Internship Log - Week ending July 2, 2010
Tags: Summer Internship, water chestnut, invasive species, otiliths, Fishing Challenge
Invasive Species Removal - Water Chestnut
This week was one of the more labor intensive weeks, but none-the-less a great turn-out. Monday started off at the crack of dawn. We were headed to the Sassafras river to help eradicate an invasive species known as Water Chestnut. For those who don't know, Water Chestnut is an annual aquatic plant with a submerged flexuous stem that anchors into the mud and extends upward to the surface of the water. It has saw-tooth edged leaves that are triangular in shape and connect to an inflated petiole, which provides added buoyancy for the leafy portion of the plant. The plant itself grows so extensively that it prevents the sun's rays from reaching the very important bay grasses. We scanned the spots where people reported sightings of this species and only pulled a couple of plants. However, on the way back to the boat launch, me and my fellow intern Ryan Gary, were on the waverunner and decided to check one of the last coves. Needless to say, there was quite a bit of it. Our team of two boats and one waverunner knocked out the cove in about 2 1/2 hours. It was said that we pulled up over 120 bushels of the Water Chestnut, so overall it was a great day!
Tagging Striped Bass
Tuesday was a big day for DNR, marking the second day of tagging for the Diamond Jim Fishing Challenge. Each month until September, one fish will be predetermined to be the official Diamond Jim worth as much as $25,000 to the angler who catches him. The other tagged “imposter” fish are worth $500 each. This year, as many as 600 fish will be tagged and released representing more than $300,000 in potential cash winnings. On tuesday, all of the boats combined tagged 154 fish, bringing the total to over 320 fish for both rounds. The fish weren't biting as well as they have been but the captains still pulled through.
Water Chestnut Removal - Round 2
On Wednesday, we were back to the Water Chestnut's! This time, we were on the Bird River, but on canoes. Our team for this day consisted of 4 canoes, and 1 boat. The canoes were needed in order to get back into the shallow waters that the boat could not reach. We did pull up some plants, however it was not nearly as much as we got on the Sassafras. It's a great thing that were out there doing this, as our goal is to preserve as much as we can.
Aging Largemouth Bass
I had an excellent, solid week in the field! To conclude the week, Ryan and I took a trip to the Manning Hatchery. Here we were working with otoliths, which are hard structures located behind the fish's brain. They aid the fish in balance, and hearing, just like humans. Here we were using the otoliths to age the fish, and to help determine growth studies. The process of aging a fish using an Otolith is very interesting. First, you have to break the otolith in half. Once you have a half that you are satisfied with, you move to the sanding process. Wet sanding allows you to smooth the side of the otolith that is going to be presented under the microscope. After you have wet sanded the half of the otolith, you move it under the microscope, into a petri dish with clay; to help support the bone. The microscope has a camera hooked up to a computer, where you take a picuture of the otolith, in order to determine the age. The next process is actually determining the age of the fish. The fish grow the fastest during the warmer seasons, and slower during winter. The darker, "translucent" zone represents a period of fast growth. The whiter area, or "opaque zone" represents a period of slower growth. So essentially, the age of the fish is determined by counting the annuli, or opaque bands that represent slower growth(winter's). Once again, it had to be one of the most interesting activities I've taken part in.