The CARMMHA field team is feeling refreshed after our day off!

We had some personnel turnover during the weekend, some folks could only be with us the first, or the second, week.

Drs. Lori Schwacke and Cynthia Smith held a second welcome/training information session for the new arrivals. Today, we ran into our first bit of bad weather. One thunderstorm looked threatening enough that Eric, our capture lead, shepherded us back to the dock at the Louisiana Department of Wildlife and Fisheries. Even though we decided to end the day early, due to the weather, we still managed to catch and assess five dolphins.

Last week, we described the steps our field team takes to collect data and samples on wild bottlenose dolphins. However, our days in the field, as long as they feel, are just the beginning of the work we’re doing as part of CARMMHA research. Today, we’ll discuss some of the analyses that we do once we’re off the water– either by our veterinary team reviewing ultrasound images/video each night here on Grand Isle or by the array of laboratories across the country that receive samples we’re collecting. Here are some brief descriptions of some of those activities:

  • Immediately after the team is off the water, the sampling processing team catalogs and organizes the samples, ships time-sensitive samples to the respective laboratories, and stores the rest of the samples appropriately.
  • One team member looks at whole blood smears under a microscope to count the number of each type of blood cell. Abnormal numbers of certain cell types or cell shapes may indicate various types of disease or illness.
  • Our team of veterinarians goes back to their camps each night and reviews/analyzes the ultrasound images and videos from our day on the water. They determine if any of the adult females we worked with may be pregnant and, if so, what trimester. They make a preliminary diagnosis of any lung disease in each animal.
  • A veterinarian specializing in dentistry looks at X-rays of the animals’ teeth to estimate their ages. We have found that this is a more accurate technique for aging some animals than body length/weight, especially here in Barataria Bay, where animals seem to be smaller than similarly aged animals in other populations such as the populations in Sarasota Bay.
  • We work with two veterinary diagnostic laboratories for blood sample analysis. Each day, one of the labs analyzes the samples we send overnight for typical blood chemistry panels (just like when we go to the doctor for bloodwork, including measurements of sodium, potassium, cholesterol, etc.), hormones and proteins (e.g., cortisol, aldosterone, globulins), evidence of infectious diseases, and complete blood counts (to back up our field measurements). Later in the year, once all of the samples have been collected, we’ll analyze additional parameters, including (but not limited to!) proteins associated with cardiac disease and additional indicators of other infectious diseases (e.g., morbillivirus titers).
  • Our immunology team will receive daily shipments of blood samples and isolate/store blood cells for the new techniques they’ve developed. They separate out different types of white blood cells (e.g., macrophages), and in turn prepare samples for immune protein measurements (e.g., antibodies and cytokines). Over the next few months, they will run all of these samples through their suite of immune function tests.
  • Our dietary team will analyze stable isotopes from skin samples and fatty acid levels from blood samples. Stable isotope data from the dolphins will be compared to stable isotope data from the fish that we think dolphins eat so that we can characterize the specific diets of each animal. We will assess whether fatty acid levels correlate with other health parameters and therefore could serve as indicators of specific illness or disease.

One of our priorities is to collect as much information as possible during the short amount of time we have with each animal.

We understand that, despite our best efforts, each animal will experience some stress from the capture-release process. Thus, we want to maximize the potential benefits from our research for bottlenose dolphins and cetaceans in general, while minimizing our impact on the animals we interact with during our fieldwork.

Today we worked with five animals: two adult males, one adult female, one juvenile female, and one female calf. The two males were some of the biggest animals we have worked with on this trip: they both measured 262 cm in length. Our field biologists were familiar with several of these animals from photo-id surveys in previous years in Barataria Bay. We were able to perform cardiac exams on three of the animals, but the approaching thunderstorm meant we had to release two dolphins before finishing their exams.

Tomorrow, we’ll talk about our unique boats and the people that keep us, and the animals, safe while we’re out on the water!

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How do dolphins find each other?

They use signature whistles! They will use a special series of clicks and whistles that represent their “names,” and they’ll repeat them to help others find them. They also spend a lot of time in family groups, where the adults and the children hang out together.

About this field update

The CARMMHA Barataria Bay Health Assessment wrapped up last month! The team spent two weeks on Grand Isle, LA and had a very successful fieldwork effort. During the trip, CARMMHA Research Coordinator Ryan Takeshita (with plenty of help from others on the team!) kept a field journal to share here on the CARMMHA website. Over the next two weeks, we’ll post daily blog entries from that field journal. In some of the entries, we have a Question and Answer section with marine mammal veterinarians responding to questions from Evie, a four and half-year-old scientist in training from Ellicott City, MD. We hope you enjoy our field updates!