exposure, Waterfall, Lighting
A local stream choked with high-flows from the drought-ending rain.
Future climate models show temperature to increase in Hoonah Alaska over the next 50 years. Data from SNAP community profiles.
Future SNAP precipitation models suggest that rainfall will remain pretty consistent, however, with warming temperatures more winter precipitation will fall as rain instead of snow. That will reduce crucial mountain snowpack that feed salmon streams.

Salmon, Alaska, Pink Salmon, Underwater Salmon, Alaska, Rain,