I am scientist, computer programmer, ocean geek, and all around nice person. Here you will find information about my studies and passions.
Eleven serranid species were intentionally stocked in the Hawaiian Islands from 1956-1961 to fill a perceived snapper-grouper niche and produce a fishery. Three of the introduced species established self-sustaining populations and eight were extirpated within 15 years. The causative factors behind the success of some of the fish and failure of others has not been fully examined. This study relies on a proven biophysical model, combining life history traits of a species and oceanographic conditions in Hawai’i, to produce a hind cast of the Hawaiian introduction. Using computer simulations, we examine physical oceanographic conditions and species life history traits which may have enabled the success of L. kasmira, C. argus, and L.fulvus, exclusive of the rest. The study draws life history data from literature for all modeled species, and relies on proven ocean circulation and global elevation relief models to compile ocean characteristics surrounding the Hawaiian Islands.
The lionfish invasion in the Atlantic and Caribbean has proceeded with vigor since their introduction in the 1980’s or early 1990’s. Lionfish effect recruitment of juvenile fish to reefs and are found in densities far surpassing that of their native Indo-pacific. There is concern that this voracious predator may become introduced and proliferate in the eastern tropical and north Pacific, through aquarium releases, transport on floating debris, or passage through the Panama Canal in ship ballast water. This study predicts the potential for establishment of lionfish in the eastern tropical and north Pacific Ocean, encompassing a region from 0° N to 40° N latitude.
The Indo-pacific panther grouper (Chromileptes altivelis) is a predatory fish species and popular imported aquarium fish in the United States which has been recently documented residing in western Atlantic waters. To date, the most successful marine invasive species in the Atlantic is the lionfish (Pterois volitans/miles), which, as for the panther grouper, is assumed to have been introduced to the wild through aquarium releases. However, unlike lionfish, the panther grouper is not yet thought to have an established breeding population in the Atlantic. Using a proven modeling technique developed to track the lionfish invasion, we track the potential spread of panther grouper in the Atlantic.
Lionfish (Pterois volitans/P. miles) are an invasive Indo-pacific marine predator that have proliferated throughout the Atlantic and Caribbean since their introduction via the aquarium trade in the late 1980’s or early 1990’s. Lionfish have become the dominant predator among multiple habitats in their introduced range. The invasion is the most successful, complete, damaging, and swift marine introduction in history. P. miles has been documented twice from the eastern Mediterranean Sea, likely via the Red Sea. As in the Atlantic, there is understandable concern that this species is also poised to establish in the Mediterranean and this study indicates the first computer-model predictions for the invasion.
Nova Southeastern University’s (NSU) Guy Harvey Research Institute (GHRI) will help shark enthusiasts take their “Shark Week 2013” to the next level with an interactive website that tracks four shark species (mako, tiger, oceanic whitetip and sand tiger) around the world. Users can interface with the technology to see where and how far the sharks travel over time.
The NSU Guy Harvey Research Institute shark-tracking website can be accessed at: www.nova.edu/ocean/ghri/tracking/.
“This multi-species shark tracking site provides an eye-opening perspective on the secret pathways and enormous distances that some sharks can cover during their seasonal migrations,” said Mahmood Shivji, Ph.D., director of NSU’s Guy Harvey Research Institute and Save Our Seas Shark Research Center.
Eighteen sharks (makos and oceanic whitetips – see names below) are currently reporting their whereabouts in the open ocean almost daily, and their wanderings can be followed in near real time on the web site, revealing novel information about their movements.
"Understanding where these animals migrate to and when they do it is crucial to their conservation," says Guy Harvey, Ph.D. "The Guy Harvey Research Institute is a worldwide leader in shark tagging and research. Dr. Shivji and his GHRI team have been able to record some of the longest tracks in the modern history of shark research."
The longest recorded track is a Tiger Shark affectionately referred to as Harry Lindo. Harry was tagged in Bermuda in 2009 and tracked for more than 3 years, providing an unprecedented long-term and detailed view of its migrations. During that time, Harry covered a remarkable distance of over 27,000 miles.
The GHRI/NSU shark tagging program, which began in 2009, has now gone worldwide, and includes New Zealand and West Atlantic Mako sharks; Tiger sharks in Western Australia, Bermuda, Grand Bahama, Bimini Chub Cay, and Grand Cayman; Oceanic Whitetip sharks in the Bahamas and Caribbean; and Sandtiger sharks in the Atlantic Shark researchers at NSU have discovered interesting patterns while tracking the various species, including:
Tiger sharks tagged in Bermuda that were tracked for 2-3 years show a seasonal pattern that they repeat year to year. They move to Bahamian and Caribbean waters during the winter, and then move to open ocean in very deep waters northeast of Bermuda where they spend a couple of months each summer before returning to warmer locales for the following winter.
Pop-up tags allow researchers to look at swimming depth as well as location data. At least one Tiger shark and a Shortfin Mako shark were recorded swimming at depths of nearly 900 meters (nearly 3,000 feet).
Shortfin Mako sharks can reach speeds of approximately 60 miles per hour for short bursts. Long-term movements for this species are not well known, but current tracks on animals tagged by the GHRI team off Ocean City, Maryland, monitored one animal as it traveled nearly 2,000 miles in the first 42 days after it was tagged. A Mako named JoAnn (tagged off Isla Mujeres, Mexico) traveled approximately 3,200 miles in 91 days since she was tagged. And yet another Mako named Carol (tagged off New Zealand) travelled to Fiji and back, covering at least 10,000 miles over the course of just over 11 months.
SPOT Tags are mounted to the fin of the shark and have an antenna that extends upward. These tags have a saltwater switch/sensor that tells the tag when it is out of the water. When the tag breaks the surface of the water, it transmits its location to a satellite, allowing researchers to track the animal over the life of the tag’s battery (typically 10 to 30 months).
Pop-up tags are archival satellite tags that are typically inserted into the shark’s top surface by its dorsal fin and collect and store data within the tag. After a pre-determined amount of time, the tag releases from the shark, floats to the surface and transmits the stored data to a satellite from which scientists can determine the position of the shark, its depth and the temperature of water in prefers to spend its time in.
For information on NSU’s Oceanographic Center, visit: www.nova.edu/ocean
About Nova Southeastern University
Situated on 300 beautiful acres in Ft. Lauderdale, Florida, Nova Southeastern University (NSU) is a dynamic fully accredited research institution dedicated to providing high-quality educational programs at all levels. NSU is a not-for-profit independent institution with 27,000 students. NSU awards associate’s, bachelor’s, master’s, specialist, doctoral and first-professional degrees in a wide range of fields. NSU is classified as a research university with “high research activity” by the Carnegie Foundation for the Advancement of Teaching, and it’s one of only 37 universities nationwide to also be awarded Carnegie’s Community Engagement Classification. For more information on NSU, visit: www.nova.edu
NSU Shark-tracking Website Helps Viewers ‘Dive Into Shark Week’ HOLLYWOOD, Fla. Nova Southeastern...
The NSU OC has partnered with WPBT to host screenings of new season 5 episodes of Changing Seas....
Expedition Lionfish South Florida: June 27 - 29, 2013 Since the species first appeared in Florida waters...
Established in 1999, the Guy Harvey Research Institute (GHRI) is a collaboration between the renowned marine artist, scientist and explorer, Dr. Guy Harvey, and Nova Southeastern University's Oceanographic Center. The mission of the GHRI is to provide the scientific information necessary to understand, conserve, and effectively manage the world's marine fishes and their ecosystems. The GHRI is one of only a handful of private organizations dedicated exclusively to the science-based conservation of marine fish populations and biodiversity. The research, education and outreach activities of the GHRI are supported by the Guy Harvey Ocean Foundation, AFTCO Inc., extramural research grants, philanthropic donations by private businesses and individuals, and NSU. Track the sharks tagged by the GHRI with our web app.
Lionfish populations have expanded throughout the Atlantic, Caribbean and Gulf of Mexico and threaten native reef ecosystems. The introduction of an exotic species with no natural predators threatens to destabilize the delicate natural balance of our local waters. OceanGate's professional crew, supplemented by leading researchers and select expedition participants, will execute at least four dives over two days utilizing a high power fish collection system to capture lionfish.
Global Invertebrate Genomics Alliance - Describing the wide functional and structural diversity of invertebrates requires an integrated approach that includes not only traditional biological sciences (e.g., anatomy, ecology, behavior, physiology, paleontology), but the burgeoning interdisciplinary efforts of genomics. Following on the success of the human genome project and the current progress of the vertebrate Genome 10K project (Genome 10K Community of Scientists, 2009), GIGA proposes to assemble or assist in the coordination and collection of samples spanning the broad spectrum of (non-insect/ non-nematode) invertebrate phylogenetic diversity suitable for whole-genome sequencing.