Sarah Boehm: Shrimp Galore, June 30, 2013

NOAA Teacher at Sea
Sarah Boehm
Aboard NOAA Ship Oregon II
June 23 – July 7, 2013 

Mission: Summer Groundfish Survey
Geographic area of cruise: Gulf of Mexico
Date: June 30, 2013

Weather at 20:40
Air temperature: 29.8 °C (85.64° F)
Barometer: 1007 mb
Humidity: 65   %
Wind direction:  221 °
Wind speed: 8.4  knots
Water temp: 29.2° C
Latitude: 29.05° N
Longitud: 88.69 ° W

Science and Technology Log

I have been on board for a week now and have learned a lot about the fish of the Gulf of Mexico. We have collected data on over 300 different species at 129 trawl stations So what happens with all this data?

Our work out here is part of SEAMAP – South East Area Monitoring and Assessment Program – a joint venture between NOAA and the states to better understand the populations of fish and invertebrates along the coast of the Gulf and Atlantic. The information we are collecting on Oregon II is combined with the data from other ships that do surveys in closer to land. The groundfish surveys began in the 1950s and happen each summer and fall. All this data tells a story of each species – how many individuals there are, how big they are, and where they prefer to live. This information can then be used to better manage the fishing industry so that marine populations stay strong.

We gather data about every species we pull up in our nets, but we pay special attention to the ones that are fished commercially like shrimp and red snapper. There are several shrimp species out here, but one we see a lot of is the brown shrimp.

Brown Shrimp
Brown Shrimp

The brown shrimp are found from Massachusetts to the Gulf. They live for about 1 ½ years and can be up to 7 inches long. Their lives start as eggs deep in the waters of the Gulf and Atlantic. After they hatch, tiny baby shrimp float in to the shallow water of estuaries (coastal areas where fresh river water mixes with sea water). They grow larger in the protected waters of the estuaries and eventually migrate out into deeper, saltier water.  They live on the bottom of the sea, moving out farther into deeper water as they grow larger. You can learn more about brown shrimp on NOAA’s Fish Watch website.

For most species we haul in we record length on up to 20 individuals, and weight and sex for only every 5th individual. But for brown shrimp we measure the length, weight and sex of up to 200 individuals. Sometimes we pull up a lot of shrimp like the 419 brown shrimp in just one trawl last night. To tell male from female you flip the shrimp over and check the spot in between its walking legs (in front) and swimming legs (in back).  A female has a wider plate. A male has extra fuzzy bits on the inside of the front swimming legs.

Male and Female Shrimp
The shrimp on the left is a female and the one on the right is male.

Shrimp fishing is a big industry here in the Gulf. Last year 221 million pounds of shrimp were taken by fishing boats from the states along the Gulf. Commercial fishing boats use similar nets to ours, but they are larger and trawl underwater for much longer. Just like we pull up many fish in addition to shrimp, shrimping boats have a large bycatch. Part of our research is to monitor the bycatch species to help make management decisions that protect them, too. NOAA works with the fishing industry to develop nets with Bycatch Reduction Devices that allow unwanted fish to escape.

shrimp boat
A fishing boat trawling for shrimp

Let me answer a few more student questions. Jared, we don’t wear lab coats; we mostly wear old t-shirts and shorts that definitely get wet, muddy and slimy working with the fish. A lab coat would help keep me clean, but it is hot and humid in our lab and the extra layer would be uncomfortable. Sabrina, we have found some plastic and other trash in the water, but have not seen any animals tangled in it. Deliana, we do all our work from the ship, so we don’t swim underwater with the fish. When they do surveys of reef fish earlier in the year they send a video camera underwater to learn more about the fish, but the scientists still stay on board.

silver fish
Clockwise from top: Rough Scad, Silver Jenny, Dusky Anchovy, Long Spine Porgy
brown fish
Shoal Flounder on the left and Big Eye Sea Robin on the right

Julissa asked about colors of our fish. Most of our fish come in two colors – silver or brown. We catch fish that live on the bottom of the sea or swim near the bottom and these colors help them camouflage with the sand and mud. But there are some that have splashes of color.

Dwarf Goatfish
Dwarf Goatfish
Lesser Blue Crab
Lesser Blue Crab

Personal Log

Several students had questions about food on board, so let me reassure you I am eating well.

the stewards
Stewards Walter and Lydell

The two stewards on board, Walter and Lydell, are responsible for feeding 30 people on board. The food is good, plentiful and there are several options at each meal. One challenge is that people on board are working different schedules and can’t always make meal times. If you ask ahead of time, they will save you a plate of food for later. There are also snacks and sandwich fixings available all the time. To give you an idea of what I am eating, yesterday I had a freshly baked muffin and juice for breakfast, a chicken fajita and Mexican veggies for lunch, fried rice, stir fry and a salad for dinner, and then some ice cream with fruit for a late night snack.

How much food does it take to feed 30 people for 2 weeks? Walter gave me a few numbers for this trip: 80 pounds of chicken, 35 dozen eggs, 100 pounds of potatoes, 12 gallons of ice cream, and a whole lot of coffee. Jennixa wondered what would happen if we ran out of food – the answer is that we would head back to land and buy more. But I’m pretty sure Walter has enough on board. Damian asked if we eat what we catch – and yes, some of the shrimp and red snapper have gone to the galley after being measured.  They were delicious.

CDCPS science students – How are the colors of fish an adaptation to survival?

sunset
sunset

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4 Replies to “Sarah Boehm: Shrimp Galore, June 30, 2013”

    1. The nets are heavy, but the really heavy part are the doors with metal weights. Those weights drag the nets down to the bottom of the sea.

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