Callie Harris: Lots to See While at Sea, August 20, 2019

NOAA Teacher at Sea

Callie Harris

Aboard NOAA Ship Oscar Dyson

August 13-26, 2019


Mission: Fisheries-Oceanography Coordinated Investigations

Geographic Area of Cruise: Gulf of Alaska

Date: 8/20/19

Weather Data from the Bridge

Latitude: 58° 27.67 N
Longitude: 152 ° 53.00 W
Wind Speed: 5.96 knots
Wind Direction: 152°
Air Temperature: 12.4°C
Sea Temperature: 15°C
Barometric Pressure: 1008 mbar


Science and Technology Log

I feel the need to start off by stating that the shark did in fact swim away. During our mid-afternoon trawl haul back, Chief Boatswain Ryan Harris called over the radio that we had caught a shark in the trawl net. We quickly put on our boots, hard hats, and life preservers and headed to the back deck. Unfortunately, a 3.2m female Pacific Sleeper Shark had gotten caught in our trawl as bycatch. Thanks to the quick response of our NOAA deck crew, we were able to release the shark back into the water alive.

Unlike most sharks, the Pacific Sleeper Shark is predominantly a scavenger and rarely hunts. They are slow swimmers, but move through the water quite gracefully without much effort of body movement. This lack of movement allows them to catch prey easy since they don’t make much noise/ vibrations in the water. They feed by cutting and suction. The sleeper shark’s large mouth allows it to suck its prey in. Its spear-like teeth help cut prey down into smaller pieces. It then swallows its prey by rolling its head. For more info about this cool shark, visit: https://www.sharksider.com/pacific-sleeper-shark/ .

Bycatch is defined as the unwanted fish and other marine creatures caught (e.g. hooked, entangled or trapped) during commercial fishing for a different species. Bycatch is both an issue ecologically and economically. Bycatch can slow the rebuilding of overfished stocks. Organisms that are discarded sometimes die and cannot reproduce. These mortalities put protected species such as whales and sea turtles even further at risk. Bycatch can change the availability of prey and cause cascading effects at all trophic levels. Bycatch can also occur when fishing gear has been lost, discarded, or is otherwise no longer being used to harvest fish (aka marine debris).

Releasing shark from net
Releasing the shark from our trawl net.

NOAA Fisheries works hand in hand with fishing industries to better understand fishing gear, and to develop, test, and implement alternative fishing gear. For example, NOAA Fisheries and their partners developed turtle excluder devices to reduce sea turtle mortality in the southeastern shrimp trawl fishery. NOAA Fisheries funds the Bycatch Reduction Engineering Program that supports the development of technological solutions and changes in fishing practices designed to minimize bycatch. Laws like the Marine Mammal Protection Act and the Endangered Species Act also uphold the reduction of current and future bycatch of species.


Personal Log

It’s hard to believe that today is already day eight at sea. To be honest, I don’t even notice that I am on a ship anymore. We have been very lucky weather wise and the seas are still very calm. I have been spending more time on the bridge assisting with the ‘marine mammal watch’. As I said in blog two, we must keep an eye out for any marine mammals in the area before conducting any water surveys. The bridge is amazing because not only do you get the best view, but you also get to observe how the ship operates in terms of headings, maneuverability, and navigation.

Shelikof Strait
Shelikof Strait

The Shelikof Strait is breathtaking. Chief Electronics Technician Rodney Terry pointed out the white ‘cloud’ above one of the snow-capped mountains was actually an active volcano with a smoke plume rising above it. It was incredible to be able to look out and see a glacier and an active volcano in the same panorama.

Map of Kodiak Island
Map of Kodiak Island and Shelikof Strait. Credit: Kodiak archipelago images.

During one of my marine mammal watches on the bridge, I noticed an oddly flat area of land in the middle of the mountain range that ran along the shoreline. NOAA Corps Officer LT Carl Noblitt explained to me this was actually where a glacier had once weathered down part of the mountain range over time. The glacier has since melted so now all that remains today is its glacial trough.

glacial trough
The remains of a glacial trough.


Animals Seen Today

Besides our unexpected visitor today in the trawl, I was thrilled to hear Chief Boatswain Ryan Harris call out from the scientific deck for Orcas on the horizon. Orcas (aka Killer Whales) have always been a dream of mine to see in the wild. They were pretty far away from the boat, but I was able to see the trademark black dorsal fin rising and sinking at the surface for a few minutes. Hoping to get a photo of one of these pods before our expedition ends.

orca dorsal
Orca dorsal fin. Photo Credit: gowhales.com

Another fun organism I got to see in person today was a Lanternfish that was caught in one of our deeper bongo net surveys. Lanternfish are a deep-water fish that gets its name from its ability to produce light. The light is given off by tiny organs known as photophores. A chemical reaction inside the photophore gives off light in a chemical process known as bioluminescence.

lanternfish
Note the photophores (silver dots).
lanternfish v pencil
This laternfish is full grown. Adults measure 5cm to 15cm in length typically.

Jason Moeller: June 17-18, 2011

NOAA TEACHER AT SEA
JASON MOELLER
ONBOARD NOAA SHIP OSCAR DYSON
JUNE 11 – JUNE 30, 2011

NOAA Teacher at Sea: Jason Moeller
Ship: Oscar Dyson
Mission: Walleye Pollock Survey
Geographic Location: Gulf of Alaska
Dates: June 17-18, 2011

Ship Data
Latitude: 52.34 N
Longitude: -167.51 W
Wind Speed: 7.25 knots
Surface Water Temperature: 6.6 Degrees C
Air Temperature: 7.1 Degrees C
Relative Humidity: 101%
Depth:  63.53 meters

All of the above information was found on http://shiptracker.noaa.gov. Readers can use this site to track exactly where I am at all times!

Personal Log

Welcome back, explorers!

It has been a very eventful 24 hours! We have started fishing, but have done so little that I will wait to talk about that in the next log. Tammy, the other Teacher at Sea, has not begun fishing yet, and as we will be writing the science and technology log together, I will save the fishing stories until she has had a chance to fish.

After turning in last night’s log, we managed to spot eight or nine humpback whales on our starboard side that appeared to be feeding at the surface. They were too far away to get any decent photos, but it was a lot of fun to watch the spouts from their blowholes tower up into the air.

Whale Spouts

Ten whale spouts rise in the distance.

This afternoon started off by dropping an expendable bathythermograph (from here on out this will be referred to as an XBT). The XBT measures the temperature and depth of the water column where it is dropped (there will be more on this in the Science and Technology section). I was told that I would be dropping the XBT this time, and was led off by Sarah and Abby (two of the scientists on board) to get ready.

Ready to launch!

The first thing I had to do was to get dressed. I was told the XBT would feel and sound like firing a shotgun, so I had to put on eye, ear and head protection. I was also put in a fireman suit to protect my body from the kickback, since I am so small. The XBT launcher is the tube in my hands.

Pranked!

This is me launching the XBT. Why no smoke? All we actually needed to do was drop the device over the side. The whole shotgun experience was a prank pulled off by the scientists on all of the new guys. Their acting was great! When I turned towards Sarah at one point with the launcher, she ducked out of the way as if afraid I would accidentally fire it. I fell for it hook, line, and sinker.

However, the prank backfired somewhat. As the scientists were all laughing, a huge wave came up over the side of the ship and drenched us. I got nailed, but since I was in all of the gear, I stayed dry with the hem of my jeans being the only casualty. Sarah didn’t get so lucky. Fun times!

Sarah

Sarah looking a bit wet.

Science and Technology Log
Today, we will be looking at the XBT (the expendable bathythermograph). Bathy refers to the depth, and thermo refers to the temperature. This probe measures the depth and temperature of the water column when it is dropped over the starboard side of the ship.
“Dropping” isn’t exactly the right phrase to use. We use a launcher that resembles a gun. See the photo below to get an idea of what the launcher looks like.

XBT Launcher

This is the XBT Launcher.

Pin

The silver loop is the pin for the launcher. To launch the probe, we pulled the pin and flung out our arm. The momentum pushed the probe out of the tube and into the water below.

The probe

The probe.

The probe is connected to a length of copper wire, which runs continuously as the probe sinks through the water column. It is important to launch the probe as far away from the ship as possible, as the copper wire should never touch the ship. If the wire were to touch the ship, the data feed back to the ship would be disrupted and we would have to launch another probe, which is a waste of money and equipment. The survey technician decides to cut the wire when he/she has determined that sufficient data has been acquired. This normally occurs when the probe hits the ocean floor.

This is a quick and convenient way to collect data on the depth and temperature of the water column. While the ship has other methods of collecting this data (such as a Conductivity, Temperature, and Depth (CTD) probe), the XBT is a simpler system that does not need to be recovered (as opposed to the CTD).

CTD

A CTD

Data collected from the most recent XBT.
Latitude: 53.20 degrees N
Longitude: 167.46 degrees W
Temperature at surface: 6.7 degrees C
Temperature at bottom: 5.1 degrees C
Thermocline: 0 meters to 25 meters.
The thermocline is the area where the most rapid temperature change occurs. Beneath the thermocline, the temperature remains relatively constant.

Thermocline

This is a graph showing a thermocline in a body of water. Source: http://www.windows2universe.org

Species Seen

Humpback Whales

Northern Fulmar

Albatross

Northern Smoothtongue

Walleye Pollock

Mackerel

Lumpsucker

Squid

Pacific Sleeper Shark

Reader Question(s) of the Day!

Today’s reader questions come from James and David Segrest, who are two of my students in Knoxville Zoo’s homeschool Tuesday classes!

1. Did pirates ever travel the path you are on now? Are there any out there now?

A. As far as I know, there are no pirates currently operating in Alaska, and according to the scientists, there were not any on the specific route that we are now traveling. However, Alaska does have a history of piracy! In 1910, a man named James Robert Heckem invented a floating fish trap that was designed to catch salmon. The trap was able to divert migrating salmon away from their normal route and into a funnel, which dumped the fish off into a circular wire net. There, the fish would swim around until they were taken from the trap.

Salmon and trap

Workers remove salmon from a fish trap in 1938. Historic Photo Courtesy of the U.S. Fish & Wildlife - Fisheries Collection - Photographer: Archival photograph by Mr. Sean Linehan, NOS, NGS.

For people who liked eating fish, this was a great thing! The salmon could be caught quickly with less work, and it was fresh, as the salmon would still be alive when taken from the trap. For the traditional fisherman, however, this was terrible news. The fishermen could not compete with the traps and found that they could not make a living. The result was that the fishermen began raiding the floating traps, using any means possible.

Salmon barge

A barge of salmon going to a cannery. Fishermen could not compete with traps that could catch more fish. Historic Photo Courtesy of the U.S. Fish & Wildlife - Fisheries Collection -Photographer: Archival photograph by Mr. Sean Linehan, NOS, NGS

The most common method used was bribery. The canneries that operated the traps would hire individuals to watch the traps. Fishermen would bribe the watchers, steal the fish, and then leave the area. The practice became so common that the canneries began to hire people to watch the trap-watchers.

2. Have you seen any sharks? Are there any sharks that roam the waters where you are traveling?

shark

Hi James and David! Here is your shark! It's a Pacific Sleeper Shark.

shark in net

The shark in the net

Shark

Another image of the shark on the conveyor belt.

This is a Pacific Sleeper Shark. It is called a sleeper shark as it does not appear to move a great deal, choosing instead to glide with very little movement of its fins. As a result, it does not make any noise underwater, making it the owl of the shark world. It hunts much faster fish (pollock, flounders, rockfish) by being stealthy. They are also known to eat crabs, octopus, and even snails! It is one of two animals known to eat giant squid, with the other one being sperm whales, although it is believed that these sharks probably scavenge the bodies of the much larger squid.

The other shark commonly seen is the salmon shark. Hopefully, we will catch one of these and I will have photos later in the trip.