Crystal Davis, Bottom Trawl for Shrimp, June 27, 2014

Bringing in a trawl

Bringing in a trawl

NOAA Teacher at Sea

Crystal Davis

Aboard NOAA Ship Oregon II

June 23 – July 7, 2014

Mission: SEAMAP Groundfish Survey

Geographical area of cruise: Gulf of Mexico

Date: Friday June 27, 2014

Weather: Partly cloudy

Winds:  15-20 knots

Waves:  5-6 feet

 

 

Science and Technology Log: Bottom Trawling

The Oregon II is a participant and contributor to SEAMAP (The Southeast Area Monitoring and Assessment Program) which monitors the biodiversity of marine life in the Gulf of Mexico. The primary way the Oregon II assists SEAMAP is by conducting bottom trawls with a 42 foot semi-balloon shrimp trawl net.The net is slowly lowered into the ocean until it reaches the bottom and is then dragged along the ocean floor for thirty minutes. The net has a tickler chain between the doors which scrapes the bottom of the ocean floor and flicks objects into the net. The net is then brought to the surface and all of the organisms inside are put into baskets (see video above). The total weight of the catch is massed on scales on the deck. If the catch is large (over 20 kilos), it is dumped onto a conveyor belt and a random sub-sample (smaller) is kept, along with any unique species while the rest of the catch is dumped overboard.

Shrimp Net

Shrimp Net

Once the sample has been selected, the marine organisms are sorted by species and put into baskets. Each species is then massed and counted while the data is recorded into a system called FSCS (Fisheries Scientific Computer System). To obtain a random sampling, every fifth individual of the species (up to twenty) is measured, massed and sexed (more on this later). Once the data has been verified by the watch manager, the marine organisms are put back into the ocean. The following are pictures of a sample on the conveyor belt and the organisms divided into a few species.

The sorting process for shrimp (white, brown and pink) differs slightly from that of the other marine organisms. Every shrimp (up to 200 of each species), is massed, measured and sexed.This data is then used by various government agencies such as the Fish and Wildlife Service, Gulf of Mexico and South Atlantic Fishery Management Councils, etc… to determine the length of the shrimping season and to set quotas on the amount that can be caught by each issued license. States will not open the shrimping season until SEAMAP reports back with their findings from NOAA’s shrimp survey.

Types of shrimp in the Gulf of Mexico

Types of shrimp in the Gulf of Mexico

The shrimp trawl net used on the Oregon II differs from a shrimp net used on a commercial boat in two main ways. Commercial shrimping boats have BRD’s (Bycatch Reduction Devices) and TED’s (Turtle Excluder Devices). BRD’s and TED’s are federally required in the U.S. to reduce the amount of bycatch (unintentionally caught organisms) and sea turtles. Shrimping boats typically trawl for hours and turtles cannot survive that long without air. TED’s provide turtles and other large marine organisms an escape hatch so that they do not drown (see the video below). Unfortunately, larger turtles such as Loggerheads are too big to fit through the bars in a TED. Additionally, TED’s may become ineffective if they are clogged with sea debris, kelp or are purposefully altered.

     

Boat Personnel of the Week:

Warren Brown:

Warren Brown

Warren Brown

Warren is a gear specialist who is working as a member of the scientific party. He is contracted by Riverside for NOAA.  While aboard the Oregon II, Warren designs, builds and repairs gear that is needed on the boat. Unfortunately, on this leg of the trip either sharks or dolphins have been chewing holes in the nets to eat the fish inside. This means Warren has spent a large chunk of his time repairing nets.

Warren is not a crew member of the Oregon II  and actually works at the Netshed in Pascagoula where he spends his time working with TED’s. He has law enforcement training and will go out with government agencies (such as the Coast Guard or Fish and Wildlife Service) to monitor TED’s on shrimping boats. He also participates in outreach programs educating fishermen in measuring their nets for TED’s, installing them. Warren will bring TED’s and nets to make sure that every everyone at the training has a hands on experience installing them. While he regularly does outreach in Alabama, Mississippi, Florida, Georgia, North Carolina and Texas, his work has also taken him as far as Brazil.

Robin Gropp:

Robin playing his mandolin

Robin playing his mandolin

Robin will be a junior at Lewis & Clark College in the Fall. He is currently an intern aboard the Oregon II. Robin received a diversity internship through the Northern Gulf Institute and is one of eight interns for NOAA. For the first two weeks Robin worked at the NOAA lab participating in outreach at elementary school science fairs. He brought sea turtle shells and a shrimp net with a TED installed. The students were very excited to pretend to be sea turtle and run through the TED. They proclaimed, “we love sea turtles.”  After leaving the Oregon II, Robin will return to the NOAA lab to study the DNA of sharks.

 

Personal Log:

Overall I have had a hard time processing and accepting the groundfish survey portion of the trip. I am a vegetarian that does not eat meat, including fish, for ethical and environmental reasons. Yet here I find myself on a boat in the Gulf of Mexico surveying groundfish so that others can eat shrimp. A large part of me feels that I should be protesting the survey rather than assisting. Because of this I spent a lot of time talking to the other scientists on my watch and Chief Scientist Andre Debose. After many discussions (some still ongoing) I do realize how important the groundfish survey is. Without it, there would be no limits placed on the fishing industry and it is likely that many populations of marine organisms would be hunted to extinction more rapidly than they are now. This survey actually gives the shrimp species a chance at survival.

Did You Know?

Countries that do not use TED’s are banned from selling their shrimp to the U.S.