Susan Brown: Who Needs Sharks Anyway? September 13, 2017


NOAA Teacher at Sea

Susan Brown

Aboard NOAA Ship Oregon II

September 3 – 15, 2017


Mission: Snapper/Longline Shark Survey

Geographic Area of Cruise: Gulf of Mexico

Date: September 13, 2017

sunset through jaws of a blacktip shark


Science and Technology Log

We have been sampling along the coast of Florida, Alabama, Mississippi, Louisiana, and Texas at varying depths – “A” stations ( 5- 30 fathoms), “B” stations (30 -100 fathoms) and “C” stations (100 – 200 fathoms). A fathom is six feet or approximately 2 meters. The longlines are baited the same – mackerel on 100 hooks spread out across one nautical mile and then set on the bottom of the ocean. As we reel in the long line, the click and whine of the line as it’s being spooled, we wait in anticipation of what it may bring. Each station yields something different and you never know what you are going to get. Below is a list of some of the animals we have encountered.


baby hammerhead

Shark species: blacktip, sharpnose, blacknose, scalloped hammerhead, great hammerhead, bull, tiger, spinner and bonnet head (to learn more about each of these species, select it for a NOAA fact sheet).

Scallop Hammerhead in cradle

Other animals: southern ray, cownose ray, roughtail stingray, red snapper, black drum, sharksuckers, catfish, red drum, yellowedge grouper, king snake eels and even some blue crabs.

So why survey sharks? Did you know that people are one of only a few species that prey on sharks — killer whales and other sharks are the others– killing over a hundred million per year?* Sharks are apex or top predators in an ocean food web and play a vital role in keeping this food web in balance. With the hunting of sharks as well as over fishing the prey that sharks eat we are disturbing the natural balance. This survey is used determine the number of sharks and other species that are present in the Atlantic Ocean including the Caribbean Sea and the Gulf of Mexico. With these numbers, the National Marine Fisheries Service (NOAA Fisheries) regulate how many sharks, swordfish and tuna can be harvested without impacting the total population. In the Pacific Ocean, NOAA fisheries work with fisheries in developing how to best manage sharks.

red snapper

Apex predators in any ecosystem are vital to the health of that ecosystem. These top predators keep numbers down on the more abundant prey species and keep their numbers in check. Here is a simplified illustration of what happens when we lose apex (top) predators in an ocean ecosystem.

If the number of sharks goes down then the food the sharks eat goes up (forage fish) because they are not being eaten by the sharks. With more of those forage fish around their need for food – the zooplankton – increase. With more forage fish eating the zooplankton there are less zooplankton and their numbers begin to decrease. If there are less zooplankton then the phytoplankton numbers increase because the zooplankton aren’t around the eat them. Removing top predators from any ecosystem can have an impact on the entire food web and this phenomena is called a trophic cascade.

Removing Hook

Personal Log

When people think of sharks, they think of the movie Jaws. Unfortunately this has given sharks a bad reputation and has vilified these animals that are essential to the ocean food webs. Sure, there have been shark attacks, but did you know that more people are killed each year by electrocution by Christmas tree lights than by shark attacks? When people imagine sharks, they think of enormous sharks that eat everything in sight. The reality is that sharks come in all sizes and shapes. A mature Atlantic sharpnose shark will only get to be 3.5 feet long with the world’s smallest shark being the dwarf lantern shark that can fit in the palm of your hand. The largest shark is the harmless-to-human whale sharks that feeds primarily on plankton and can grow up to 60 feet!

Smooth-hound (Mustelus Sinusmexicalis)

Did You Know?

Scientists can tell the age of a shark by counting the rings on its vertebrae (similar to how they can tell how old a tree is by counting its rings!)

Question of the day:

What is an example of a terrestrial (land) apex predator that has been over hunted impacting the entire ecosystem?

hint: watch this video clip:




Methea Sapp-Cassanego, July 19, 2007

NOAA Teacher at Sea
Methea Sapp-Cassanego
Onboard NOAA Ship Delaware II
July 19 – August 8, 2007

Mission: Marine Mammal Survey
Geographical Area: New England
Date: July 19, 2007

NOAA Ship Delaware II
NOAA Ship Delaware II

Delaware II: Ship Specifications 
Length: 155ft
Breadth: 30ft
Draft 16.6 ft
Hull: Welded steel
Displacement: 891 tons
Cruising Speed: 10 knots
Range: 5,300 nm
Endurance: 24 days
Commissioned Officers: 4
Licensed Engineers: 3
Crew: 10 Scientists: 14 (Max)
Launched: December 1967
Commissioned: March 12th 1975
Builder: South Portland
Engineering, S. Portland Maine

I arrived in Woods Hole Massachusetts at 10:30 pm and rolled my luggage up and down the main street trying to find the DELAWARE II.  Following a not so encouraging conversation with a bus station security officer who said to me “The DELAWARE II never docks here”, I managed to indeed find the ship that would be home for the next 3 weeks.

A large tiger shark awaits examination and tagging
A large tiger shark awaits examination and tagging

Over the course of a calendar year, the DELAWARE II will be at sea for ~200 days during which a crew of 17 will attend to her maintenance and operation.  Most of its crew members are hired via the National Oceanic and Atmospheric Administration NOAA; 6 of which work on deck, 4 others serve as engineers, 2 work in the galley, 1 serves as an electronic technician, and 4 more are NOAA  Corp officers. These officers are in charge of ship operations and manage all other operations which are carried out on board.  The DELAWARE II conducts a variety of fishery and marine resource research in support of NOAA. The ship has also been utilized to carry out research conducted by private entities, such as the Woods Hole Oceanographic Institution, and the US Geological Survey in addition to other government agencies and universities.  Typically DELAWARE specializes in 5 different survey projects which are as follows:


The Northeast Ecosystems Monitoring Survey monitors the Northeast continental shelf by assessing both its physical and biological aspects.  For example, one of the methodologies employed during this survey uses a set of Bongo tows which are designed to catch plankton, small fish fry, larvae, and other small invertebrates.  These minuscule creatures are the foundations for most of the ocean’s food webs and therefore their populations are used to indicate and predict the overall health of the ecosystem.  The Northwest survey is conducted on a repetitive basis so that these populations may be monitored over time, thus enabling researchers to monitor changes over time.

A smaller tiger shark will receive a tag before being released as part of the ongoing Apex predator survey
A smaller tiger shark will receive a tag before being released as part of the ongoing Apex predator survey

Apex Predator Survey is conducted every three years and is designed to assess the relative abundance, distribution, population structure, species composition, and to tag sharks so that migration patterns may be studied.  Sharks are captured via longlining and then released after tagging and biological samples have been gathered.

Atlantic Herring Hydroacoustic Survey combines a variety of advanced technologies including multi-frequency echo integration, omni-directional sonar, and underwater video to assess hearing populations. The stability of herring populations is central to the sustainability of many commercial fisheries as well as the ecosystem as a whole.

Ocean Quahog and Surf Clam Survey conducts dredges through the silty and/or sandy portions of the ocean floor where these filter feeding bivalves dwell. Such dredges enable researchers to calculate relative abundances and thus derive sustainability yields.  Since both the ocean quahog and surf clam are edible bivalves, they are of commercial value and contribute to the economic stability of the Atlantic fisheries.  The surf clam is especially coveted in the restaurant and other food industries for making clam strips and chowders. The ocean quahog has a stronger flavor and is used in recipes where the clam is used in conjunction with other strong flavored ingredients like pasta dishes.  (who knew you would get a cooking lesson here) Also of significance is the reproductive biology of the quahog: This bivalve is extremely slow growing and long lived, it does not reach maturity for 20 years and will live up to 200 years.  Those that are eaten are typically between 40-100 years old.

Marine Mammal, Large Whale Biology aims to examine the relative abundance and distribution of the Atlantic’s large whales.  A variety of data gathering methodology is used, ranging from visual and photographic recording to biopsy sampling for genetic studies. Studies which focus on the whales’ food abundance are also included in this survey.

Commanding Officer (CDR) Richard Wingrove
Commanding Officer (CDR) Richard Wingrove

So who’s in charge of all this nautical navigation and science? As one can imagine there is allot going on aboard the DELAWARE II at any given time.  Of course, numerous highly trained personnel insure that the engines work, that everyone gets three meals a day, that the toilets flush, that scientific protocols are being met, and that we are on course. But one individual is ultimately responsible for the coordination of these individual efforts. During my tenure aboard the DELAWARE II that role was fulfilled by the Commanding Officer (CDR) Richard Wingrove.  CDR Wingrove has spent a lifetime working in, and studying marine environments.  After earning a degree in Marine Science from the University of Miami, the Commander joined the Peace Corp and was stationed on the Caribbean island of Antigua. As a fisheries officer for the Peace Corp, his job was to monitor fishing practices while helping fishermen develop and implement techniques that would improve their catches. Following his service in the Peace Corp, CDR Wingrove went to work as a Satellite Oceanographer for the private sector; it was during this job that he happened to attend a conference and met a NOAA officer:  Soon after, it was on to officer training school in Fort Eustis, Virginia where after 5 months of training, officers emerge with the foundational knowledge to navigate the seas and drive a ship.  

Following completion of officer training, CDR Wingrove was appointed to the NOAA Ship MILLER FREEMAN which is stationed in Alaska.  After enjoying the northern latitudes for two years, NOAA then sent him back to his home state of Florida where he worked in the Looe Key National Marine Sanctuary.  Following two years in the sanctuary he returned to the Western Seaboard and set to work on the NOAA Ship JOHN N. COBB which is stationed out of Seattle.  Again, after two years of surveying salmon, killer whales and other marine mammals CDR Wingrove was headed back to the Eastern Seaboard. This time he would spend three years based in Miami where his job was to oversee oil spill responses for South Carolina, the Gulf of Mexico, and the Caribbean.   As he explained to me, working to clean up such an event is a rather delicate job since each of the involved entities including the company who spilt the oil, state agencies, federal agencies, and community leaders are each represented by their own biologists, ecologists, scientists, and researchers which then assess the spill, evaluate its impacts, and determine how the clean up should be executed. CDR Wingrove’s job was to take all the data and information presented to him by each of the involved parties, and then coordinate their findings in order to determine a course of action for clean-up, as well as monitor the clean-up process.

After three years of cleaning up other peoples’ messes CDR Wingrove was appointed as Executive Officer aboard the NOAA Ship DELAWARE II. He worked aboard the DELAWARE for two years before being sent to the Great Lakes area where he spent another three years coordinating the clean-up oil spills.  Then once again he was headed back to the DELAWARE II this time as the ships Commanding Officer.  CDR Wingrove will finish his service aboard the DELAWARE II in May yet he does not know where NOAA will send him next.  Regardless of the locale I have little doubt that CDR Wingrove will continue his legacy of service to the natural world and to all whom benefit from healthy seas.