When I arrived at the airport in Minnesota I received a warm greeting from Bob Whaley, Chief Ranger, and his wife Barb Griffin, the Superintendent’s Secretary, who are both park divers. On Monday, we loaded up the pontoon with tanks and dive gear. Also, Bob showed me how to prepare the boat trailer for driving on the road and how to change the boat battery.
When we got down to the river to launch the boat, the color of the water surprised me-it looked like cloudy iced tea! The orange hue of the water comes from tannins that are leeched from the leaves that fall from the trees as they biodegrade in the water. For the first time in months, I put my 2 piece, 7 millimeter wetsuit on again. I forgot how restricting it is because this was the first time I wore it since diving in warmer water. It worked well and I was not cold in the water, but it certainly limits mobility and feels clumsy on land.
First, we did a check out dive so I could familiarize myself with the river current and visibility. Another goal of this dive was to search for zebra mussels by picking up rocks and feeling around their edges. Once underwater, I understood why, prior to the dive, Bob explained to me how a Zebra mussel feels instead of how it looks. He described them as feeling like a loose tooth that will wiggle but won’t come off of the rock. Even in only 4 feet of water the visibility was very low. I knew Bob was right by my side because I could hear him breathing through his regulator, but if I drifted more than 4 feet away from him, he became invisible. When we were less than 4 feet from each other, I would look for either his hand or his yellow regulator hose which were the only visible objects because everything else was dark colored and practically disappeared underwater. Also, since I have never been diving in a river before I had to get used to the current. To me, it felt like a strong ocean surge that only pulled in one direction. In swifter conditions, a device called “The Creeper” is used. They are not manufactured, but are known among river divers and scientists who need to stay in one place while working. Barb, a woman who built her own beautiful log house, welded up a fine creeper over the weekend that worked very well. Later during the week I joked that Barb probably sewed the dive flag herself, and she actually had. It seems to me that Midwesterners have more of a “Do it yourself” mentality compared to the rest of the nation.
Later that day, Law Enforcement Ranger Anna Snyder drove us to another site to dive along a retaining wall to look for more mussels. Luckily, we still found none. Mussels were discovered downstream but still have not been found farther up river. The dive team continues to monitor various places along the river checking for mussels to make sure they have not spread.
Next, I dove a known mussel bed looking for an endangered species of mussel. As we worked along the bottom, every time I found a new mussel and showed it to Bob, we stood up in the 4 feet of water we were diving in and he told me its name. I was impressed by the wide variety of mussels and was humored by their creative names, such as the Monkeyface mussel, the Purple Wartyback, the Strange Floater, the Pistolgrip mussel, the Pink Heelspitter, or the Fat Mucket among others. Out of the 42 known species found in the river, only two have disappeared. Part of this study is to discover why those mussels have disappeared, and why others are becoming endangered. We were looking for gravid Winged Mapleleaf mussels. Gravid is a term used to describe mussels that contain fertilized eggs and are looking to lure in a host fish.
Winged Mapleleaf mussel reproduction is a very interesting process. After the males shed sperm into eggs on the gills of females are fertilized when the female siphons in water containing sperm. After fertilization, the female mussels store the developing larvae in their gills. The larvae must attach to the gills or fins of a specific fish in order to complete development, so the female displays the packet of larvae so it looks like the natural prey of the host fish. When the packet is bitten by the fish, the larvae inhabit the gills. Without harming the fish, the larvae grow in its gills and transform into juveniles. Then, they drop off and land on the river bottom where they mature into adults.
The next day Bob, Barb and I dove to look for invasive Zebra mussels again. For this dive, the river entry and exit were a little more challenging because the water was about 7 feet deep. To prevent from getting swept away, we jumped in holding on to the anchor line and descended along it. Then, we crept along the bottom with The Creeper, and surfaced along the anchor line as well. Bob and Barb completed the next dive while I explored on land to see a beaver dam.
The next day, Jon Putnam, acting chief of resource management, joined Bob and me to team up with the Department of Fish and Wildlife divers to return to the same site we visited before to continue to search for gravid Winged Mapleleaf mussels. We did find the right species of mussels, but none were gravid. However, it is still early in the season so it was proposed that they may not be fertilized yet.
The following day, a thunder storm rolled through so I took the opportunity to catch up on emails and paperwork, as well as plan the rest of my internship. I never realized how challenging it would be to keep up with that aspect of the program, but it is difficult because I have been in the field or traveling constantly. Also, I am often in remote locations with no internet and spotty cell phone coverage. Luckily, I tied up everything until the end of my internship so I had airplane tickets to the final destinations and cars to drive to the places I would stay when I arrive.
On Friday, I acted as the surface support for Bob and Barb as they dove looking for either invasive Zebra mussels or endangered Winged Mapleleaf mussels.
The next day, I had the chance to attend the Minnesota State Fair to have a true Midwestern experience. It was a huge event with so many interesting things to see. I watched a demonstration on harvesting honey, saw an enormous 1,036 pound pumpkin, watched a chicken hatch and saw a calf that had been born hours earlier. Also, I was amused by the “all you can drink” milk stand, and pretty much anything you can imagine fried on a stick, even Snickers bars and cheesecake! Yuck! I did have fried cheese curds though, which everyone told me is a must have at the fair. As odd as it sounds, they were pretty good! All and all I had a wonderful time at St. Croix, enjoyed the kindness of the people there, and appreciated the unusual experience of diving in the river looking for mussels.
Thanks to Bob Whaley, Barb Griffin, Anna Snyder, Scott Yess, Phil Delphey, Jorge Buening, Jon Putnam, Woody Wimberely, Julie Galonska, and Mindy Coy.
I was fascinated to see that one of your dive destinations was the Saint Croix National Scenic River. My native American origins through my mother are the tribal Ho-Chunk peoples. Historically the Ho-Chunk people were located in Wisconsin, which included many of its rivers such as the Saint Croix River, Black River and Wisconsin River. The Ho-Chunk’s cousins, the Souix, were situated next door in Minnesota. Eventually both tribes were chased out of their lands. Only recently have the Ho-Chunks returned to a small representation of their original ancient homelands.
It was enlightening to learn that there were so many fresh-water mussels. I shall make a point to do more research on them as your narrative has been a superb stimulus. I was particularly fascinated by your description of the Winged Mapleleaf mussel . What a brilliant adaptation by natural selection. I have never read anything dealing with a bivalve that was so extraordinary .
I shall look forward to your return. The tales of your special adventure will be intriguing.