The Capture from a Boat/Open Water Susan's Full Report on Open Water Capture (Contributed by Susan Butler, General Biologist, Sirenia Project) Preparing for captures: We have to do a lot of preparation work before we do an open water capture. We usually start planning the capture and assembling the needed equipment one to two months before the actual capture date. The planning process entails scheduling the capture crew, which means making sure that the people and the boats are available on the capture dates. We try to have around 15 people, plus one capture boat and one extra boat for spotting and helping with nets. We also check the capture site beforehand and make sure that it will suit our needs both for processing the captured manatee and for safety factors. Assembling the equipment involves building several belts of each size (because we never know exactly what size belt the manatee will need until we measure its peduncle), tethers of all strengths and the number of transmitters that we would like to attach to the manatees (usually 5 to 7). The Morning of the Capture: On the day of the capture, we begin early in the morning by launching the boats and getting the equipment ready. Everyone involved with the captures will gather together and a meeting is held. Bob and Jim explain to the group how the captures will work, who will be on the capture boat, who will be on the spotting and helping boat, and who will be on land ready to help evaluate the manatees. They also discuss safety issues and answer any and all questions asked. When all of this is completed it is time to begin! Making the Capture: The capture boat usually has 7-8 people on board and the net. The net is arranged in the back of the boat so that when we are ready to deploy it, it will go out without tangling as the boat moves forward. The net is 300 feet long and 20 feet deep. The top line of the net has many floats (this is called the float line), which hold the top of the net at the surface. The bottom line of the net has many lead weights (this is called the lead line), which help the net to sink to the bottom. Typically, both the capture boat and a second spotting boat go out at the same time and begin looking for a manatee of suitable size (we try to capture animals that are adult size). We try to focus on a manatee that is in an acceptable area for maneuvering the capture boat and that is not in a large group of manatees. This is very important as it can become very complicated when we end up with several animals in the net at one time. Once we locate an animal, the driver of the capture boat begins a large circle around the manatee. As the boat circles the net is deployed off the stern of the boat. The driver steers the boat around to where the beginning of the net was deployed so that the net encircles the manatee. At this point the capture boat stops and usually puts out anchors. We take a moment to make sure the manatee is inside the large circle of net and that it is surfacing to breathe. The net is then pulled in from one side of the circle or the other, with two teams of people pulling. One team will pull the float line and one team will pull the lead line. As the net is being pulled in, the people on the spotting boat will assist if there is a snag in the net. They also keep an eye on the manatee to make sure that it is breathing in a normal fashion and to note its location within the net in order to advise the capture crew on which side of the net to pull. When most of the net is pulled on board it is time for the entire capture crew to use all of their strength in order to pull the manatee up onto the back of the boat. This usually means a count to three and everyone pulling at once. This can be a dangerous point of captures because often the manatee is flipping its tail about, so we have to be very careful that neither the manatee nor people get hurt. Manatees are very powerful, large animals and the capture crew is very respectful of that. Fortunately, most manatees become very calm and quiet when they are out of the water. Once the manatee is pulled safely onto the capture boat, both boats head to shore where the manatees will be evaluated and tagged. Two Manatees are safely captured and placed on the boat Credit: USGS, BRD, Sirenia Project Evaluating and Tagging the Manatee When the capture boat reaches shore, the net is removed from the manatee and a stretcher is placed underneath the animal. A small crane is used to lift the manatee in the stretcher up out of the boat and on to shore. The crane has a scale attached to its cables, which enables us to get a weight when the manatee is lifted on to land. Sometimes the manatee is left in the boat for the assessment and tagging. It's a heavy load Credit: USGS, BRD, Sirenia Project   At this point we have several different teams working on various duties. Bob and a veterinarian will draw blood from the flipper, collect urine and fecal samples if possible, and measure the fat layer using an ultrasound. The overall health of the manatee is also assessed. Jim and Susan take a measurement of the peduncle and fit the proper belt size to the manatee. Once the belt is tightened around the peduncle, a tether of appropriate strength, and transmitter are attached. Jim and Susan also photograph and sketch all of the scars on the manatee. Another team of helpers takes measurements of total length and girth. Others fill buckets of water to pour over the manatee while it is out of the water because we do not want the animal to overheat while on land. Another team will insert two PIT tags (Passive Integrated Transponder) under the skin on either side of the shoulder area of the manatee. These PIT tags can then be read with a scanner and can help identify this individual if the belt and tag becomes unattached and it is captured again, or if it is recovered dead. These tags operate in a similar fashion to the bar codes on many products that can be scanned for prices in stores. We all try very hard to work quickly as we do not want to keep the manatee out of the water any longer than necessary. When all of this is completed we are ready to release the manatee back into the water. Don't worry, we'll have you back in the water in a jiffy! Credit: Naples Daily News Time for release! Once again, the crane is used to lift the manatee in the stretcher back down to the capture boat. The manatee is then transported back out to the approximate capture location and gently pushed off of the back of the boat and into the water. At this point there is usually a round of applause by all of the folks involved as we watch the manatee swim away with its new tag! Work continues, however, as samples must be labeled and processed, while the capture crew prepares for another net set. Copyright 2002-2004 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form