Plankton Guide Project	...Working Draft
HOLOPLANKTON
CNIDARIA
PLATYHELMINTHES (FLATWORMS)	NEMATODA	CHAETOGNATHS ("ARROW WORMS")
CRUSTACEA
Ostrocods	Copepods	Amphipods
Mysid (Opossum) Shrimp	Cumaceans (Hooded Shrimp)	Euphasiids (Krill)
MEROPLANKTON
ANNELIDA LARVAE
BRYOZOAN LARVAE
CRUSTACEAN LARVAE
Nauplii	Zoea	Late Stage Zoea or Megalopa
Mantis Shrimp / Alima Larva	Mycid Megalopa Larva	post-larval juvenile decapod
GASTROPOD LARVAE
ECHINODERM LARVAE
Kina	Starfish
CHORDATA
Tunicate Larva
FISH
Fish Eggs	Fish Larvae	Fish Juveniles
INVERTEBRATE EGGS
NOT ZOOPLANKTON OTHER INTERESTING THINGS IN THE SAMPLE
Phytoplankton	Algae	Seagrass
Hydroid Colony	Bryozoans	Ascidians
Polychaete - Ragworm (Nereididae)	Isopods	Skeleton Shrimp (Amphipod)
Camouflage Shrimp	Crabs	Burrowing Sea Cucumber
Brittle Star	Gastropods	Baby Octopus
Fish	Unidentified, Bits and Pieces...	Algal Bits, Detritus, Sediment
		Microplastics

NOTE: Size information imprinted on the images from the Olympus microscope may be inaccurate due to operator error.*

OVERVIEW
As a summer volunteer at the Marine Studies Centre, I am working to build a collection of plankton photos for a revised plankton guide.  The current guide used for classes is a collection of images gleaned from various sources and websites.  The goal is to build a guide with the Centre's own images.  I also think it could be improved by developing/adding a consistent size scale graphic to go along with the text notations currently on the pages ("up to 2mm," "up to 30mm"); however this would be challenging because of the great variation in sizes. 

I started during my visit of 18 November when teaching fellow Rob Lewis collected a plankton sample off the wharf.  There were lots of small bits moving around in the bucket.  Rob removed some large algae bits, several visible worms, and even a small fish.  Returning inside, Rob ran the sample through plankton mesh into a bottle to concentrate it.  Then I was introduced to the Andonstar 207S digital microscope, and we saw about eight different zooplankton including a hydroid medusa, ostrocods (seed shrimp), copepods, amphipods, zoea, megalopa, a snail, a fish egg.  There was also a colonial phytoplankton and a microplastic strand.  The image quality is fairly good, but not to the point where one could print and frame them and put them up on the wall. 

I spent a fair bit of time in the succeeding weeks seeing if it would be possible to get better image quality.  My first approach was to see if I could adapt a Nikon SMZ-2T dissection scope (circa 1987), which had a film camera attached, to work with my DSLR camera.  I connected with Nikon's regional headquarters, which is in Australia, and with Amateur Microscopy facebook page, where several members provided suggestions.  An engineer probably could have made it work, but the technical complexities proved too much for me. 

Rob also tried a microscope attachment for cell phones, but that proved a bit finicky.  Duong Le, a researcher whose work focuses on kelp, showed me the Nikon ECLIPSE Ts2 inverted microscope which is used for viewing samples below and is really handy in that the camera, software and computer are all linked. 

Shortly before Christmas, with with a lot of assistance from lead technician Linda Groenewegen, I was able to use the Olympus BX51 with Olympus XC50 5 megapixel digital camera and CellSens software on a sample of sea urchin pluteus larvae.  What a revelation!  Pluteus larvae are shaped somewhat like the four legged lunar landing modules of the Apollo program, and the particular pluteus I was looking at seemed very cooperative, not zipping around as many zooplankton are prone to doing.  Every so often it attempted to launch but couldn't seem to take off.  One could see the phytoplankton going through the digestive tract of the larva, and the skeletal rods.  That pluteus was so cooperative!  However, Linda pointed out that it was probably hitting the cover slip, and couldn't go anywhere.  In addition to the cover slip, the small depression in concave microscope slides limits how far the zooplankton go, but more active and mobile zooplankton are more challenging.  This microscope and software has many capabilities that I did not have occasion to use, such as fluorescence imaging or the tool in CellSens that allows one to make notations on the images.

I did make one critical mistake* using the Olympus BX51.  When changing the objective lens, it is essential at the same time to change the lens setting in CellSens for the size information imprinted on the images to be accurate.  I neglected to to this consistently, and did not figure it out until after many weeks, rendering the numbers nonsense.

My conclusion is that the Olympus is the right tool for viewing smaller organisms and bringing out details that one cannot see with the digital scope. At the same time, it does not provide the full colour experience, and it does have limitations in terms of depth of field and viewing larger or more mobile zooplankton.  The ideal solution would be to find something like the Andonstar, but with a higher resolution camera.

Andonstar 207S    |   Nikon SMZ-2T   |   Cell Phone Attachment and Dissecting Scope   |   Nikon ECLIPSE Ts2   |   Olympus BX51
 
Everyone here has been very positive and encouraging, patiently answering my questions: director Sally Carson, Rob Lewis, Linda Groenewegen, Aaron Heimann, Ella Robinson, Adam Brook (@a.brook.photography), Korena Peterson, Hannah, Joe, and Will; Jean McKinnon, teaching fellow, helped with identification (>); professors and students have explained the research they are working on. 


See also:
https://drive.google.com/drive/folders/1XnpyoamJPJ_7r8jGTlcdLzLtYKD09zAu?usp=sharing
Kane'ohe Bay Plankton Guide.  Hawaii Institute of Marine Biology, 2020.
Introductory Guide to Zooplankton Identification.  CSIRO, 2014.
Ngā Tini o te Waitai: Plankton.  University of Otago.
Amateur Microscopy Facebook page.