Vanessa J. Mintzer

• Ph.D.
• Director of Dolphin Research & Conservation at Galveston Bay Foundation

The Amazon River dolphin (Inia geoffrensis), or boto, is illegally harvested for use as bait in fisheries for the catfish Calophysus macropterus. To determine the effect of this harvest, we estimated apparent survival for a boto population in the central Brazilian Amazon where direct harvest is known to have occurred since 2000. For our analysis, w...

The use of aquatic mammals as bait to enhance the harvest of fisheries species has garnered little attention by the scientific and conservation communities, often receiving only brief mention in reports focused on the human consumption or bycatch of aquatic mammals. A number of studies, however, highlight the negative impact of this practice on aff...

The potential value of protected areas for the conservation of cetaceans is widely recognized; however, few evaluation methods exist to assess their effectiveness. In this study, a modeling approach based on long-term mark-recapture/resight data was used to assess the effectiveness of a Brazilian reserve in protecting endangered Amazon River dolphi...

Bottlenose dolphins (Tursiops truncatus) that inhabit urban estuaries like Galveston Bay, Texas, are exposed to cumulative stressors including pollution, fisheries, shipping, freshwater inflows, and construction operations. With continuing development, it is imperative to understand the key environmental variables that make the Galveston Bay estuar...

Negative interactions between fishers and the Amazon River dolphin (Inia geoffrensis), or boto, have increased substantially in the last few decades. Herein, we investigate these interactions with focus on assessing fisher perceptions, attitudes, and behaviors toward botos. Moreover, we evaluate the effect that the Mamiraua Sustainable Development...

In the last decades, knowledge about the biology of the Amazon river dolphin Inia geoffrensis has increased considerably. Accordingly, we present a review of the published literature on this river dolphin, with a focus on topics with the most advancements and those that are important to the species conservation. We also present new information, inc...

Coastal common bottlenose dolphins (Tursiops truncatus) that inhabit urban estuaries are exposed to a myriad of anthropogenic threats. To manage and conserve these populations, it is imperative to understand their habitat use and residency patterns. In this study, we evaluated the site fidelity of common bottlenose dolphins in upper Galveston Bay (...

River cetaceans are particularly vulnerable to anthropogenic impacts due to their constrained ranges in freshwater systems of China, South Asia, and South America. We undertook an exhaustive review of 280 peer-reviewed papers and grey literature reports (1998−2020) to examine the current status of knowledge regarding these cetaceans and their conse...

From August 26 to 30, 2017, Hurricane Harvey inundated the Galveston Bay estuary in Texas with record-breaking rainfall. As a result, salinity levels in the bay declined rapidly from an average of 14 to < 1 ppt, altering aquatic habitat in the weeks following the storm. Long-term photo-identification monitoring efforts provided an opportunity to un...

In the 1980s and 90s, surveys suggested that few bottlenose dolphins inhabited upper Galveston Bay (UGB), a highly-industrialized estuary influenced by commercial shrimp and recreational fisheries, heavy ship traffic, urban runoff, toxic pollutants, systematic dredging, altered hydrology and freshwater inflow. Although the area continues to be a ho...

Deliberate killing for use as bait in a regional catfish (Calophysus macropterus) fishery is the primary threat affecting the survival of the Amazon river dolphin, or boto (Inia geoffrensis). Establishing and improving freshwater protected areas has been suggested as a possible course of action to protect the species. However, the ecology of the bo...

Critical data gaps exist for all Texas bay, sound and estuary bottlenose dolphin (Tursiops truncatus) stocks and managers consider Galveston Bay a high priority for research. Surveys conducted in 2013-2015 suggest that a bottlenose dolphin population regularly utilizes upper Galveston Bay (UGB) and the Houston Ship Channel (HSC). This highly indust...

The Amazon River dolphin (Inia geoffrensis), or boto, has shared the same aquatic resources and space with fishers for thousands of years. In the last decades, due to human population expansion, growing markets, and technological advancements, interactions between botos and fishers have increased substantially. Since the mid-1990’s, botos are being...

We examined the stomach contents of 27 short-finned pilot whales (Globicephala macrorhynchus) that mass stranded on the North Carolina coast on 15 January 2005. Eleven whales had prey parts in their forestomachs. We used frequency of occurrence and numerical abundance to assess the relative importance of prey. Brachioteuthis riisei (numerical abund...