Project Leader

Dean Grubbs

Dean Grubbs

Who I am

I am a fish ecologist and much of my research is geared towards providing answers needed for the sustainable management and conservation of coastal and deep-water sharks and rays. A Florida native, I grew up fishing and exploring the waters of the north-eastern Gulf of Mexico, which led to an early interest in marine biology in general, and a fascination for sharks and rays in particular. Studies at the University of Miami, a PhD through the College of William & Mary’s Virginia Institute of Marine Science, and a post-doctoral stint at the University of Hawaii gave me the opportunity, and good fortune, to work under the guidance of some of the academic giants in this field. I have now been studying sharks and rays for more than 25 years and have tagged and released more than 10,000 sharks from over 40 species during that time.

Where I work

I am based at the Florida State University Coastal and Marine Lab in the USA, although I spend as much of my time at sea doing research as I spend on land, and for much of that time I am working in the same ecosystem studying the same shark populations that inspired me in my youth. I lead a very active lab of bright graduate and undergraduate students and maintain a core of talented collaborators that allows me to work on an array of subject areas.
My SOSF-funded project focuses on the biology and ecology of the smalltooth sawfish. The sawfishes are a small group of large tropical batoids (relatives of skates and rays) that are considered by the IUCN Shark Specialist Group to be the most imperilled of all families of sharks and rays. All five species in the group are currently listed as Endangered or Critically Endangered. As most species reach lengths of five metres or more, sawfishes are among the top predators in the ecosystems where they live.
The smalltooth sawfish is listed as Critically Endangered by the IUCN and was the first native marine fish ever listed as Endangered under the US Endangered Species Act. The primary threat to sawfishes in the USA is by-catch, particularly in trawl fisheries. Our work on smalltooth sawfish in the Florida Keys and the Florida Everglades uses fishery-independent surveys and satellite telemetry to examine their movement and migration patterns. Understanding these patterns will help us to predict areas where sawfish are most likely to be taken by the fisheries so that management efforts can be implemented to decrease by-catch. In addition, we use blood chemistry to assess physiological stress in captured individuals, as well as their reproductive status.

What I do

The recovery of this Critically Endangered species will depend on the number of viable populations that remain. Most recent records outside Florida have come from The Bahamas, primarily from Andros Island. Andros is a very large, remote island that is home to as much mangrove backcountry – preferred sawfish habitat – as the Florida Everglades. In 2010 we conducted a pilot study to examine the feasibility of conducting sawfish research on Andros to complement the work we are doing in the USA. Thanks to funding through the SOSF and support from Flamingo Cay Lodge on Andros, we will be able to develop the Andros sawfish project. We will seek to fit smalltooth sawfish in The Bahamas with archiving pop-off satellite tags, to complement the more than 40 individuals we have tagged in Florida. The aim of this is to examine migration and habitat-use patterns and to assess possible movements between Andros and other Bahamian islands, or even between The Bahamas and the USA. We will also use state-of-the-art genetics techniques to determine whether Bahamian and US sawfish populations are distinct or whether significant mixing takes place.
Prior to this project, sawfish pupping had not been documented anywhere in the western North Atlantic outside Florida. During our first trip in 2015, we documented for the first time the presence of young-of-year sawfish on the west side of Andros, the first evidence of sawfish giving birth in The Bahamas. This region has recently been designated the Andros West Side National Park. Current evidence suggests that the smalltooth sawfish population in US waters is slowly increasing. This positive trend probably stems from the sawfish being fully protected from harvesting, and from the fact that a significant amount of its primary habitat in US waters is federally protected within Everglades National Park and the Florida Keys National Marine Sanctuary. Through our SOSF-supported research, we are perfectly poised to assess whether the newly designated national park in Andros could have a similar effect on the sawfish population in The Bahamas.

My project

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