Galveston Bay Dolphin Research Program Activities
October – December 2022
Galveston Bay Foundation and the Environmental Institute of Houston (University of Houston at Clear Lake) are pleased to share the latest Galveston Bay Dolphin Research Program (GDRP) quarterly newsletter. Thank you for your interest in our research!
A Splashy Overview
The field crew was able to take advantage of good weather days and completed six survey days in the last quarter of 2022- a great way to end the year! Effort totaled 409km (43hrs) during which the team sighted nearly 300 dolphins in 47 groups, with many sightings in or near the Houston Ship Channel. Halloween was a particularly busy day, with the sighting of nearly 100 dolphins!
The highlight of the quarter took place during two October surveys, shortly after the first cold front of the season. During these surveys, the crew observed several dolphins engaging in fish tossing, as well as actively leaping. The timing of these observations corresponds with the “flounder run”. This is when flounder, and other fishes, head out of the Bay seeking the warmer waters in the Gulf for the winter. Researchers were pleased to see dolphins actively taking advantage of this annual prey migration. Dolphins in Galveston Bay spend a lot of time following shrimp trawlers for an easy meal, so it was good to see them foraging naturally on other common Bay species.
On Halloween, a dolphin surprised the crew with very spooky behavior – the beheading of a catfish! The dolphin was observed tossing the fish up in the air and carrying it around in its mouth. Immediately after, the crew found the floating bloody head. Catfish have dangerous spines that can make them difficult to swallow, so this “catfish decapitation” fishing technique is a way of enjoying the fish without the spines. The technique is rarely observed, but it has been documented and studied in other regions of the Gulf.
We hope you enjoy this map that displays the 160 dolphin sightings documented by the GDRP in 2022! These sightings were the result of 138hrs and 1588km of on-the-water effort, and they resulted in the observation of approximately 1100 dolphins. At the start of 2022, we expanded our survey area to include areas of lower Galveston Bay. This has been an exciting change that will enable us to answer new questions about Galveston Bay dolphins!
Along with the above map that displays all of our dolphin sightings in 2022, we wanted to summarize and share with you the GDRP’s main accomplishments of 2022…
It has been nearly a decade since the start of our photo-identification work, and we were thrilled to reach 1000 unique individuals in our catalog! KPRC Channel 2 joined us on our research boat to feature this milestone. It was particularly rewarding to reach this milestone during a year when our scientific output highlighted results obtained from our long-term efforts. In November, the article “Site fidelity of common bottlenose dolphins (Tursiops truncatus) in a highly industrialized area of the Galveston Bay estuary” was published in the journal Marine Mammal Science. This study showed that there are long-term resident dolphins in upper Galveston Bay. In addition to the publication, we also presented this study at the Restore America’s Estuaries 2022 Coastal & Estuarine Summit in December. In August, GDRP researchers traveled to Palm Beach, Florida, to attend the 24th Biennial Conference on the Biology of Marine Mammals, the largest international conference on marine mammal science. GDRP’s co-principal investigators presented the study “Salinity and Water Temperature as Predictors of Bottlenose Dolphin (Tursiops Truncatus) Encounter Rates in Upper Galveston Bay, Texas”, another study based on our multi-year surveys.
In the Fall, we launched our new interactive map for citizens to report their dolphin sightings. Once you submit a sighting, you can immediately see your sighting on the map, see all dolphin sightings reported since 2013, and filter sightings by person. Please take advantage of this fun new tool and report dolphin sightings!
Earlier in 2022, we presented and participated in two collaborative workshops focused on Galveston Bay dolphins. The first was entitled “Greater Houston Area Bottlenose Dolphin Data Gaps”. The workshop was hosted by the Coastal Response Research Center and NOAA’s Assessment and Restoration Division, in partnership with the National Marine Fisheries Service Office of Protected Resources and the Southeast Regional Office’s Protected Resources Division. Then, we presented and participated in a second workshop The Cumulative Effects of Multiple Stressors on Marine Mammals: a Restore Workshop on Houston-area Dolphins and the Threats they Face”. The 4-day workshop was hosted by the National Marine Mammal Foundation and NOAA’s Restore Science Program. These were both great opportunities to build partnerships and collaborations with a diverse group of scientists and natural resource managers.
It was a very productive and fun year for the GDRP, and we want to give a huge thank to everyone that contributed to the program’s successes! A special thank you to our partners and Dolphin Society members for your continued support. And we are immensely grateful to our volunteers and interns that dedicated over 400 hours in 2022 to field and office work.
We welcomed two new GDRP team members in October! Sherah McDaniel (left) returned to the Environmental Institute of Houston as a Research Associate. She previously completed her masters degree at EIH-UHCL studying the foraging ecology of Galveston Bay dolphins, so we are thrilled to have her back! Kristina Simons (right), a recent graduate from Texas A&M University at Galveston in Marine Biology and Marine Fisheries, joined the team as a Galveston Bay Foundation Dolphin Research Assistant.
The content of this section is available to current members of our Dolphin Society. To become a member and receive updates on our individual dolphins, please adopt or name one of our dolphins. Adoption kits are a fun and unique gift! All funds go directly to the Galveston Bay Dolphin Research Program.
We want to extend a huge THANK YOU to everyone that adopted or named a dolphin during the holiday season. We are very grateful for the four namings that took place during the last quarter of 2022.
Earle B (#14) was named by Pat Hammond in memory of her father.
Otis (#34) was named by The Prioleau Family in memory of Leon M. Payne, Jr.
JakLuk (#35) was named by J.P. Fjeld-Hansen.
Suri (#222) was named by Marian and Austin Cornelius.
If you are interested in naming a dolphin, please consider naming #85! We first met him in the Houston Ship Channel in 2014, and with 53 sightings, he is one of our most sighted dolphins. Based on his behaviors and associates, we suspect that he could be a young “teenage” male. He is a year-round resident of upper Galveston Bay, so if you like to boat or fish in upper Bay, this would be a great dolphin for you
What YOU want to Know…
“How big do bottlenose dolphins get?”
The body size of common bottlenose dolphins (Tursiops truncatus) in the wild can vary considerably depending on a multitude of factors. Average adult body length ranges from about 6 to 13 feet, and their weight can range from 300 to 1,400 pounds. Just like us, dolphins and other animals may grow different from one another depending on the size of their parents, their sex (known as sexual dimorphism), and environmental conditions that impact their growth. These environmental conditions can include food availability, nutritional intake, habitat, geographic range, and physical stressors.
Estuarine bottlenose dolphins like those in Galveston Bay tend to be smaller than the members of their same species living offshore beyond the continental shelf. The difference between inshore and offshore bottlenose dolphins is an example of an ecotype. An ecotype is a genetically and geographically distinct “variety” within a species. It may have different morphological traits than other members of the same species due to specific environmental conditions. In some instances, an ecotype can be different enough from their original counterparts that they can be declared as a new sub-species or an entirely new species. For example, coastal western North Atlantic bottlenose dolphins are an ecotype that has recently been suggested to be declared as its own species due to how different they are from the bottlenose dolphins that live close by offshore. Among these differences, the body size of the coastal species was significantly smaller compared to the body sizes of their offshore neighbors. So, to answer the question “How big do bottlenose dolphins get?”…The answer is – It depends!
If you have a question regarding the GDRP, Galveston Bay dolphins, or dolphin biology, please submit your question using the button below. We select questions to answer from your submissions. We look forward to knowing what YOU want to know!
All activities are conducted under a NMFS Scientific Research Permit.
Galveston Bay Foundation
1725 Highway 146
Kemah, TX 77565
Environmental Institute of Houston
University of Houston at Clear Lake
2700 Bay Area Blvd.
Houston, TX, 77058