PDA

View Full Version : More marine growth in summer or winter?



RFNK
09-29-2012, 09:32 PM
Many people think that boats accumulate more growth on the hull in summer, yet colder water is supposed to be more fertile than warm water, due to higher oxygen levels. So, do moored boats gather more growth on their hulls in summer or in winter?

Rick

chas
09-29-2012, 10:37 PM
Not sure. They do gather more growth when you don't use 'em. / Jim

rbgarr
09-29-2012, 11:38 PM
Many people think that boats accumulate more growth on the hull in summer, yet colder water is supposed to be more fertile than warm water, due to higher oxygen levels. So, do moored boats gather more growth on their hulls in summer or in winter?

Rick

"...pronounced increase in the warm season.":

http://www.scubadubacorp.com/marinegrowth.htm

RFNK
09-30-2012, 01:34 AM
I wonder why? I know that kelp grows much more quickly in winter in Tasmania - the kelp forests virtually vanish in summer My guess is that certain underwater plants are more responsive to the higher oxygen level in winter but others are more responsive to either warmth or increased sunlight. It would be interesting to get a marine biologist's view on this.

Rick

jsjpd1
09-30-2012, 01:45 AM
The algae that grows on boats here was definitely a better crop on the sunny side of my dad's boat and the water is a lot greener/less clear in the summer. So there must be some species of algae that bloom in summer. Red tide, a poisonous algae filtered by shelf fish is also a summer phenomena for the most part.

Jim

RFNK
09-30-2012, 01:51 AM
That's a good point about red tide. My understanding is that red tide occurs when the algae present in cold depths, is forced by currents into warmer conditions, it blooms as a red tide. This would also lend weight to the argument that some algaes, or maybe even all algaes, grow more in warmer water. Or maybe in increased sunlight.

Rick

Boston
09-30-2012, 02:06 AM
warmth increases metabolic rates, so plants and cold blooded species grow and propagate faster in warmer conditions, depending on size. Cold water is higher in oxygen, and it does support larger populations of larger species, but low oxygen tolerant/smaller life forms grow fastest in warmer waters. Smaller cold water species grow slower but are more abundant. Its kinda half one and a dozen the other. Depends on size.

ThorBue
09-30-2012, 04:01 AM
You might also have to consider, that oxygen levels are more important to fish and that kind of critters, than to plants and algea who produce it themselfes.

Larks
09-30-2012, 04:08 AM
Might be different down south, but my experience seems more dependent on wet season or dry season, with different and more prolific growth in the wet season when the top 2' or more in the marina has been mostly fresh water, though admittedly also quite a bit warmer.

Breakaway
09-30-2012, 07:14 AM
Besides O2,which applies mostly to critters, consider sunlight, a large contributor to plant fouling/growth. There is more intense and more hours of sunlight in summer.

Round here plant fouling is higher in the warmer ( lighter) seasons; barnacle growth appears to be equally robust warm or cold ( darker)

Kevin

Ron Williamson
09-30-2012, 08:34 AM
We get more algae and slime when it's warm and bright.
During the winter, ice movement grinds it back.
In June,the viz can be 40' and by August it drops to 20-ish.
IMHO,improved water clarity, attributed to the accidental introduction of zebra mussels, has recently increased the amount of growth on rocks and boat bottoms in our area.
R