Galveston Bay Dolphin Research Program Activities
April – June 2021
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
Rain, rain, and more rain! If you live in the Houston area, you know that we were pummeled by rainstorms throughout the last quarter. This made it difficult to get out on the water, but fortunately we were able to achieve full coverage of our study area in June, as well as some coverage of lower Bay throughout the quarter. The field research crew completed 29hrs of surveying in five days (420km of effort) resulting in the observation of 220 dolphins in 30 groups. Unfortunately, it was evident that some dolphins are feeling the effects of low salinity associated with the heavy rains. When we are hit with heavy precipitation, much of this freshwater drains into the Bay and this quickly decreases its salinity.
Bottlenose dolphins are physiologically adapted to live in brackish and oceanic water with salinity ranging from 18 to 35 ppt (parts per thousand). They will experience negative health consequences with prolonged exposure to salinity below 10 ppt. Effects of low salinity on dolphins may include changes in blood chemistry and electrolytes, swelling of the cornea, development of skin lesions, and even death. After heavy rain, salinity levels in upper Galveston Bay often drop below the 10 ppt threshold. Since the inception of our program, we have observed the development of skin lesions following low salinity events, and this issue became clearly evident after Hurricane Harvey when 96% of observed dolphins had at least one lesion.
The topic of low salinity effects on bottlenose dolphins is an issue we mention often because of its importance, and it is receiving considerable attention by scientists and natural resource managers throughout the Gulf coast. It has become a “hot topic” primarily because of the increase in the frequency of heavy precipitation events and because of proposed coastal development projects (e.g. water diversion, coastal protection barriers) that could alter estuaries inhabited by dolphin populations. Over the last couple of years, multiple webinars, workshops, and meetings have been dedicated to discussing the effects of low salinity on dolphins, and recently the results of an expert elicitation on this topic were published. Our observations on skin lesions in Galveston Bay have been included in the ongoing discussions.
Over the next year, GDRP, in collaboration with experts on this topic, will be focusing efforts on analyzing our long-term data to tackle some of the pending questions regarding this important issue. Some of these questions concern dolphins that have high site fidelity (i.e., resident dolphins) to areas frequently affected by low salinity events. Although some dolphins may leave their preferred habitat during a low salinity event and return once salinity increases, dolphins are unlikely to abandon their home range completely, even in unfavorable conditions. Accordingly, one of our main priorities is to determine which of our cataloged animals are long-term residents of upper Galveston Bay. Once we have identified these potentially vulnerable individuals, we will look closely at the development of skin lesions on these dolphins.
Spring is always an exciting time of year because the crew meets YOYs (young-of-the-year)! Our researchers have sighted 10 YOYs so far this year and have also seen several one-year old calves that we first met last year.
GDRP developed and executed several community outreach and education initiatives throughout the quarter! Through our partnership with Harris County Precinct 2, the GDRP hosted the second annual dolphin-viewing class at Juan Seguin Park. Observing dolphins from the park provided a great opportunity for Bay-area citizens to learn how to best and safely view dolphins. For this event, a Dolphin Activity and Coloring Book was developed and distributed for young participants to enjoy at the event. Please spread the word about this fun printable resource! We also developed a slideshow called “Eavesdropping on Galveston Bay” where we showcase an array of sounds recorded by our hydrophones (underwater recorders we use to monitor dolphin sounds). Finally, we were excited to participate in virtual Bay Day through a video where GDRP Principal Investigator Kristi Fazioli provides a first-hand introduction on how we conduct our research. Be sure to check out the GDRP at 40:40 mins!
We welcomed four new GDRP interns in May! Aaron Bouwkamp (Texas A&M Galveston), Cecilia Thompson (Eckerd College), and Nicolas Dunn (Texas A&M Galveston) (pictured left to right) are assisting with field work, photo-identification and data management. They have also played a vital role in developing outreach resources like the Dolphin Activity and Coloring Book and the Eavesdropping on Galveston Bay slideshow. Alyssa Quackenbush (North Carolina State University) is our data analyses intern. Primarily, she is working on a site fidelity analysis to determine which dolphins are residents of upper Galveston Bay. These dedicated students and recent graduates are playing a huge role in executing GDRP projects this summer, and we are extremely grateful for their hard work!
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.
What YOU want to Know…
“How are dolphins born?”
After a gestation period of about 12 months, a bottlenose dolphin will give birth to a single calf. To avoid drowning, calves are born tail first. Like most mammals, newly born dolphins are connected to the mother’s placenta with an umbilical cord. The cord breaks away after birth leaving a belly button! Immediately after birth, the mother may assist the newborn to the surface to take its first breath. It will take a few hours for the uncoordinated newborn to master swimming and breathing. A newborn calf is completely dependent on its mother, and it will obtain all of its nutrition from its mother’s thick and rich milk. Newborn dolphins can be readily recognized because of their tiny size, dark coloring, close association with their mothers and/or fetal folds. If you’re curious, this short video shows the birth of a bottlenose dolphin at the Brookfield Zoo.
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!
We want to extend a huge thank you to everyone who named or adopted a dolphin as a gift for Mother’s Day. We exceeded our fundraising goal and with your help raised $6400! These contributions provide essential support for our research and helped fund two 2021 summer internships.
A special thank you to the generous donors that named dolphins this past quarter:
Brett Mossman named Sandy (#4, pictured above with her calf) in honor
of his mother Sandra Mossman.
Mariloli and Marvin Odum named Surfy (#302) in honor of their grandchildren.
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