Tag: grouper

Posted on

Chris Imhof, November 17, 2009

NOAA Teacher at Sea
Chris Imhof
Onboard NOAA Ship Pisces
November 7 – 19, 2009

Mission: Coral Survey
Geographic Region: Southeast U.S.
Date: November 17, 2009

Science Log

We sailed last night to our first “station” – The North Florida Marine Protected Area – and by 7:00 am this morning the ROV pilots Lance Brown and Glenn Taylor were going through the “pre-flight” checklist on the ROV; Lance working the controls in the lab, Glenn outside taking care of the deployment and extraction of the vehicle on the starboard weather deck. Soon they were meeting with the Lead NOAA scientist Andy David to talk through the operations of the deployment and extraction and more specifically the methodology of what they were trying to accomplish at this site.

The North Florida MPA area has been protected since 2004 – meaning no sailing or fishing occurs in this area. Some of the area has been mapped by multi-beam sonar – so what scientist then do with ROV technology is “Ground-Truthing” in which after examining the multi-beam maps – choose features to explore and check visually how they compare with their maps. Since the ROV sends real time video feed to the lab, the scientist watch and note the features, the animals that are present or not present in the habitat. They also perform a down shot every 2 minutes, or stop the ROV – point the camera down and take a picture – later in the lab they quantify the habitat by gridding the photograph and counting the number of species. Todays North Florida site tested sites inside the Marine Protected Area as well as sites/features outside the MPA for comparison as well as to help make future decisions of extending possible areas into the protective zone or even species.

After the scientists met, the Pisces crew and captain Jeremy Adams met on the weather deck to talk through the operation – sync their communications and what if scenarios. In all, there were 3 ROV dives which went extremely smooth, mainly due to the organization and communication of everyone involved.

The highlights of the dive were the spectacular features of the exposed limestone near the drop offs and the amazing habitats – for all my preparation the diversity of fish was overwhelming – I could identify a few featured fish like the Lionfish, barracudas and Moray Eels – I was unprepared to see a real sea turtle hanging out by some rocks or a Goliath Grouper which came out of nowhere. I learned many new fish which I hope to be able to call out from the monitor tomorrow like the Reef Butterfly, Squirrel Fish, Amberjack, Scamp, Soldier fish, Purple and Yellow Tail Reef Fish. I was helpful in identifying some of the Occulina deep coral species, the sponges (which you couldn’t miss) as well as pick out old fish line, a bottle and and an old anchor jammed into the rocks near the edge.

I’ll let the pictures and video slices tell most of the story. We are cruising all night again to our most northern site Edisto – off South Carolina and then work back from there.

Posted on

Tara Treichel, April 26, 2008

NOAA Teacher at Sea
Tara Treichel
Onboard NOAA Ship Nancy Foster
April 15-27, 2008

Mission: Lionfish Survey
Geographical Area: Atlantic Ocean, off the coast of North Carolina
Date: April 26, 2008

One of the Survey Technicians operates the Multi-Beaming mapping system.
One of the Survey Technicians operates the Multi-Beaming mapping system.

Weather Data from the Bridge 
Visibility: 10 n.m.
Wind: 11 knots
Waves: 1-2 feet
Ocean swells: 2-4 feet
Sea temperature: 23.5
Air temperature: 22.0

Science and Technology Log 

In addition to the Lionfish survey, the other research that is being conducted while aboard the NANCY FOSTER is benthic habitat mapping of the ocean floor. This is accomplished using highly sophisticated, computerized multi-beam SONAR technology. Two survey technicians aboard the ship are responsible for running and monitoring the system, which is run all through the night. The operators make sure that the system is recording data properly and that the ship stays on course (within about 5 meters), and process the data as it is recorded. The course is set and followed, lawnmower style, back and forth along long narrow parallel lines, producing a beautiful rainbow colored map coded for “depth by color,” where red is high and blue is low. After five nights of mapping, the white digital nautical chart contains five tiny rainbow swatches, each one representing about 10 square miles of mapped space. Each year the research team adds to the swatches, until one day perhaps the entire bay floor will be mapped. Scientists later use the maps to support their research; in this case, Paula used them to determine where to dive. With countless miles of ocean floor (much of which is sand, or poor fish habitat) and limited time and research budgets, the maps are a critical part of the research effort. 

Tara holds up a specimen that some of the scientists said was the biggest Spiny Lobster they had ever seen!
Tara holds up a specimen that some of the scientists said was the biggest Spiny Lobster they had ever seen!

There are a lot of variables such as temperature and salinity that can  influence the transmission of the sound waves produced by the multi-beam sonar to measure seafloor depth.  In order for the data to be as accurate as possible the survey technicians need to measure these variables throughout the water column using a CTD (conductivity (salinity), temperature and depth). They conduct three CTD ‘casts’ a night by first lowing and raising the CTD on a long cable that is controlled by a winch.

Personal log 

Today, the Chief Engineer caught a Wahoo off the stern of the boat. Wahoo! Can you think of a fish with a cooler name? It’s a cool fish, too, sleek and streamlined, with large jaws and a loud stripy pattern on blue gray skin. It was perfect timing, since a barbeque was planned for our last afternoon at sea. The fish is nearly all muscle, and yielded 25 steaks, almost enough for each one of our full ship of 35 people aboard. How was it, you ask? Delicious! The scientists also caught several large Spiny Lobsters, a Scamp (a Grouper), Hogfish, Sea Bass, and of course, many Lionfish. In addition, they saw a Mola Mola (Sunfish) and several Loggerhead Turtles. 

Posted on

Thomas Nassif, July 20, 2005

NOAA Teacher at Sea
Thomas Nassif
Onboard NOAA Ship Nancy Foster
July 15 – 24, 2005

Mission: Invasive Lionfish Survey
Geographical Area: Southeast U.S.
Date: July 20, 2005

A underwater photograph of the City of Houston shipwreck. Over time the ribs of the ship’s hull have been covered by sponges (pink fluff) and soft coral (colorful branches). Tomtate fish are pictured to the right.
A underwater photograph of the City of Houston shipwreck. Over time the ribs of the ship’s hull have been covered by sponges (pink fluff) and soft coral (colorful branches). Tomtate fish are pictured to the right.

Weather Data

Latitude: 33°38’N
Longitude: 76°55’W
Visibility: 10 nautical miles (nm)
Wind direction: 240°
Wind speed: 13 kts
Sea wave height: 1-2′
Swell wave height: 2-3′
Sea water temperature: 28.9°C
Sea level pressure: 1018 mb
Cloud cover: 6/8, Cumulus, Altocumulus

Science & Technology Log  

My excitement and fascination with this entire diving expedition grew even more when I heard that the divers would be exploring two shipwreck sites on the ocean floor today – “18 Fathom” in the morning and “City of Houston” in the evening. Fathoms are an old unit of measurement still used by navigators today to describe the depth of the ocean (1 Fathom = 6 feet deep). The dive site “18 Fathom” is a mystery shipwreck that was discovered at a depth of 108 feet (18 Fathoms). Shipwrecks provide excellent habitats for a variety of fish, including lionfish. The broken down hull and old passageways of a  shipwreck create a manmade reef upon which algae and coral grow, smaller fish hide, and larger fish feed. Rather than scrap old ships, many countries around the world clean and sink their old ships to the ocean floor to create artificial reefs for fish and other marine organisms.

An explosion of Tomtate (white fish) and Vermilion Snapper (red fish) envelop the water in a silvery red glow.
An explosion of Tomtate (white fish) and Vermilion Snapper (red fish) envelop the water in a silvery red glow.

After lunch, the boat steamed ahead to the next dive site, City of Houston. Far beneath the ocean surface looms an old Civil War Era shipwreck. Thousands of fish including Tomtate, Vermilion Snapper, and Silverside enveloped the divers, making the surrounding waters shimmer with silvery red. At times the number of fish were so great that the divers had trouble seeing even a few feet in front of them! Over one  hundred years after the City of Houston wrecked and fell to the seafloor, you can now see coral and algae taking over the entire manmade structure. Even so, it is still possible to make out obvious structures of the ship, including the engine and the hull.

Personal Log 

Today I went snorkeling off the NF4 once again and had a fantastic time swimming in the 84°F water under a beaming sun – It’s unbelievable that the Atlantic Ocean can be so warm during the summer months! Also, I’ve watching the divers in action as they descend to the ocean floor, collect live lionfish, and take stupendous photos of the deep ocean all inspire me to someday become a professional SCUBA diver myself.

Question of the day

What type of air do SCUBA divers breathe?

This depends on how deep you plan to dive. Regular air (the kind we breathe on land) is mostly nitrogen and only 21% oxygen. The tanks that the deep-sea divers carry on their back are filled with regular air, and they can dive up to 150 feet by breathing this air through a mouthpiece (or regulator). Other divers that only need to dive up to 113 feet (like our safety divers) use Nitrox, which has more oxygen (36%) than regular air. Finally, at depths up to 20 feet deep, SCUBA divers can breath pure oxygen (100%). The deep-sea divers on our cruise switch to pure oxygen 20 feet before they reach the ocean surface to speed up their decompression.

The two dangers with SCUBA diving and the air they breathe are:

1 – Too much oxygen can be toxic to your body. The deeper you dive, the less oxygen you should have in the air you breathe. 2 – At the same time, too much nitrogen can make you feel light-headed and put you to sleep underwater. Jacques Cousteau, French inventor of the SCUBA, called this “Rapture of the Deep.” That is why it is so dangerous for divers to spend too long in the deep ocean.

Posted on

Thomas Nassif, July 19, 2005

NOAA Teacher at Sea
Thomas Nassif
Onboard NOAA Ship Nancy Foster
July 15 – 24, 2005

Mission: Invasive Lionfish Survey
Geographical Area: Southeast U.S.
Date: July 19, 2005

“A fiery ball of radiant yellow…penetrated the hues of deep blue and wispy whites.”
“A fiery ball of radiant yellow…penetrated the hues of deep blue and wispy whites.”

Weather Data

Latitude: 33°38’N
Longitude: 76°55’W
Visibility: 10 nautical miles (nm)
Wind direction: 240°
Wind speed: 13 kts
Sea wave height: 1-2′
Swell wave height: 2-3′
Sea water temperature: 28.9°C
Sea level pressure: 1018 mb
Cloud cover: 6/8, Cumulus, Altocumulus

Science & Technology Log  

Today was by far the most beautiful sunrise we’ve had since our departure from land last week. A fiery ball of radiant yellow captured the sky, as its luminous rays penetrated the hues of deep blue and wispy whites in the surrounding sky. This morning the divers visited Kinny 1 and 2 (also known as K1 and K2). But this was no ordinary dive… K2 happened to be the most challenging and strenuous dive yet. The ocean currents were moving faster than we expected. The ship pulled up-current from the dive site (marked by an orange buoy), to put the divers in position. All they would have to do is jump off the ship and drift down-current to find the buoy. But when the divers jumped off the ship they were swept away by the strong ocean currents well past the buoy. The NF4 picked up the divers, who had to take off all 200lbs of their SCUBA gear, and wait to be taken to the correct diving site. The divers eventually finished their mission at K2, but were very exhausted when they returned to the NANCY FOSTER.

Thomas Nassif aboard the NF4 dive boat. The NANCY FOSTER is pictured in the background.
Thomas Nassif aboard the NF4 dive boat. The NANCY FOSTER is pictured in the background.

Today I finally got my chance to step off the NANCY FOSTER for the afternoon. I boarded the NF4 (diver recovery boat) and we steamed off into the open sea. Soon thereafter we watched from a distance, as the divers leap off the NANCY FOSTER. Our job was to keep an eye on the divers to ensure their safety during the 130-foot descent to the ocean floor. The NF4, along with the NANCY FOSTER and RHIB, all bear the “divers flag” when we deploy SCUBA divers into the ocean. This red flag with a diagonal white stripe warns other ships in the immediate area that there are divers in the water.

I also went snorkeling in the ocean to watch the SCUBA divers decompress underwater. After the divers finished their dive to the ocean floor, they stopped at 20 feet from the ocean surface to breath pure oxygen from a long tube supplied from the surface by the RHIB (the air we breathe everyday is only 21% oxygen). If the divers chose instead to shoot straight up to the ocean surface, they risk getting the “bends,” a painful experience that occurs when nitrogen bubbles form in the blood.

The divers safely returned to the ship with 6 lionfish in their nets – the aquarium aboard the NANCY FOSTER now has a total of 25 live lionfish! The scientists plan to transport them to a more permanent home at the NOAA Beaufort Laboratory when we arrive at port next week. To simulate the natural conditions of the ocean, scientists will place the lionfish in a “flow through aquarium” that transports ocean water through a pipe into and out of the aquarium. By having several aquaria full of lionfish in the lab, scientists hope to learn more about their diet and how often they reproduce.

Question of the day

Do lionfish reproduce in the same way as fish? How often do they reproduce?

Yes – Lionfish reproduce like most fish, through External Fertilization. Eggs are released from the female into the water and then fertilized by sperm from a male fish. The thing that makes lionfish so different from most fish is this: Female lionfish release a floating mass of eggs that stick together (most fish release eggs that disperse and spread out from each other in the water). Scientists think that lionfish are more successful at reproducing because the floating masses of eggs are more likely to be fertilized. We do not know how often lionfish reproduce – this is one of the biggest questions scientists want to find out! The reproductive periods of fish overall can be very different. Some species of fish, like Salmon, reproduce only once in their entire lifetime. Tropical organisms like the Parrotfish, on the other hand, reproduce every day! It will be very helpful for us to know how often female lionfish reproduce so that we may better understand their impact on the local ecosystem.

Posted on

Thomas Nassif, July 18, 2005

NOAA Teacher at Sea
Thomas Nassif
Onboard NOAA Ship Nancy Foster
July 15 – 24, 2005

Mission: Invasive Lionfish Survey
Geographical Area: Southeast U.S.
Date: July 18, 2005

Diver Christine Addison conducts a visual transect survey with a clipboard and meter tape along the ocean floor.
Diver Christine Addison conducts a visual transect survey with a clipboard and meter tape along the ocean floor.

Weather Data

Latitude: 33°38’N
Longitude: 76°55’W
Visibility: 10 nautical miles (nm)
Wind direction: 240°
Wind speed: 13 kts
Sea wave height: 1-2′
Swell wave height: 2-3′
Sea water temperature: 28.9°C
Sea level pressure: 1018 mb
Cloud cover: 6/8, Cumulus, Altocumulus

Science & Technology Log  

Today we awoke to a cloudy overcast day, providing the divers some relief from the sweltering heat we’ve had the past few days. The jet-black wet suits that keep the divers thermally insulated on the ocean floor can become extremely hot under a scorching sun! Every day for the remainder of the cruise we will try to complete 2 dives in the morning and 2 dives in the afternoon, each at a different location along the seafloor. (The divers are divided into two rotating teams, so that each person will only have to dive once in the morning and once in the afternoon).

Thomas Nassif watches Roldan Munoz perform a lionfish dissection, removing the stomach and gonads for further analysis.
Thomas Nassif watches Roldan Munoz perform a dissection, removing the stomach and gonads for further analysis.

This morning the divers visited Big Fish 1 and Big Fish 2, appropriately named after an 18-inch lionfish that was caught by a local fisherman. At Big Fish 2, the dive team descended to a depth of 143 feet, and they were stunned at the sight of 5 enormous lobsters; several were hiding beneath rocks while two other lobsters chased after one another across the sand. They also spotted several large grouper (approx. 30 lbs each). They conducted a 100-meter visual transect by steadily unreeling meter tape in a straight line. Along those 100 meters of line, they counted 17 lionfish (mostly juveniles), a big surprise considering the sandy bottom and featureless bathymetry (elevation) of the region. Lionfish typically thrive near rocky outcrops and coral reef structures that provide niches for other organisms that would serve as potential food sources (including baby shrimp, grouper, and snapper). Findings like the one at Big Fish 2 suggest that lionfish can flourish anywhere, from flat sandy bottoms to hard rocky outcrops, we suspect that as long as the water temperature remains warm enough to support a tropical habitat.

On the fourth and final dive of the day, the divers speared 3 lionfish and brought them back onto the ship for analysis. The scientists dissected the lionfish within 30 minutes of being brought onto the ship to ensure high quality stomach and reproductive system samples. First they recorded the weight, total length, and standard length (backbone only) of the lionfish. Next they removed both gonads and recorded the combined weight to determine the reproductive status of the lionfish. Finally they removed the stomach to determine the diet of the lionfish. We found two small fish that the lionfish had ingested. The lionfish remains were then frozen for future morphological (external) analysis. Scientists at the NOAA Beaufort Laboratory will conduct spine & ray counts on the fins and observe the facial features to see if there is any correlation with the development of the bearded spine, a feature that lionfish are thought to acquire as they age.

Question of the day

Do lionfish have any predators?

Great question! Lionfish do not have any known predators, but scientists aboard the NANCY FOSTER are hoping to someday answer this question. In Florida there was a reported sighting of a goliath grouper eating a lionfish. Other than that we do not know for sure. Of course it would be a good thing to find out. If it turns out that lionfish do not have any predators, then that would be bad news for the local ecosystem. Lionfish would be able to reproduce without limit and continue eating prey until resources are heavily depleted, thereby starving other fish that are important to the fisheries industry such as grouper.