My next stop on my list of parks to visit was Crater Lake National Park, the fifth park I’ve visited this summer. I arrived just in time for Crayfish Week, a week that the Natural Resources- Aquatic Division team devotes to the study of this small but dangerous invasive species.
Crater Lake is an incredibly complex ecological system, made only more complicated by the introduction of crayfish in 1915. The freshwater crustaceans were introduced to provide a food source to trout in Crater Lake, but in recent years the crayfish population has exploded, and now threatens native species such as the endemic Rough-Skinned Newt.
The lake is unique in many ways. The 7,700 year old lake was formed by a volcanic eruption, and is the deepest lake in the United States at almost 2,000 feet deep. Known for it’s blue water, the lake also has the highest UV light penetration in the world- higher even than the waters surrounding Antarctica. And because the unpolluted water of Crater Lake is fed only by rain and snowfall, it’s actually good enough to drink! Suffice it to say, Crater Lake is a pretty special place.
Our team for the week consisted of Scott Girdner, a Fisheries Biologist and Limnologist, Drew Denlinger, a Seasonal Biological Technician and Kristin Beem, a Student Conservation Association (SCA) intern. Armed with crayfish traps, bait and some elbow grease we set out to catch some crayfish!
Kristin and Scott pulling up crayfish traps.
Our goal for the week was to catch crayfish at different sites and different depths around the lake. By measuring and noting the length, weight and sex of each crayfish, the team is able to extrapolate the data to determine larger population models. Unfortunately recent population models have not been positive. In 2008 crayfish were present at 50% of monitored shoreline sites- it’s estimated that crayfish are now present at 80% of the sites in 2014.
The presence of invasive species in national parks has unfortunately been a common thread throughout my internship. Between lake trout in Yellowstone, lionfish in Biscayne and Dry Tortugas and now crayfish in Crater Lake, it seems impossible to shake these aquatic invaders. Scott spoke about the difficulty of watching the decline of native species due to the increase of invasive species, saying “It’s easier to prevent the introduction of invasive species like crayfish than it is to deal with them after their introduction.” I did my part to keep the crayfish population down by eating a whole mess of them for dinner! Waste not.
Luckily the mood wasn’t all doom and gloom while at Crater Lake. Being on the water each day and surrounded by the mountains of the caldera was an incredible experience, and each day brought something new. One morning Drew, Kristin and I saw two bald eagles sitting in a nearby tree, and then 30 minutes later we pulled up a newt in one of the crayfish traps! Seeing this lovable newt was a great way to visualize why the the Natural Resources team spends so much time on this research- to protect threatened species like the newt.
A Rough-skinned Newt
I also got to see some other popular features of the lake, including Wizard Island, Phantom Ship (a smaller island) and the Old Man of the Lake, a 30-ft tall tree stump that has been floating around the lake for over a century! The lake’s temperature (cold!) and relatively low productivity has slowed the decomposition process on the log.
On calm days you can see all 30 feet of Old Man!
Calm water makes gorgeous reflections
The natural beauty of the lake was just astounding. I’m pretty sure Kristin, Scott and Drew got tired of me saying “Wow” so much! Still, it couldn’t be helped, especially when we saw some beautiful waterfalls catching the light just right.
All in all I had a great week assisting the crayfish monitoring research at Crater Lake National Park. Between the glorious views, great people and fascinating research, it was the experience of a lifetime. To all researchers combating invasive species- keep up the good fight!
Left to Right: Scott, myself, Kristin and Drew