NOAA Teacher at Sea
Dieuwertje “DJ” Kast
Aboard NOAA Ship Henry B. Bigelow
May 19 – June 3, 2015
Mission: Ecosystem Monitoring Survey
Geographical areas of cruise: Mid Atlantic Bight, Southern New England, George’s Bank, Gulf of Maine
Date: June 1, 2015
Science and Technology Log:
Bongo Patterns!
Part of my job here on NOAA Ship Henry B. Bigelow is to empty the plankton nets (since there are two we call them bongos). The plankton is put into a sieve and stored in either ethanol if they came from the small nets (baby bongos) or formalin if they came from the big nets (Main bongos).
What are plankton? Plankton is a greek based word that means drifter or wanderer. This suits these organisms well since they are not able to withstand the current and are constantly adrift. Plankton are usually divided by size (pico, nano, micro, meso, macro, mega). In the plankton tows, we are primarily focused on the macro, meso and megaplankton that are usually with in the size range of 0.2- 20 mm (meso), 2-20 cm (macro), and above 20 cm (mega) respectively.
| Group | Size range | Examples |
| Megaplankton | > 20 cm | metazoans; e.g. jellyfish; ctenophores; salps and pyrosomes (pelagic Tunicata); Cephalopoda; Amphipoda |
| Macroplankton | 2→20 cm | metazoans; e.g. Pteropods; Chaetognaths; Euphausiacea (krill); Medusae; ctenophores; salps, doliolids and pyrosomes (pelagic Tunicata); Cephalopoda; Janthinidae (one family gastropods); Amphipoda |
| Mesoplankton | 0.2→20 mm | metazoans; e.g. copepods; Medusae; Cladocera; Ostracoda; Chaetognaths; Pteropods; Tunicata; Heteropoda |
| Microplankton | 20→200 µm | large eukaryotic protists; most phytoplankton; Protozoa Foraminifera; tintinnids; other ciliates; Rotifera; juvenile metazoans – Crustacea (copepod nauplii) |
| Nanoplankton | 2→20 µm | small eukaryotic protists; Small Diatoms; Small Flagellates; Pyrrophyta; Chrysophyta; Chlorophyta; Xanthophyta |
| Picoplankton | 0.2→2 µm | small eukaryotic protists; bacteria; Chrysophyta |
| Femtoplankton | < 0.2 µm | marine viruses |
(Omori, M.; Ikeda, T. (1992). Methods in Marine Zooplankton Ecology)
We will be heading to four main geographical areas. These four areas are: the Mid Atlantic Bight (MAB), the Southern New England (SNE), Gulf of Maine (GOM), and George’s Bank (GB). I’ve been told that the bongos will be significantly different at each of these sites. I would like to honor each geographical area’s bongos with a representative photo of plankton and larval fish. There are 30 bongos in each area, and I work on approximately 15 per site.
Here is a video of a Bongo launch.
The plankton nets need to be wiped down with saltwater so that the plankton can be collected on the sieve.
Day 1: May 19th, 2015
Day 2: May 20th, 2015
Day 3: May 21st, 2015
Day 4: May 22nd, 2015
Day 5: May 23, 2015
Photo by DJ Kast.
Below are the bongo patterns for the Southern New England area.
I have learned that there are two lifestyle choices when it comes to plankton and they are called meroplankton or holoplankton.
Plankton are comprised of two main groups, permanent or lifetime members of the plankton family, called holoplankton (which includes as diatoms, radiolarians, dinoflagellates, foraminifera, amphipods, krill, copepods, salps, etc.), and temporary or part-time members (such as most larval forms of sea urchins, sea stars, crustaceans, marine worms, some marine snails, most fish, etc.), which are called meroplankton.
Day 6: May 24th, 2015
Photo by: DJ Kast
Day 7: May 25th, 2015
Georges Bank- It is a shallow, sediment-covered plateau bigger than Massachusetts and it is filled with nutrients that get stirred up into the photic zone by the various currents. It is an extremely productive area for fisheries.
Today, I learned that plankton (phyto & zoo) have evolved in shape to maximize their surface area to try and remain close to the surface. This makes sense to me since phytoplankton are photosynthesizers and require the sun to survive. Consequently, if zooplankton are going to consume them, it would be easier to remain where your food source is located. I think this would make for a great lesson plan that involves making plankton-like creatures and seeing who can make them sink the least in some sort of competition.
Day 8: May 26th, 2015 Very Diverse day, Caprellids- skeleton shrimp, Anglerfish juvenile, Phronima inside of salp! Photo by DJ Kast
Video of the phronima:
Video of the Caprellids:
Day 9: May 27th, 2015= Triggerfish and colorful phronima (purple & brown). Our sieves were so clogged with phytoplankton GOOP, which is evidence of a bloom. We must be in very productive waters,
Day 10: May 28th, 2015= change in color of copepods. Lots of ctenophores and sea jellies
Did you know? Sea Jellies are also considered plankton since they cannot swim against the current.
Day 11: May 29th, 2015: Border between Georges Bank and the Gulf of Maine!
Gulf of Maine! Water comes in from the North East Channel (the Labrador current), coast on one border and George’s Bank on the other. Definitely colder water, with deep ocean basins. Supposed to see lots of phytoplankton. Tidal ranges in the Gulf of Maine are among the highest in the world ocean
Day 12: May 30th, 2015: day and night bongo (Just calanus copepods vs. LOTS of krill.)
Krill are normally found lower in the water column. The krill come up at night to feed and avoid their predators and head back down before dawn. This daily journey up and down is called the vertical migration.
Video of Krill moving:
Day 13: May 31th, 2015: Calanoid Copepod community. Calanoida feed on phytoplankton (only a few are predators) and are themselves the principal food of fish fry, plankton-feeding fish (such as herring, anchovies, sardines, and saury) and baleen whales.
Day 14: June 1st, 2015:
Day 15: June 2nd, 2015: Last Day
Through rough seas and some amazingly calm days, we have all persevered as a crew and we have done a lot of science over the last 16 days. We went through 153 stations total. I have learned so much and I would like to thank Jerry, the chief scientist for taking me under his wing and training me in his Ecosystem Monitoring ways. I would also like to thank Dena Deck and Lynn Whitley for believing in me and writing my letters of recommendation for the Teacher at Sea program. I would love to do this program again! -DJ Kast