NOAA Teacher at Sea
Aboard NOAA Ship Pisces
July 6 – 19, 2012
Mission: Marine Protected Areas Survey
Geographic area of cruise: Subtropical North Atlantic, off the east coast of South Carolina
Date: July 11, 2012
Weather Data from the Bridge
Air Temperature: 28.1C (82.4F)
Wind Speed: 9.75 knots ( 11.2 mph)
Wind Direction: From the SSW
Relative Humidity: 86 %
Barometric Pressure: 1017
Surface Water Temperature: 27.7C (80.6F)
Science and Technology Log
Even though our mission focuses on the five species of grouper and the two species of tilefish that I have shared in earlier postings, something that has surprised us all is the sheer number of lionfish that have invaded these reef areas. I sat down with Andy David, Co-Principal Investigator on our cruise, to get the full scoop on this invasive species.
An invasive species is one that does not naturally occur in an area but was either deliberately or accidentally released into the wild and competes with native species. Alien invasive species often have very few, if any, natural predators to help keep their populations in check. As a result, invasive species populations often explode. These invasive species begin competing with the native inhabitants for the same food supply potentially starving out the native fish and forcing them to move out of that region in search of food.
Lionfish are native to the western Pacific. They were first observed in the Atlantic Ocean in 1992 on coral reefs off West Palm Beach, FL. Since the water temperature and bottom habitat in the South Atlantic very closely resemble that of the lionfish’s native habitat, conditions were favorable for the population to spread very rapidly. Unlike most fish in this region the lionfish spawns year round, so it does not have a normal spawning season. A female lionfish can spawn every couple of days and each time can release up to 15,000 eggs. These eggs were carried off by the current and spread to other parts of the east coast. Since few of the native Atlantic predators eat lionfish, they were able to reach maturity and continue building their population. So what the genetic analyses indicates started as six individual lionfish off West Palm Beach in 1992, now has spread all the way north to Cape Hatteras, North Carolina via the Gulf Stream, then on other currents across to Bermuda and down to the Bahamas, Cuba, Puerto Rico, the Virgin Islands. And they have now made their way into the Gulf of Mexico and are moving along the coastal states in the Gulf. Check out this animation demonstrating the spread of the lionfish.
Lionfish tend to live in the same rocky reef habitats as the grouper and short bigeye, so we see them together quite frequently on our ROV dives. All of these reef fish are competing for the same food supply — small fish and crustaceans. The grouper, short bigeye, and lionfish prefer to live in rocky overhangs or crevasses. Lionfish are ambush predators and will wait for their prey to swim by and suck them into their mouths. They also have a voracious appetite.
All of the lionfish we have seen are extremely fat and happy. They are gobbling up the food supply just as fast as they can. Often times we will see multiple lionfish using the same rock as shelter. In fact, in a single three-hour dive covering about 1.5 nautical miles, we saw upwards of 150 lionfish!! And that was only within the 6-10 foot wide field of view from the ROV camera. There are plenty more that we were not able to document since they were out of view. In one week alone we have seen nearly 700 lionfish! Imagine how much of the available food source a whole gaggle of lionfish can consume on the reef. The concern is that the lionfish are using up all of the food available so that the commercially important fish such as grouper and snapper will no longer have anything to eat and will be forced to leave the area. This could be devastating to the grouper population which could result in fewer fish being available for commercial and recreational fishermen as well as a blow to the species in general.
So what can we do about this? Agencies like NOAA are encouraging divers to hunt any lionfish they see and take them home to eat. Lionfish derbies are sponsored by local diving organizations, such as REEF, to encourage divers to participate in these hunts. But hunting lionfish with scuba divers will not solve the entire problem.
On this particular research cruise, we have seen lionfish down to depths of about 100 meters (330 feet). This is well below the limits of recreational scuba diving. Lionfish have been seen at depths of 300 meters (1,000 feet). How can we control the spread of this invasive species at depth? Some groups such as the Roatan Marine Park think that training sharks to prey on lionfish might be a solution. This is a lengthy process and it is uncertain if the sharks would continue to hunt lionfish once they are out in nature on their own. Some species of grouper and moray eels can also eat lionfish, but they prefer to just leave them alone rather than risk being the recipient of a sharp sting from those pesky poisonous fins. The cornet fish might also prey upon juvenile lionfish by sneaking up on them from behind. We have seen about a dozen cornetfish in this first week of ROV footage compared to the one per year that are seen normally. Could the cornetfish be a partial solution to this invasion? We can only hope.
There is also a concern with the push to make lionfish a commercial species. Since they inhabit coral reefs, it is possible that lionfish, along with grouper and amberjacks, could become tainted with a toxin called ciguatera. In a joint study between NOAA and the FDA in the seas surrounding the Lesser Antilles islands of St. Maarten, Virgin Islands and Puerto Rico, ciguatera was found in 26% of the lionfish sampled. These larger reef fish prey upon the smaller herbivorous reef fish that have eaten the algae carrying the ciguatera toxin. Through biomagnification, the lionfish, grouper, amberjacks and snapper carry enough of the toxin to make humans extremely ill. Symptoms of ciguatera poisoning include nausea, vomiting, diarrhea, headaches, muscle aches, and reversal of hot and cold sensation, just to name a few. Symptoms can last for weeks to years depending on the individual. This toxin cannot be removed from the fish by cooking, so the debate continues as to whether lionfish are safe enough to be marketed as a commercial fish in areas where ciguatera is present.
I am amazed at how quickly the lionfish have spread throughout the Western Atlantic region. So what started out as six lionfish in 1992, now numbers over 10,000,000 just twenty years later. Their coloring allows them to remain camouflaged so they are able to just sit and wait for food to come to them. When we are looking at the ROV screen, it is not always easy to spot these invaders at first. Their prey probably don’t even realize that they are about to be eaten, they blend in that well. Andy David says that with most invasive species, we see a spike in numbers initially, but eventually the numbers should come back down as the lionfish run out of food and as other predators learn how to eat them. How long until we start to see a decline? That remains to be seen. Things may get worse before they get better, or we may already be seeing a decline in numbers. More research needs to be done.
Ocean Careers Interview
In this section, I will be interviewing scientists and crew members to give my students ideas for careers they may find interesting and might want to pursue someday. Today I interviewed Andrew David, Co-Principal Investigator on this expedition.
What is your job title? I am a Research Fishery Biologist and the Chair of the NOAA Diving Control and Safety Board.
What type of responsibilities do you have with this job? As a fishery biologist for NOAA, I am currently conducting research on the commercial fish of the South Atlantic such as grouper and tilefish. As part of my research, we also study the habitat that these fish live in which are the shelf edge and deep reefs. The data that we collect on these species is used to help fishery managers determine where the South Atlantic and Gulf of Mexico MPAs should be placed and if they should be maintained.
As the Chairman of the NOAA Diving Control and Safety Board, I work with the diving officers of other NOAA programs to monitor the safety of the roughly 500 divers in the agency. We do this by creating a set of standards that all divers in NOAA must adhere to, testing new diving equipment, and working with other diving organizations to ensure safe and effective procedures are followed. Our safety record is very good. We normally make close to 15,000 dives a year with an incident rate of below 0.01 percent.
What type of education did you need to get this job? I earned my Bachelor’s Degree in Chemistry and Biology from Stetson University in Deland, Florida. My Master’s Degree is in Marine Science from the University of Southern Florida. My Master’s work focused on the effects of genetically engineered bacteria in the marine environment. It wasn’t exactly what I thought I would study in graduate school, but it was an excellent opportunity that I could not pass up and it helped me to network with other scientists in the field. This led to me getting my job with NOAA straight out of graduate school where I work on topics that have a greater interest to me.
What types of experiences have you had with this job? Working on these deep corals projects has been very rewarding. We have discovered many things on these projects, such as a greater coverage of deep coral reefs than was previously thought, new species of crustaceans, and range and depth extensions for several species. Plus I get to spend time at sea every year while we conduct our research.
What advice do you have for students wanting a career in marine biology? You do not have to go straight into marine biology at a school near the coast as an undergraduate. In fact, it is probably better if you major in a core science such as chemistry or biology for your Bachelor’s and then focus more on marine science when you start looking for a graduate school. Send your applications out to professors at universities with good marine biology programs. If you are offered a position working with a professor who offers you research support, you should strongly consider taking it even if the research topic is not your favorite. Graduate school is about learning how to become a good scientist — you have plenty of time to specialize in an area of interest to you when you get out of school.
Also, take internship opportunities when you can find them! That is how scientists in the field get to know you and what you are capable of. Internships might lead you to your first job out of college. For example, Stacey Harter, the Chief Scientist on our cruise, started with Andy David as an intern. When she graduated from college, they offered her a job! Get internships!