Invasive species represent the second most significant cause of species extinction worldwide after habitat destruction, and in islands, they are undisputedly first. The impacts of alien invasive species are immense, insidious, and usually irreversible - IUCN
Invasive Atlantic lionfish have demonstrated measurable ecosystem damages in their invaded range. As a matter of urgency, strategies to suppress lionfish have therefore risen to the fore amongst the ocean management community. We use a biophysical model and ocean climate data to demonstrate how Atlantic lionfish larvae are dispersed by currents and how this, combined with their breeding strategy, negates effective control using methods traditionally executed on a local scale. This study quantitatively emphasizes the high level of larval connectivity that exists between the many nations whose waters now support established lionfish populations. For any given area, our results indicate the key to suppressing the invasion is to simultaneously choke all upstream linkages that supply external larvae and renourish the local population. On the basis of a case study developed for the Carolinas, U.S.A., an area of high lionfish abundance, the model suggests that such a strategy requires monthly culls that remove 20% of lionfish biomass in the Carolinas and all locations to which the Carolinas are linked hydrographically. Conversely, if culls target only those locales that deliver the majority (95%) of lionfish larvae to the Carolinas, and therefore ignore those locations which contribute the remaining 5% of lionfish larvae, the requisite cull rate exceeds 60% and suppresses lionfish abundance for only five years. The latter finding exposes an intrinsic danger; sparse lionfish left uncontrolled may derail a concerted, but yet not comprehensive, effort to control the invader. This study provides a modelling approach to quantitatively target and manage the lionfish population for nations whose waters are now plagued by invasive lionfish.Johnston, M.W., Purkis, S.J. (In Press) A coordinated and sustained international strategy is required to turn the tide on the Atlantic lionfish invasion. Marine Ecology Progress Series. http://dx.doi.org/10.3354/meps11399
In this study, we demonstrate how perturbations to the Florida Current caused by hurricanes are relevant to the spread of invasive lionfish from Florida to the Bahamas. Without such perturbations, this current represents a potential barrier to the transport of planktonic lionfish eggs and larvae across the Straits of Florida. We further show that once lionfish became established in the Bahamas, hurricanes significantly hastened their spread through the island chain. We gain these insights through: 1) an analysis of the direction and velocity of simulated ocean currents during the passage of hurricanes through the Florida Straits and, 2) the development of a biophysical model that incorporates the tolerances of lionfish to ocean climate, their reproductive strategy, and duration that the larvae remain viable in the water column. On the basis of this work, we identify 23 occasions between the years 1992 and 2006 in which lionfish were provided the opportunity to breach the Florida Current. We also find that hurricanes during this period increased the rate of spread of lionfish through the Bahamas by more than 45% and magnified its population by at least 15%. Beyond invasive lionfish, we suggest that extreme weather events such as hurricanes likely help to homogenize the gene pool for all Caribbean marine species susceptible to transport.Johnston, M.W., Purkis, S.J. (In Press) Hurricanes accelerated the Florida-Bahamas lionfish invasion. Global Change Biology.
The Atlantic invasion of Indo-Pacific lionfish (Pterois volitans/P. miles) has been as swift as it has been disastrous. Lionfish are non-native to the Mediterranean, but an invasion is perhaps even more likely than for the Atlantic. First, as for the Atlantic, there are many major cities on the coast of the Mediterranean (where aquarium-keeping is a common practice and chances of accidental and deliberate releases are high), and second, lionfish are native to the Red Sea, to which the Mediterranean is connected via the Suez Canal. Furthermore, there have already been four records of lionfish in the Mediterranean and so the pretext for an invasion is already in place. Up until now, however, it has been difficult to gauge the likelihood of an infestation of lionfish in the Mediterranean as, unlike the Atlantic, this sea has not been examined in terms of its hydrodynamics, ocean climate, and bathymetry, all factors known to be relevant to assessing the possibility of invasion. Motivated by this knowledge-gap, this study used remote sensing and computer modeling to investigate the connectivity between areas along the Mediterranean coastline that fulfill the necessary physical criteria to serve as potential lionfish habitat. Model results from the Mediterranean were compared and contrasted to those from the Atlantic and eastern Pacific. The Atlantic was considered because the lionfish invasion there has been voracious. Meanwhile, the eastern Pacific is interesting as a site without native lionfish, but with plenty of opportunity for their introduction, but no invasion yet recorded. Results indicated that, unlike in the Atlantic, connectivity among potential lionfish habitats in the Mediterranean was low in the study and comparable to that in the eastern Pacific. Although oceanographic conditions in the Mediterranean were found unfavorable for wide dispersion of lionfish larvae, hotspots where numerous lionfish sightings would forewarn an impending invasion were identified. This paper can therefore serve as a guide to the most efficient monitoring of lionfish in the Mediterranean and to where removal efforts should be concentrated, should the species become established.Johnston, M.W., Purkis, S.J. (2014) Are lionfish set for a Mediterranean invasion? Modelling explains why this is unlikely to occur. Mar. Pollut. Bull. http://dx.doi.org/10.1016/j.marpolbul.2014.09.013
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 presents the first known prediction of the potential for establishment of lionfish in the eastern tropical and north Pacific Ocean, encompassing a region from 0° N to 40° N latitude. This study compares and contrasts the dynamics of hypothetical introductions of lionfish in the Pacific and Atlantic oceans in order to highlight the different dynamics of an invasion. Transition matrixes are constructed to illustrate connectivity between discrete precincts and settlement densities are calculated to indicate potential for establishment of breeding lionfish populations. This study suggests that lionfish, which are very successful in the Atlantic, may not be as efficacious in the Pacific due the lack of equitable conditions for the species. Additionally, the study indicates that connectivity within the Pacific study region is not conducive to the rapid spread of larvae over great distances.
Eleven serranid species were intentionally stocked in the Hawaiian Islands from 1955-1961 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 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.
Pterois volitans and Pterois miles, two sub-species of lionfish, have become the first non-native, invasive marine fish established along the United States Atlantic coast and Caribbean. The route and timing of the invasion is poorly understood, however historical sightings and captures have been robustly documented since their introduction. Herein we analyze these records based on spatial location, dates of arrival, and prevailing physical factors at the capture sights. Using a cellular automata model, we examine the relationship between depth, salinity, temperature, and current, finding the latter as the most influential parameter for transport of lionfish to new areas. The model output is a synthetic validated reproduction of the lionfish invasion, upon which predictive simulations in other locations can be based. This predictive model is simple, highly adaptable, relies entirely on publicly available data, and is applicable to other species.
Johnston, M.W., Purkis, S.J. (2011) Spatial analysis of the invasion of lionfish in the western Atlantic and Caribbean. Marine Pollution Bulletin 62 (6), 1218–1226.
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.