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Old 19-07-2017, 05:37   #16
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Re: Check plankton while you cruise!

Than you for your reply and confirmation. Fair winds !
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Old 19-07-2017, 06:37   #17
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Re: Check plankton while you cruise!

Quote:
Originally Posted by Odontella View Post
the yacht/boat/ship really does need to be slow moving (drifting) or 'stationary' (although it does not need to be anchored of course) f.

The standard method for Secchi Disk measurements is from a stationary or slowly drifting vessel with a vertical drop for the disk.
Hi Richard,

I agree with Toaster. Stopping the boat twice per day is not going to happen on the vast majority of cruising boats.

It's a pity you cant devise some way to take a reading whilst moving.

If the research has value in it then devising a good system is essential.

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Old 19-07-2017, 12:53   #18
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Re: Check plankton while you cruise!

Hi

We are not asking for a stop to take a measurement twice a day, just as and when people feel inclined or it is convenient. It maybe a reading once a day, once a week, or once a month. The study works by numbers of participants and duration (years of measurements). The idea with open-ocean measurements is that sailors tend to follow the same routes at the same time of year, year after year and so the data builds up. Coastal sailors tend to travel the same waters weekly. So both cruisers and day sailors can collect useful, but differently scaled, data.

The method dates to 1865 and has been in use since then and so it is very important for consistency to follow the protocol, which is for a vertical descent of the Secchi Disk. Drifting on a calm day obviously presents a good opportunity to take a measurement.

Have a look at the Website Secchi Disk study and the data map. We are getting open-ocean measurements. Our seafaring Ambassador yachtswoman Susie Goodall took some excellent readings during her passage across the Atlantic and wrote a marvelous entry in her log, which you can read on the website.

Even if you find the study isn't for you, I would be grateful if you tell others about it. The Secchi Disk study's success relies upon awareness.

Best Wishes
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Old 21-07-2017, 23:37   #19
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Re: Check plankton while you cruise!

Hi Richard,

If we are making way at 3-4 knots or more, we're not going to want to slow down or stop. On the other hand, there are times when winds are light and speed through water is perhaps two knots or less. If we could take data at two knots, it would be great. Is that slow enough for the Secchi disk? I guess with enough weight on the disk, it would be.

I like the idea of just having the device ready so that when those balmy days strand you with nothing else to do, at least you can have something to look forward to at noon. (As well as the GLOBE Clouds app from NASA).
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Old 22-07-2017, 01:43   #20
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Re: Check plankton while you cruise!

Hi Toaster,

As long as you can achieve a vertical drop of the disk, all will be fine.

In any case, you won't be stationary if not 'anchored' and even then the current may be 2 knots or more. Most vessels that cannot maintain position will be underway to some extent, and certainly not anchored in the open ocean.

What we need to avoid is 'inventions' added to achieve a vertical drop, other than the addition of a heavier weight.

The amount of weight depends on the disk material, the current, and windage.

The Secchi depth measurement takes approximately 5 minutes.

To pick up on another point you made about waves and turbulence, the simplicity of the Secchi Disk measurement and the distances measured make it very robust, which is why it has been used for 150 years. And of course, nobody will be taking measurements if the sea is rough as it will also be too windy, back to the underway problem.

Look forward to seeing your lunchtime break Secchi Disk data if you take part.
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Old 07-12-2017, 01:44   #21
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Re: Check plankton while you cruise!

The Secchi Disk study has reached a key achievement with the publication of the first scientific paper entitled:

Seafarer citizen scientist ocean transparency data as a resource for phytoplankton and climate research

The paper is published in the journal The Public Library of Science ONE or PLOS ONE, and it can be accessed for free HERE

As you will see, YOU, the seafarers taking part in the Secchi Disk study are the first authors as it is very much a result of seafarer citizen science.

The key findings of this first publication are

1) Sailors acting as citizen scientists can collect useful scientific data using a simple DIY piece of equipment matched to a Smartphone application,

2) The sailors' data is vital to help us better understand the ocean’s phytoplankton. While satellites now survey the sea surface from space to determine phytoplankton by measuring ocean colour, the Secchi Disk data collected from the sea is important to help interpret the satellite data,

3) Using sailors as citizen scientists it is possible to obtain measurements from far more places than scientists could achieve alone,

4) In years to come, as the sailors' data continues to accumulate, the data will help us better understand the long-term changes in the phytoplankton.

I hope you find this first publication interesting and hopefully, it will be the first of many more.

Why not take part in the Secchi Disk study if you are not doing so already ?

The publication is Open Access, which means it is free to download and distribute, so please share with family and friends and perhaps send a copy to your yacht club or marina office.

Best wishes to everyone.
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