Recovery time of Rivers/fisheries after Hurricanes

[BruceC2C]

Interested to get thoughts, experiences and facts based on previous, significant weather events.

How long does it take for rivers & fisheries to show signs they r beginning to recover ?

Understanding this will b a pretty broad based topic.
Please, let the dialog begin.

 

[Sharknado5]

Related, Hurricane Beryl may have caused adverse effects in Potter/Cameron county streams a couple months ago. It dumped 6 inches of rain up there. Anyone know how it affected the streams?

 

[sandflyx]

The broad heads lost the green drakes in 1955 and has never recovered.

 

[sandflyx]

Not sure what Debbie did here, we had major flooding here. Not seeing any slate drakes only October Caddis.

 

[PennKev]

Interested to get thoughts, experiences and facts based on previous, significant weather events.

How long does it take for rivers & fisheries to show signs they r beginning to recover ?

Understanding this will b a pretty broad based topic.
Please, let the dialog begin.

Here's a previous discussion on severe flooding:

Previous Flood Discusion

Here's a document from Vermont regarding brook trout population data in regard to major floods:

Flood Impacts to Wild Trout Populations in Vermont


My experience as an angler in PA has been that is is hard to correlate floods with population fluctuations since we often deal with low/warm water years suppressing populations also. Additionally, my experience has been that the smaller the stream, the more populations fluctuate in a way noticeable to me, but It's hard to correlate that to a specific event. For larger streams, like the bigger central PA trout streams or my local smallmouth bass waters, I can't recall a flood event that I felt ruined the fishery, if only temporarily. To the contrary, I'm often amazed how well they fish as soon as the water levels return to normal. In the later example I'm thinking of floods that register in the 10,000 cfs neighborhood on the USGS gauges.

 

[Swattie87]

In 2011 I had very good Brookie fishing in the Fall after the floods in September. Starting, I don’t know, a handful of days after the water receded.

I think floods can be bad over the longer term in terms of what they do to habitat, but I think fish are pretty good at living through the actual flood event itself. Fins and they can swim and all.

 

[Bamboozle]

The broad heads lost the green drakes in 1955 and has never recovered.

The Brodhead Creek was literally scoured from the dam breach at Devil's Hole Creek to the mouth, however the subsequent channelization probably had more to do with screwing things up than Hurricanes Connie & Diane.

 

[globug15]

Tropical storm Lee brought catastrophic flooding to the Loyalsock drainage in September 2011. Roads were ripped up and stream banks scoured. The Susquehanna also impacted many riverside towns.

Working on the PFBC unassessed waters initiative, we surveyed over 150 streams Summer 2011 working with Jon Niles at Susquehanna University. This gave us baseline population estimates for many of the headwater streams in the drainage of the Loyalsock.

Returning to survey a handful of those streams on the same reaches in October 2011 indicated a dramatic decrease in the populations. Say a stream that had 75 fish pre-flooding across all year classes, we may have only found 8-10. Not surprising these were fish in the the older year classes (6-8 inch fish) to remain post-flood.

Sampling in Summer 2022 following the spawn, we found the populations had exploded with huge YOY classes, presumably due to lower competition. I'm saying 2x the number of fish in that reach with about 70x of them being YOY.

Summer 2023 we saw population still that were relative high, say 1.25x the original year of sampling. Ages classes began to stabilize again. Still great recruitment of YOY.

Summer 2024 we were still slightly higher, say 1.1x. More adult fish noted and YOY returning closer to the first year.

Interesting as well, we took macroinvertbrate kick net samples at all of those original sampling times in Summer 2011. Samples for macros were then taken monthly following the storm for over a year.

Macros had a dramatic drop as well, but rebounded much more quickly. Multi-brood species like baetidae and chironomids were the first to see that population explosion just like the YOY trout.

That was a last of my fisheries biology experience, so I am no expect. My impressions of the situation after reviewing the data and reading additional published papers are that species will recover. Often a high recruitment class to follow as long as there are no further stressors or stochastic events in these areas. Granted these are all "wild areas" with limited impacts from development.

-John

 

[BradFromPotter]

They are catching trout on Pine below Ansonia.

 

[JeffK]

Brodhead is a great example. Hurricanes have clobbered it repeatedly since 1955. Had relatively good period of 50 years, then early 2000's was a bad time when the stream actually changed course by about 200 yds near the ballfields in Stroudsburg. Can see the remains of the old dam over by the hillside above the park. The ballfields were partly washed away and the retaining wall was built to protect the park and the ballfields filled in. It always came back, but some losses too. One local guide told me back around 2000 after the Hurricane damage to check out rocks before fishing. If the rocks are scoured and have no bugs - fish elsewhere. Look for where bugs are. Fish have to eat and will avoid overly scoured areas.

IMHO, one problem lately in PA and Catskills is the crazy weather. Back in early 2000's we had 4 major floods in short order and exposed banks couldn't recover before next hurricane hit. Then there is the drought/flood yo-yo. The Raritan R near me reached flood stage 4 times between Dec 2023 and January 2024. Historic average is hitting flood stage every other year. Then we got low, warm water in summer. Little Lehigh had one day where temps didn't get below 70F for the whole. The flood/drought yo-yo is tough on rivers IMHO.

 

[lycoflyfisher]

If we leave well enough alone, mother nature is excellent at fixing herself. More damage is done post flood by "fixing" or "cleaning" streams in the realm of bulldozing and channelizing streams. Those activities cause reoccuring problems and instability overtime that can take years if not decades for watersheds to find equilibrium again. Floods are natural events, the stream and its inhabitants will recover if we allow them to.

Improved stormwater management, protecting the natural functions of floodplains and improving floodplain access are some of the most cost effective means of improving flood resiliency.