Galveston Bay Dolphin Research Program Activities
July – September 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
Please spread the word and help support our dolphin research this holiday season when you adopt or name a Galveston Bay dolphin! Details below.
The summer months are usually the busiest time of year for our boat crew, and this summer was no exception! Our team spent 10 days on the water, completing a total of 62hrs of observation covering 720.84 kilometers. Approximately 670 dolphins were sighted in 76 groups in upper and lower Galveston Bay. We were thrilled to achieve this level of coverage and see many familiar dolphins, especially since the first half of 2021 we faced relentless wind, rain and fog that limited our field work.
We highly encourage all Bay-users to report dolphin sightings. If you’re boating, fishing, or taking a walk along the Bay, please keep your eyes peeled for dorsal fins! Because we are unable to cover our study area continuously, it is beneficial to see what patterns opportunistic sightings can provide. Moreover, sightings from areas outside our study area can provide information about what habitats dolphins are using that we would not know otherwise. Check out the map below that shows all citizen sightings that have been reported to the GDRP since 2013. What sightings stand out to you compared to our survey sighting map above? Did you know dolphins can occasionally be seen in Taylor Lake and in Buffalo Bayou near the San Jacinto Monument?
In late August, Hurricane Ida made landfall in Louisiana. Texas was on the western “dry” side of the storm, so instead of the heavy precipitation that we have come to expect with hurricanes over the past years, Hurricane Ida pushed water from the Gulf of Mexico into the Bay. This helped to balance out the spring freshwater influx from heavy rains and raised the salinity in the Bay back up to “normal” levels. At the same time, this led to improved water clarity (still only 12-18 inches of visibility, but better than normal). We enjoyed being able to see the dolphins underwater swimming around the boat – a rare opportunity in the murky waters of the Bay!
We observed some of our well-known dolphins scavenging from shrimp trawlers this summer. During ‘scavenging’ behavior, dolphins actively approach the vessel and feed on by-catch as the fishermen throw them overboard while sorting their catch. This differs from the commonly observed dolphin ‘patrolling’ behavior, when they follow the trawl net, feeding on weak or trapped prey.
What’s hanging on this dolphin?
It’s a remora! Remoras, or suckerfish, are often found holding/sucking the skin of large marine animals such as dolphins and sharks.
Can you see the scar on the flank of this dolphin?
The team captured several photos of dolphins with shark bite scars! Sharks are Galveston Bay dolphins’ only natural predator, and we occasionally see evidence of encounters between the two species.
Do you “spot” something unusual on this dolphin?
This dolphin has a large dark birthmark! Like humans, dolphins have birthmarks and these can aid researchers in identifying individuals.
We want to extend a huge thank you to our summer interns Aaron Bouwkamp, Nicholas Dunn, Alyssa Quackenbush, and Cecilia Thompson for helping with a multitude of projects throughout the past few months. Among many tasks, they participated in field work, photo identification, data management, data analyses, and education and outreach initiatives. We are excited that two of our interns will be continuing to work with us through next summer. Aaron, a current student at Texas A&M, will be completing his senior thesis in partnership with the GDRP. He will be analyzing photographs for skin lesions to evaluate the effects of freshwater on our dolphin population. Alyssa, who assisted remotely with data analyses this summer, will be returning in January as a part-time Research Assistant through GBF.
We were thrilled to welcome back GDRP Field Assistant Volunteers this past quarter! Due to Covid-19 restrictions, volunteers had been unable to participate in GDRP activities since the spring of 2020. Like our interns, volunteers are an essential part of the team, and it was very challenging to keep up with field work without their help. Diane Forthman (left) and Lori Friemel (center), two of our long-term volunteers, are pictured here with intern Cecilia Thompson (right) on a hot, calm summer day. Welcome back!
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.
A huge thank you to Marian and Austin Cornelius for generously naming Sheba (#314). She’s pictured here with her new calf! We have met two of her previous calves #451 and #873. During this holiday season, please help us spread the word about dolphin adoptions! Sheba will be one of several dolphins available for adoption! Gift adoption kits are delivered electronically and include photographs, a sighting map, and membership in our Dolphin Society.
What YOU want to Know…
“If I see a dolphin alone, is it okay?”
Probably. It is not unusual or concerning to see a dolphin alone in Galveston Bay. Coastal bottlenose dolphins do not typically form large, cohesive pods like other marine mammals (e.g. orcas) that have more permanent family structures. Instead, their social dynamics are more fluid (referred to as a fission-fusion society) and an individual can interact with many different dolphins. We do see long-term partnerships like male-pair bonds and mother-calf pairs, but generally speaking, Galveston Bay dolphins may hop from one group to the next, engage in various activities with different individuals, and some times, hang out alone. During our surveys this quarter, the team sighted groups that ranged in size from 1 to 38 dolphins! The average was nine dolphins per group. As long as a solitary dolphin is swimming and behaving “normally”, you do not need to be concerned. Signs of a dolphin in distress and/or abnormal behavior include rolling to one side while repeatedly swimming in circles at the surface, difficulty breathing or swimming, pushing up onto a beach, visible entanglement in fishing gear or other debris, and/or a large fresh injury.
If you see a sick, injured, entangled, stranded or dead dolphin, please call the Texas Marine Mammal Stranding Network immediately at 1-800-9MAMMAL. If you live or travel outside of Texas, please check out the NOAA Fisheries’ website. Numerous organizations throughout the United States have the training and capacity to respond to marine mammals that need help.
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