Daily Data

Below is information and other related documents that will help you interpret and understand the seagrass and manatee data Katie and Caryn are collecting. There are also links to their actual data. This page is divided into two main sections—Manatee Information and Seagrass Information. These sections are further divided into subsections. There are supporting documents throughout.

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Manatee Information

Manatee Sightings and Scans

Caryn and Katie are counting manatees to find out how many manatees live in this area and how they are using the habitat. Here is there descriptions of their process.

Once on the boat, one of the first things we do to catalogue our expeditions is to document our Record of Effort. The record of effort is the timeline for specific activities on the boat. The activities include: Travel, Scan, Survey, Sighting, Other Work, Sampling, Other Free, and Lunch. Each of these activities is marked with a start and stop time, waypoint or GPS location, GPS Accuracy, and number of Manatees seen. We also track our travel speed and distance using these data sheets.

  • Travel: When boat and researchers are traveling long distances within the study area. Travel occurs at faster speeds and in deep channels to avoid hitting a manatee.
  • Scan: When the boat and researchers are stopped at one location for 30 minutes, while looking for manatees in all directions.
  • Survey: When boat and researchers are traveling at a slow speed in shallow water between scan locations while looking for manatees.
  • Sighting: When a manatee is spotted.
  • Other Work: When boat and researchers are engaged in work other than travel, scan, survey, or sampling, for example setting a transect.
  • Sampling: When boat is stationary and researchers are collecting environmental data and seagrass samples, counting seagrass density, and measuring seagrass percent cover.
  • Other Free: When the boat is stationary and researchers are engaged in free activities such as snorkeling or watching dolphins.
  • Lunch: When the boat is stationary and researchers are engaged in eating lunch.

You can use the Record of Effort sheets below to see how we spend our time on the boat and how many manatees we see each day. You can also use the waypoints to plot our location on a map.

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Supporting Documents

Manatee Sightings

You can use manatee sighing data to compare how many manatees are seen in different locations, observed behavior, how many we were able to approach close enough to see identifying marks, and what type of habitat and bottom type were in the sighting location.

Definitions of Behavioral States:
  • REST: When the manatee’s only movement is in the vertical direction. The manatee surfaces in approximately the same location each time it breathes. No horizontal movement is observed and no evidence of feeding or socializing is observed.
  • TRAVEL: When the manatee’s movement is directional in the horizontal plane. Each time the manatee surfaces to breath it has moved some distance away from the last breath in the same direction. Or, when the manatee can be seen moving continuously in one direction beneath the water’s surface.
  • MILL: When the manatee’s movement is in both the vertical and the horizontal plane, but, there is no directionality to the horizontal movement. Sometimes it surfaces left of the last breath and sometimes it surfaces right of the last breath, etc. Or, when the manatee can be seen moving around beneath the water’s surface, but not in any continuous direction.
  • SOCIAL: When there are 2 or more manatees and the manatees are observed touching each other. In other words, there must be physical contact between 2 or more manatees. Examples: kissing, suckling, rubbing against each other, mouthing each other, climbing on each other’s back.
  • FEED: When evidence of feeding is observed. This can be in the form of (1) seagrass leaves, roots, rhizomes floating away from the place where the manatee is located; (2) a constant mud plume or trail floating away from the place where the manatee is located; (3) seagrass is seen hanging out of the manatee’s mouth when it surfaces to breath; (4) the manatee is actually observed feeding by an underwater observer.
  • UNDETERMINED: When we are unable to determine what the manatee’s behavioral state is because (1) the manatee is too far away, or (2) because the manatee left the area before we could observe it long enough to determine behavioral state.
  • OTHER: Any other behavior that is not described above. For example, RUBBING (aka CLEANING) is when the manatee is observed rubbing up against an object (such as a rock or pole) or against the bottom of the sea floor Or, MUDDING is when the manatee is observed “eating” mud where no grass is evident.

Supporting Documents

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Behavioral Data

When a manatee is observed for a period of time, behavioral data are taken. Behavioral data show the manatee’s behavioral state, number of breaths per minute, any movement and comments. You can see on the Manatee Sighting Data sheets below which manatees have behavior data.

Supporting Documents

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Introduction to Animal Behavior

Ethology is a relatively new approach to the study of animal behavior, which encourages the development of Scientific Perspectives in understanding, explaining, and/or describing animal behavior. This is different from Folk Psychology which is intuitive, based upon the perspective of the individual observing, taking into account their own experiences and observations. Interpreters at zoos and oceanariums tend to use Folk Psychology to explain animal behavior. Scientists also use Folk Psychology when they first observe a behavior. Later they try to use Scientific Perspectives to better understand and describe the behavior.

For example, in answering the question why does a mating herd follow a female manatee? Folk psychology would say that it is because they “desire” to mate with her and have babies. Ethology or science would say, it is because when she is in heat or ready to mate she produces a signal that is picked up by the males, which triggers their herding behavior.

Another example is when answering the question why does a calf stay with its mother for as long as two years?
Folk Psychology would say it is because the mother “wants” to make sure the baby calf can learn its travel routes and feeding grounds. Ethology or science would say when a calf stays with its mother for a longer period of time it is more likely to survive to adulthood.

The important piece here is that an ethological or scientific perspective has data to support its answers, while Folk Psychology uses more human terms like “wants”, “desires” and “beliefs”.

Using Ethology, much of animals’ behavior can be described from two perspectives: Proximate and Ultimate. Proximate answers the how questions about individual animals while Ultimate answers why questions about an entire population.

Pattern-Static “Snapshot”
Process-Dynamic “Video”

Individual Animals
“How Questions”

behavioral triggers:
internal state/
external stimuli
changes in behavior as an animal ages: maturation and/or learning

“Why Questions”
adaptive significance: effect on reproductive fitness
changes in behavior (genotype) as populations/
species diverge

To learn more about how scientists study and discuss animal behavior, read this informative document on Ethology, a multi-perspective scientific approach to the study of animal behavior.

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Seagrass Information

Seagrasses form extensive beds on the shallows fringing mangrove islands. In the Caribbean, there are three predominant types of seagrass - turtle grass, shoal grass and manatee grass. Turtle grass and shoal grasses are an important food source for manatees. (Manatees may not eat very much manatee grass at all!)

Turtle grass is probably the most abundant marine plant in the Caribbean. It has flattened strap like leaves that are about 3/4 in (1.8 cm) wide and about 1 ft (30 cm) tall. New plants grow from a dense rhizome system rather than from seeds. Rhizomes are a modified root system. As a result, grass shoots from a single area are clones of each other.

Shoal grass is found in smaller pockets. It also has strap like leaves, but they are much smaller than turtle grass. Shoal grass is 2-3 mm wide and 4-10 cm tall. New plants also grow from rhizomes rather than seeds.

We measure three features of the grassbeds to describe them.

Biomass is a measure of the amount of living matter in a particular area or ecological system. It is typically defined as the amount of plant matter (primary productivity) in an area and measured in units of weight such as grams or ounces.

Percent cover
is the amount of the bottom that is covered by seagrass. In some places, the entire bottom is covered by seagrass like a continuous meadow. In other places, disturbances such as wave action, grazing by manatees or foraging by rays, cause grass meadows to have bare patches.

Density is the number of seagrass shoots counted in a certain area. We use a 1/4-meter square quadrat. In some places, seagrass grows in thick clumps. In other places, it is fairly sparse.

Seagrass Documents and Data

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