crabs – Page 2 – NOAA Teacher at Sea Blog

July 8, 2010April 15, 2021

Bruce Taterka, July 8, 2010

NOAA Teacher at Sea: Bruce Taterka
NOAA Ship: Oregon II

Mission: SEAMAP Summer Groundfish Survey
Geographical Area of Cruise: Gulf of Mexico
Date: Thursday, July 8, 2010

Sexing the Catch

Weather Data from the Bridge

Time: 1630 (4:30 pm)
Position: Latitude = 28.20.93 N; Longitude = 095.58.98 W
Present Weather: Could cover 100%
Visibility: 4-6 nautical miles
Wind Speed: 18 knots
Wave Height: 6-8 feet
Sea Water Temp: 28.9 C
Air Temperature: Dry bulb = 27.2 C; Wet bulb = 25.3 C
Barometric Pressure: 1011.56 mb

Science and Technology Log

As you can tell from our previous blogs, we spend a lot of our time on the Oregon II counting, measuring and weighing our catch and loading the data into FSCS. These data are critical to NOAA and the states in managing fish stocks and the Gulf ecosystem. In addition to knowing population size, weights, and lengths of individuals it’s also important to know the sex of the organisms. Information on the male:female ratio helps NOAA and the states assess the ability of the population to reproduce, and to establish sustainable catch levels for commercial fishing.

But how do you determine the sex of marine organisms? For most fish and invertebrates you can only tell the sex by internal anatomy, which almost always requires cutting the animal open. This is time consuming and not always practical when we have a large catch to process and other tasks take priority, such as preparing samples to be analyzed for contamination from the oil spill which is our top priority right now.

For some organisms, however, sex can be determined externally. One of the things we’ve learned in the past week is how to determine the sex of shrimp, flatfish, crabs, sharks, skates and rays. Here’s how:

Shrimp: the males have a pair of claspers (called petasma) on their first set of legs.The petasma are absent in females. The males use the petasma during mating to grasp the female and transfer the sperm sac.

Shrimp M — Male – arrows show the petasma

Crabs: On most crab species females have wide plates curving around the rear of the abdomen, while males have a long narrow plate or plates. On females, the eggs develop under the curved plate.

Flatfish: When you hold a flatfish up to the light you can see through it, which enables you to do an internal examination without cutting it open. On female flatfish, the gonad extends in a dark red, curved wedge which is absent in the male.

Flatfish F — Female showing long curved gonad

Flatfish M — Male – long gonad is absent

Sharks, skates and rays. Males have external claspers that they use in mating, while in females the cloaca is smooth and claspers are absent.

Shark M — Male Angel shark – arrows point to claspers

Shark F — Female Angel shark – claspers are absent

Personal Log

A tropical depression moved through the Gulf yesterday evening, making it too rough and windy to fish. So instead of counting, measuring and loading data into FSCS, my watchmates and I cleaned the lab, secured our gear, and headed up to the lounge to watch Shutter Island on the large-screen TV. Last night my bunk was like a roller coaster, tossing me from side-to-side and head-to-toe as the ship rolled and pitched in the big swells. Today has been a slow day for the scientists on board, waiting for the storm to pass so we can start trawling again, while the crew and officers remain as busy as ever.

May 10, 2009April 5, 2021

Lollie Garay, May 10, 2009

NOAA Teacher at Sea
Lollie Garay
Onboard Research Vessel Hugh R. Sharp
May 9-20, 2009

Mission: Sea scallop survey
Geographical Area: North Atlantic
Date: May 10, 2009

The dredge is hoisted to the sorting table

Weather Data from the Bridge
Stationary front persists
West winds 10-20KT Seas 4-6 ft

Science and Technology Log

We began our shift today sampling in an area called Del Marva Closed Area, which is an area currently closed to scallop fishing. We conducted 8 dredge hauls last night in spite of the turbulent weather that pursued us. But today, we had calmer seas and beautiful blue skies.

The serious work of sorting and measuring the catch begins right after the dredge is brought up and secured. As it is coming up, someone on either side of the dredge uses a rake to shake the net which allows the catch to fall out. After the net is secured, readings are taken using from a sensor mounted to the dredge. The sensor is called an inclinometer; it measures the dredge angle during the 15minute tow. This allows the scientists to calculate the amount of time the dredge is on the bottom. Then I hop on the table to hold a whiteboard with the pertinent station information written on it next to the catch which is photographed for documentation. Then the frenzy begins! I leave and someone else gets on the sorting table to rake the catch towards waiting sorters who have several buckets and baskets ready.

The catch is a mixture of scallops, crabs, fish, lots of starfish, assorted other specimens and sometimes sand. We are primarily sorting out sea scallops and fish, but have had some stations that require us to sort out crabs as well. We work quickly to separate the catch which is then taken into the wet lab for measurement. I have been working with Larry Brady from NOAA Fisheries, learning how to measure scallops using the FSCS system. The FSCS is the Fisheries Scientific Computer System which is a collection of integrated electronic devices used to gather and store station and biological data. FSCS uses touchscreen monitors, motion compensation scales and electronic measuring boards. I feed Larry the scallops one after the other as he measures them using a magnetic wand. This information is automatically recorded into the data base. Last night we had a large number of scallops to process. However, today we have seen less and less; in fact we had one catch with none! The fish are not as plentiful either although we have seen various different specimens.

There are also special scallop samples that need to be processed. First, the scallops are cleaned with wire brushes. Then they are weighed in their shells. After this is recorded, they are opened to remove the meat and gonads, which are weighed separately. This information provides us with the gender of the scallop and can approximate their age. I dry the shells and number them. Then I put them into a cloth sack, tag them with identifying information and put them into the deep freeze.

The fish are also weighed and their species is recorded. Sometimes specimens need to be counted (I counted small crabs today). Once all the measurements are taken, everything is washed down! That includes the deck, the sorting table all the catch buckets, the FSCS measuring boards and the lab floors. We are then ready for the next dredge haul which follows approximately 20-30 minutes later. This pace continues throughout the shift, barring any mechanical or weather issues.

Personal Log

Lollie and Larry Brady scrub scallop shells for special samples.

I am very impressed by the precision of the work that the science team does. As I waited for the dredge to unload a catch this evening I reflected on how everyone does their job quickly and efficiently. It’s something I never fully appreciated – that there are people out on the seas doing this very thing all the time! Already in one full day, they have taught me so much about how the fisheries system works, and they have expanded my knowledge of different marine organisms. Even as we sort quickly through the catch, they are always identifying specimens to me and answering my questions.

One of the most amazing sights for me has been the incredible number of starfish that each catch brings up! I have never seen so many, and I am learning about the different types. I am also learning how to shuck scallops for the galley for dinner. So far this has not been strength of mine, but I am determined to master this skill! By the way, our lunch today was scallop soup! The beautiful sunset today gave way to the almost-full moon shining on the seas. My shift is over for tonight, I’d best get some sleep.

Animals Seen Today

Dolphins—made a quick but too brief appearance alongside the ship today. I caught a glimpse as they raced by. Polka dot Kuskeel; Baby Goosefish; Loligo Squid (pronounced Lollie go!) Snake Eel; and Clear Nose Skate.

August 9, 2006March 26, 2021

Linda Depro, August 9, 2006

NOAA Teacher at Sea
Linda Depro
Onboard NOAA Ship Albatross IV
July 31 – August 11, 2006

Mission: Sea Scallop Survey
Geographical Area: Georges Bank, New England
Date: August 9, 2006

Science and Technology Log

The dredge caught a monster lobster today. The scientists seemed to think it was more than twenty years old. When held up it was the size of an adult’s length from shoulders to knees, and two hands were needed to hold it! A spiny dogfish (looks like a shark) was also caught. I held it to have my picture taken and I plan to hang it on my classroom door! Otherwise the catches were the usual—some with lots of rocks, some with sand, others with many star fish or skates. All these fantastic sea creatures that I have only seen in books have become part of my life here on board the ALBATROSS IV. The star fish and hermit crabs are my favorites, skates are cool to look at and pick up by the tail and put in the bucket, goosefish (known as monk fish in the grocery store) have a face that “only a mother could love”, and the scallops, even though I’ve seen thousands of them are each a little different.

Personal Log

Sunset was beautiful again tonight and the moon is spectacular. With my binoculars the craters were very clear. A lone seagull followed us for a while; his white body against the black sky would have inspired me to write a poem if I were a poet. Hard to believe the adventure is coming to an end, and what an adventure it was. The crew has been super, very kind, and willing to talk and answer questions. The scientists have an important job collecting and recording data; they are an interesting group to work with. Thanks to all for making my time on the ALBATROSS IV the adventure of a lifetime.

August 7, 2006March 26, 2021

Linda Depro, August 7, 2006

NOAA Teacher at Sea
Linda Depro
Onboard NOAA Ship Albatross IV
July 31 – August 11, 2006

Mission: Sea Scallop Survey
Geographical Area: Georges Bank, New England
Date: August 7, 2006

Science and Technology Log

It’s a small world here on the ALBATROSS IV. Chad Meckley is a 1996 Wilson High School graduate. Wilson is in Berks County and I live in Lancaster County, less than forty minutes away. If you want to talk to Chad, look on the bridge.

Chad earned a geography/environmental science degree from Shippensburg University and moved to Colorado to be near the mountains. After working several years in sales, Chad happened to be talking to a friend who knew about the NOAA Corps. He applied, was accepted, and began training in February 2006.

We are on Leg 2 of the Sea Scallop Cruise and it is Chad’s third cruise with NOAA. He enjoys being on the ocean and plans to continue his NOAA career. Chad has two goals: to become Officer of the Deck (so he can command the ship) and to experience his first winter at sea.

It is evident that Chad enjoys what he’s doing; you can see it in his smile. Best Wishes, Chad!

Last watch was not quite as busy as the night before. We had two stations that were mostly Brittle Stars, very interesting little starfish. They are a tannish color about the diameter of a coffee mug, with long thin arms that visibly move. When they were shoveled into laundry size baskets each time we had two baskets full, and that’s a lot of Brittle Stars!

Personal Log

Yesterday, Sunday, was an absolutely, drop dead gorgeous day on the ocean. The sun was out and the water was calm. Whales were sighted, but in the distance. I did see them surfacing and took pictures. Imagine a 4×6 all bluish-green and a fourth-inch dot of black. Sunset was working on spectacular, but just as the sun reached the water it went behind a layer of clouds. We are almost at full moon and the night time was just as beautiful in its own way.

August 5, 2006March 26, 2021

Linda Depro, August 5, 2006

NOAA Teacher at Sea
Linda Depro
Onboard NOAA Ship Albatross IV
July 31 – August 11, 2006

Mission: Sea Scallop Survey
Geographical Area: Georges Bank, New England
Date: August 5, 2006

Science and Technology Log

Yesterday was quite a day—many stations, lots of scallops, and BIG rocks. I am amazed that the trawl net liner was not damaged. Last night, though, a rock the size of a small car was hauled onto deck—that one did tear the liner. It’s interesting to watch the winch drop it in the ocean.

My new special position (I’m still sorting, shoveling, and measuring) is taking the inclinometer, or bottom contact sensor, reading. To you landlubbers, it’s a device attached to the trawl that gathers data and tells the scientists whether the net was parallel to the bottom of the ocean. So when the net comes up with very little the information from the inclinometer is helpful.

Here’s what I do. I have an optic shuttle (about the size of a hot dog) that I secure in the inclinometer located on the trawl. Each part has sensors and when put together properly the inclinometer sends the data to the optic shuttle (like a zip) and when all information is received and a little green light flashed I take in into a computer and transfer the data onto the hard drive. It’s an important piece to the mission.

What I have been doing here is an example of how important hands-on learning really is for understanding and transfer. I could have read all about this experience (like you are with this journal), but until I held the fish, scrubbed the scallops, cut into a Monk fish to discover the ovaries, etc., I had no real understanding. Amazing!

Personal Log

The weather remains beautiful, the people are great, and the food is delicious.