Galveston Bay Dolphin Research Program Activities
July – October 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
It was a another productive quarter for the field crew, and we achieved good coverage of both our upper and lower Galveston Bay study areas. Our team sighted just over 300 dolphins in 45 groups during 33hrs of observation effort (343 km). The team enjoyed covering new areas in lower Bay and meeting new dolphins!
This summer we reached 1000 unique individuals in our catalog! KPRC Channel 2 joined us on our research boat to learn about our work and feature this program milestone. Watch the video to meet some of our team members and catch a glimpse of a dolphin observational survey.
We are excited to share our most recent publication: “Site fidelity of common bottlenose dolphins (Tursiops truncatus) in a highly industrialized area of the Galveston Bay estuary“. The article was published in the journal Marine Mammal Science, the official journal of the Society for Marine Mammalogy. In this study, we evaluated the presence of individual dolphins in upper Galveston Bay (UGB). From 2016-2019, GDRP identified 442 individuals within UGB, and we used their sighting histories to determine their site fidelity – their tendency to stay and return to UGB.
We calculated three site fidelity metrics – occurrence, periodicity, and permanence – and then used a cluster analyses to divide dolphins into groups based on these metrics. This modeling revealed three groups: year-round and seasonal long-term residents (Group 1), one-time visitors/transients (Group 2), and short-term users (Group 3).
Long-term resident (Group 1) individuals need to be monitored closely, as these dolphins are continuously exposed to diverse threats. Moreover, this study is especially important in helping us to meet GDRP goals and guiding our future research, because it identified the long-term residents. Now, we will be able to make comparisons between our resident dolphins, and others, to better understand what makes our dolphins unique in terms of their behaviors and the threats they face. The results of our study have received coverage by some local media outlets including the Galveston County Daily News.
The Houston Ship Channel Widening and Improvement Project 11 started this summer, and the crew has observed numerous dolphins very close to the dredging operations. It does not appear that they are avoiding the areas with active dredging. One of the dolphins we recently spotted next to dredge operations was #1000 and her calf (pictured in the inset).
If you have been following our updates, you likely already know that earlier this year we expanded our standardized survey monitoring to include a larger area of Galveston Bay. Instead of focusing only on upper Galveston Bay (as in the study above), we are now covering areas of both upper and lower Galveston Bay on a quarterly basis. One of the most exciting and intriguing aspects of expanding our study area is that we are now getting to know “new” dolphins – presumably some that are residents of Galveston Bay as whole but that do not spend a lot of time in upper Galveston Bay (i.e., likely short-term users of UGB-Group 3). So far this year, we have recorded some dolphins multiple times that we had never cataloged before, or that we had only seen once or twice in our eight years of research.
This quarter, we observed numerous dolphins during opportunistic sightings. These are sightings that do not occur during our dolphin observational boat surveys, but typically during other field work. In September, one of our team members recorded opportunistic sightings when researchers were in the Bay to sample for an EIH-UHCL microplastic study. Microplastics are very small particles of plastic that are created when larger plastic breaks down and/or during the manufacturing of commercial products. Microplastics can be ingested by dolphins and other wildlife (and even us!), and chemicals found in microplastics may cause detrimental health effects.
In August, we said goodbye to Alyssa Quackenbush (Research Assistant) who is now pursuing a masters degree in Marine Mammal Science at the University of St. Andrews in Scotland. Aaron Bouwkamp, a long-term GDRP volunteer intern, transitioned to Project Research Assistant. He is assisting with a multi-year project focused on evaluating freshwater skin lesions on resident dolphins.
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.
Astro II and a buddy are jumping for joy! Celebrate the Astros starting the World Series tonight by adopting Astro II, or by making a general donation to join our Dolphin Society and support our research on dolphins like Astro II. GO ASTROS!
What YOU want to Know…
“Do dolphins stay together as family groups?”
No, not exactly. Bottlenose dolphins tend to have mostly fluid social relationships. Male dolphins do not stay with the female that they mate with or their offspring. However, relatedness can be an important factor in some parts of dolphin society. Female dolphins may return to spend time with the same group of moms and calves that their mother is part of, and “grandmother” dolphins are sometimes seen helping to care for their next generation offspring. For example, here in Galveston Bay, Jersey (#43) is one of our well known moms. She is often seen in a tight-knit group with her new offspring and her older daughter, #44, who now has her own calves. Males often form strong long-term alliances with other males after they mature. These bonds may form with kin, such as “cousins”, or may be with unrelated individuals, and are thought to increase fitness and reproductive success. Overall, dolphin society is complex and varies by individual and community, much like with humans.
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